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Project Specific Discussions => Dynamic Processors => Topic started by: mathsieve on January 24, 2010, 07:12:54 PM

Title: TG1 - advice from any one who has built it...
Post by: mathsieve on January 24, 2010, 07:12:54 PM
I hope this isn't going to ruffle anyone's feathers but I was wondering if anyone who has built a TG clone could let me know how it sounds.  Now, I haven't heard an original EMI unit, or one of the new Chandler ones.  I've only heard the VST plugin, which is damned good for a plugin.  But I can't help noticing that the controls seem different on the clone to both the original (which lacks HPF, input and attack) and the Chandler version (which lacks HPF, hold, and attack).  So I'm wondering whether it's worth spending 200E on a case and board, which might not produce the effect I'm looking for. 
Title: Re: TG1 - advice from any one who has built it...
Post by: sintech on January 24, 2010, 07:28:08 PM
Hi, I've self built the circuit in three guises now, and also done direct A/B's with vintage EMI units. I'd say the results are good, but you can't clone the EMI transformers! :) and that's a big part of the original tone. (Transfer console version)

The Chandler versions transformer steps up on the front end that drives the limiter, but has become a mix classic in it's own right. The EMI console version is way more subtle.
Title: Re: TG1 - advice from any one who has built it...
Post by: strangeandbouncy on January 24, 2010, 07:38:18 PM
I have used chandler pre's and comp, and also an original TG on several occasions. Chandler is really good stuff, but just doesn't quite have the mojo imho. I think that the mixbus is also critical to "that" sound, but trannies must surely be crucial too. I also love the crude but effective TG eq! I thought that some GArdners transformer stuff featured, but I could be wrong. They come up from time to time, and iirc, someone has the blueprints.



         If you can build something that sounds at least as good as the chandler stuff, you wont be wasting your time, even of it doesn't quite measure up. Anyway, the chance of you actually finding an original to compare is rather low to say the least . . .



   `Kindes rgeards,


    ANdyP
Title: Re: TG1 - advice from any one who has built it...
Post by: sintech on January 24, 2010, 07:47:35 PM

To give you the size difference against a Carnhill (as used on early chandler TG1's/1272 output) verses 70's EMI trafos  :P


(http://i44.photobucket.com/albums/f23/sin-tech/IMG_5724.jpg)

Title: Re: TG1 - advice from any one who has built it...
Post by: strangeandbouncy on January 24, 2010, 07:49:54 PM



Ouch! that's some weight of iron. Did you see if Grdners were on input, or am `i mistaken?
Title: Re: TG1 - advice from any one who has built it...
Post by: sintech on January 24, 2010, 08:02:38 PM



Ouch! that's some weight of iron. Did you see if Grdners were on input, or am `i mistaken?

All the trafos are unbranded apart from EMI part numbers, but the outputs look like giant 70's Marinair's to the eye
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on January 25, 2010, 02:32:11 PM
What are the EMI part numbers?
Title: Re: TG1 - advice from any one who has built it...
Post by: sintech on January 25, 2010, 07:06:11 PM



Ouch! that's some weight of iron. Did you see if Grdners were on input, or am `i mistaken?

The inputs look like Gardners in form, they've now been taken over buy Greenwoods who still wind some replacements to original specs..the output has different studs on the top board (to the one pictured with the Carnhill for scale), but it's actually the same number, although the issue number differs to the console outputs.

(http://i44.photobucket.com/albums/f23/sin-tech/EMITRAFOS.jpg)
Title: Re: TG1 - advice from any one who has built it...
Post by: strangeandbouncy on January 25, 2010, 07:47:16 PM
Sintech,


  do you mean that Greenwoods have taken over gardners transformer production, or EMI transformer production?



     KIndest regards,


       ANdyP
Title: Re: TG1 - advice from any one who has built it...
Post by: sintech on January 26, 2010, 06:04:28 AM
Sintech,


  do you mean that Greenwoods have taken over gardners transformer production, or EMI transformer production?



     KIndest regards,


       ANdyP

Greenwoods must've bought out Gardners, and kept winding what I guess would earn them revenue. All EMI console production finished in 1974/5
Title: Re: TG1 - advice from any one who has built it...
Post by: simonsez on January 26, 2010, 06:47:38 AM
i thought the original was transformerless ?
Title: Re: TG1 - advice from any one who has built it...
Post by: sintech on January 26, 2010, 07:55:15 AM
i thought the original was transformerless ?

in the context of the console it is, but surrounded by iron, input, insert send and return.

The transfer console version is slightly different and has remote iron. I think the idea is the mojo is more in the oversized trafos, rather than the circuit.

Really we don't know too much about anything EMI related! heheh but for me that makes it way more fun than Neve!
Title: Re: TG1 - advice from any one who has built it...
Post by: strangeandbouncy on January 26, 2010, 08:20:16 AM
Can anyone get their hands on the iron for CJ to decipher perhaps?
Title: Re: TG1 - advice from any one who has built it...
Post by: dustbro on January 26, 2010, 08:30:23 AM
Can anyone get their hands on the iron for CJ to decipher perhaps?

I saw one on ebay about a month ago. almost grabbed it so it could be dissected.
Title: Re: TG1 - advice from any one who has built it...
Post by: edanderson on January 26, 2010, 09:18:15 AM
Greenwoods must've bought out Gardners, and kept winding what I guess would earn them revenue. All EMI console production finished in 1974/5

not sure how this relates, but avon magnetics in the uk has most of the gardners units on file.  i remember asking them for a quote on some of the large octal can transformers many years ago and they were >100GBP each.

ed
Title: Re: TG1 - advice from any one who has built it...
Post by: sintech on January 26, 2010, 10:16:23 AM
Greenwoods is a dead end, Peter (sinestaraudio) just gave them a ring, and they don't Audio trafos, they took over Gardners M.O.D work.
Title: Re: TG1 - advice from any one who has built it...
Post by: fazeka on January 26, 2010, 01:56:30 PM
Huh. And here I was thinking I would build it without trannies.

Would it not make sense to build this thing without trannies then?
Title: Re: TG1 - advice from any one who has built it...
Post by: sintech on January 26, 2010, 02:08:37 PM
Huh. And here I was thinking I would build it without trannies.

Would it not make sense to build this thing without trannies then?

It's nice to have all options, the Chandler way with Neve iron is a Parallel compression classic in it's own right, but one sound
Title: Re: TG1 - advice from any one who has built it...
Post by: fazeka on January 26, 2010, 08:21:47 PM
Er, maybe it's a matter of semantics, but "vibe" and "character" from this circuit I would expect from only the iron. My understanding is that with no iron, the limiter is more subtle than with.

Am I understanding correctly?

 ???
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on January 26, 2010, 11:13:50 PM
I would think the vibe and character have most to do with the circuit as a whole...rather than seperate parts. One vs the other, maybe transformers contribute in some way more. Distortion?

The pictures i've seen of the TG 12413, there are no transformers in the module, but yes, they would be proceeded and followed with iron in the desk(i'm assuming)...so it's fair to assume there were transformers involved. As for which is better, i would think whichever way agree's with the overall design concept.

.002
Title: Re: TG1 - advice from any one who has built it...
Post by: mathsieve on January 27, 2010, 06:26:09 AM
thanks guys - that was more discussion than I was expecting to get.  everyone seems so secretive about this build.  anyways, it does at least sound like those of you who have built this are pretty happy with its sound even if it's not as good as the chandler.
my only remaining query is then about the controls - and this is based on my ignorance of the original EMI schematic (which is not available to the general public, right?).  How come the controls are different from the original & chandler units? it suggests to me that there's something different going on under the hood.
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on January 27, 2010, 06:41:59 AM
thanks guys - .....................even if it's not as good as the chandler.

Don't recall reading that !
Title: Re: TG1 - advice from any one who has built it...
Post by: mathsieve on January 27, 2010, 07:14:23 AM
not explicitly, but no one was suggesting that a self build was likely to be better than the Chandler, or closer in sound to an original EMI.  my extrapolation, I guess.
Title: Re: TG1 - advice from any one who has built it...
Post by: Skylar on January 27, 2010, 09:36:51 AM
Read this thread if you haven't already.

http://www.groupdiy.com/index.php?topic=6481.0 (http://www.groupdiy.com/index.php?topic=6481.0)

A link to the schematic is there somewhere.
Also there's some talk about how the Chandler is different than the original and lots of other interesting bits.
It's a fun thread.
Title: Re: TG1 - advice from any one who has built it...
Post by: RedNoise on January 31, 2010, 01:32:33 PM
Hi , could someone give advices with the resistors for the HOLD ? which value do you use ?
I also have an ELMA 04-1130 but it is not for pcb mount.As I am not able to find datasheet (without being obliged to register!) , did someone know if it would do the trick for output?(I wonder because of MBB etc datas...)
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on January 31, 2010, 04:54:03 PM
Another question

Which switch is the on-off-on switch.  In the build thread at the other site that nobody responds to (at least not for weeks at a time) it mentions that one should be used, but it's not entirely clear where
Title: Re: TG1 - advice from any one who has built it...
Post by: API on January 31, 2010, 05:07:52 PM
Andy, that input transformer in your EMI compressor looks very much like an old Sowter.
It looks exacty like the input transformer of some mid 70´s Helios modules which used Sowters.

Also the big output transformers look very much like the Marinairs on the outputs in my Cadac desk.
The number on those is T1803 and they look like giant Lo1166!

Dennis

Title: Re: TG1 - advice from any one who has built it...
Post by: RedNoise on January 31, 2010, 06:03:49 PM
Another question

Which switch is the on-off-on switch.  In the build thread at the other site that nobody responds to (at least not for weeks at a time) it mentions that one should be used, but it's not entirely clear where

IIRC fester answered we need a ON/OFF/ON for the bypass switch , I intend to use this one:
http://fr.farnell.com/c-k/7103p3yzqe/interrupteur-spdt-ctr-off/dp/9575049?Ntt=9575049
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on January 31, 2010, 06:23:16 PM
Another question

Which switch is the on-off-on switch.  In the build thread at the other site that nobody responds to (at least not for weeks at a time) it mentions that one should be used, but it's not entirely clear where

IIRC fester answered we need a ON/OFF/ON for the bypass switch , I intend to use this one:
http://fr.farnell.com/c-k/7103p3yzqe/interrupteur-spdt-ctr-off/dp/9575049?Ntt=9575049

From Fester
Quote
2. WHERE and HOW to connect the switches that engages the rele's for the TRAFO or OPAMP selection ?... 'cause i see only the bypass switch ... dear UNCLE can you give me some hints ??

This is ON-Off-ON switch.

Looking at what uncle F posted I'm not sure that he's saying the on-off-on is the bypass switch, or whether its the limit/THD switch.  After all why would you need 3 positions on a bypass switch, they're normally either in or out surely.  Unless i'm missing something ?
Title: Re: TG1 - advice from any one who has built it...
Post by: RedNoise on February 01, 2010, 01:57:48 AM
you're 'quite' right!I 'meant' the trafo-pass...sorry ,I'm confused!
This said , you can see at the other forum page 2 , a new picture of the "new case" , apparently designed for V1.2 , were you can read "IRON/BYPASS/CLEAN" just near the vu meter .
In your quote , I'm pretty sure Fester wanted to highlight the fact bypass and trafopass were mixed in only one switch.(I really hope this is the truth , otherwise I do not see where to connect this switch !)

Quote
Re: TG build thread
by Uncle Fester on Wed Sep 30, 2009 9:59 am

Quote
So if i understand correctly, when i use an ON-OFF-ON switch i will have IRON, BYPASS, CLEAN ?

Yes, exactly.
Title: Re: TG1 - advice from any one who has built it...
Post by: RedNoise on February 01, 2010, 02:29:28 AM
I really think this thread would be cool if it's re-named : TG build & help thread ...Moderators???
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 01, 2010, 08:22:13 AM
Understand re switch

I think you're right about the thread title.  The thread at the other forum hardly gets looked at, & it would be much better to have it here.
Title: Re: TG1 - advice from any one who has built it...
Post by: sintech on February 01, 2010, 09:12:46 AM
I think the official build thread is on the DIY-Racked forum, and it should stay at that place and be supported by the Team that sold the project to you.
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 01, 2010, 09:17:58 AM
I think the official build thread is on the DIY-Racked forum, and it should stay at that place and be supported by the Team that sold the project to you.

The reality is that it isn't supported very well there, & there seems to be no reason why we can't discuss it here that I can think of.   
Title: Re: TG1 - advice from any one who has built it...
Post by: RedNoise on February 01, 2010, 09:52:56 AM
it would be much better to have it here.
I even cannot get registred at the other site so...
Let's continue here as long as moderators do not lock this thread!(Or explain why it cannot be done here)

So : can someone help me regarding the HOLD switch?Which resistors (and why if possible) do you use here?
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 01, 2010, 11:30:50 AM
it would be much better to have it here.
I even cannot get registred at the other site so...
Let's continue here as long as moderators do not lock this thread!(Or explain why it cannot be done here)

So : can someone help me regarding the HOLD switch?Which resistors (and why if possible) do you use here?

If you look at the pdf of the diagram in the bottom left corner it has values written for the hold switch.
Title: Re: TG1 - advice from any one who has built it...
Post by: RedNoise on February 01, 2010, 11:46:29 AM
thanks!
In fact I was looking at the mb schemo provided in the v2 , where the values are replaced by "*".
Title: Re: TG1 - advice from any one who has built it...
Post by: sintech on February 01, 2010, 05:58:38 PM
I think the official build thread is on the DIY-Racked forum, and it should stay at that place and be supported by the Team that sold the project to you.

The reality is that it isn't supported very well there, & there seems to be no reason why we can't discuss it here that I can think of.   

It would be nice to see Fester and Purusha actually support the project you guy's invested in, that's why it's maybe best supported on the DIY-Racked forum, or is it profit and run?
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on February 02, 2010, 12:50:11 PM
No, i don't think it's profit and run. In reality, it's DIY. Fester's a good guy...i'm sure he'll be around.
The boards look fantastic.

I've almost finished the parts list...whew. Sourcing stuff for this was a bit tricky.
Weird cap values, extinct parts, etc etc..

Biggest thing here i'm thinkin...is matching stuff, AOT...and meters.
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 02, 2010, 01:46:19 PM
I'm close to powering up, but I keep getting other work come in which takes priority unfortunately.

Title: Re: TG1 - advice from any one who has built it...
Post by: fazeka on February 02, 2010, 01:51:08 PM
desol and others...

Do you have a BOM you'd like to share with the group?  :)
Title: Re: TG1 - advice from any one who has built it...
Post by: RedNoise on February 02, 2010, 02:24:46 PM
Partial cahotic bom ... may help for some # (hope so!)

http://www.keepandshare.com/doc/view.php?id=1725437&da=y
Title: Re: TG1 - advice from any one who has built it...
Post by: simonsez on February 03, 2010, 11:46:53 AM
is the HOLD is same as input control? I can't find input pot at the schematic...
Title: Re: TG1 - advice from any one who has built it...
Post by: tommypiper on February 03, 2010, 12:02:21 PM
Partial cahotic bom ... may help for some # (hope so!)

http://www.keepandshare.com/doc/view.php?id=1725437&da=y

I cannot get this file to open, or make any sense when it does open.  I'm on a Mac.  I've used Stuffit which opens it into folders which make no sense...

It won't unzip properly.  Word and Excel cannot read it...

Can you use a better format please?
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on February 03, 2010, 12:28:48 PM
I can send it to you if you want Tommy. Unzipped, in word or text file.

PM your email if you want.

EDIT: this file is in XLSX format and needs to be converted to normal XLS, with the microsoft converter.
Also, how old is this BOM file(partial cahotic etc). The BOM included in the zip released last june may be newer anyway?
Title: Re: TG1 - advice from any one who has built it...
Post by: warpie on February 03, 2010, 01:16:46 PM
well, a bit out of topic but does anyone knows if it's possible to buy only the bypass pcb from somewhere/someone  ???
I'm not interested in the rest of the unit. I just want to try it with one of my projects.
Title: Re: TG1 - advice from any one who has built it...
Post by: RedNoise on February 03, 2010, 01:42:47 PM
Partial cahotic bom ... may help for some # (hope so!)

http://www.keepandshare.com/doc/view.php?id=1725437&da=y

I cannot get this file to open, or make any sense when it does open.  I'm on a Mac.  I've used Stuffit which opens it into folders which make no sense...

It won't unzip properly.  Word and Excel cannot read it...

Can you use a better format please?

This file is for exc*l 2007 , maybe you should get a 2007 reader ?Otherwise PM me !
Title: Re: TG1 - advice from any one who has built it...
Post by: RedNoise on February 03, 2010, 01:45:43 PM
desol : I cannot remember how old it is , but I'm quite sure it was based on the "rev2" zip from fester ...
It's cahotic because of colors and some missing # .
Title: Re: TG1 - advice from any one who has built it...
Post by: RedNoise on February 03, 2010, 01:47:10 PM
is the HOLD is same as input control? I can't find input pot at the schematic...

IIRC you can find an answer in the "DESCR" (txt file) , it's HOLD or Input pot :

Quote
Fester's clones can be built either with input pot or hold control
Title: Re: TG1 - advice from any one who has built it...
Post by: kooma on February 03, 2010, 02:14:50 PM
Partial cahotic bom ... may help for some # (hope so!)

http://www.keepandshare.com/doc/view.php?id=1725437&da=y

I cannot get this file to open, or make any sense when it does open.  I'm on a Mac.  I've used Stuffit which opens it into folders which make no sense...

It won't unzip properly.  Word and Excel cannot read it...

Can you use a better format please?
opens fine on my mac
Title: Re: TG1 - advice from any one who has built it...
Post by: simonsez on February 03, 2010, 02:24:42 PM
Thank's Red..
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on February 03, 2010, 03:39:35 PM
desol : I cannot remember how old it is , but I'm quite sure it was based on the "rev2" zip from fester ...

Hmm. Well i hope so, for those that are using it. I'm using the BOM's (bypass and motherboard) that came in the zip file. I'd never seen this colorful one b4. The only part, i think, that i could see missing were the 220u aluminum caps in the power section. Any others that you know of?
Title: Re: TG1 - advice from any one who has built it...
Post by: simonsez on February 03, 2010, 04:51:15 PM
Any substitution for 1N751A? What about using any 5.1v/0.5w Zener diode? Thank you..
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on February 03, 2010, 05:20:56 PM
Any substitution for 1N751A? What about using any 5.1v/0.5w Zener diode? Thank you..

Don't think so. Only HS2051.
Title: Re: TG1 - advice from any one who has built it...
Post by: fazeka on February 03, 2010, 10:24:54 PM
Partial chaotic bom ... may help for some # (hope so!)

http://www.keepandshare.com/doc/view.php?id=1725437&da=y

Thank you.
Title: Re: TG1 - advice from any one who has built it...
Post by: RedNoise on February 04, 2010, 03:42:35 AM
I just would like to tell everyone I ofently make mystakes in my boms so please check everything.
My colour code is just a personnal way to know the statuts of the parts (To order / ordered / received / soldered ...)
Title: Re: TG1 - advice from any one who has built it...
Post by: tommypiper on February 04, 2010, 10:52:49 AM
Partial cahotic bom ... may help for some # (hope so!)

http://www.keepandshare.com/doc/view.php?id=1725437&da=y

I cannot get this file to open, or make any sense when it does open.  I'm on a Mac.  I've used Stuffit which opens it into folders which make no sense...

It won't unzip properly.  Word and Excel cannot read it...

Can you use a better format please?
opens fine on my mac
How did you open it?  Thanks.
Title: Re: TG1 - advice from any one who has built it...
Post by: simonsez on February 09, 2010, 01:18:13 AM
I nearly finish this box, get some kind of thumping issues, any thought? Thanks you..
Title: Re: TG1 - advice from any one who has built it...
Post by: Grand Master Audio on February 09, 2010, 03:39:33 AM
get some kind of thumping issues, any thought?

Have you adjusted the AOT's?

Title: Re: TG1 - advice from any one who has built it...
Post by: simonsez on February 09, 2010, 04:06:38 AM
Yes, but no luck (AOT 8?) Can you tell me the voltage at Emitter VT1 & VT4? my schema is too blur. Thank you,,
Title: Re: TG1 - advice from any one who has built it...
Post by: simonsez on February 11, 2010, 12:04:17 PM
Walking in the dark, I'm done  ;). Amazing sound....Oohmmss and crushhh...

(http://i473.photobucket.com/albums/rr98/SIMONSEZ/IMG_4910.jpg)

(http://i473.photobucket.com/albums/rr98/SIMONSEZ/IMG_4900.jpg)
Title: Re: TG1 - advice from any one who has built it...
Post by: Skylar on February 11, 2010, 12:07:55 PM
Dig the sideways meters!
Title: Re: TG1 - advice from any one who has built it...
Post by: Grand Master Audio on February 11, 2010, 12:36:30 PM

Simonsez, what was your issue in the end?

Best
Pete
Title: Re: TG1 - advice from any one who has built it...
Post by: simonsez on February 11, 2010, 12:45:22 PM
Thump is gone, I got some kind of oscillation  at near max hold...still playing with it..
Title: Re: TG1 - advice from any one who has built it...
Post by: Kingston on February 11, 2010, 05:42:29 PM
demo sounds please!
Title: Re: TG1 - advice from any one who has built it...
Post by: simonsez on February 11, 2010, 10:20:36 PM
demo sounds please!

As you wish.. but a few to tell, for now ...this is transformerless, I substitute all diode/zener, I adjust not only AOT....so don't expect to much.. ;)

http://www.mediafire.com/?znywe03inmd
http://www.mediafire.com/file/3tmvidymcdi/TG12345DIY MAX.mp3
Title: Re: TG1 - advice from any one who has built it...
Post by: simonsez on February 12, 2010, 11:16:00 AM
Perfectly working now....  ::) ::)

Title: Re: TG1 - advice from any one who has built it...
Post by: simonsez on February 12, 2010, 11:37:57 AM
Yeah, I like it very much, it's superb on acoustic gtr strumming. 1N4148 for OA202, I don't know what zener, the seller says it's substitutes for 1N751A...
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on February 12, 2010, 12:38:09 PM
Lotta squash. Thanks for the basic example.
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on February 12, 2010, 12:52:18 PM
Yeah, I like it very much, it's superb on acoustic gtr strumming. 1N4148 for OA202, I don't know what zener, the seller says it's substitutes for 1N751A...

I sourced some original HS2051's, but can't find the oa202's, so i'll sub those with 4148.
Also, bc177/179 is hard to find?
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 12, 2010, 01:09:09 PM
Also, bc177/179 is hard to find?

http://www.donberg.co.uk/catalogue/semiconductors/semiconductors_b-bc/page_2.html
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on February 12, 2010, 03:08:35 PM
I sourced some original HS2051's, but can't find the oa202's, so i'll sub those with 4148.

The BOM specifies a 1N4153 as a substitute for the OA202.


Mark

Oh. Your right. That's what i meant to say.  ;)
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on March 06, 2010, 07:49:38 AM
I'm probably going blind & have a question for members with better sight than me :

What is the value of R115 which is mounted on the back of the attack/recovery/hold  switch pcb ?   It just seems to be marked with an * on everything I look at with no value.

Title: Re: TG1 - advice from any one who has built it...
Post by: RedNoise on March 06, 2010, 07:55:01 AM
R115: this is the part of HOLD switch if you like to build it like EMI.
See descr.txt for HOLD switch etc.
according to Fester's post ...
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on March 06, 2010, 08:20:49 AM
R115: this is the part of HOLD switch if you like to build it like EMI.
See descr.txt for HOLD switch etc.
according to Fester's post ...

You mean it's the 5k resistor in this bit

Quote
To get more precision in range of +/-15 db gain,
5k log pot connected in series with 5k resistor can be good option.
To get precision steps, possible to use switch,
Title: Re: TG1 - advice from any one who has built it...
Post by: RedNoise on March 06, 2010, 08:29:40 AM
Yes , put here a 5K resistor as described if you use the hold pot.As it is "on the trace" (sorry for the poor english) of the Lorlin for hold and the Molex connector.(pin6)
This is what I understood , but I have no electronic habilities.
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on March 06, 2010, 08:53:39 AM
Rednoise thanks for that I'll take a look at it.
Title: Re: TG1 - advice from any one who has built it...
Post by: RedNoise on March 06, 2010, 09:13:34 AM
I do my best! ;D
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on March 06, 2010, 10:02:15 AM
Still a bit confused by this.

The ladder of resistors on the hold switch add up to 9k67, but since the steps are not equal, it cannot be considered to be the 10k linear that Fester says EMI used.    Or maybe EMI actually used a 10k "log", & not linear for the hold.  Although on the original diagram it looks like it says "lin", but the writing is blurred


In Festers text he says to use a 5K log post with the 5k resistor can be a good solution.  So maybe one should half the values that are written on the diagram for the hold switch to use with the 5k resistor.

Or just use the 10k log values & insert a link where R115 goes.

Anyone got anything to add here ?

By the way I have my unit powered up now, & it isn't working correctly, but I suspect it's probably to do with the abaove & other similar hook up issues
Title: Re: TG1 - advice from any one who has built it...
Post by: simonsez on March 08, 2010, 04:22:38 AM
I use 10K linier pot for HOLD and it's work fine,I think this is not your problem Rob. it's easier using pot than rotary switch. The GR meter reading meter is different than any compressor else. I'ts react with Hold control even without signal. Just like the TG plugins . 
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on March 08, 2010, 06:48:27 AM
I got one channel working, so far.  You're right about the meter behaving very differently depending on where the hold control is set.  I guess that's something to do with the unusual scale on the meter.  The sifams that everone seems to be using do not really have the right scale for this compressor.

I get the meter showing GR when I turn the hold control down, even without a signal present, which seems a boit wierd.  Do you get the same thing ?
Title: Re: TG1 - advice from any one who has built it...
Post by: simonsez on March 08, 2010, 09:03:58 AM
Mine is when hold control at center the meter is at center too, hold max ==> meter max left, hold min==>meter max right. That's the opposite direction compare to the plugins version (1969 ver). May be i connected in reverse. may be i should reverse the hold pot connection, I don't have a clue..do u have experience with the original one?
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on March 08, 2010, 09:20:32 AM
You have the same happening with regards to the meter as me.   

I don't have expoerience with the real EMI, but have a friend with a Chandler.   Although I'm not sure that comparisons with the Chandler are that useful, since this circuit is more like the original TG.

Do you have the bypass boards wired for transformer & transformerless use.  Mine is wored for both, but I haven't installed the transformers yet.   I am finding that when i switch between iron & non iron modes I still get a signal, which seems wrong if I have no iron in the box just yet.
Title: Re: TG1 - advice from any one who has built it...
Post by: simonsez on March 08, 2010, 09:42:04 AM
I look at the schemo, may be it have something to do with J1,J2 and J7,J8?. not sure...I don't use that pcb..
Title: Re: TG1 - advice from any one who has built it...
Post by: sintech on March 08, 2010, 10:58:13 AM
Didn't the original EMI TG show 'range of compression', so If you want 10db, with no audio.. you move the hold whilst watching the meter to the 10dB mark, the meter then moved back the other way from the 10bB mark to show GR, Chandler do it different so it's more like an SSL.

like this: http://www.youtube.com/user/sintech67?feature=mhw4#p/u/3/F4y9-dQBagQ

The run of TG meters I did are both the same meter spec as the original, and Chandler, but have the chandler scale.
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on March 08, 2010, 11:12:20 AM
I now have both channels working & it sounds REALLY good, & punchy, which I hope will encourage some others to finish theirs.

I have some Gardeners Transformers I'm hoping to use on this so I have a proper British sound, but I only have one 10k:10k for the input (so if anyone has a spare MU7530 lying around).  

Andy thanks for that description of the hold function.   I couldn't work out why the meter wasn't bouncing about in this mode & was just stationary at , say -10dB.  It turns out I wasn't winding enough signal into it for it to bounce.
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on March 08, 2010, 11:15:16 AM
Also thanks to Fester for this project, I appreciate all the grief he put up with to make this happen.
Title: Re: TG1 - advice from any one who has built it...
Post by: phatmateo on March 08, 2010, 01:47:48 PM
Congrats Rob!  You went transformerless for the time being?  I think I'm going to stick to 1:1 trannies.  Is it worth it?  Any pics Rob?
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on March 08, 2010, 04:01:27 PM
I only went transformerless, because I wanted to keep the thing as simple as possible while I got it working.

I don't have a facility to take pics at the moment, sorry.
Title: Re: TG1 - advice from any one who has built it...
Post by: Kid Squid on March 12, 2010, 08:10:24 AM
Hi Lads,

Andy, Peter & Rob,

The current Gardners manufacturers are indeed AML, and here is the link

http://www.avonmagnetics.com/news.php

They ain't cheap tho  ;)

Steve
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on March 19, 2010, 05:22:41 PM
I'm thinkin of going with the 10k:10k Carnhill that someone mentioned sounded nice. New transformer for them i think? Gardner's or Sowter's nice too. Also sent email to participate in the second meter run. Wanted to get in on the first one, but couldn't at the time. Sure as hell don't want a poopy meter.

Yes, i saw that pic long time ago at gearslutz. I clearly remember wiping the drool from my mouth. Obviously, transformers are in the desk. I can imagine the price on those.

Nyway, cheers. Sounds like your project is coming along good.
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on March 19, 2010, 06:15:12 PM
Larger pic for slightly better viewing. Sharpened a tad..

(http://img693.imageshack.us/img693/6277/emipiclarge.th.jpg) (http://img693.imageshack.us/i/emipiclarge.jpg/)
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on March 30, 2010, 06:29:21 PM
Nice one Mark,  I have yet to get the transformers in mine.   Hopefully they will turn up tomorrow.   In reality the limiter sounds fantastic without the transformers, so it will only get better with them I'm hoping.
Title: Re: TG1 - advice from any one who has built it...
Post by: simonsez on March 30, 2010, 06:40:10 PM
Nice Mark!! Can u tell me the setting (attack/recovery, etc)? I run your dry clip to mine (with zener subs), and i got "different" sound here.
Title: Re: TG1 - advice from any one who has built it...
Post by: simonsez on March 30, 2010, 07:48:44 PM
Yeah...It's different, I like yours  :P. Warmer than mine. Did u hear the different between using input trafo and not?
Title: Re: TG1 - advice from any one who has built it...
Post by: Johndcx on March 31, 2010, 08:00:16 PM
great work,this is very high on my list to build...
Title: Re: TG1 - advice from any one who has built it...
Post by: leadbreath on April 01, 2010, 05:18:21 AM
........holy sh*t.............u boys r building EMI limiters? this place is scary.........
Title: Re: TG1 - advice from any one who has built it...
Post by: simonsez on April 01, 2010, 08:44:58 AM

[/quote]

Did you end up using a 604 opamp on the input?

Mark
[/quote]

No, I just connect direct to input (unbalanced)
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on April 01, 2010, 12:36:28 PM
........holy sh*t.............u boys r building EMI limiters? this place is scary.........

It was only a matter of time, and it had to be done.
Whether we get them right or not, is another matter.
Title: Re: TG1 - advice from any one who has built it...
Post by: simonsez on April 01, 2010, 04:46:27 PM
I think i found the problem, i use 8k2 for R105 instead 2k2 (attack sw), now it's sound just like yours mark! Happy..happy... ;D
Title: Re: TG1 - advice from any one who has built it...
Post by: DIYnoob! on April 02, 2010, 01:51:13 AM
Hey guys! Has anyone thrown together a BOM for this build? I'm thinking of building this guy and going transformerless for now.
Title: Re: TG1 - advice from any one who has built it...
Post by: DIYnoob! on April 02, 2010, 04:27:04 AM
well what I really mean is a BOM with no errors.. :)
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on April 02, 2010, 12:49:36 PM
well what I really mean is a BOM with no errors.. :)

The only way you'll guarantee that is if you make the BOm yourself.

By the way the comp sounds great without transformers.
Title: Re: TG1 - advice from any one who has built it...
Post by: ArnauTS on April 02, 2010, 04:21:45 PM
I think i readed more than 3 times all the post in diferent days. I must do that project soon, it's really a nice project and top on my list too
Also great pictures and samples
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on April 02, 2010, 08:16:50 PM
Hmph. This is kinda neat: http://www.youtube.com/watch?v=2bsgNzcttvE
Title: Re: TG1 - advice from any one who has built it...
Post by: DIYnoob! on April 03, 2010, 12:26:20 AM
dude looks at all those modules... :o
Title: Re: TG1 - advice from any one who has built it...
Post by: phatmateo on April 03, 2010, 01:52:59 AM
someone has the sniffles
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on April 03, 2010, 01:39:42 PM
That's just wrong Mark.  :P
Title: Re: TG1 - advice from any one who has built it...
Post by: strangeandbouncy on April 06, 2010, 03:44:42 PM
6n8 . . .

   surely 6.8nF . . . .nanoFarads?
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on April 06, 2010, 04:37:43 PM
Charts like this can help suss out seemingly odd capacitance values.
http://www.hamradio.cc/electronics/capacitance_conversion_chart.php

ie: Look at 6n8 on the chart for example. The uf value is .0068. Searching this value; more capacitors appear.
Title: Re: TG1 - advice from any one who has built it...
Post by: DIYnoob! on April 07, 2010, 01:17:47 AM
Thanks desol for the help!

@Biasrocks  what cap did you use for C13 - C17. I just bought these:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=390064738932
Title: Re: TG1 - advice from any one who has built it...
Post by: DIYnoob! on April 07, 2010, 03:29:04 AM
sweet man! sourcing is going good now  ;)   btw is there a equivalent sub for BC214?
Title: Re: TG1 - advice from any one who has built it...
Post by: fazeka on April 07, 2010, 03:41:40 AM
DIYnoob,

May I suggest Mouser or Digikey as your first place to source?

http://www.mouser.com/Search/Refine.aspx?Keyword=TE-1305

You didn't pay too much more on eBay than Mouser, but you can get a lot from either Mouser or Digikey and really save $, especially on the shipping.

Cheers,
Chris
Title: Re: TG1 - advice from any one who has built it...
Post by: DIYnoob! on April 07, 2010, 04:18:10 AM
Yeah I'm almost completely finished sourcing parts. Mouser has about 95% of the parts. Some of the other harder parts I got from ebay. After completion of this build I'll go ahead and post a US "updated BOM list".

oh wait......whats "mouser" again?  lol jk jk
Title: Re: TG1 - advice from any one who has built it...
Post by: Michael Tibes on April 09, 2010, 09:53:42 PM
Does someone know what PE (power earth?) at the power supply connectors is supposed to be connected to? It seems to just be passed through on the main pcb and goes to a different gnd plane on the bypass board - if I got it right. I don't have Festers psu board, so I can't check with it.

Michael
Title: Re: TG1 - advice from any one who has built it...
Post by: simonsez on April 10, 2010, 01:30:23 AM
Graet work  Mark! I like those meter. Are u having problem with those meter?
Title: Re: TG1 - advice from any one who has built it...
Post by: Michael Tibes on April 10, 2010, 12:06:02 PM
Thanks Mark, that's good to know. The black boards are hard to trace... There was in fact a little psu board offered later, but I don't have that either. I only have the schematic (317 / 337 basics) and the pcb top view. The PE seems to be going to mains earth only, connecting to the screen of the XLR in / out leads on the bypass board. I just don't see the point in doing that, I wish I'd get the idea why Fester did it like that.

Michael
Title: Re: TG1 - advice from any one who has built it...
Post by: simonsez on April 10, 2010, 02:18:11 PM
I'm using modified vintage 1000mA meter, I take out the series resistor inside and adding small resistor in parallel. Now it's bounce properly. You can mod your meter Mark.
Title: Re: TG1 - advice from any one who has built it...
Post by: oceres on April 22, 2010, 03:50:41 AM
I'm gathering parts for this and couldn't find what diodes for the psu pcb. There's no markings on the pcb or in the bom. There are 4 big ones and 4 smaller ones. Should 1N5401 and 1N4001 work? I'm just a newbie so I'm not sure what diodes are fit for this ^^;
Title: Re: TG1 - advice from any one who has built it...
Post by: crisotop on April 22, 2010, 03:54:42 AM
Most of us didn't get a psu pcb with the kit - have you got a schematic for the psu? that would certainly help ;)

cheers
christoph
Title: Re: TG1 - advice from any one who has built it...
Post by: oceres on April 22, 2010, 04:07:23 AM
here

I bought it last year lol... I think it was from the first batch dunno
Title: Re: TG1 - advice from any one who has built it...
Post by: crisotop on April 22, 2010, 04:40:52 AM
I used on the same power supply for a Sontec build the following diodes:

D2, 4, 5, 7 = 1N5400
D1, 3, 6, 8 = 1N4004

hth, christoph
Title: Re: TG1 - advice from any one who has built it...
Post by: oceres on April 22, 2010, 05:34:42 AM
thanks christoph  :)
Title: Re: TG1 - advice from any one who has built it...
Post by: tomcat on April 25, 2010, 04:04:56 PM
Im little bit confused. Fester wrote somewhere:

---
Simplest way to build TG with iron and transformers bypass option
is to use 1:1 input and output transformers. In this case, use
1:1 input balanced line receiver and ommit output amp on bypass board.
Input trafo is 10k:10k Sowter etc, output is 600:600.
---

and

---
Another very nice sounding option is use of Neve 31267-like 10k:2k4
on input and Neve LO1173-like (70:600) as output transformer.
---

Somewhere else i found the combination from a crossref what chandler is using

VTB9045 & VTB9057

shouldnt it be

VTB9046 & VTB9057 (10k:2k4 & 50:600) ???
Title: Re: TG1 - advice from any one who has built it...
Post by: Michael Tibes on April 25, 2010, 06:17:11 PM
That's one of the many hard bits on that project - figuring out and digesting all the I/O options Fester had in mind.
1 - no transformers - input electronically balanced, output unsymmetrical (poor mans)
2 - as 1, but with 1:1 in and output trannys (10k:10k / 600R:600R) (EMI with trannys)
3 - with Neve type iron 2:1 / 1:2 - that's a 6 dB level drop at the input and a 6-8dB or so gain at the output
4 - the C. version with 1:2 / 1:3 trannys.
Version 2-4 have the option to bypass the transformers and replace them with the opamp curcuits on the I/O boards in order to make the bypass idea reasonable and therefore to maintain the gain structure.
One could also take this further and for example do version 4 with 1:2 / 1:3 trannys but keep the transformer bypass circuit at unity gain in order to have 2 really different flavours...

I hope I didn't confuse you even more  ;)

Michael
Title: Re: TG1 - advice from any one who has built it...
Post by: briomusic on April 25, 2010, 06:51:22 PM
the ch*ndler version (aka option 4 in michaels post) and its history is explained in this post:
http://www.groupdiy.com/index.php?topic=6481.msg395357#msg395357 (http://www.groupdiy.com/index.php?topic=6481.msg395357#msg395357)

basically - in reply to tomcats post - what should be, gainwise, doesn't come into it....

to achieve the 1:2 (6 dB) boost on the input the VTB9045 does make sense, even though it is a mic input transformer used in a line level application. (whatever this means in terms of impedances is for someone else to explain...)
in fact, frank einstein reckons the primaries were wired in parallel for a blistering +12dB gain, however this is not reflected in the uncle fester variant 4.

as for the output transformer, in order to achieve a ratio close to 1:3 the 1166 type output transformer (VTB9057 or similar from Carnhill) would also need the primaries wired in parallel.

afaik, variations 2 and 3 are suggestions by fester and not based on cloning existing machines.
Title: Re: TG1 - advice from any one who has built it...
Post by: Michael Tibes on April 26, 2010, 04:15:22 AM
Just wanted to add that I remember something like 'a Neve mic transformer will not do here' from Festers description, I assume it can't hold the levels if used as line in and that Mr. C seems to have custom wound transformers on his version. I don't know enough about the suggested Neve line transformers for version 3, being 2:1 they'd be 1:2 if reversed, paralleling the prim coils would be 1:4? Maybe with even more relay switching all the versions could be done in one box?

I am currently still on 'phase one', just opamp balanced input and it already works great. It can certainly only get better with good transformers, but to get going that's a good starting point - and closest to the EMI channel version.

Michael
Title: Re: TG1 - advice from any one who has built it...
Post by: tomcat on April 26, 2010, 07:23:43 AM
to achieve the 1:2 (6 dB) boost on the input the VTB9045 does make sense, even though it is a mic input transformer used in a line level application. (whatever this means in terms of impedances is for someone else to explain...)

This is exactly the part which puzzled me  :-\ Was hoping to add the transformers to another order i have to do right now, well maybe i have to be more patient and build it discrete first.
Title: Re: TG1 - advice from any one who has built it...
Post by: tomcat on April 26, 2010, 07:34:35 AM
3 - with Neve type iron 2:1 / 1:2 - that's a 6 dB level drop at the input and a 6-8dB or so gain at the output

I hope I didn't confuse you even more  ;)

Well you did ;)

So regarding the option 3:

VTB9046 is 10k : 2k4 and both sides wired ins series create a -6dB Gain
VTB9056 is 70 : 600 and creates a +8dB gain

looks good on paper to me. Have to order these trannies anyway for a 33609 ... should be able to test this config.

Oh man ... audio transformers ... still a big mistery for me ;)
Title: Re: TG1 - advice from any one who has built it...
Post by: Hank Dussen on April 28, 2010, 05:22:08 AM
Can't find the BC214's. Anyone knows a good alternative?
I searched the forum and there's some suggestions.
Someone suggested MPSA56 connected reversed.
Or maybe the BC184's will do?

The same goes for the BC177. Anyone knows a good substitute?

What did you guys use?
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on April 28, 2010, 06:45:02 AM
Can't find the BC214's. Anyone knows a good alternative?
I searched the forum and there's some suggestions.
Someone suggested MPSA56 connected reversed.
Or maybe the BC184's will do?

The same goes for the BC177. Anyone knows a good substitute?

What did you guys use?

Did you look on ebay ??
Title: Re: TG1 - advice from any one who has built it...
Post by: Jim50hertz on April 28, 2010, 07:02:42 AM
BC214 here (http://uk.farnell.com/jsp/search/browse.jsp;jsessionid=AXVVLHA41EXXSCQLCIPJLTQ?N=0&Ntk=gensearch_001&Ntt=bc214&Ntx=mode+matchallpartial&suggestions=false&ref=globalsearch&_requestid=733078)

BC177 here (http://uk.farnell.com/jsp/search/browse.jsp?N=500006+1004177&Ntk=gensearch_001&Ntt=bc177&Ntx=mode+matchallpartial)

 :)
Title: Re: TG1 - advice from any one who has built it...
Post by: baadc0de on April 28, 2010, 09:29:40 AM
BC214 here (http://uk.farnell.com/jsp/search/browse.jsp;jsessionid=AXVVLHA41EXXSCQLCIPJLTQ?N=0&Ntk=gensearch_001&Ntt=bc214&Ntx=mode+matchallpartial&suggestions=false&ref=globalsearch&_requestid=733078)

BC177 here (http://uk.farnell.com/jsp/search/browse.jsp?N=500006+1004177&Ntk=gensearch_001&Ntt=bc177&Ntx=mode+matchallpartial)

 :)


Yes but you can't buy anything on the first URL by virtue of everything being "No Longer Stocked" or "No longer manufactured". Bummer.
Title: Re: TG1 - advice from any one who has built it...
Post by: Jim50hertz on April 28, 2010, 09:51:23 AM
Aah, sorry dude, didn't catch that  :(
Title: Re: TG1 - advice from any one who has built it...
Post by: Tekay on April 28, 2010, 10:30:53 AM
How about BC550C and BC560C
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on April 28, 2010, 10:39:39 AM
Another place apart from ebay that you can get these transistors from is http://www.ssi-uk.com/

I even got the correct output transistors from them.
Title: Re: TG1 - advice from any one who has built it...
Post by: Hank Dussen on April 28, 2010, 11:37:38 AM
Thanks guys,
I'll check out SSI. Otherwise eBay.

Now another one:
I read somwhere that the transformers should be ungapped? Or was is gapped? Oh sh*t, now I don't know anymore...
How impotant is that anyway?
Is there a reason why cheap OEP's shouldn't work here?
Title: Re: TG1 - advice from any one who has built it...
Post by: Michael Tibes on April 28, 2010, 11:53:14 AM
There's no dc around, I don't see why the xformers should be gapped?

Michael
Title: Re: TG1 - advice from any one who has built it...
Post by: simonsez on April 28, 2010, 12:38:17 PM
I use BC550 and BC560, i don't think transformer  should be gapped...theres output cap there..
Title: Re: TG1 - advice from any one who has built it...
Post by: warpie on May 20, 2010, 06:56:16 AM
hi,

does anyone know if the lundhal LL1540 and LL1517 can be used here?

thanks
mike
Title: Re: TG1 - advice from any one who has built it...
Post by: crisotop on May 20, 2010, 10:05:53 AM
what I got out of the datasheets:

LL1540 could be used as an Output (use only one primary / secondary winding)
LL1527 is not suitable

hope this is correct,
christoph
Title: Re: TG1 - advice from any one who has built it...
Post by: warpie on May 20, 2010, 10:24:22 AM
what I got out of the datasheets:

LL1540 could be used as an Output (use only one primary / secondary winding)
LL1527 is not suitable

hope this is correct,
christoph

I'm afraid I got a bit confused.

According to the datasheets LL1540 is a Line Input Transformer and LL1517 (not LL1527) an Output Transformer  ???
Title: Re: TG1 - advice from any one who has built it...
Post by: crisotop on May 20, 2010, 10:29:44 AM
As far as my knowledge goes there's no such thing as a dedicated in- or output transformer. What counts ins the turns ratio and the impedance of the windings. Depending on your version of the trafo / bypass board you roughly need a 10k/10k input- and a 600:600 output tranny. The 1540 if you only use one primary and one secondary winding would give you 600:800 which should be fine as an output trafo for the tg1.

hth, christoph
Title: Re: TG1 - advice from any one who has built it...
Post by: warpie on May 21, 2010, 04:00:35 AM
As far as my knowledge goes there's no such thing as a dedicated in- or output transformer. What counts ins the turns ratio and the impedance of the windings. Depending on your version of the trafo / bypass board you roughly need a 10k/10k input- and a 600:600 output tranny. The 1540 if you only use one primary and one secondary winding would give you 600:800 which should be fine as an output trafo for the tg1.

hth, christoph

ok I see. Now makes more sense.. :)
I'll try this.

I assume the 1540 can't be used in 1:2 ratio as 150:600, is this correct?

thanks
mike
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on May 21, 2010, 08:17:16 AM
If you look at the documentation that Fester provides it tells you how to use transformers with other ratios.  You just change some of the resistors on the switch board, to accomodate more or less gain.
Title: Re: TG1 - advice from any one who has built it...
Post by: echotodd on May 26, 2010, 12:56:41 PM
I'm going to post this here too because it seems folks are looking for a 1:2 output transformer.  I've been in contact with Colin over at Audio Maintenance.  He's going to have available a bracket mounted L01173 really soon from Carnhill.  It's going to have a smaller bobbin than the VTB9056 which is more in line with the original.  Good news!
Title: Re: TG1 - advice from any one who has built it...
Post by: electrochronic on May 28, 2010, 05:31:22 AM
.



Title: Re: TG1 - advice from any one who has built it...
Post by: noulou on May 28, 2010, 10:36:10 AM

just found 6x NPN Mot' 2N4910 for $.45 each, but need the PNP compliment


Care to share the source of the 2n4910s? I'm looking for one for my build.

Thanks,
Nikos
Title: Re: TG1 - advice from any one who has built it...
Post by: warpie on May 28, 2010, 11:29:49 AM
does anyone have issues with R77 (56 Ohm) resistor?
I'm using a 1Watt one and still runs hot.

Also, I don't use C3, C4, C7, C121 because I don't have any spare ones at the moment.
Could this cause R77 getting hot?
FWIW, a JLM Audio PSU (AC/DC) supplying the circuit with +/-28 Volts.

thanks
mike
Title: Re: TG1 - advice from any one who has built it...
Post by: electrochronic on May 28, 2010, 03:49:47 PM
.
Title: Re: TG1 - advice from any one who has built it...
Post by: crisotop on June 03, 2010, 05:04:08 PM
My unit is finally running as well, very happy with the sound, extremely versatile compressor.

Two questions though:

I have a slight volume drop when switching the transformers (1:1 variant, 10k:10k edcor input, 600:600 sowter output) in the circuit, but I haven't installed an Rz/Cz at the output trafo yet. As far as I know this is just to correct frequency response and should not affect overall level?

And just to confirm I got the attack and release controls right, I'd like to know how the auto settings behave on your already finished units.

Many Thanks,
Christoph 
Title: Re: TG1 - advice from any one who has built it...
Post by: T-rex on July 02, 2010, 10:46:50 PM
Just jumping in to say I am starting to source parts for this build starting tomorrow.  Samples so far sound great!
Title: Re: TG1 - advice from any one who has built it...
Post by: oceres on July 11, 2010, 06:37:00 AM
I'm trying to figure out which relays are suitable for the bypass board...

Does it need to be a specific coil resistance`?
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on July 11, 2010, 07:55:05 AM
I'm trying to figure out which relays are suitable for the bypass board...

Does it need to be a specific coil resistance`?

Nope just 24v in the required footprint.
Title: Re: TG1 - advice from any one who has built it...
Post by: Michael Tibes on July 13, 2010, 08:05:23 AM
I'm trying to figure out which relays are suitable for the bypass board...

Does it need to be a specific coil resistance`?

http://cgi.ebay.de/Relais-Takamisawa-RY24W-K-Relay-2x-UM-z-B-Audio-Signal-/310199115141?cmd=ViewItem&pt=Audio_Zubeh%C3%B6r&hash=item48394edd85 is what I just ordered. Haven't put them in yet, but specs seem very good and so's the price. Shipping to Finland (that's where you are?) is 7,55€ unregistered ...

Michael
Title: Re: TG1 - advice from any one who has built it...
Post by: oceres on July 13, 2010, 08:24:48 AM
I'm trying to figure out which relays are suitable for the bypass board...

Does it need to be a specific coil resistance`?

http://cgi.ebay.de/Relais-Takamisawa-RY24W-K-Relay-2x-UM-z-B-Audio-Signal-/310199115141?cmd=ViewItem&pt=Audio_Zubeh%C3%B6r&hash=item48394edd85 is what I just ordered. Haven't put them in yet, but specs seem very good and so's the price. Shipping to Finland (that's where you are?) is 7,55€ unregistered ...

Michael

Thanks!  :)
I came across RY24W-K too and found similar type from Mouser: Omron G5V-2-H1-DC24
either should work
Title: Re: TG1 - advice from any one who has built it...
Post by: Michael Tibes on July 13, 2010, 09:12:57 AM
The minimum switching current is factor 10 lower (better) with the Takamisawa types, but I believe the Omrons should do fine as well.

Michael
Title: Re: TG1 - advice from any one who has built it...
Post by: warpie on July 13, 2010, 07:31:22 PM
Has anyone used these: http://uk.farnell.com/nec/ea2-24nu/relay-dpco-24vdc/dp/1094032?Ntt=1094032
Title: Re: TG1 - advice from any one who has built it...
Post by: briomusic on July 14, 2010, 05:28:41 AM
that footprint looks wrong to me, I would expect to find 4 pairs of pins, the one for the coil slightly further away from the other pairs. like in the earlier ebay link.
Title: Re: TG1 - advice from any one who has built it...
Post by: warpie on July 14, 2010, 01:00:14 PM
that footprint looks wrong to me, I would expect to find 4 pairs of pins, the one for the coil slightly further away from the other pairs. like in the earlier ebay link.

thanks  briomusic. didn't notice...
Title: Re: TG1 - advice from any one who has built it...
Post by: baadc0de on July 21, 2010, 04:29:20 AM
Though it's a small difference when listening at the job with my crappy headphones, the upgraded one feels less congested with the kick and clearer with the rest.
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on July 21, 2010, 10:51:31 AM
It's better to my ears.

Letting more bottom through.
Holding the snare/room longer.
A touch nicer on the top.

More towards the original type sound imo.
Title: Re: TG1 - advice from any one who has built it...
Post by: StudioSQ on July 24, 2010, 12:09:00 AM
I am having some trouble with this build. Everything seems to work fine except that the unit responds to the hold knob being turned whether there is signal applied or not. The cv test point has between 2 and 5v DC on it depending on where the hold control is set. AC voltage appears when an input signal is applied but the compressor barely responds to it, it does however still respond to the dc. the amp sections work and the AOT trimpots i installed all function as you would expect. when you turn the hold know quickly you can see the attack and release respond and the differnt attack and release position all function correctly. the only thing i cannot get it to do is compress. any help would be great.
Title: Re: TG1 - advice from any one who has built it...
Post by: briomusic on July 24, 2010, 03:01:27 AM
I am having some trouble with this build. Everything seems to work fine except that the unit responds to the hold knob being turned whether there is signal applied or not. The cv test point has between 2 and 5v DC on it depending on where the hold control is set. AC voltage appears when an input signal is applied but the compressor barely responds to it, it does however still respond to the dc. the amp sections work and the AOT trimpots i installed all function as you would expect. when you turn the hold know quickly you can see the attack and release respond and the differnt attack and release position all function correctly. the only thing i cannot get it to do is compress. any help would be great.

this is actually how the tg limiter works! with hold turned up you get maximum 'swing' in gain reduction and as you turn the hold knob down a fixed gain reduction is preset which remains constant. the needle (and the actual gain reduction) has less swing. the whole signal is now of course lower compared to lowering the threshold on a normal compressor, use the output level to compensate. with the hold knob turned down a lot, you need quite a strong signal to see any 'swing' in GR at all.
hope this makes sense, I am finding it quite difficult to explain....  :P
Title: Re: TG1 - advice from any one who has built it...
Post by: StudioSQ on July 24, 2010, 02:47:53 PM
ok so, from that description it seems more like an amp with a fader on it. than a compressor. how is it meant to be used then, if it reduces with no signal what is the idea? i am just trying to understand how to use it.
Title: Re: TG1 - advice from any one who has built it...
Post by: StudioSQ on July 24, 2010, 02:50:38 PM
good to know i'm not crazy though, i was messing with this for soooo long.
Title: Re: TG1 - advice from any one who has built it...
Post by: briomusic on July 24, 2010, 07:02:34 PM
ok, how to explain. basically just feed it a loud, dynamic signal with hold fully turned up. you should have loads of swing on the needle, the G.R. going up and down according to your time constant settings. Maybe too much? then just turn the hold knob down a little, now the signal will swing between maximum reduction and 'some reduction' but never fully recover back to no G.R. Now turn up the output level until the average signal level is back where you want it. basically it works like a normal compressor, only the "resting" point is not at 0dB but rather at a preset reduction dialled in with the hold knob. you can still achieve "a lot" and "just a little" compression like with any other box, it's just achieved in a bit of a roundabout way. interestingly the compressor will be at its least 'active'  with hold turned all the way down, and loads of static gain reduction applied, but no needle swing and no dynamic G.R.
Can't explain it any better than that. Hope this helps :)
Title: Re: TG1 - advice from any one who has built it...
Post by: StudioSQ on July 24, 2010, 08:34:58 PM
ok so i had the hold knob backwards because of that. ii get it now, i will give it another shot and see what happens
Title: Re: TG1 - advice from any one who has built it...
Post by: StudioSQ on July 26, 2010, 03:22:10 AM
yeah, ok... it has worked for some time now. I just didn't know how it worked. sounds great.
Title: Re: TG1 - advice from any one who has built it...
Post by: Tekay on July 28, 2010, 08:16:39 AM
Regarding the OA202 or 1N4148. My book says OA202 = BA159? The MKII Zener Limiter uses BAY38 which is more or less equal to 1N4148.
Title: Re: TG1 - advice from any one who has built it...
Post by: echotodd on August 06, 2010, 01:06:02 AM
Maybe I'm thick or just tired but I'm stumped here.  I'm doing mine in the EMI style with the hold pot.  According to the schematic the signal comes in and goes out for the hold/attack/release through J6 1-6 on the attack recovery board.  So what the heck is IN_POT 1-3 on the Bypass PCB all about?  As far as I can tell I want to jumper 2-3 but is this actually wired to the hold pot also?

Thanks
Title: Re: TG1 - advice from any one who has built it...
Post by: briomusic on August 06, 2010, 01:58:01 AM
Nothing to do with the hold pot, just short IN_POT 2 and 3 to bypass input level control.
Title: Re: TG1 - advice from any one who has built it...
Post by: echotodd on August 06, 2010, 09:05:55 AM
Thanks!  That's what I thought but I needed that extra bit of confirmation.
Title: Re: TG1 - advice from any one who has built it...
Post by: electrochronic on September 02, 2010, 01:13:49 PM
Is there any documentation on jumpers JP1 - JP6 on main PCB board , could not locate usage or description
of jumpers here. Used to jumper resistors R48 - R53 on the main board.

Read thru all available build notes , but no info.
Title: Re: TG1 - advice from any one who has built it...
Post by: wmtunate on September 02, 2010, 01:29:58 PM
There's something under the final test procedure in DESCR.txt:

Quote
Testproc:
1). +/-20v
JP1...6, TP+20v, TP-20v

That's the only place they're mentioned.  From what I gather, I think that means to jumper all the points, then check for +20VDC at "TP+20v", and -20VDC at "TP-20v".  I assume you remove the jumpers after that test.
Title: Re: TG1 - advice from any one who has built it...
Post by: electrochronic on September 02, 2010, 01:41:30 PM
helpful, I somehow missed it at the bottom of the build docs page. easy to miss.
Title: Re: TG1 - advice from any one who has built it...
Post by: baadc0de on September 06, 2010, 03:07:59 PM
Did anyone wire TG1 up with the chandler output trafos? What would you recommend/have used for CZ/RZ of the zobel network?
Title: Re: TG1 - advice from any one who has built it...
Post by: echotodd on September 08, 2010, 02:28:33 AM
Is anybody else not getting any output?  I'm stymied.  Obviously bypass is fine but when I switch in either the clean or fmrs, nothing.  I am using an SPDT so it's not that.  My meters are dancing so I know I have something coming in.  I've checked, rechecked and triple checked my wiring, it all seems right.  Voltages look good, 20V where it's supposed to be, ground to the tops of my 2N4898 and 2N4910 show 28.3V.  This is happening on both channels, so it must be something I did, twice... I went with 1:1 xfmrs, and the balanced input with the 604.  All appropriate jumpers are in place.  Is there anything I might be missing?

Thanks
Title: Re: TG1 - advice from any one who has built it...
Post by: briomusic on September 08, 2010, 02:51:37 AM
are you getting a signal on the unbalanced output of the main board? this is where it connects back to the bypass board.
Title: Re: TG1 - advice from any one who has built it...
Post by: echotodd on September 08, 2010, 03:03:24 AM
I'm getting nothing off the unbalanced out.  Also the 2N4910s don't seem to be getting warm at all.  The unbalanced in seems good.  I just rechecked and the positive and negative voltage rails are solid.
Title: Re: TG1 - advice from any one who has built it...
Post by: briomusic on September 08, 2010, 04:18:12 AM
you are aware that you should have one 2N4910 and one 2N4898 each on the out amp, right? how about going to the output level pcb, are you getting signal at S3-1?
Title: Re: TG1 - advice from any one who has built it...
Post by: wmtunate on September 08, 2010, 08:20:13 AM
I had the exact same problem.  Make sure you use an isolator underneath the output transistors.  I had mine soldered down and I was getting contact with the shell and the middle pad on the top of the board.  I desoldered the transistors, cut out some small circles of rosin paper, lined them up on the board, and pushed the pins through the paper.
Title: Re: TG1 - advice from any one who has built it...
Post by: echotodd on September 08, 2010, 08:49:08 AM
Thanks guys,

I do have signal S3.  I have mica insulators underneath the transistors, the transistors are placed correctly.  I even tried disconnecting the screws I used to mount them to the PCB and I'm still showing nothing at the unbal. output.  I even tried a little sleep, that didn't help much either!  Diodes look good and the caps are oriented properly.  Time to go to work, more digging later.  Thanks again guys!
Title: Re: TG1 - advice from any one who has built it...
Post by: echotodd on September 08, 2010, 10:01:47 AM
Thanks for the tip!  It was ages ago that I stuffed the transistors but I remember checking the datasheets and everything looked okay.  I'll double check when I get home, though I would think that if the 214s weren't right I wouldn't be getting a signal at S3, which feeds the ouput amp.  I also re-checked the pin-out for the 107/177s this morning, looks good there too.  Something has got to be funky at the amplifier, I just haven't figured it out yet.  The fact that I did it twice tells me it's super obvious.  I metered for continuity between the shell of the transistors and the solder tab wmtunate mentioned in case my insulators had failed but it looks fine.
Title: Re: TG1 - advice from any one who has built it...
Post by: crisotop on September 08, 2010, 10:16:06 AM
I think (as far as I remember, built mine months ago) that there shouldn't be any insulation between the output transistors case and the mounting holes on the pcb, as this is the emitter connection.

but please double check before trying ;)
Christoph
Title: Re: TG1 - advice from any one who has built it...
Post by: wmtunate on September 08, 2010, 10:19:28 AM
I even tried disconnecting the screws I used to mount them to the PCB and I'm still showing nothing at the unbal. output.

That may be the problem.  You may have too much isolation.  Make sure you're also getting continuity between the shell of the 4910 and T_OP right next to it.  The shells of those things need continuity to the screw pad.  The shell is considered "Pin 3".

I see crisotop already beat me to it.
Title: Re: TG1 - advice from any one who has built it...
Post by: echotodd on September 08, 2010, 10:26:37 AM
Hmm,  I'll check it out when I get home!  If I remember correctly I was showing 28V at the shell of the 4910, 4898, as well as T-OP with respect to ground.  I thought when I looked at the boards that pin 3 was on the same line as the pads around the screws to lock the shells down.  This also could be where I over thought things and it all went hopelessly wrong!
Title: Re: TG1 - advice from any one who has built it...
Post by: echotodd on September 08, 2010, 11:17:26 AM
Well thanks a ton guys!  I really hope that takes care of it as it certainly qualifies as something obvious and something I did twice (four times actually but we'll just say twice as my ego is pretty bruised about this already).  So much for erring on the side of caution!
Title: Re: TG1 - advice from any one who has built it...
Post by: electrochronic on September 08, 2010, 12:14:59 PM
Have you checked all diodes for proper orientation ?

ocasionally about 1 in a 1000, I find a bad diode or one that was banded in reverse.
sometimes the body can crack very unnoticeably due to bending leads
Title: Re: TG1 - advice from any one who has built it...
Post by: echotodd on September 08, 2010, 02:06:25 PM
Thanks Frank,

I know all the diodes are properly oriented.  I would hope like heck I don't have cracked diodes across two boards!  I'm really hoping that it's just a matter of the insulators.  They seemed like such a good idea when I put them in!  I'm pretty eager to get hope tonight and tear it apart!
Title: Re: TG1 - advice from any one who has built it...
Post by: crisotop on September 08, 2010, 02:13:09 PM
prepare yourself, as this is probably my most favorite compressor ever - I was so blown away after the first use (still need to finish my frontpanel though, and haven't had time to try stereo linking)

good luck!
christoph
Title: Re: TG1 - advice from any one who has built it...
Post by: nielsk on September 08, 2010, 06:15:55 PM
Tekay, did you determine if BC500c &560C are the correct pinout?
Title: Re: TG1 - advice from any one who has built it...
Post by: echotodd on September 08, 2010, 07:48:12 PM
Always the obvious.  The issue was not insulators my dear friends.  It turns out the lock washers on the kepps nuts I was using overshot the pads.  Now my only issue is that I am slamming the hell out of my input.  My guess is that I have the hold wired wrong.  To be honest, I'm embarrassed.
Title: Re: TG1 - advice from any one who has built it...
Post by: wmtunate on September 08, 2010, 10:19:10 PM
Always the obvious.  The issue was not insulators my dear friends.  It turns out the lock washers on the kepps nuts I was using overshot the pads.  Now my only issue is that I am slamming the hell out of my input.  My guess is that I have the hold wired wrong.  To be honest, I'm embarrassed.

Been there too.  Though in my case, I tightened them down enough that they went through the soldermask and into the ground plane.  I ended up putting the nuts on the top.
Title: Re: TG1 - advice from any one who has built it...
Post by: echotodd on September 12, 2010, 01:16:10 PM
I just wanted to post a word of thanks again to all those that offered advice with my output problem.  Even though it was something silly that I overlooked it was great getting all those responses when I was feeling anxious about it.  A word of advice of my own from those who are still working on it.  Get mica insulators for TO-66 package transistors if you are going with the 2N4910/2N4898 to put between the PCB and the transistor.  It can save some headaches.  This compressor sounds wonderful.  Thanks to neilsk I have some Trident A-Range 10K:10K input xfmrs and I used some Carnhills I had laying around for the outputs.  The combination is incredible.  Switching between the balanced "clean" driver and the "iron" setting is not subtle at all.  It's like it sucks the room right out of the drum tracks and pulls it out front.  Pretty amazing.  I also wanted to tip my hat to Andy (sintech) and Frank (electrochronic).  Thanks for putting in the extra work to make it easier for us to get some parts.  If you haven't pulled the trigger on the meters from Andy yet, do it.  They are beautiful and they are a lot more accurate than the Retros (I tried).  Also to Fester for taking the time to churn this out.  There was a lot of controversy about this unit early on about it being a clone of another unit.  Fester's boards give the opportunity to make it in a way that is more true to an original unit, something many of us will never have the opportunity to use.  I chose to wire mine up the old school way and I'm very glad I did.  Even if this is not a "true" recreation of the old TG, it is one hell of a great sound compressor.
Title: Re: TG1 - advice from any one who has built it...
Post by: electrochronic on September 12, 2010, 04:36:01 PM
Glad to see your success

First , we know that the case of the TO-66 transistor 2N4898 forms the collector connection ( collector = case) which mustbe isolated from the pads in the center where the two legs push thru( emitter and collector). there is enough tinned pad exposure on the pcb for the case to make contact and short. So its good that this is now something to be aware of.

several questions:

How are most of you finding the temperature at which the transistors are running at (2N4898 & 2N4910 specifically) ?
the orignal is mounted to the pcb with no heatsink, but improvements can be made if heat buildup is a problem. Not
sure if the original uses any type of insulator between the component and pcb.

Could the transistors be put on two short aluminum standoffs instead of a mica insulator.
reason I ask. This is how the Neve BA mic pre card does it with the 2N3055 which in effect is the same. this may or maynot
be required , just a option.

Another reason for the short standoffs is keeping heat away from the PCB  and offering a little more thermal dissipation that
may benefit the transistors service life, since these Motorola transistors are rapidly becoming expensive and hard to find.  
Title: Re: TG1 - advice from any one who has built it...
Post by: echotodd on September 12, 2010, 05:02:22 PM
The temperature buildup isn't too bad.  I've had mine on all day and I can still hold my finger to the 2N4898 which seems to get quite a bit warmer than the 2N4910.   A heatsink with aluminum standoffs would probably help the situation quit a bit and there are a few available for the TO-66 package.   At least it would eliminate the need for an insulator at the board.  To be honest, I'm surprised that more aren't running into problems by not using an insulator.  There's really not a lot of room for error when positioning the transistor so that neither of the pin 1 or 2 pads short to the shell, hence my suggestion in my previous post.
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on September 13, 2010, 10:15:46 AM
+1 for using 1/4" standoffs for the TO-66 transistors.
Anybody have a source for the ELMA switches?  I need 4.
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: oceres on September 13, 2010, 04:27:06 PM
Hi,

Would it be possible to use Ed Anderson's EA-1166 output transformer in TG1 build?

http://hairballaudio.com/docs/1166/1166.pdf

Thanks!
Title: Re: TG1 - advice from any one who has built it...
Post by: briomusic on September 13, 2010, 04:46:23 PM
Hi,

Would it be possible to use Ed Anderson's EA-1166 output transformer in TG1 build?

http://hairballaudio.com/docs/1166/1166.pdf

Thanks!

this transformer and the VTB1148 that I am using in my TG build are based on the same vintage transformer (LO1166) and have the same impedance ratios, so I'd say - why not?
Title: Re: TG1 - advice from any one who has built it...
Post by: echotodd on September 14, 2010, 10:13:37 PM
A picture of the guts.
Title: Re: TG1 - advice from any one who has built it...
Post by: tommypiper on September 14, 2010, 11:06:54 PM
...and I used some Carnhills I had laying around for the outputs.  ...

What model Carnhills did you use and how are they wired?  (sorry if I missed it earlier, I looked and didn't see a mention of it...)

Congrats! 
Title: Re: TG1 - advice from any one who has built it...
Post by: echotodd on September 14, 2010, 11:18:36 PM
They're VTB1148s wired 1:1.  Thanks!  I started it a long time ago and kind of got stuck on the options.  I'm still mulling over trying Ed's 1166 on the outputs but it sounds so good right now!  
Title: Re: TG1 - advice from any one who has built it...
Post by: briomusic on September 15, 2010, 02:35:11 PM
They're VTB1148s wired 1:1.  Thanks!  I started it a long time ago and kind of got stuck on the options.  I'm still mulling over trying Ed's 1166 on the outputs but it sounds so good right now!  

hi echo,
how do you wire the 1148 1:1? I didn't think it was possible with 1+1:1.7+1.7? according to the carnhil design guide it's never 0dB voltage gain....

also what are you using on the input? sowter?

cheers
briomusic
Title: Re: TG1 - advice from any one who has built it...
Post by: echotodd on September 15, 2010, 02:49:15 PM
I really need to drink the coffee BEFORE I post.  It's wired in series giving me +4 on the output.  I probably should trade them out for 600:600 ohm xmfrs, but it sounds so good.  The inputs are gardners 10k:10K.
Title: Re: TG1 - advice from any one who has built it...
Post by: electrochronic on September 17, 2010, 01:45:59 PM
From the BOM

4   *       1/4W MF 1%       R205, R206, R207, R208  A1, A2 RELEASE        
10  *       1/4W MF 1%       AOT1, AOT2, AOT3, AOT4, AOT5, AOT6, AOT7, AOT8, AOT9, AOT10

Testproc:
1). +/-20v JP1...6, TP+20v, TP-20v
2).Unity gain Initial gain is set by AOT1,2
3).Distortion w/o compression minimum distortion adjustment AOT 7,9
4).Distortion at 20dB GR distortion under hard compression adjusted by AOT8/10, usually 10R is fine
5).Com threshold Com threshold adjustment: AOT3,4
6).Lim threshold Lim threshold set by AOT5,6.
7).Check: reqresp, max gain, min  gain, S/N, timeconstants.



* = ?

A lot of requests on this , is there any indication what starting values should be for these  ?
seems this is a source of confusion with most builders. Looks like a good place for trimpots.
Title: Re: TG1 - advice from any one who has built it...
Post by: crisotop on September 17, 2010, 01:49:00 PM
have a look at festers notes (txt file, that came with the bom), it's all in there ;)
Title: Re: TG1 - advice from any one who has built it...
Post by: electrochronic on September 17, 2010, 02:10:50 PM
From mb_schem

AOT 1/4/6 ........not used
A.O.T. 8 ........Not used

From test procedure above in txt file.

AOT 8/10 ......10r


somewhat difficult to follow, seems test procedure is only directly related
info on this, the body of notes do not go into much detail about AOT values.
Its seems these values will be different will each individual unit or the
values would be published.
Title: Re: TG1 - advice from any one who has built it...
Post by: crisotop on September 17, 2010, 02:30:45 PM
pm'd just in case you missed the notes file
Title: Re: TG1 - advice from any one who has built it...
Post by: electrochronic on September 17, 2010, 03:07:54 PM
yes, missed the notes file , thanks.
Title: Re: TG1 - advice from any one who has built it...
Post by: wmtunate on September 17, 2010, 03:47:53 PM
Here's what I used:

A.O.T. 8 = not used
A.O.T. 10 = 10R
aot1 = 330R
aot2 = not used
aot3 = 47k
aot4 = not used
aot5 = 3k
aot6 = not used
aot 7 = 3.3k
aot 9 = 68k
Title: Re: TG1 - advice from any one who has built it...
Post by: warpie on October 04, 2010, 05:51:03 PM
does anyone have issues with R77 (56 Ohm) resistor?
I'm using a 1Watt one and still runs hot.

thanks
michael

Sorry to bring this up again but I'm still having the same problem. Just wondering how hot is on other people's units (?)

thanks again,
michael
Title: Re: TG1 - advice from any one who has built it...
Post by: echotodd on October 04, 2010, 07:31:34 PM
Check to make sure you don't have any of the pins shorted on the output transistors.  That'll make it get hot in a hurry.
Title: Re: TG1 - advice from any one who has built it...
Post by: echotodd on October 04, 2010, 09:45:24 PM
Mark,

Did you ever find out more about the time constants?

Todd
Title: Re: TG1 - advice from any one who has built it...
Post by: warpie on October 05, 2010, 08:41:07 AM
Check to make sure you don't have any of the pins shorted on the output transistors.  That'll make it get hot in a hurry.

thanks for the advise echotodd but unfortunately that's not the problem. I start to believe that there's something wrong with the power supply, although I'm getting all the voltages right and the circuits seems to work fine...  ::)
Title: Re: TG1 - advice from any one who has built it...
Post by: echotodd on October 05, 2010, 12:46:14 PM
Thanks Mark,

I'm good with the release times.  It's the attack times I'm wondering about.  I suppose it's mostly nit-picking as it just sounds great, but I'd like to know.

warpie,

what are you using for output transistors?  Is it happening on one channel or both?
Title: Re: TG1 - advice from any one who has built it...
Post by: warpie on October 05, 2010, 01:35:09 PM
warpie,

what are you using for output transistors?  Is it happening on one channel or both?

On both channels yes.
I'm using MJE2955T and MJE3055T. I have omitted C3 and C4 though but I don't think that's the problem.
I'm using a JLM PSU (AC/DC)
Title: Re: TG1 - advice from any one who has built it...
Post by: echotodd on October 05, 2010, 02:21:06 PM
I using the JLM myself.  I wanted a dedicated source for my meter lamps so I'm sure you're fine there.  Why eliminate the caps at C3&C4? i'm not super great with my electronics know-how but, especially C4 provides an AC ground path for both the MJE2955.  My guess is that you have a stability issue that's causing MJE2955 to draw excessive current and looking at the schematic it seems like C4 is a pretty good place to start.
Title: Re: TG1 - advice from any one who has built it...
Post by: warpie on October 05, 2010, 09:06:22 PM
I using the JLM myself.  I wanted a dedicated source for my meter lamps so I'm sure you're fine there.  Why eliminate the caps at C3&C4? i'm not super great with my electronics know-how but, especially C4 provides an AC ground path for both the MJE2955.  My guess is that you have a stability issue that's causing MJE2955 to draw excessive current and looking at the schematic it seems like C4 is a pretty good place to start.

I don't have any spare caps at the moment. I only found a 200uF (50V) lytic and used it as C4 but the problem remains.
It runs hot even with a 2W resistor... ::)

I'll get some caps asap but I don't believe it will solve the problem...
Title: Re: TG1 - advice from any one who has built it...
Post by: echotodd on October 05, 2010, 09:39:30 PM
Once again, thanks Mark!  I think the addition of the Auto attack setting threw me and should probably just have come to the logical conclusion that nothing was really changed in the faster attack settings.  I don't really find myself using the slower settings anyway!

Warpie,  Sorry man, I wish I could be more help!  Have you checked D15 and D14?  What are you reading at T_OP?
Title: Re: TG1 - advice from any one who has built it...
Post by: warpie on October 06, 2010, 09:27:32 AM
Warpie,  Sorry man, I wish I could be more help!  Have you checked D15 and D14?  What are you reading at T_OP?

sure, no worries man  :)

I'm getting around 23V on D14,D15 and around 10.5V at T_OP.
I might be wrong but I think these voltages are OK...
 
...but yes, anyway, thanks again  :)
Title: Re: TG1 - advice from any one who has built it...
Post by: johnmellor on October 07, 2010, 09:41:18 AM
I now have both channels working & it sounds REALLY good, & punchy, which I hope will encourage some others to finish theirs.

I have some Gardeners Transformers I'm hoping to use on this so I have a proper British sound, but I only have one 10k:10k for the input (so if anyone has a spare MU7530 lying around).  

Andy thanks for that description of the hold function.   I couldn't work out why the meter wasn't bouncing about in this mode & was just stationary at , say -10dB.  It turns out I wasn't winding enough signal into it for it to bounce.

So how did you get on with the gardeners transformers?
Title: Re: TG1 - advice from any one who has built it...
Post by: tommypiper on October 12, 2010, 12:18:38 PM
Guys, where do I get documentation?  I have the PCBs from Ixxxxxxx, (aka Fester Addams), and I just ordered meters from Sintech.   :D  But in researching parts lists and documentation I realize I don't have any.   ::) :o 

I sent an email to Ixxxxx /aka Fester Addams via his Fester e address a couple weeks ago asking for docs, but no reply.  Is there someone here, (preferably on a Mac in case there are any format issues), who could send me the docs, please?

cheers.
Title: Re: TG1 - advice from any one who has built it...
Post by: ArnauTS on October 12, 2010, 12:22:05 PM
Guys, where do I get documentation?  I have the PCBs from Ixxxxxxx, (aka Fester Addams), and I just ordered meters from Sintech.   :D  But in researching parts lists and documentation I realize I don't have any.   ::) :o 

I sent an email to Ixxxxx /aka Fester Addams via his Fester e address a couple weeks ago asking for docs, but no reply.  Is there someone here, (preferably on a Mac in case there are any format issues), who could send me the docs, please?

cheers.
it's posted on the pcb's thread
http://twin-x.com/groupdiy/displayimage.php?album=325&pos=13 (http://twin-x.com/groupdiy/displayimage.php?album=325&pos=13)
Title: Re: TG1 - advice from any one who has built it...
Post by: tommypiper on October 12, 2010, 05:44:27 PM
Thanks.  I'm getting up to speed.   8)

Anyone have Mouser/Digi part numbers for USA sources for the transistors?  Small ones -- but also large versions if you have them.  

Or whole BOM if you have one handy.  :)  But transisters will get me going.  Anyone use MPSA-18? 
Title: Re: TG1 - advice from any one who has built it...
Post by: wmtunate on October 12, 2010, 06:14:29 PM
but also large versions if you have them.

Get the large output transistors from electrochronic, and the OA202 diodes from him also while you're at it.  Definitely worth the small additional cost.
Title: Re: TG1 - advice from any one who has built it...
Post by: wmtunate on October 12, 2010, 06:32:48 PM
I guess I'll make this available for anybody who wants it.  It's a mouser cart with most of the resistors, caps, voltage regulators, and small signal transistors for a stereo TG1 build with "HOLD" control.  Not included are the output transistors, relays, switches, pots, smaller connectors, wire, LEDs, other miscellaneous hardware, etc.

Use at your own risk, and I make no claims about the completeness of this cart or the accuracy of the parts listed.  Looks like some of the parts I purchased are no longer available already, so you'll have to find subs.

https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=ed86c418ea
Title: Re: TG1 - advice from any one who has built it...
Post by: tommypiper on October 12, 2010, 10:46:46 PM
Thanks for the partial shopping cart list!  I'll go through it after I post.  It's the transistors and the relays I'm most concerned about.

but also large versions if you have them.

Get the large output transistors from electrochronic, and the OA202 diodes from him also while you're at it.  Definitely worth the small additional cost.

Yes, I'd love to, but he's running short on the output transistors and only including them with new board purchases.  He's got plenty of diodes, so I'll for sure get those.  

So I still need to source the large transistors.  What have you guys used?
Title: Re: TG1 - advice from any one who has built it...
Post by: warpie on October 13, 2010, 09:24:58 AM
Hi tommypiper,

I don't know if it's of any help but I found these.....

http://www.questcomp.com/QuestDetailsAll.aspx?pn=2N4898&pnid=125155&stock=Yes
http://www.questcomp.com/QuestDetailsAll.aspx?pn=2N4910&pnid=34528&stock=YesOnly

I haven't bought anything from there yet, as it gives me an option of $45.00 for shipping.
That's way too expensive. I'm located in UK but I think the rate is a flat fee for anywhere in the world.

If you decide to go with them and shipping is cheaper in US, would it be possible to get a couple more and ship them to me? I'll paypal you of course.

I can't believe they charge $45.00 for an envelope  ::)

thanks
Michael
Title: Re: TG1 - advice from any one who has built it...
Post by: tommypiper on October 13, 2010, 04:13:20 PM
Hi tommypiper,
....
If you decide to go with them and shipping is cheaper in US, would it be possible to get a couple more and ship them to me? I'll paypal you of course.

....

thanks
Michael

Hi Michael,

Thanks for the link. I ordered a pair of each for you.  I got cheap shipping in the US.  They should be here next week. I'll send you a PM after I get them, with cost of shipping to UK.  Maybe you can PM me your address in the meantime.

Anyone else in Europe who is interested, I *may* have a second pair available. I'll post here later.

For everyone else in the US or Canada, shipping is not that expensive so I suggest you place your own orders.

Electrochronic is offering these output transistors with purchases of new PCBs, so anyone who's buying new boards needn't worry about this.

I'll post here if I have an extra pair of these output transistors to sell later on.  Please don't PM me.   ;)
Title: Re: TG1 - advice from any one who has built it...
Post by: warpie on October 13, 2010, 05:15:47 PM
Hi Michael,

Thanks for the link. I ordered a pair of each for you.  I got cheap shipping in the US.  They should be here next week. I'll send you a PM after I get them, with cost of shipping to UK.  Maybe you can PM me your address in the meantime.

 :) thanks tommypiper, that's good news!


michael
Title: Re: TG1 - advice from any one who has built it...
Post by: lsskmki on October 13, 2010, 05:50:42 PM
I ordered some Italian 24pos rotarys from electronique diffusion in France recently and noticed they've got both the diodes and transistors for TG in stock.
Title: Re: TG1 - advice from any one who has built it...
Post by: baadc0de on October 14, 2010, 09:50:28 AM
Hey,

I'm a bit of a noob, so some questions are bound to be silly, but oh well. I have two TG1 boards complete with a separate power supply board. I'm wondering about all those regulators and power supply caps/resistors on the bypass board.. Do I need to populate just the bypass board, just the power board or both? If only the power board, which things must I leave out on the bypass board?

Thanks,
B.
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on October 14, 2010, 11:14:32 AM
Hey,

I'm a bit of a noob, so some questions are bound to be silly, but oh well. I have two TG1 boards complete with a separate power supply board. I'm wondering about all those regulators and power supply caps/resistors on the bypass board.. Do I need to populate just the bypass board, just the power board or both? If only the power board, which things must I leave out on the bypass board?

Thanks,
B.

if your talking about the psu part of the bypass board then yes you need to populate it, if you are using the board.  It regulates the main psu down to levels to operate the relays & op amps on the bypass board
Title: Re: TG1 - advice from any one who has built it...
Post by: baadc0de on October 14, 2010, 11:26:57 AM
Hey,

I'm a bit of a noob, so some questions are bound to be silly, but oh well. I have two TG1 boards complete with a separate power supply board. I'm wondering about all those regulators and power supply caps/resistors on the bypass board.. Do I need to populate just the bypass board, just the power board or both? If only the power board, which things must I leave out on the bypass board?

Thanks,
B.

if your talking about the psu part of the bypass board then yes you need to populate it, if you are using the board.  It regulates the main psu down to levels to operate the relays & op amps on the bypass board


D'oh... makes perfect sense now! Thanks
Title: Re: TG1 - advice from any one who has built it...
Post by: wmtunate on October 16, 2010, 02:58:51 PM
Finally got mine finished today.  UTC H-13 trannys on the input, Nishaminy AF-672 on the outputs (UTC A-20 clones).  OPA134 opamps on the bypass boards, which meant dropping the local board voltage to +/-18V.  NOS output transistors and OA202 diodes from electrochronic.  The meters had to be disassembled to replace the scale.  I was going to repaint them black, but when I stripped off the old finish with steel wool and mineral spirits, I liked the look so much that I left them in that "worn" state.  The front panel is Rustoleum Dark Bronze Hammered finish that I had laser engraved.  Then I put a coat of car wax on it and buffed it to a shine.

(http://natedort.com/images/gear/tg1.jpg)
(http://natedort.com/images/gear/tg2.jpg)
(http://natedort.com/images/gear/tg3.jpg)
Title: Re: TG1 - advice from any one who has built it...
Post by: tommypiper on October 22, 2010, 11:41:33 AM
Looks great, love the finish.  Are those 1 miliamp meters?  What kind of meters were they originally?  How are the ballistics behaving?

Is it my eyes, or do I only see one channel's worth of boards there?
Title: Re: TG1 - advice from any one who has built it...
Post by: grantlack on October 22, 2010, 11:54:12 AM
Looks great, love the finish.  Are those 1 miliamp meters?  What kind of meters were they originally?  How are the ballistics behaving?

Is it my eyes, or do I only see one channel's worth of boards there?

that threw me too.
Title: Re: TG1 - advice from any one who has built it...
Post by: wmtunate on October 22, 2010, 12:29:27 PM
The boards are stacked on top of each other with 1" aluminum standoffs.

Those are 100uA meters and I used a pretty low value shunt resistor to get them to scale correctly.  I think they were Westons originally.  I'm not real happy with the ballistics, but I can at least see what my Hold control is doing.
Title: Re: TG1 - advice from any one who has built it...
Post by: grantlack on October 22, 2010, 02:43:10 PM
sneaky!  the perspective shot makes the depth of the case a bit deceptive.  now that i look harder i can see your wire color coding.
Title: Re: TG1 - advice from any one who has built it...
Post by: tommypiper on October 22, 2010, 04:55:09 PM
Yeah I'm almost completely finished sourcing parts. Mouser has about 95% of the parts. Some of the other harder parts I got from ebay. After completion of this build I'll go ahead and post a US "updated BOM list".



Any chance to see this?  thanks
Title: Re: TG1 - advice from any one who has built it...
Post by: tommypiper on October 22, 2010, 04:57:32 PM
+1 for using 1/4" standoffs for the TO-66 transistors.
Anybody have a source for the ELMA switches?  I need 4.
Best,
Bruno2000

Did you manage to find them?  Maybe we can do a small group buy direct from Elma.  I've bought direct from them before and picked up directly at their office.
Title: Re: TG1 - advice from any one who has built it...
Post by: tommypiper on October 22, 2010, 05:09:16 PM
Some dumb questions: 

what does A.O.T. mean?  (Is it a form of calibration?  )

How do you calibrate?  (I'm not even close, just wondering)

I don't quite understand the bypass board.  (I know it's to create options for iron etc, and uses relays and op amps?.)  Do I NEED to use it?  Do I need to use op amps?  Can't I just hook up the unit without the bypass board, with iron in and out, or direct without iron and without the bypass board?

What is the scheme for all the connection points on the schematic?  Like "INTR1-4."  (I never understand these codes on any project...)  Where do we find these connections?
 :)
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on October 22, 2010, 05:22:15 PM
+1 for using 1/4" standoffs for the TO-66 transistors.
Anybody have a source for the ELMA switches?  I need 4.
Best,
Bruno2000

Did you manage to find them?  Maybe we can do a small group buy direct from Elma.  I've bought direct from them before and picked up directly at their office.

Yes, i got some, thanks! There has already been a small group buy.
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: tommypiper on October 22, 2010, 06:28:40 PM
All right... I guess I'm still playing catch up.  I had no idea there was a group buy.  I seem to be late to the party on everything....  do you have a part number for the Elmas?  Haven't been able to find that either.  thanks.
Title: Re: TG1 - advice from any one who has built it...
Post by: T-rex on October 23, 2010, 06:44:46 PM
Finally got mine finished today.  UTC H-13 trannys on the input, Nishaminy AF-672 on the outputs (UTC A-20 clones).  OPA134 opamps on the bypass boards, which meant dropping the local board voltage to +/-18V.  NOS output transistors and OA202 diodes from electrochronic.  The meters had to be disassembled to replace the scale.  I was going to repaint them black, but when I stripped off the old finish with steel wool and mineral spirits, I liked the look so much that I left them in that "worn" state.  The front panel is Rustoleum Dark Bronze Hammered finish that I had laser engraved.  Then I put a coat of car wax on it and buffed it to a shine.


So how does it sound?  Are you happy with it?
Title: Re: TG1 - advice from any one who has built it...
Post by: wmtunate on October 25, 2010, 09:10:35 AM
So how does it sound?  Are you happy with it?

I'm really happy with it.  You can dial as much or as little grit as you want.  The transformers give a subtle but useful alternative to the clean option. You've really got to slam the input to make it respond though.  I've been using it on the drum bus this past week and I like what I'm hearing.
Title: Re: TG1 - advice from any one who has built it...
Post by: electroslut on October 25, 2010, 07:10:43 PM
wow that looks way cool, are there schematics for these?
Title: Re: TG1 - advice from any one who has built it...
Post by: T-rex on October 25, 2010, 08:10:37 PM
So how does it sound?  Are you happy with it?

I'm really happy with it.  You can dial as much or as little grit as you want.  The transformers give a subtle but useful alternative to the clean option. You've really got to slam the input to make it respond though.  I've been using it on the drum bus this past week and I like what I'm hearing.

Thats good to know.  I have two songs left to mix for the album I am working on now and then I start building this beast.  Can't decide whether hold or not.  Maybe input based on what having to drive it hard. . .you both went with Hold right?
Title: Re: TG1 - advice from any one who has built it...
Post by: Hank Dussen on December 03, 2010, 05:06:20 PM
Just finished my TG1 but I don't get it to work. The only output I get is some low hum. 20Hz @ -40dB or so. Doesn't seem to make a difference what I do with the controls. Meter doesn't move.
I also couldn't get the negative voltage to anything other then -18,3. No matter which jumper I use.
I'm thinking it might be something with the transistors?
The only ones of which I'm not sure are the BC214's. It's not really clear what's the flat side on them. The base was pre-bend in one direction when I bought them and I just inserted them in that way. But I'm not absolutely sure whether that's the right way.
I tried to identify the emitter and collector but found only a very small difference in the 2 voltage drops or resistance.

Anyway, can any one check the orientation of the BC214's on my boards?
Or give some other advice?
(http://s4.postimage.org/5sf94da1j/BC214_close_small.jpg)(http://s2.postimage.org/y7qw44qyn/populated_TG1_main_PCB_small.jpg)
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on December 03, 2010, 05:21:22 PM
The output transistors get quite hot.  I fabricated some heatsinks out of angle aluminium for mine.
Title: Re: TG1 - advice from any one who has built it...
Post by: electrochronic on December 03, 2010, 06:08:42 PM
Rob

Hot, Which output transistors ? 2Nxxx or MJExxxx, or TIP31A , 42A ( insulate with Mica insulators for TO-66 types ?)
__________________________________
Hank Dussen
Make sure 2Nxxxx output transistors are mounted with mica insulators or put on short standoffs.
The short standoffs allow the 2Nxxx deviice to cool from underneath, which is good.
With regards to BC214 , should be ECB , pin 1(emitter), 2(base),3(collector)
you can confirm each junction on the transistor using a simple diode test mode on a DVM. Make sure
your BC214 are not L type , then you would expect CEB for the leg orientation which is not recommended
on the TG board.

Check your 2Nxxxx transistors with hfe setting using modified TO-66 socket with wire leads plugged
into your DVM, works great !!! Its not uncommon to come across some bad ones.
_______________________________
WMTunate, nice work !!!
_________________________________

Tommypiper


ELMA rotary 04-1133-20 is correct part for TG
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on December 03, 2010, 06:21:37 PM
Rob

Hot, Which output transistors ? 2Nxxx or MJExxxx, or TIP31A , 42A ( insulate with Mica insulators for TO-66 types ?)

The 2 big silver ones on the bottom right in the picture above.   Use the mica washers & use some silicon heatsink compound/goo
Title: Re: TG1 - advice from any one who has built it...
Post by: electrochronic on December 03, 2010, 08:01:08 PM
Rob,

from my experience , consensus from other builders , the TO-66's should be warm , not hot.

this might indicate short of some kind.
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on December 04, 2010, 06:20:22 AM
Rob,

from my experience , consensus from other builders , the TO-66's should be warm , not hot.

this might indicate short of some kind.

There's not a problem my unit works fine.   I just like to keep my semiconductors cool, especially when they're difficult to get hold of in the first place ;)
Title: Re: TG1 - advice from any one who has built it...
Post by: Hank Dussen on December 04, 2010, 07:16:16 AM
Just finished my TG1 but I don't get it to work. The only output I get is some low hum. 20Hz @ -40dB or so. Doesn't seem to make a difference what I do with the controls. Meter doesn't move.
I also couldn't get the negative voltage to anything other then -18,3. No matter which jumper I use.
I'm thinking it might be something with the transistors?
The only ones of which I'm not sure are the BC214's. It's not really clear what's the flat side on them. The base was pre-bend in one direction when I bought them and I just inserted them in that way. But I'm not absolutely sure whether that's the right way.
I tried to identify the emitter and collector but found only a very small difference in the 2 voltage drops or resistance.

Anyway, can any one check the orientation of the BC214's on my boards?
Or give some other advice?
(http://s4.postimage.org/5sf94da1j/BC214_close_small.jpg)(http://s2.postimage.org/y7qw44qyn/populated_TG1_main_PCB_small.jpg)

Any one else used BC214's that look like these ones?
How should they be orientated?
Like I said the pins were pre-bend, so I inserted them like that, but maybe it's not correct...

Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on December 04, 2010, 07:26:07 AM
Hank

I used have those ones before, put them in the way the pins are bent.  They work fine.

If you're really really worried about it you can check them in a meter ;)
Title: Re: TG1 - advice from any one who has built it...
Post by: electrochronic on December 04, 2010, 01:17:55 PM
Hank Dussen,

From closer inspection it appears the silkscreen is labelled correctly on the board for a TO92
standard transistor package, it should read CBE, just as it is silkscreened on the TG board
for VT22 and all others using BC214.

Flat face of the TO92 transistor facing forward. Pin 1 Collector to left, pin 3 Emitter to right.

Hank, the package you have there is not TO92 standard package for that BC214.

I think the BC214 "P" you are using are reversed from normal BC214 , you need
to flip the device opposite the current position

Here is your pin layout for those odd looking BC214's P version (EBC) ?
Pin 1 , Emitter
Pin 2,  Base
Pin 3 , Collector

(http://img.photobucket.com/albums/v611/maxwall/MotBC214.jpg)

Normal BC214 is (CBE) for A, B, C and K versions
Pin 1 , Collector
Pin 2 , Base
Pin 3 , Emitter

BC214L version (BCE) L version only (not recommended for TG board -legs must be twisted )
Pin 1 , Base
Pin 2 , Collector
Pin 3,  Emitter

Hope this helps
Let us know if this works ?
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on December 04, 2010, 01:32:51 PM
I would check them with a meter, because they look like the ones I used, which worked the way the pins were bent.   With the legs bent the way they are it might reverse the pin order for you !
Title: Re: TG1 - advice from any one who has built it...
Post by: haima on December 04, 2010, 08:05:27 PM
yep, check them with a meter...

i used the BC214L (the L version) on my igor 2245c - just re-orientated it 45degrees so the legs were in the right holes. worked a treat.

the main thing is you have to check with a meter to know what pinout you have, then just follow the handy silkscreen.
Title: Re: TG1 - advice from any one who has built it...
Post by: Hank Dussen on December 05, 2010, 05:19:36 AM
I did meter them and it kept showing me that they were positioned correct. But now it appears the EBC/CBE-labeling is wrong.
Electrochronic, so what you're actually sayings is that since the printing is incorrect, I am the first who inserted the BC214's correctly as it was labelled!
And thus wrong...  :-\
Anyway, I'll reposition them.

Which brings me to the next question: How much heat, for how long, can these (old) transistors take? I only a hand pump for desoldering so they'll feel some heat.
Should I try to borrow a good desoldering machine for this?
Or just buy new ones, being the capitalistic consumer that I am?
Title: Re: TG1 - advice from any one who has built it...
Post by: haima on December 05, 2010, 05:24:04 AM
i'd say you'll be safe enough using a standard hand desolder-er... (i do love my hakko 808 though!)

you can clip on a little heatsink - like a bulldog clip to keep it cool.

give it a bit of time to cool down between legs.

good luck!
Title: Re: TG1 - advice from any one who has built it...
Post by: lsskmki on December 05, 2010, 06:44:23 AM
To me perhaps the simplest way to remove already soldered parts has been using a desolder pump. Patience and timing is the key here...

Btw, I used BC214Ls in my TGs and had to bend their legs.
Just made sure which leg had to go where and confirmed with a multimeter to be sure about the pinout. Stuffing them in the board was easy as the 'bended BC214L's" could be put in the board simply reversed (compared to normal bc214's).
Title: Re: TG1 - advice from any one who has built it...
Post by: e.oelberg on December 05, 2010, 09:52:35 AM
Hi all,

I built two board, both are working, but one introduces hum into the system audible on both channels
and I really dont find the mistake i did

sigh,  nicholas
Title: Re: TG1 - advice from any one who has built it...
Post by: wmtunate on December 05, 2010, 10:53:48 AM
Hmmm...  the datasheet for the fairchild version of the BC214 shows it as CBE
http://www.datasheetcatalog.org/datasheet2/f/0ckd42zsaggdhhoiya3k0es9lspy.pdf (http://www.datasheetcatalog.org/datasheet2/f/0ckd42zsaggdhhoiya3k0es9lspy.pdf)

While the motorola sheet shows EBC
http://www.datasheetcatalog.org/datasheet/motorola/BC213.pdf (http://www.datasheetcatalog.org/datasheet/motorola/BC213.pdf)

I actually used BC559B, which is CBE, and everything seems to be working fine.
Title: Re: TG1 - advice from any one who has built it...
Post by: electrochronic on December 05, 2010, 12:49:00 PM
Hank & Nathan, Rob, Haima etc ....

BC214 = the most confusing part ever  ?

I have to say I have never run into such a mess regarding pinout orientation. I usually
rely on datatsheets , but in this case the datasheets do not agree with some of my findings.
I thought this would be worth digging a little deeper to do some fact finding regarding this
BC214 part.


(http://img.photobucket.com/albums/v611/maxwall/MotBC214.jpg)
copied directly from Motorola manufucturers datasheet, appears this is not true with the BC214
parts I have ,and they are Motorola's. I tested a few of my own BC214's in a DVM on the hfe
setting and found the orientation starting with pin 1 as CBE. Which proves opposite the datasheet, but
correct for the TG board. Had these BC214 Motorola's tested as the datasheet suggests ,
the TG silkscreening would be wrong, but this is not the case. I mistakenly was misled by the
datasheet orientation.

I still think your BC214 are reversed , the hum is a tell tale sign of pin reversal.


After physically checking a TG board , the schematic and a actual BC214A Motorola part
the labeling on the TG board is correct. CBE (Pin 1 C with TO92 flat face foward)

Your part should work fine , unless pin 1 on your device is E which would make it
a EBC not CBE. The only way to confirm this is with the hfe transistor test function on a
DMM, DVM.

The last information I posted was pulled directly off a www transistor reference page , which
has made this ever more confusing , because it does not agree with my actual
findings and suggests manufacturer specific layout which may not represent what we are dealing with here. Specifically,  regarding your part ,  regarding the BC214A Motorola I have , and the TG board we all have.. I have changed and updated that last post to represent my actual findings.

Could it be the Datasheet is wrong or maybe the spec was changed regarding orientation , I don't know
it seems to be a moving target. Rely on your DVM in this case, as Rob suggested.

At least we know the TG boards are silkscreened correctly.
Title: Re: TG1 - advice from any one who has built it...
Post by: StudioSQ on December 05, 2010, 04:05:35 PM
I have a two channel unit with the nos diodes and transistors that has been in use for a couple of months. It functions correctly and sounds good, however it seems to be a little noisy compared to other units i built. the noise is only present when the unit is active. the bypass in my unit passes through the transformers but not the actual boards, and it is not noisy in this state. the noise is related to the level of the output pot, but not the setting of any other switch. everything that carries audio is sheilded, I have moved stuff around inside the unit to no avail. any ideas out there?
Title: Re: TG1 - advice from any one who has built it...
Post by: haima on December 05, 2010, 07:06:42 PM
define "noisy" - hiss, hum, buzz....?
Title: Re: TG1 - advice from any one who has built it...
Post by: StudioSQ on December 05, 2010, 07:38:00 PM
sorry..
It is a hiss more like an interference noise, not a ground hum.
Title: Re: TG1 - advice from any one who has built it...
Post by: wmtunate on December 05, 2010, 08:41:57 PM
I discovered a new issue with mine tonight.  The +28VDC regulator is dropping out of regulation when I have the input and output transformers switched in circuit, but only when both channels transformers are activated.  It looks like I'm right on the threshold.  It's dependent on my line voltage, which was measuring 119VAC tonight.  Usually it's around 123VAC, but it's been really cold today and everybody is running their heaters.

I'm using an Antek 0225, which is 25VAC x 2 @ 25VA.  I measured ~31.3VDC at the input to the +28VDC regulator when I have the unit bypassed.  When I switch it to "clean" mode (no transformers in circuit), it drops to about 30.8VDC.  With the transformers in circuit on both channels, I'm reading 30.1VDC, and the +28VDC rail drops to 27.4VDC.  At that point, I get a loud 120Hz buzz at both channels which responds to the output rotary switch, so it's appearing in the audio path at the main boards.

This all make sense because when the transformers are switched in, all the relays on the bypass boards are running.  I used some Multicomp brand relays from Newark, which supposedly draw 200mW each when the coil is energized.

I'm thinking I may have to go up to a 28VAC x 2 transformer to give myself a little more of a voltage buffer.

Anybody else have any issues with voltage sag?
Title: Re: TG1 - advice from any one who has built it...
Post by: StudioSQ on December 06, 2010, 01:36:50 AM
sounds like maybe you are pulling too much current, maybe a bad cap in one channel?
Title: Re: TG1 - advice from any one who has built it...
Post by: electrochronic on December 06, 2010, 07:48:16 AM
TG PSu requirement is +/- 28v output

Use 56-60vct (2x28vac) or (2x30vac) /30-50va transformer

Mark called it first.
Title: Re: TG1 - advice from any one who has built it...
Post by: wmtunate on December 06, 2010, 09:17:41 AM
The PSU schematic I have shows 25VAC, and the silkscreen on the board shows that also, but that's obviously not cutting it.

Title: Re: TG1 - advice from any one who has built it...
Post by: electrochronic on December 06, 2010, 09:22:38 PM
Nathan,

I see why you chose 25vac from Antek, they don't have a 28-28 or 30-30 secondary offering
wondering if your Antek 0225 is just lacking the needed reserve current. Maybe the Antek 0525 (50VA)
would solve the issue ?
Title: Re: TG1 - advice from any one who has built it...
Post by: AW_music on January 06, 2011, 06:58:15 PM
hello,
I have the very same problem: drop outs and I am using a 25+25 VAC transformer with LM317 and LM337 regulators.
do you guys think I could use a 30 + 30 VAC transformer with no problem?
from the regulators data sheet I can see they will only accept 40VDC input MAX, and if I was to use a 30VAC I would be injecting 43VDC onto them.

any thoughts?

Title: Re: TG1 - advice from any one who has built it...
Post by: Tekay on January 07, 2011, 04:48:58 AM
40V is the maximum differential between in and out! We use LM317T for the 48V in all our supplies. Higher differential = more heat!
Title: Re: TG1 - advice from any one who has built it...
Post by: e.oelberg on January 07, 2011, 10:41:01 AM
Hi TG Builders
I have a ground problem and I"m to stupid to solve it:

I built a stereo TG Limiter, both channels work no buzz no noise if I have just one channel connected to the PSU if I connect both
I have a ground loop and I just dont find the problem  arggh !    any hints ?


nicholas
Title: Re: TG1 - advice from any one who has built it...
Post by: electrochronic on January 08, 2011, 07:08:15 AM
pics ?
Title: Re: TG1 - advice from any one who has built it...
Post by: e.oelberg on January 08, 2011, 07:23:49 AM
I can make some !
Title: Re: TG1 - advice from any one who has built it...
Post by: waldorfcave on January 09, 2011, 08:47:09 AM
does the transistors 2N4910 need heatsinks? they get pretty warm :o
Title: Re: TG1 - advice from any one who has built it...
Post by: e.oelberg on January 10, 2011, 04:07:23 AM
here is a pic of my beauty. each channels runs fine. If I connect both to the psu I have a ground hum. It must be some small stupid mistake


nicholas
(http://studiobeige.de/DL/IMG_2910.JPG)
Title: Re: TG1 - advice from any one who has built it...
Post by: briomusic on January 10, 2011, 04:18:27 AM
If you leave off the bypass boards and just run the main boards in unbalanced mode, do you still have the same problem? With the bypass boards connected, does it happen in clean and iron mode?
Title: Re: TG1 - advice from any one who has built it...
Post by: e.oelberg on January 10, 2011, 04:38:46 AM
it"s in clean and iron mode, I disconnected all irons  with no change running unbalanced with same result. If I disconnect the psu from one board, the other one is clean !
Title: Re: TG1 - advice from any one who has built it...
Post by: briomusic on January 10, 2011, 05:59:32 AM
ok cool, but what I mean is disconnecting the entire balancing/bypass board and use the unbalanced in and out on the mainboard, just to narrow down the problem to a specific pcb.
by the way, I see you have all four power pins connected, I am not sure if I remember correctly, but I think one is audio ground, the other chassis ground or similar. I only have one (the audio) ground connected, this might be something worth trying for you too.
Title: Re: TG1 - advice from any one who has built it...
Post by: e.oelberg on January 10, 2011, 08:26:12 AM
the problem is on the main board. I run in unbalanced direct into the board. It"s before the last  amplification stage before he output pot
Title: Re: TG1 - advice from any one who has built it...
Post by: wmtunate on January 10, 2011, 08:52:33 AM
Are you sure it's ground hum?  I had a similar problem because of voltage sag dropping the PSU out of regulation, causing a buzz/hum.  That would be consistent with you having to run both boards before it starts.  What are your toroid specs?
Title: Re: TG1 - advice from any one who has built it...
Post by: e.oelberg on January 10, 2011, 08:59:00 AM
well thats a good hint, the toroid seemed a bit stressed
Title: Re: TG1 - advice from any one who has built it...
Post by: jackies on January 10, 2011, 11:12:36 AM
Are you using LL1517 both on input and output?
Title: Re: TG1 - advice from any one who has built it...
Post by: e.oelberg on January 10, 2011, 02:17:49 PM
Are you using LL1517 both on input and output?

no 1540 and 1517  but I'm not happy with the result, I have a roll off of the highs. This is the next problem. But I really like this unit transformerless

nicholas
Title: Re: TG1 - advice from any one who has built it...
Post by: e.oelberg on January 10, 2011, 02:21:38 PM
Are you sure it's ground hum?  I had a similar problem because of voltage sag dropping the PSU out of regulation, causing a buzz/hum.  That would be consistent with you having to run both boards before it starts.  What are your toroid specs?
thanks very much... this was the hint. I replaced the 24 24 trafo with a 30 30 the hum/buzz is gone. It wasn't a ground loop the toroid was to stressed.

so I learned something, thank you very  much,   Nicholas
Title: Re: TG1 - advice from any one who has built it...
Post by: haima on January 10, 2011, 07:13:07 PM
Great! that makes sense.  8)
Title: Re: TG1 - advice from any one who has built it...
Post by: briomusic on January 17, 2011, 11:31:12 PM
Quote
I'm planning to stick to the original 6 positions (instead of 9) on the Recovery switch. I've been comparing the original EMI schematic to the TG1 build version and the resistors on the switch are similar in value in most positions on each schm. My question is regarding what to do with the positions I'll be leaving out.
On the TG1 build schematic the unused positions (10 & 11) on the 12 position Recovery switch run off to 2 resistors; R208 and R205. Should I do the same with the empty positions I will have after using 6 of the intended 9 positions? BTW, position 12 on the schematic is not connected to anything at all. Why is this? I would appreciate some help on what I should do with the 3 empty spots I'll be creating by going down to 6. Thanks.

you can limit the lorlin rotary switch to as many - or few - positions as you like by changing a little washer type thing from the front. you don't need to connect anything to the remaining, inactive positions and related pins. alternatively, you can connect everything if you later decide that you would like the additional options. in that case you just need to change the 'limiting-washer' back to 11.
Title: Re: TG1 - advice from any one who has built it...
Post by: grantlack on January 25, 2011, 05:56:37 PM
finally getting around to this one, had a quick question- in the 'bypass versions' documentation, when referring to R1-4 i'm assuming it's in reference to what's labeled as RIN1-4 on the bypass boards and not R1-4 on the mainboard?

now i have to track down the packet of bc177's i ordered off ebay and promptly misplaced f($#*@king two months ago  ::)
Title: Re: TG1 - advice from any one who has built it...
Post by: pachi2007 on February 01, 2011, 07:30:11 PM
Motorola papers say the bc214 should be put opposite way as marked on the pcb. I´m I right? should I turn it or just go to sleep?
Thx people
Pachi
Title: Re: TG1 - advice from any one who has built it...
Post by: haima on February 01, 2011, 07:45:14 PM
There's actually numerous (3?) pinouts for the BC214... if you do a search in this thread and the 2254c build thread you'll find some discussions. I've used the BC214L in my 2254C - i just had to partially rotate them to get the pins in the right holes.

Best thing to do is to use your multimeter to check the pinout of the devices you have, and then place them in the holes accordingly. You might need to rotate or flip - or you might match the top screen print. Igor has kindly put marked "E", "B" & "C" so it's pretty easy.
 
Title: Re: TG1 - advice from any one who has built it...
Post by: Hank Dussen on March 08, 2011, 06:40:10 PM
OK back to my TG1.
Finally solved my transistor and power problems. Unit passes audio and compresses but I'm still struggling to get the satifying threshold levels and meter readings.
I tried 5K and 10K for the hold pot and different values for R115.
Compression only happens in the last quarter of the hold knob.
Meter swings only between +5 and +15. And not a lot.
This doesn't feel completely right.

What values do you guys use for the hold pot and R115 and at what position do you get unity level?
At what position do you get the meter to zero?
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on March 08, 2011, 07:40:46 PM
I would be interested to know what value resistors people are using on the hold rotary switch ?

I used the values on the original diagram with a wire link for R115.  but I'm thinking that R15 might be needed bacause with the switch fully clockwise the output has massive gain & is clipping wildly.  I assume that fully clockwise should be unity gain ????

Title: Re: TG1 - advice from any one who has built it...
Post by: StudioSQ on March 12, 2011, 07:17:17 PM
I just went through my working unit again and it turns out that the two channels are slightly out of phase, maybe 90deg. when i put it up on the console meter it goes from full +1 to centered at 0 when the unit is engaged. and ideas about this? edcor 10k/10k in/out no bypass board nos transistors and diodes.
Title: Re: TG1 - advice from any one who has built it...
Post by: StudioSQ on March 13, 2011, 09:06:57 PM
I just needed to calibrate it better, sorry guys
Title: Re: TG1 - advice from any one who has built it...
Post by: Hank Dussen on March 14, 2011, 03:36:44 AM
Just curious: what's there to calibrate except for the optional hold pot trimmer?
Title: Re: TG1 - advice from any one who has built it...
Post by: lsskmki on March 14, 2011, 08:01:32 AM
Just curious: what's there to calibrate except for the optional hold pot trimmer?
Check the projects docs, there's much more to it.
For me it took longer to get the calibration about right than any other project I've built (incl. the 760 which has quite a time consuming calibration).
Title: Re: TG1 - advice from any one who has built it...
Post by: Hank Dussen on March 15, 2011, 05:48:36 AM
These are the only 'calibration'-notes I can find:

Testproc:
1). +/-20v
JP1...6, TP+20v, TP-20v
2).Unity gain
Initial gain is set by AOT1,2
3).Distortion w/o compression
minimum distortion adjustment AOT 7,9
4).Distortion at 20dB GR
distortion under hard compression adjusted by AOT8/10, usually 10R is fine
5).Com threshold
Com threshold adjustment: AOT3,4
6).Lim threshold
Lim threshold set by AOT5,6.
7).Check: reqresp, max gain, min  gain, S/N, timeconstants.


but most guys here seem to go with the standard AOT-resistors tough.
Am I missing something here?
It would be really helpful if people gave me some directions concerning, for example, the compression and limiter threshold adjustment.
How did you calibrate yours?

Also, what changes should I make if I want to use the meter in the Chandler way, showing gain-reduction?
Title: Re: TG1 - advice from any one who has built it...
Post by: lsskmki on March 15, 2011, 06:09:56 AM
I found the 'basic' calibration was pretty easy, but the real challenge was to get two units matched as closely as possible for stereo operation.  Especially the distortion adjustments complicated the calibration.
Btw, I used multiturn trimmers for all AOT resistors in an effort to get best possible stereo tracking.  The best stereo matching I could reach is about 0,5db (when compressing 0-20db).
I can't really describe the procedure much, because it was like adjusting a trimmer here and then adjusting another, then getting back to adjust the other...
 
For a mono unit the calibration may not be that time consuming at all.

 
Title: Re: TG1 - advice from any one who has built it...
Post by: pacemaker on March 15, 2011, 06:14:06 AM
hi guys,
i started to build the TG1 this morning,
and was looking at output transformer options,
as it seems there's no DC output ,
can i use some LO2567 trannies in place of the LO1173 ?
regards,
francois
Title: Re: TG1 - advice from any one who has built it...
Post by: ChuckD on April 06, 2011, 01:33:39 PM
I have an issue with one side of my TG1

Here are the clues....

It passes audio. Although not  totally clean I do not believe
Also when I disengage THD thus putting VT14 back into the circuit I get a complete DC voltage drop = 0V
Output signal drop out and the meter pegs for a moment.
The output signal and voltage recover BASED ON the RECOVERY TIME selection
With THD ON the circuit no longer compresses, at least the meter does not show any compression.
This also happens if I switch from Limit to Comp mode.

The output transistors all have proper DC levels
I Doubled checked all the transistors and diodes for proper component placement.
I checked most voltages vs the working side.
double checked the Limit, Comp switches as correct.


Any educated guesses out there??
Thanks in advance guys!


Chuck






 
Title: Re: TG1 - advice from any one who has built it...
Post by: briomusic on April 07, 2011, 06:33:31 AM
Hi Chuck, the THD switch essentially disables the sidechain circuit, so you shouldn't be hearing or seeing any compression with THD on. with THD off (aka 'compressor IN') the meter moves to the preset voltage determined by the position of the 'hold' switch. the lowest preset voltage is at the highest 'hold' setting, and this is where you get the most compression 'swing'. It's the unique way this machine works, discussed at length earlier in the thread.
Title: Re: TG1 - advice from any one who has built it...
Post by: ChuckD on April 12, 2011, 01:56:21 PM
Hello Brio,

Thanks for your reply.
In my current configuration I have opted to ground out the Hold switch and use a Carnhill input transformer into an input pot. Same as Chandler does their TG1.

My problem is on one channel only in Limit Mode if the input signal is turned up suddenly it pegs the meter for an instant. Then the output signal craps out / cuts out and distorts then recovers.
This also seems to happen if a change modes from Limit to Comp and back again.

This does not occur on the other channel.
The hfe of VT13 and VT14 are matched now but it did not seem to fix this issue. 
I have double checked the resistor values a fourth time but cannot find any problems.
The input signal level going to the side chain is the same for both sides.
I used BC184C and BC214C transistors everywhere except VT13/14 where I put matched non-"C" versions in last night.

Is it safe to assume the problem is definitely in the side chain?? I am assuming so.

Anyone with some thoughts?
I am a bit stumped

Chuck

Title: Re: TG1 - advice from any one who has built it...
Post by: ChuckD on April 14, 2011, 05:05:49 AM
Guys,
CASH PRIZE to whomever can get me fixed! I would like to offer a cash prize to who ever can come up with a theory that in turn fixes the problem! I very much want this saga to end. Let's say 100 USD to the 1st guy who can get me fixed!


After replacing the entire Side Chain and all the input stage transistors the issue is still present on one channel.
Here is what I am seeing:

When the input signal hits a certain level 0.3 Vpp the whole circuit gets slammed. The DC voltages go crazy and the feedback loop causes the signal to clip. This only happens for a moment then the whole thing recovers.

The problem is inside the feedback loop as nothing strange happens to the signal when the side chain is either diconnected or the recovery switch is open. Or the THD is on. So it is safe to suggest that the amplifier is ok.

Normal reference DC Voltages taken from zero input signal to max input signal
VT15 (B = 0.8 to -1.33) (E= 0.545 to -0.165) (C= -20)
VT16 (B= 0.545) (E= 0) (C= 1.0 to 3.3)
VT17 (B= 1.0 to 3.3) (E= 0.5 to 2.8) (C= 18.26 to 17.97)

Broken
When the sidechain input hits 0.28 Vpp during that instant things get off
VT15 (B = -0.8) (E= -0.98) (C= -20)
VT16 (B= 0.430) (E= 0) (C= 4.0)
VT17 (B= 3.8) (E= 3.5) (C= 17.77)

If you continue past 0.28 Vpp the circuit does recover and acts as it should. DC voltages pretty much track the above reference.

I should also note that the circuit only does this peaky clip thing when coming from 0 up to 0.28 on the input of the side chain. Crossing 0.28 Vpp from a greater value does not cause it to ocurr again.

Another note is that the non-working side has a much higher swing in voltages on the collectors of VT2 and VT3. VT2 (C= -10.3 to -9.30) VT3 (C= -7.94 to -9.0)

The working side only has a 0.3VDC swing for each.





Chuck
Title: Re: TG1 - advice from any one who has built it...
Post by: ChuckD on April 14, 2011, 01:42:54 PM
Thanks

the problem is triggered as I said by the sidechain input signal hitting 0.28 Vpp
I am using an Input Pot by that is not relevant. as I said the Amplifier is working fine with out the Sidechain engaged.

Chuck
Title: Re: TG1 - advice from any one who has built it...
Post by: ChuckD on April 14, 2011, 11:57:21 PM
Thanks for the suggestions please keep them coming! Most of them I tried already But heating it I didn't think of that, It actually does make the Error different.


it may be a sort of Oscillation after all.
If I stick a heat gun on the area of the board on top of those 3 diodes going to the emitter of VT15 and heat all the surround parts just a bit it has an effect:

The Base voltage at VT16 is dropped to 4.5 and steady. The circuit no longer clips out but Oscillates a few times when the input signal is turned up to the same level.

As the heated circuit cools off the magnitude of the "few oscillations" gets larger and larger until it is a single large clip as before. As well the Base Voltage at VT16 is slowly raised back to 5.4 VDC (which is the steady base voltage on the working side)

What does heating up the diodes and surrounding parts do I wonder????


Chuck
Title: Re: TG1 - advice from any one who has built it...
Post by: ChuckD on April 20, 2011, 05:54:04 AM
Works! R7 was shorting to the top ground plane!! Arrgh


Is it normal to have a big jump in volume between pin14 and 15 on the output gain switch??
Why is it like that? It doesn't seem natural but the resistors all  check out to the schematic.



Chuck
Title: Re: TG1 - advice from any one who has built it...
Post by: baadc0de on June 14, 2011, 03:13:01 AM
Hey guys,

It's 600:600 transformers for the output and 10k:10k for the input, right? What if I only had 4 600:600 transformers, would that work, so one pair for inputs one pair for outputs?

Cheers,
B.
Title: Re: TG1 - advice from any one who has built it...
Post by: baadc0de on June 23, 2011, 01:56:33 AM
Nevermind, I got myself some carnhill 10k:10k inputs. Should be fun.

By the way, is +15dBm 20-40.000cps a good spec for a 600:600 output transformer? Don't want it to crap out on me..
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on August 09, 2011, 04:54:45 PM
Hey guys

I'm trying to understand a little more about the bypassing on this unit. ie: Thd/limit in relation to iron/bypass/clean.

For instance, if i have thd/limit switch set to thd, but iron/bypass/clean set to bypass...is everything bypassed...even thd?

Title: Re: TG1 - advice from any one who has built it...
Post by: Hank Dussen on August 09, 2011, 05:25:29 PM
I'm pretty sure the bypass is true bypass. In- and output directly connected (through relays) without anything else.
Title: Re: TG1 - advice from any one who has built it...
Post by: briomusic on August 09, 2011, 06:14:01 PM
thd/limit is basically a "sidechain-off" switch.
the signal will still be passed through the gain changing sections, but no compression will take place.
bypass is a hard bypass of the whole unit.
Title: Re: TG1 - advice from any one who has built it...
Post by: Michael Tibes on August 10, 2011, 01:01:06 PM
By the way, is +15dBm 20-40.000cps a good spec for a 600:600 output transformer? Don't want it to crap out on me..
You can easily give it a try, with a perfectly transparent transformer the iron/clean switch just won't make any difference...

Michael
Title: Re: TG1 - advice from any one who has built it...
Post by: baadc0de on September 21, 2011, 05:43:31 PM
Question: C23 on the main board and COP1 on the bypass board are noted as "470m" capacitors. Is this 47uF, 470uF or .. ?
Title: Re: TG1 - advice from any one who has built it...
Post by: haima on September 22, 2011, 04:38:00 AM
470m = 470uF

 :)
Title: Re: TG1 - advice from any one who has built it...
Post by: baadc0de on October 03, 2011, 04:24:47 AM
Hey guys,

I just did mine and now it's time to do some troubleshooting.. I thought to dump a few questions here and see if I get any answers :) I'll be off to work now and tackle this again in the afternoon..

For now I only "calibrated" +- 20V lines. All AOT resistors are as specified in the notes. I left the "unused" AOTs empty, should I replace them with wire links?

I did mine with R115 = link and with the optional 100k trimmer. I didn't check the schemo yet, but maybe I have to break connection at R115 for the trimmer to be in?

The problems I'm having right now are pretty basic I think.. the left channel's VU goes "down" and pegsa, instead of "up" to center at 0. The right one pretty much centers at zero (both are with hold set at middle, link disabled). If I turn the hold knob I can get the left one to deflect a little, while the right one seems to have a pretty much healthy swing imitating my hold setting. Both VUs and hold pots are wired the same (I checked) as are the wires connecting the small attack/release boards to the main boards.

After some time (say one minute) the right one's VU starts oscillating a bit, i.e. the needle goes up and down like a metronome. I think it's about 60bpm.

I put some sound through the left channel, but in iron mode I'm not getting anything and in clean mode I'm getting sound that isn't dependent on the input sound or volume (input can be muted / non present / disconnected but it will still do this). It's kind of like a complex square wave with some additional stuff soperimposed on it. It's definitely "synthesized" sounding. I may record a clip of it. It's very quiet though, about -50dB on my interface.

Thanks to all who read this and even more to any that are willing to help :)
Title: Re: TG1 - advice from any one who has built it...
Post by: Michael Tibes on October 03, 2011, 07:37:30 AM
I left the "unused" AOTs empty, should I replace them with wire links?

no

The problems I'm having right now are pretty basic I think.. the left channel's VU goes "down" and pegsa, instead of "up" to center at 0. The right one pretty much centers at zero (both are with hold set at middle, link disabled). If I turn the hold knob I can get the left one to deflect a little, while the right one seems to have a pretty much healthy swing imitating my hold setting. Both VUs and hold pots are wired the same (I checked) as are the wires connecting the small attack/release boards to the main boards.

The VU on mine is zeroed if hold is off (full clockwise) and then rises when hold is turned counterclockwise. I believe that's how it's supposed to be?

After some time (say one minute) the right one's VU starts oscillating a bit, i.e. the needle goes up and down like a metronome. I think it's about 60bpm.

I put some sound through the left channel, but in iron mode I'm not getting anything and in clean mode I'm getting sound that isn't dependent on the input sound or volume (input can be muted / non present / disconnected but it will still do this). It's kind of like a complex square wave with some additional stuff soperimposed on it. It's definitely "synthesized" sounding. I may record a clip of it. It's very quiet though, about -50dB on my interface.

Recheck your wiring, probably somethings mixed up. If you can't figure it out you might brake thinks down into logical parts - check your input stage - check your output stage. Remove the compressor pcb from the audio circuit, connect only the out of the input stage with the in of the output and make sure it works as advertised etc...

Hope this helps a bit,

Michael
Title: Re: TG1 - advice from any one who has built it...
Post by: baadc0de on October 03, 2011, 08:29:17 AM
Thanks Michael,

it seems I actually populated some AOTs a lot of time ago that don't have to be populated (bought the PCBs 2 years ago, first ones I ever got... heh). Like AOT4, so I have to check what happens if those go away.

Okay thanks for clearing up things.. I connected the hold pot (a 10k lin) to the 3 pads on the attack/release PCB and removed the part with the rotary switch. I hope there weren't any additional links or connections there. If they are I think I could duplicate them. Hm. I'll take a look at the broken away part.

I have a modified Sifam meter pair that, when no voltage is applied to the meter rests at the bottom of the scale (the scale is horizontal). When I start with the hold centered, the good channel will rise to center on the VU scale and move up and down with the hold pot. Unfortunately, then it starts to undulate / oscillate after some time. The other one however, doesn't move up, but DOWN (which is very very weird) from zero to the minimum that the VU can deflect negatively (a few mm of course and it pegs).

Yup, I'll check the wiring .. again.. sigh.
Title: Re: TG1 - advice from any one who has built it...
Post by: baadc0de on October 06, 2011, 05:27:48 PM
The VU meters being mirrored, so are the wirings for them, sigh .. beginner mistake

I found out what the problem of the oscillations is.. the 317 heats up rapidly and then protect cuts out in waves. So that's the +28 rail crapping out. Interestingly, the 337 (-28 rail) isn't doing this. The 317 has maybe a bit worse contact with the heatsink, but I don't think it should affect it this much?? I'll try and find some of that thermal transfer material and lodge it there so that it will have better conductivity.

Aside from that, ideas? Why would the +28 rail be more hot than the -28 one?

EDIT: Also, is the output pot wiring correct like this: pin 1 minimum, pin 3 wiper, pin 2 ground (not connected in my case). And should the output pot affect the VU meter? It doesn't in my build.. the hold works "as expected" I think, that is, moving hold is moving the meter. Also, I have used trimmers to get both meters to center together on same hold value.

Thanks,
B.
Title: Re: TG1 - advice from any one who has built it...
Post by: Hank Dussen on October 07, 2011, 02:51:57 AM
Output pot shouldn't affect the meter.
Voltage regulators got overheated very fast on mine as well. I attached them to the case as a big heatsink (with mica insulators) and now it's OK.
I'm not sure whether the positive rail got warmer but it could be that some of the transistors (the big ones?) only use the posive rail?
Title: Re: TG1 - advice from any one who has built it...
Post by: baadc0de on October 07, 2011, 06:18:15 AM
Hi,

solved the voltage problem for now by improving contact with the 317 heatsink.

2N4898 gets much more warm than the other output transistor, so much so that I can't put my finger on it after a bit of warmup.

I did a bit of scoping..
- the input board gives out correct signal to the input board, however it has a cyclic DC shift to it of +- 0.4..0.6V (like a very low frequency AC has been superimposed on it, say, 10Hz or less)
- signal before the output pot seems to contain only this very-low-frequency AC

We'll see what else I can get later.. if anyone has an idea, don't be afraid to postulate some theories..
Title: Re: TG1 - advice from any one who has built it...
Post by: baadc0de on October 10, 2011, 05:07:25 PM
My unit now compresses - the VU meter reacts to input material, the hold knob works as advertised (very natural once you get the hang of it!) and attack, release, THD (bypass), lim/comp etc.. all seem to work with the VU meter as they should. It was a case of mirrored wire arrangement from the I/O board to the main board (insert homer d'oh!).

However, I get no sound through (except in hard bypass of course). At the output knob position on the main board I get only noise on pins 1 and 3.. I disconnected the pot to remove that from the equation and am using either a jump between 1-3 or nothing so I can test without the output section loading down. But there's only noise.. on shields of the output transistors and the output itself.

I'm a bit confused what may be the problem.. I'm obviously losing signal somewhere and it's not affecting the sidechain.
Title: Re: TG1 - advice from any one who has built it...
Post by: electrochronic on October 10, 2011, 07:58:39 PM
solder bridges or component shorting ?

Send a test signal thru and spot check half way thru the circuit ?

I always test my components before I solder them in

Transistor legs reversed by mistake ECB, CBE ? (TO-92 type) (TO-18) (TO-5,39)

any sockets being used ?

I'm sure you have considered the above but realizing simple errors are the ones
most likely .....
Title: Re: TG1 - advice from any one who has built it...
Post by: providedrailroad on November 10, 2011, 11:38:56 PM
A few simple questions - I'm having trouble understanding how the power transformer should be connected to the power supply board. Do I need a 2x 25v power transformer? I'm uncertain about the ~ markings, I'm assuming they are supposed to indicate phase somehow?

Sorry I'm a newb. Also, I'm thinking about also building an insert controller and m/s stereo encoder/decoder into the same box. Does anyone know how much current a stereo TG limiter draws? I'm trying to decide if I should just use this power supply or build a new one I can draw more current from. I guess the amount of current that can be drawn is mainly limited by the regulators and choice of transformer, probably to some extent the diodes too.
Title: Re: TG1 - advice from any one who has built it...
Post by: baadc0de on November 11, 2011, 01:44:26 AM
Hi mate,

the ~ markings indicate where each leg from the power transformer connects to the PSU board. There is another point called CT where you will connect your center tap of the transformer. I think I used a 2x30V transformer.

Cheers,
B.

A few simple questions - I'm having trouble understanding how the power transformer should be connected to the power supply board. Do I need a 2x 25v power transformer? I'm uncertain about the ~ markings, I'm assuming they are supposed to indicate phase somehow?

Sorry I'm a newb. Also, I'm thinking about also building an insert controller and m/s stereo encoder/decoder into the same box. Does anyone know how much current a stereo TG limiter draws? I'm trying to decide if I should just use this power supply or build a new one I can draw more current from. I guess the amount of current that can be drawn is mainly limited by the regulators and choice of transformer, probably to some extent the diodes too.
Title: Re: TG1 - advice from any one who has built it...
Post by: providedrailroad on November 11, 2011, 04:32:29 PM
Hi mate,

the ~ markings indicate where each leg from the power transformer connects to the PSU board. There is another point called CT where you will connect your center tap of the transformer. I think I used a 2x30V transformer.

Cheers,
B.

A few simple questions - I'm having trouble understanding how the power transformer should be connected to the power supply board. Do I need a 2x 25v power transformer? I'm uncertain about the ~ markings, I'm assuming they are supposed to indicate phase somehow?

Sorry I'm a newb. Also, I'm thinking about also building an insert controller and m/s stereo encoder/decoder into the same box. Does anyone know how much current a stereo TG limiter draws? I'm trying to decide if I should just use this power supply or build a new one I can draw more current from. I guess the amount of current that can be drawn is mainly limited by the regulators and choice of transformer, probably to some extent the diodes too.

Oh okay that makes sense ha ha. I feel stupid now. Well on the board layout one was marked '25' and one was marked '1', and I didn't see where the Center tap was supposed to go. Did you use a 3A transformer since the regulars can draw up to 1.5A a piece?
Title: Re: TG1 - advice from any one who has built it...
Post by: baadc0de on November 11, 2011, 05:19:28 PM
Quote

TG PSu requirement is +/- 28v output

Use 56-60vct (2x28vac) or (2x30vac) /30-50va transformer

Mark called it first.

I think it was on the first page of this thread :)
Title: Re: TG1 - advice from any one who has built it...
Post by: providedrailroad on November 11, 2011, 06:15:35 PM
Now if only someone can  measure current how much current the limiters draw for me I will know FOR SURE whether I need to redesign my power supply, ha ha. I guess I can just use 24v linear regulators with PNP power transistors to increase output current
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on November 11, 2011, 06:45:41 PM
Now if only someone can  measure current how much current the limiters draw for me I will know FOR SURE whether I need to redesign my power supply, ha ha. I guess I can just use 24v linear regulators with PNP power transistors to increase output current

Use LM317/337 pair they will supply 2 channels with no problems
Title: Re: TG1 - advice from any one who has built it...
Post by: providedrailroad on November 12, 2011, 12:25:43 PM
Well, like I mentioned earlier in this post I'm running some Relays and Lighted Switches and a Mid Side Stereo decoder off the same supply. I just modified the existing design with darlington PNP pass transistors on the positive rail, added a 18v regulator for the M/S supply and laid out a new circuit board. Everything is good on the power supply front.

Last question. The molex connectors used - will I need special tools to make cables for these? They use normal .1" spacing, correct? And the switches - they are just normal size PCB mount, not mini or submini? Ordering for this project without having the boards in person yet is a little frustrating. I wish there was better documentation.
Title: Re: TG1 - advice from any one who has built it...
Post by: haima on November 12, 2011, 12:32:53 PM
I just strip the wire and crimp mine manually with a pair of long nose pliers. Then I flow a little bit of solder into the join to make it extra tough :)

No fancy tools required... if you had to do 1000s of them then you might want a tool, but for one offs I find the manual method totally fine.

If you look around on synth diy forums there's probably a detailed explanation with photos out there somewhere...

EDIT: this is advice for the crimp types - there's also IDC types that work a different way... you can get a cheap plastic tool for these though - might even be easier...
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on November 13, 2011, 08:45:33 AM
I am also running a bunch of relays with my power supply,  I don't think you will have a problem with the LM317/337 combination.  If you are worried you can easily calculate what all the relays are pulling using ohms law, & the lamps using ohms law & P=IV.


I used to crimp with pliers & solder, but I bought a proper crimp tool several years ago,for £10 & the connections I now get are vastly superior to what I was doing before, much quicker to make with no soldering is required.  For £10 it's worth every penny in my view.
Title: Re: TG1 - advice from any one who has built it...
Post by: haima on November 13, 2011, 11:45:33 AM
Hey Rob - that does sound worth 10 quid.... do you have a link to the tool you bought?
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on November 13, 2011, 12:32:04 PM
Hey Rob - that does sound worth 10 quid.... do you have a link to the tool you bought?

OK gone up a bit in price but still worth the cash http://www.rapidonline.com/Tools-Equipment/Ratchet-Action-Crimp-Tool-Ht225d-85-0262/?sid=beb63ebc-e413-4328-81ef-0e0a754ec748 (http://www.rapidonline.com/Tools-Equipment/Ratchet-Action-Crimp-Tool-Ht225d-85-0262/?sid=beb63ebc-e413-4328-81ef-0e0a754ec748)
Title: Re: TG1 - advice from any one who has built it...
Post by: haima on November 13, 2011, 03:05:59 PM
thanks mate!
Title: Re: TG1 - advice from any one who has built it...
Post by: electrochronic on November 18, 2011, 05:58:08 AM
have'nt posted here in a while ........

Q : has anyone been able to locate a source for the original HS2051 Zener Diode for the TG Diode bridge ?

Currently all that is available is the 1N751A which is also a 5v1 Zener diode. The HS2051 seems
unobtainable and no datasheet exits thru normal www searches. Apparently the HS2051 part #
is also used in a digital chip which is 100% unrelated to the diode and the TG limiter.

There are other 5v1 zener diodes available too , ex : BZX850, but it seems the basic operating
voltage is of little concern with the diodes base line character compared to the 1N751, in other words
no noticable difference in audio quality.

Also , is there a source for the original TG layout ? not he Fester unlimited version.
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on November 18, 2011, 06:17:39 PM

Q : has anyone been able to locate a source for the original HS2051 Zener Diode for the TG Diode bridge ?


 ;)
Title: Re: TG1 - advice from any one who has built it...
Post by: baadc0de on January 02, 2012, 06:27:16 AM
Well guys,

it's the new year and I've decided to try my luck again with the TG1 doorstopper / boat anchor that I have stashed away in hopes of some time getting it together..

Anyway, the +- 20V points are good as are the +- 28V and the signal is entering the board, however it gets beat up in the process..

This is a spectrograph power cycle of the board.. first you have a nice healthy signal coming through the relays and when you switch it on through the opamp input, look at the spectrograph. There's a click, some weird harmonics (weak weak signal). The other click and healthy signal is of course when I switch it off and relays click the signal back. I can only get this weak signal if I turn compression on (THD off) and take HOLD to the rightmost extreme (which puts the VU to above +10 on sintech's VU scale).
(http://dl.dropbox.com/u/12679166/TG1/TG1_on_off.png)

These are the oscilloscope scans of the testing points on the PCB:

T_A
(http://dl.dropbox.com/u/12679166/TG1/TP_A.png)

T_B
(http://dl.dropbox.com/u/12679166/TG1/TP_B.png)

T_C
(http://dl.dropbox.com/u/12679166/TG1/TP_C.png)

T_D
(http://dl.dropbox.com/u/12679166/TG1/TP_D.png)

T_E
(http://dl.dropbox.com/u/12679166/TG1/TP_E.png)

T_F
(http://dl.dropbox.com/u/12679166/TG1/TP_F.png)

T_G
(http://dl.dropbox.com/u/12679166/TG1/TP_G.png)

T_H
(http://dl.dropbox.com/u/12679166/TG1/TP_H.png)

T_J
(http://dl.dropbox.com/u/12679166/TG1/TP_J.png)

T_K
(http://dl.dropbox.com/u/12679166/TG1/TP_K.png)

I could use some help debugging this, as it's way over my head, all these transistors and how it works together. Just so to repeat, symptoms are extremely low output signal and high distortion.
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on January 02, 2012, 07:08:36 AM
Maybe you already got asked this but did you use the right version of the BC214 ?  There are 2 different pin outs for this transistor.  The pcb has the ebc pins marked.  If you bought the BC214L (I think) then the pin outs will be wrong & you will need to turn them round.

If you have the right ones then please ignore the above !

You can check the V's on the transistors in a basic way by checking that there is around 0.6v between base & emitter.   But this may not hold true for all configurations.
Title: Re: TG1 - advice from any one who has built it...
Post by: baadc0de on January 02, 2012, 07:33:03 AM
Thank you for a prompt reply.. I bought transistors from Frank (electrochronic), this is what came with them:

Transistor mapping , refer to silkscreen on PCB
BCY71
(qty 11) = VT1, VT2, VT3, VT4,VT7, VT12,VT15,VT18,
VT21,VT22, VT25,
BC109
(qty 15) = VT5, VT6, VT8, VT9,VT10, VT11,VT13,VT14,VT16,VT17
VT19, VT20,VT23,VT24,VT26
BCY34
=VT27
2N4910
= VT28
2N4898
= VT29

The small signal transistors are all metal can type with a tail that indicates the E pin. I didn't rotate any pins, so it was a simple method of matching the tail indicated pin to the silkscreened "E" on the board.
Title: Re: TG1 - advice from any one who has built it...
Post by: electrochronic on January 02, 2012, 04:04:54 PM
What TG Board version are you working with , Fester or other ?

The transistors are tested prior to shipping , but I always identify
pin leads and test for beta prior to soldering in the circuit. This eliminates
tiresome trouble shooting of dead or problematic components which can exist even in
a brand new batch of parts.

The 2N4898 & 2N4910 should not be lying against the PCB board and
insulators are required.

BC109 (NPN) - tab is closest to Emitter, middle pin is base , last pin is collector
BCY34 (PNP)  - tab is closest to Emitter, middle is base, last pin is collector
BCY71 (PNP) -  tab is closest to Emitter, middle is base, last pin is collector

Make sure the 2N4898 and 2N4910 have not been installed in the wrong PCB pad
One is PNP and the other NPN, and the pad orientation is the same footprint for both.

Check to make sure all diodes are good and none are installed in reverse, I have seen
diodes that have had the band (cathode end) applied to the wrong end of the diode , even though the
diode works perfectly fine. If installed this way , it would be reversed and cause some havoc in the circuit.

Also , Check your resistors prior to soldering into the circuit. I have seen countless times when a builder
solders a wrong value resistor into the circuit. Take a second for each resistor and measure them before
soldering them into the circuit. Deal with each one individually not the whole batch. The extra seconds it takes to measure the resistor saves hours of painstaking troubleshooting down the road.

I remember my first Neve 1272 preamp  15 years ago using self etch PCB and various components including sowter transformers. I fired it up and was really disappointed because no sound came out of it , just white noise. Turned out I had almost all the BC184C transistors reversed. I was lucky enough to remove them from the PCB board and re-use them without any harm from the heat of de-soldering the components. Second time around , I was very happy with the preamp, sounded amazing.

Maybe I don't need to repeat this as I assume most builders put the needed quality control into their builds. However, Sometimes the excitement in building a new project can hinder the build process, causing anyone to overlook simple steps or component details which can effect the end result. This is why I always keep a DMM handy when I'm soldering components in my boards. Double check everything even if it costs a few minutes in time for each component.

Title: Re: TG1 - advice from any one who has built it...
Post by: baadc0de on January 02, 2012, 04:28:17 PM
Thank you for the hints. It's a Fester Unlimited "TG-2".

I actually did check some transistors with a transistor checker before soldering in, but that was mainly to double-check on the orientation side of things. I'll check again however..

Is it possible to run the circuit without the output section? Because I might have fried the big transistors when I put them in wrong once (and without micas) so desoldering might have been a bit brutal to them at high temperatures.. They are insulated though with mica insulator but there are screws going through the far end holes to connect the transistor body to the pads on the PCB. I guess that's all OK right? Maybe I should test for continuity between body and each of the pins?

I'll check that, the rotation of each transistor and diode and come back. Thank you for the support guys, this really helps. If you have any other ideas based on the testpoint scopes, please let me know..

What TG Board version are you working with , Fester or other ?

The transistors are tested prior to shipping , but I always identify
pin leads and test for beta prior to soldering in the circuit. This eliminates
tiresome trouble shooting of dead or problematic parts.

The 2N4898 & 2N4010 should not be lying against the PCB board and
insulators are required.

BC109 (NPN) - tab is closest to Emitter, middle pin is base , last pin is collector
BCY34 (PNP)  - tab is closest to Emitter, middle is base, last pin is collector
BCY71 (PNP) -  tab is closest to Emitter, middle is base, last pin is collector

Make sure the 2N4898 and 2N4910 have not been installed in the wrong PCB pad
One is PNP and the other NPN, and the pads are the same footprint for both.

Check to make sure all diodes are good and none are installed in reverse, I have seen
diodes that have had the band applied to the wrong end of the diode , even though the
diode works perfectly fine. If installed this way , it would be reversed and cause some
havoc in the circuit.
Title: Re: TG1 - advice from any one who has built it...
Post by: electrochronic on January 02, 2012, 04:42:56 PM
You must run the output transistors for the amp to work properly.

It is posssible to check the output transistors with a DMM in Diode mode.

here is a short tutorial on how to check for open or shorted transistors
with TO-3, TO-66, TO-220 or TO-92 types.

Set your meter to the continuity / diode "bleep" test. Connect the red meter lead to the base of the transistor. Connect the black meter lead to the emitter. A good NPN transistor will read a junction drop voltage of between 0.45v and 0.9v. A good PNP transistor will read "OL". Leave the red meter lead on the base and move the black lead to the collector. The reading should be the same as the previous test. Reverse the meter leads in your hands and repeat the test.

Now connect the black meter lead to the base of the transistor. Connect the red meter lead to the emitter. A good PNP transistor will read a junction drop voltage of between 0.45v and 0.9v. A good NPN transistor will read "OL". Leave the black meter lead on the base and move the red lead to the collector. The reading should be the same as the previous test.

Finally place one meter lead on the collector, the other on the emitter. The meter should read "OL". Reverse your meter leads. The meter should read "OL". This is the same for both NPN and PNP transistors.

With the transistors on a pcb in circuit, you may not get an accurate reading, as other things in the circuit may affect it, so if you think a transistor is suspect from the readings you have got, remove it from the pcb and test it out of circuit, repeating the above procedure.

Note : Transistor that shows shorted juctions indicates a bad device, the meter will usually beep continuous.

OL = Open Line


You can check for beta which is the easiest, but the Beta tester sockets on most DMM's do not allow for the big TO-3 or TO-66 packages to fit. In this case you can build a test jig that plugs into the DMM sockets
and is wired to the transistor plug in socket, example  TO-66.
Title: Re: TG1 - advice from any one who has built it...
Post by: drask on March 19, 2012, 05:54:13 AM
Hie,
I'm actually building a fester TG. I've a question.
for the meters can I use this : http://hairballaudio.com/shop/product_info.php?cPath=25&products_id=86

Thank's you
Title: Re: TG1 - advice from any one who has built it...
Post by: trampo on March 31, 2012, 05:03:30 PM
Hi Guys

Having an issue with my TG build and would like some help trouble shooting.

The unit is set up EMI style and is compressing as you would expect with attack and release all functioning ok, but when I switch between clean and bypass the bypassed signal is considerably louder than the clean signal (even without any compression) also there is very little gain makeup. I have checked the bypass board and all is ok there, so it seems to be on the main board.

I have the same problem on both channels so I am guessing I have put the wrong values in somewhere.

Does anyone have a list of voltages for the TPs and or ideas of where to start?
Title: Re: TG1 - advice from any one who has built it...
Post by: simonsez on April 07, 2012, 11:35:47 PM
Hie,
I'm actually building a fester TG. I've a question.
for the meters can I use this : http://hairballaudio.com/shop/product_info.php?cPath=25&products_id=86

Thank's you

I don't think so, that meter won't dance nicely in this circuit. You need 2.4ma meter, but it can work even without meter.
Title: Re: TG1 - advice from any one who has built it...
Post by: drask on May 02, 2012, 02:50:51 PM
Hello,
I've just finish to build the TG.
I've 18,6v on T+20 and -18,6 on T-20.
And less 28v at the PSU out. So I think it's the PSU transfo, I use a 2x25v. So I'll change this.

But I want to know is what serves the jump 1-6.
And what is T_K and T_J.
And what value we do have at this point?

Thank's,
Jr
Title: Re: TG1 - advice from any one who has built it...
Post by: pachi2007 on May 06, 2012, 10:07:19 AM
I didn´t build this but from what I read jumpers 1-6 fine tune the voltage. I guess putting one or more jumpers at different positions will change +-V slightly...
 but just guessing :-)

Pachi
Title: Re: TG1 - advice from any one who has built it...
Post by: pachi2007 on May 06, 2012, 10:44:34 AM
One doubt about HOLD.
If you use a pot instead of switch (5k log with 5k resistor in series for +-15bd).
Is the attached drawing correct? Just cut the pcb, put 5k at R115, solder 5k  pot to ATTACK pcb (are the pin numbers correct?) and short 2/3 at the I/O board INPUT/HOLD molex?
If this is correct it seems  better to solder the pot before soldering the attack knob.
Just trying to figure it out before build. Thx
Pachi
Title: Re: TG1 - advice from any one who has built it...
Post by: drask on May 09, 2012, 02:49:46 PM
Hie All,
I've fix my last post on the topic.

But I've yet a problem. On one channel, when I turn on the power, R77 on mainboard burn.
I don't find why.
Before R77 I've 25v and after 9v.
But on the second channel I've 25v before and 22,2V after.

If someone have a idea :)
Title: Re: TG1 - advice from any one who has built it...
Post by: late on June 06, 2012, 02:11:36 PM
Hi

I've readed docs and start building soon. But wondering that how to wire stereo link switch, it is LNK1?

Do i need use R115 if i use hold switch and what the R115 do?
Title: Re: TG1 - advice from any one who has built it...
Post by: Igor on July 14, 2012, 08:27:40 PM
lnk 1 is for stereo link.

I revised Fester's boards to 51X format, and found little, for most people irrelevant, buggie at current version of rack format boards.

IIRC, this fix was already posted; anyway.

Funny, this buggie wasn't present in old version boards.  Gremlins? Dunno ;)
Old version boards are very first ones without components values at silkscreening; there were 18 mono boards;
only me and some of first builders used them. First version boards had no transformer / bypass board.

If you plan to build it with HOLD or already have HOLD control at your unit, please refer to archive.
http://ij-audio.com/downloads/TG_FIX.rar

IF USED IN CH**R CONFIGURATION - J_CH*R SHORTED, NO HOLD CONTROL - THIS FIX IS NOT RELEVANT.
FOR USE WITH HOLD CONTROL ONLY!!!!
CUT TWO TRACES AND CONNECT 2 WIRES AS SHOWN AT PICTURES.

Fix takes 2 minutes exactly. Worst case, if you have to open/remove knobs at existing unit, 5 minutes.
Title: Re: TG1 - advice from any one who has built it...
Post by: DonnieDarko on August 22, 2012, 04:46:28 PM
Hey,

I´m in the midst of building this unit and have some problems. I went all vintage parts: Allen Bradley military resistors (even baked them 9 hours in the oven to ensure proper tolerance), vintage semi conductors from Electro Chonic and so on…

It would be great if you guys could help me out.


PSU PCB:

Some (a lot of) parts on the PSU Board are not mentioned in the BOM.

I guess the four big Diodes can be 1N4007 rated up to 1000V ore similar. The four smaller ones between the IC´s need to be IN4004 I guess. Is this right?


BYPASS  PCB:

There is a Cap labeld "CZ" on the board near  the power hook up. In the schematic, this seems to be a 3300uf cap. Didn´t find a 3300uf cap in that small size and put in a 3300pf which fits perfectly. Can this be right?

Also, there is a resistor "RZ" next to it, that has no known value.


MAINBOARD PCB:

Could´t find a 200uf cap and put in another 220uf. Fine?

SWITCHES PCB:

There is a rsistor "R115"- someone earlier in this thread asked what should be placed there but I didn´t find any answer. Does anybody have an idea?

Thanks guys!



Title: Re: TG1 - advice from any one who has built it...
Post by: DonnieDarko on August 23, 2012, 04:26:07 AM
Thanks, that helped me already!
Title: Re: TG1 - advice from any one who has built it...
Post by: bieckmusic on August 23, 2012, 10:41:34 PM
Hey everyone,    :) :) :)
I'm putting together my bom and, have a question about the steppedswitches for the tg1 front panel.  For attack do I install a 3k3 resistor, then a .6k, then a .8k and so on?(cumulative style) or do I actually install a 3k3, then 3k9, then 4k7…

I saw an earlier thread that said something about the values being cumulative, and got confused, because the schematic doesn't seem to indicate it being cumulative...

Does this same technique apply to the other stepped switches, it looks like it does not apply to the hpf switch.  I'm guessing I just install the values exactly like on the schematic.  c110 33n, c108 22n etc,,,

Also, is the recovery cumulative or do I install the values on the schematic?

thanks to anyone who can help clear this up.  This project is a little scary for a newbie like me!! 

bless,
greg
Title: Re: TG1 - advice from any one who has built it...
Post by: loopermc5 on August 23, 2012, 10:46:58 PM
Just follow the bom and schematic and youll be fine.
Title: Re: TG1 - advice from any one who has built it...
Post by: bieckmusic on August 23, 2012, 11:31:29 PM
 :)  thanks loopermc5

that's good news! 

I apologize, and swear I'm not being lazy, possibly a little lazy ;) but does anyone have a part number mouser, digikey, newark for a transformer that meets these specs?

TG PSu requirement is +/- 28v output

Use 56-60vct (2x28vac) or (2x30vac) /30-50va transformer

I've been entering that data in the last several hours, and nothing comes up?  possibly, I'm mis-reading something...

thanks so much, I've almost got everything entered in now, ready to hit purchase, and crank up the soldering iron!!!  woo-hoo   :) :) :)
Title: Re: TG1 - advice from any one who has built it...
Post by: Igor on August 26, 2012, 12:10:29 PM
I used to use here 2x25V 50VA toroids. 35 VDC on capactors after the bridge is quite enough to take it down to 28.
Take into account, most of transformers have some "spare" volts (specs are measured at max load).
Title: Re: TG1 - advice from any one who has built it...
Post by: muffy1975 on August 28, 2012, 08:43:15 AM
Team,

BC184C HFE range

I have searched using

TG-1 BC184C HFE

I can find no answers to what the recommended figure for the BC184C HFE should be?

Is 440 HFE too low?

Should they all be in the 600HFE range?

Thanks for any help

Michael

Title: Re: TG1 - advice from any one who has built it...
Post by: muffy1975 on August 28, 2012, 09:12:56 AM
lnk 1 is for stereo link.

I revised Fester's boards to 51X format, and found little, for most people irrelevant, buggie at current version of rack format boards.

IIRC, this fix was already posted; anyway.

Funny, this buggie wasn't present in old version boards.  Gremlins? Dunno ;)
Old version boards are very first ones without components values at silkscreening; there were 18 mono boards;
only me and some of first builders used them. First version boards had no transformer / bypass board.

If you plan to build it with HOLD or already have HOLD control at your unit, please refer to archive.
http://ij-audio.com/downloads/TG_FIX.rar

IF USED IN CH**R CONFIGURATION - J_CH*R SHORTED, NO HOLD CONTROL - THIS FIX IS NOT RELEVANT.
FOR USE WITH HOLD CONTROL ONLY!!!!
CUT TWO TRACES AND CONNECT 2 WIRES AS SHOWN AT PICTURES.

Fix takes 2 minutes exactly. Worst case, if you have to open/remove knobs at existing unit, 5 minutes.

When i click on this link to find out how to fix the new PCBs it comes up as &&%^%$$&^$&^$^&%%%&

Can anyone repost the bug fix please so that My Mac can read it.

Thanks

Michael
Title: Re: TG1 - advice from any one who has built it...
Post by: letterbeacon on August 28, 2012, 09:20:50 AM
You need to 'Download linked file as...' and then use Xrar or something similar to extract the data from the .rar file.
Title: Re: TG1 - advice from any one who has built it...
Post by: muffy1975 on August 28, 2012, 09:46:38 AM
I have no idea why there can't be a JPG of this bug fix. Why does this all have to be such a trek.

Ok, going through the docs that I can download.........

I can't find any info on the  whole AOT*. Does anyone have a list of suggested resistors for these points?

There is no info on how to calculate these anywhere.

Michael
Title: Re: TG1 - advice from any one who has built it...
Post by: loopermc5 on August 28, 2012, 12:20:09 PM
I would go here
 http://www.ij-audio.com/store/50051x/tg12423_stereo_preorder/

download this it has a folder in it for the racked vrs i found it to be the most comprehensive it spells out the info you seek
Title: Re: TG1 - advice from any one who has built it...
Post by: muffy1975 on August 29, 2012, 05:11:58 AM
Thanks,

I still have this problem with .rar files. What are these?

Can anyone JPG these or PDF them? What is wrong with this file type?

Michael
Title: Re: TG1 - advice from any one who has built it...
Post by: letterbeacon on August 29, 2012, 08:38:51 AM
They're compressed files -basically zip files- containing a whole bunch of files.  I use unrarX on the Mac to uncompress them.
Title: Re: TG1 - advice from any one who has built it...
Post by: loopermc5 on August 29, 2012, 11:47:34 AM
Thanks,

I still have this problem with .rar files. What are these?

Can anyone JPG these or PDF them? What is wrong with this file type?

Michael
send me a pm with you email i can send you the folder if you havnt figured out how to open it
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on August 29, 2012, 06:52:10 PM
Thanks,

I still have this problem with .rar files. What are these?

Can anyone JPG these or PDF them? What is wrong with this file type?

Michael

Just use winrar.
Title: Re: TG1 - advice from any one who has built it...
Post by: Majestic12 on September 17, 2012, 06:24:15 AM
I've got a question on how to get a stereo link in this unit. Is is possible? I just cant find a stereo link option in the schematics. Do I have to come up with my own solution?


EDIT...already found it a few post above mine :)
Title: Re: TG1 - advice from any one who has built it...
Post by: Majestic12 on September 20, 2012, 11:01:30 AM
My 3HE frontpanel version...

(http://i50.tinypic.com/2v187f7.jpg)
Title: Re: TG1 - advice from any one who has built it...
Post by: SubhumanRecords on September 20, 2012, 12:02:11 PM
Very nice front panel....
Title: Re: TG1 - advice from any one who has built it...
Post by: Majestic12 on September 21, 2012, 01:15:40 PM
Does anybody know if the 1mA Sifam Meters I have will work? I'm not quite sure if I can get them to a more or less exact reading when the original unit needs 2.4mA
Title: Re: TG1 - advice from any one who has built it...
Post by: muffy1975 on September 28, 2012, 02:56:40 PM
Team,

does anyone know what range the bc184c and 214 c should be for this project. What have people been using?

Team,

BC184C HFE range

I have searched using

TG-1 BC184C HFE

I can find no answers to what the recommended figure for the BC184C HFE should be?

Is 440 HFE too low?

Should they all be in the 600HFE range?

Thanks for any help

Michael
Title: Re: TG1 - advice from any one who has built it...
Post by: muffy1975 on September 29, 2012, 01:30:49 PM
Also,

can anyone supply me with the correct 1W 5.1V zeners and the 11V zener?

I think i have the 12v 1 watt zener.

thanks in advance

Michael
oxford
england
Title: Re: TG1 - advice from any one who has built it...
Post by: wade goeke on October 02, 2012, 01:57:58 PM
My 3HE frontpanel version...

(http://i50.tinypic.com/2v187f7.jpg)

WOW that looks just like ours.....except sh*ttier.....
Title: Re: TG1 - advice from any one who has built it...
Post by: loopermc5 on October 02, 2012, 02:14:32 PM



Hey wade love your curve bender had it for a couple months now . just sayin  ???
Title: Re: TG1 - advice from any one who has built it...
Post by: SubhumanRecords on October 02, 2012, 02:50:22 PM
Wade bro,I have 2 of your germ pre-di's, f**king they rule, would love to have about 14 more of those.There badass...
Title: Re: TG1 - advice from any one who has built it...
Post by: sintech on October 04, 2012, 06:20:51 AM
My 3HE frontpanel version...

(http://i50.tinypic.com/2v187f7.jpg)

WOW that looks just like ours.....except sh*ttier.....

Wade, why bother posting such rude comments. Group DIY is about making/learning/sharing/enjoying audio electronics... nothing more.
Title: Re: TG1 - advice from any one who has built it...
Post by: sintech on October 04, 2012, 06:37:04 AM
My build from years past:


(http://i44.photobucket.com/albums/f23/sin-tech/TG.jpg)
(http://i44.photobucket.com/albums/f23/sin-tech/Image268.jpg)
(http://i44.photobucket.com/albums/f23/sin-tech/Image269.jpg)
Title: Re: TG1 - advice from any one who has built it...
Post by: SubhumanRecords on October 04, 2012, 09:28:11 AM
Andy, you are the man bro,absolutely beautiful my friend..
Title: Re: TG1 - advice from any one who has built it...
Post by: Majestic12 on October 04, 2012, 09:57:15 AM
My 3HE frontpanel version...

(http://i50.tinypic.com/2v187f7.jpg)

WOW that looks just like ours.....except sh*ttier.....

Wade, why bother posting such rude comments. Group DIY is about making/learning/sharing/enjoying audio electronics... nothing more.

Don't know whats the problem. Sure, my design is copied from the Ch**ler unit, but I'm not selling these things and use it only for my own stuff.
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on October 04, 2012, 12:34:43 PM
But still, it is copied from the chandler unit...so..........Wade's not really unjustified.
I'd probably do the same thing, the same way, if it were me.
 ;)
Title: Re: TG1 - advice from any one who has built it...
Post by: sintech on October 04, 2012, 06:56:39 PM
But still, it is copied from the chandler unit...so..........Wade's not really unjustified.
I'd probably do the same thing, the same way, if it were me.
 ;)

It looks like someone 'mixing and matching' and proud enough to post a picture of a personal build. To put this down in my opinion is.. Bad Manners.
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on October 05, 2012, 09:07:02 AM
Well, i mean....it probably annoyed him slightly? It's understandable...i see his point, etc

Life goes on.  8)
Title: Re: TG1 - advice from any one who has built it...
Post by: bieckmusic on October 12, 2012, 12:33:42 PM
Hey you'all   :)     :

Quick couple of questions - I'm noticing some inconsistencies between the BOM, schematic and PCB overlay printing...

For example:
the PCB overlay says c108 = 33n
Bom says c108 = 22n
and Schemo says c108 = 22n

I've noticed the same issue with
c110, c105, c106, c103, c104, c108

The value on the PCB overlay, schemo and BOM conflict.  I downloaded the latest info from twin-x, i believe...  What have you'all done in regards to this, gone with the values in the BOM, Schemo or PCB overlay??  These look like the filter caps for the HPF...       :)

Also R19 is 3k9 on bom/schemo, it's also a 10k resistor on BOM.

R20 on bom is 10r, it's also a 15k on the bom and 15k on the PCB??

Lastly there is an unlabeled resistor symbol with no numbers by it right by pwr and pwr2 on the main PCB.  Anyone know what the value is of that one??

Also, there is an unlabeled cap right below d14 at the top of the main pcb board?

Thank you all so much!!!!! 

Greg 
Title: Re: TG1 - advice from any one who has built it...
Post by: bieckmusic on October 14, 2012, 10:13:46 PM
Ok I probably didn't need to ask those last questions as I studied the schematic.  The side chain caps make sense being progressively larger.  So I'm going to go with the schematic and not the silk screen.

Also the missing labels on the pcbs are found in the component layout pictures. 

Got everything passive stuffed now on to transistors
Title: Re: TG1 - advice from any one who has built it...
Post by: haima on October 14, 2012, 10:31:53 PM
Glad you figured it out! - Just letting you know you're not alone out there, someone is reading this thread ;D
Title: Re: TG1 - advice from any one who has built it...
Post by: bieckmusic on October 27, 2012, 01:03:41 AM
Quick question on transformer choices:   Looking at the build notes it says the neve transformer options are very nice sounding.  The 1:1 option is the simplest.  Has anyone built one of both or experimented with both?  I'm trying to decide which way to go.

Also, for 20$ on eBay I bought a component tester that does caps, resistors diodes and transistors.  It identifies the legs of the transistors.  This will help me get everything installed properly.  A good deal for 20 bucks...  8-)

Thanks!! Greg
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on October 27, 2012, 07:59:02 PM
I'm assuming you've chosen not to install the iron/clean option? If i wasn't going to build it the chandler way(which is pretty sweet for what it does)...i'd probably stick to DOA only. I seem to remember hearing a few samples, and i liked the clean quite a bit more. Freq response was significantly more extended top to bottom.
Title: Re: TG1 - advice from any one who has built it...
Post by: bieckmusic on October 29, 2012, 09:43:59 PM
Hi Desol,  thanks for your response!  I'm installing the iron/clean option, and I wasn't going to go Cha-dl-r but original emi.  I'm going to try and find those sound samples, good idea  :) :)

best!
greg
Title: Re: TG1 - advice from any one who has built it...
Post by: simonsez on November 14, 2012, 07:34:15 AM
My build from years past:


(http://i44.photobucket.com/albums/f23/sin-tech/TG.jpg)


Lovely build...i like that...
Title: Re: TG1 - advice from any one who has built it...
Post by: baadc0de on November 28, 2012, 07:22:57 AM
(http://farm7.staticflickr.com/6171/6218640902_8c9fd8ddb1.jpg) (http://www.flickr.com/photos/[email protected]/6218640902/)


http://tinyurl.com/ceta32n

http://tinyurl.com/d4monng

10k:10k carnhill, 600:600 thordarson. I will probably mod this to Ch*ndler input arrangement from the hold I currently have. So far the only thing I reaaaaly like with it is to smash things into oblivion, might as well make that easier to do..

Thansk guys!
Title: Re: TG1 - advice from any one who has built it...
Post by: warpie on November 28, 2012, 07:34:28 AM
beauty...  :)

But, other than room mics I can't think of any possible usage of so much compression. Maybe is just me though... :)
Title: Re: TG1 - advice from any one who has built it...
Post by: bieckmusic on November 28, 2012, 12:53:35 PM
Hi baadc0de,

that looks great!!! Good job, how did you make that panel?

I'm really close to being done with my unit.   :)

Everything's stuffed, just got to wire it up.  Was there anything you noticed you had to fix or change or possible issues? 

I'm just going to do the 1:1 deal for now, and add transformers down the road I think...
Frank and electrochronic has been very helpfull   :)

best!

greg
Title: Re: TG1 - advice from any one who has built it...
Post by: baadc0de on November 28, 2012, 06:06:40 PM
Thanks,

the most important fix is the one that Igor outlines before with cut traces and doing some wire links. I never did finish it on my own so I let someone else do it and there were some AOT resistors not installed (but apparently they are on the schem, so ..)

Yeah, I too wouldn't want to use that much compression except for cases like these (room mics) but I just don't find it THAT exciting on other stuff, in other modes. It's no 1176 or LA2A or something else I find instant love for. Maybe I've just spent not enough time with it. But I will mod it to ch*ndler input knob spec, which will make it easier to distort which it just seems to do SO well. Better for crushing drums than any other compressor I have, and I have plenty.
Title: Re: TG1 - advice from any one who has built it...
Post by: Dylan W on November 28, 2012, 06:21:28 PM
Thanks,

the most important fix is the one that Igor outlines before with cut traces and doing some wire links. I never did finish it on my own so I let someone else do it and there were some AOT resistors not installed (but apparently they are on the schem, so ..)

Yeah, I too wouldn't want to use that much compression except for cases like these (room mics) but I just don't find it THAT exciting on other stuff, in other modes. It's no 1176 or LA2A or something else I find instant love for. Maybe I've just spent not enough time with it. But I will mod it to ch*ndler input knob spec, which will make it easier to distort which it just seems to do SO well. Better for crushing drums than any other compressor I have, and I have plenty.

Can't speak for the clone (though I hope to soon... any news on these meters?!), but the real one can do a really cool thing to piano parts and some electric guitars. Maybe more useful in a rock/hip-hop/indie mix than leveling out solo piano, etc.

Dylan
Title: Re: TG1 - advice from any one who has built it...
Post by: bieckmusic on November 30, 2012, 09:33:41 AM
Thanks baadc0de  :)

BTW, what did you end up using for your zobel network resistor and cap?   

thanks!

Greg
Title: Re: TG1 - advice from any one who has built it...
Post by: Majestic12 on December 12, 2012, 05:00:00 PM
Anyone has seen this ? Looks like a commercial ripoff of the Chandler unit to me.... Nearly the same features, Zener diode circuit etc...
Wade won't be happy about this, I'm sure ;)

(http://www.gemaudiolabs.com/wp-content/uploads/2012/07/Gem-Audio-Labs-Preceptor-A-front-hi-res.jpg)
Title: Re: TG1 - advice from any one who has built it...
Post by: dirty1_1garry on January 06, 2013, 05:14:05 PM
Hello everyone!
Couple days ago purchased TG-1 pcb's from Igor. Happy to start building process! :)
Began to discover project and faced with some difficulties.
At my level first difficulty is fiddly bom, so I've done my more comfortable version of TG-1 BOM. Check it out.

http://narod.ru/disk/65190058001.3daa3d449019eba236d8dd9f546f4a4d/TG-1%20EXEL%20BOM.xlsx.html

Another problem is that I did not find bom for power pcb! Have somebody some information about power BOM?!
I find some info on previews pages but nothing defined.
Title: Re: TG1 - advice from any one who has built it...
Post by: peskado on January 06, 2013, 05:43:37 PM
It same with Sontec(without ms) but some resistors different


Resistors      

2 x 200R 1/4W MF 1%   R2, R5   
2 x 4K22 1/4W MF 1%   R3, R4   
1 x 10K 1/4W MF 1%   R1          

Ceramic      

4 x 0.1UF    C3, C4. , C7. , C8. ,

Electrolytic Low Essr      

4 x 100UF 50V pitch 3.5mm diam 8mm   C5. , C6, C9, C10
2 x 3300UF 40-63V   C1’, C11’   

Diode      

4 x 1N5004   D2, D4, D5, D7   
4 x 1N4004   D1, D3, D6, D8   

IC      

1 x 317   IC1   
1 x 337   IC2   

Heatsink      

2 x Heatsink TO-220      

Connectors      

2 x Molex 4Pin Header 3.96      
2 x Molex Crimp 4P 3.96      
8 x Solder Terminal      


Title: Re: TG1 - advice from any one who has built it...
Post by: drask on January 06, 2013, 05:59:46 PM
Hello everyone!
Couple days ago purchased TG-1 pcb's from Igor. Happy to start building process! :)
Began to discover project and faced with some difficulties.
At my level first difficulty is fiddly bom, so I've done my more comfortable version of TG-1 BOM. Check it out.

http://narod.ru/disk/65190058001.3daa3d449019eba236d8dd9f546f4a4d/TG-1%20EXEL%20BOM.xlsx.html

Another problem is that I did not find bom for power pcb! Have somebody some information about power BOM?!
I find some info on previews pages but nothing defined.
Hey Guy,

You can find all information in the files from Igor. it's available on his website.
http://www.ij-audio.com/store/compressors/tg-1_pc/
Click on "Docs" and you will dowload a Rar files with all you need.

I think information about it's not write.
So D2 D4 D5 D7 it's 1n5400
and the four others 1N4004 or 1N4007 (Not sure for this, I can't remember but I can check ;) )In other cas, it's write somewhere in this topic.
Title: Re: TG1 - advice from any one who has built it...
Post by: dirty1_1garry on January 09, 2013, 03:03:46 AM
Thank you guys for details!

Hey Guy,
You can find all information in the files from Igor. it's available on his website.
http://www.ij-audio.com/store/compressors/tg-1_pc/
Click on "Docs" and you will dowload a Rar files with all you need.

Yes, could find all information in docs accept info about power pcb))
All other information possible to find only on this pages. And that great! :)
Title: Re: TG1 - advice from any one who has built it...
Post by: bieckmusic on January 09, 2013, 11:38:49 PM
also, I think there's a mistake...

 the R47 8K2 (8200 ohm), not 82K (82000 ohm). 8K2 It is used in Origial TG design.

good luck!
greg
Title: Re: TG1 - advice from any one who has built it...
Post by: mrclunk on January 22, 2013, 06:39:02 AM
Anyone have the self etch pcb docs for this? 
I can't find them, i'm sure there used to be some at one point.
Title: Re: TG1 - advice from any one who has built it...
Post by: electrochronic on January 22, 2013, 10:32:24 PM
Anyone have the self etch pcb docs for this? 
I can't find them, i'm sure there used to be some at one point.

I agree , I know who has them , but I don't think their fists are loosening. maybe I'll do a layout and make it public around here. Although , you might have a rough time etching a two layer from home.
Title: Re: TG1 - advice from any one who has built it...
Post by: bieckmusic on January 23, 2013, 10:58:53 PM
Hi TG1 folks!    :) :) :)

After 6 months or so, I got my TG-1 completed.  The Right channel sounds great, though still has some minor calibration issues.  The left channel still needs troubleshooting. 

I had a question, Does anyone have the part numbers they used for the molex sockets and headers for this build? 
I always just solder wires directly to the board, but in this build it makes trouble shooting a drag.


thanks!!!
greg
Title: Re: TG1 - advice from any one who has built it...
Post by: Majestic12 on January 24, 2013, 12:35:20 AM
all Farnell part numbers:

pcb connector: 1675500
header:            1675491
crimp pins:       1675488

unfortunately, there's a minimum order quantity of 50 pieces each.
Title: Re: TG1 - advice from any one who has built it...
Post by: mrclunk on January 24, 2013, 05:58:36 AM

I agree , I know who has them , but I don't think their fists are loosening. maybe I'll do a layout and make it public around here. Although , you might have a rough time etching a two layer from home.

Ah i didn't realise they were secret... Thought the links had just died. From what i've seen its not a particularly complex  2 layer layout, could probably just p2p one side.

Well if you do fancy doing a layout, fantastic. Can i help? My first two layouts have failed tho so....
I'd rather put the money from purchasing the pcb's into (£300!!) pcb engraving software for my cnc.
Title: Re: TG1 - advice from any one who has built it...
Post by: bieckmusic on February 01, 2013, 11:38:32 PM
WOW  ;D  does this thing sound amazing!!  I got my second channel working finally and ran some stereo tracks through...  MR. TG-limiter really knows what to do with transients.  I have no transformers installed, and am using the vintage semiconductors from Electrochronic.

My hold controls are too sensitive so I'm going to try the 5k log pot connected in series with a 5k resistor as suggested.

One issue, On my unit, when the switch is set to THD the unit distorts like crazy and is super loud.  Is that right, I doubt it?  I thought the THD deactivates the side-chain and I thought THD was supposed to be more of a bypass and not a distortion...  I might have something messed up in the THD or hold department. 

But even as is, I'm very happy with the results, thank you to everyone responsible for getting this project off the ground!!!!

 :) :) :)

Greg
Title: Re: TG1 - advice from any one who has built it...
Post by: bieckmusic on February 09, 2013, 01:25:57 PM
I Love this thing!  Thanks to everyone who helped make it happen...   :) 

 8)
Title: Re: TG1 - advice from any one who has built it...
Post by: warpie on February 09, 2013, 05:38:25 PM
Team,

does anyone know what range the bc184c and 214 c should be for this project. What have people been using?

Team,

BC184C HFE range

I have searched using

TG-1 BC184C HFE

I can find no answers to what the recommended figure for the BC184C HFE should be?

Is 440 HFE too low?

Should they all be in the 600HFE range?

Thanks for any help

Michael

I'm quite curious too if anyone knows...
Title: Re: TG1 - advice from any one who has built it...
Post by: JdJ on February 13, 2013, 03:44:24 PM
also, I think there's a mistake...

 the R47 8K2 (8200 ohm), not 82K (82000 ohm). 8K2 It is used in Origial TG design.

Hey Greg - I don't have any other schem than the Fester version which lists R47 as 82K with a "/"  Did you go with an 8k2 here?  Anyone else care to comment?

I'm psyched to try to complete this after 1+ years...

Thanks!

Josh
Title: Re: TG1 - advice from any one who has built it...
Post by: bieckmusic on February 13, 2013, 04:11:25 PM
Hi yes there's the original schematic which says R47 8k2.  I believe it's in the folder with all the project documents that you can access off igor's website.  The file name is Recipe_-_sharpened-fixed.

Good luck, it's definitely worth the effort!
Title: Re: TG1 - advice from any one who has built it...
Post by: imo on February 14, 2013, 12:13:51 PM
hmm. On Igor's new schematic, for the 500 series version, he actually has a 100k in there. Any reports from builds using the 8.2k there?
Title: Re: TG1 - advice from any one who has built it...
Post by: bieckmusic on February 14, 2013, 01:02:01 PM
Interesting, my unit seemingly works great with the 8.2k???

Electrochronic pointed out to me a good hint...  Use sockets for the A.O.T's to easily swap out resistors.  I made a pcb with trimmers on it and hooked it up to the aots... 

Greg
Title: Re: TG1 - advice from any one who has built it...
Post by: imo on February 15, 2013, 03:10:01 PM
wow. Thats a pretty big disparity. Looks like Igor went up from an 82k to 100k. Definitely see the 8.2k
Out of curiosity, did anybody use 1mA meters? I am having a hard time finding a 2.4mA meter, especially for the 500 series size. Andy isn't doing another run as far as i know, and his meter is too big for my faceplate. If you used the 1mA, how is it tracking?
Ian
Title: Re: TG1 - advice from any one who has built it...
Post by: Majestic12 on February 17, 2013, 04:07:31 AM
Out of curiosity, did anybody use 1mA meters? I am having a hard time finding a 2.4mA meter, especially for the 500 series size. Andy isn't doing another run as far as i know, and his meter is too big for my faceplate. If you used the 1mA, how is it tracking?
Ian

Igor once sent me a mail concering this topic:

"I read that a 2.4mA meter is required but is there any chanche of using an easy availably 1mA sifam meter?

Yep, easy. Just an adjustable shunt - take about 22r resistor connected in series with 200r multiturn trimpot;
than connect them in parallel to your meter.

Feed some voltage thru appropriate variable resistor (for 5V, the 2.4mA current will be at 2.083 Kohm);
monitor the current with milliampermeter (Fluke at 20mA range) and adjust the shunt for FSD (full scale deflection, 100%)
when the current is exactly 2.4 mA. For this purpose, 2k083 resistor (may bit vary due to total resistance of shunt and meter)
done from 1k5 resistor and 2k potentiometer, connected in-series.
Adjust 2.4 ma - adjust FSD - readjust 2.4ma - readjust FSD - done."

(http://i50.tinypic.com/wv4vu8.jpg)
Title: Re: TG1 - advice from any one who has built it...
Post by: JdJ on February 18, 2013, 12:04:03 PM
wow. Thats a pretty big disparity. Looks like Igor went up from an 82k to 100k. Definitely see the 8.2k

Fo sho.  I'm not qualified to actually determine what effect the difference would have - or even posit a guess for that matter...  anyone else?  All of the other values in that area of both schems seem the same.  I wonder if it is intentional or a mistake?  I'd think if Igor changed it for the 500 version it was intentional...

I'm gonna leave the 82k's I already soldered in there stay until I hear differently...

Title: Re: TG1 - advice from any one who has built it...
Post by: JdJ on February 18, 2013, 02:02:57 PM
Okay - I feel like this maybe the dumbest question I have asked on this board...  Is the switch for the Iron/Bypass/Clean is a SPST?  I am planning on going with the 1:1/Trafo Bypass setup - although I will add the iron later.  How would a SPST switch accomplish 3 things?!  Or do you sacrifice hard bypass by having iron/no iron switching?  I've looked over the various BOMs, Bypass Schem and Bypass Versions PDF and I am as confused as ever!  Time for lunch I guess...

Thanks!

 
Title: Re: TG1 - advice from any one who has built it...
Post by: peskado on February 18, 2013, 02:18:20 PM
You can build with opt out stage and use Clean or Bypass position on switch, Iron will work after you add transformers
Title: Re: TG1 - advice from any one who has built it...
Post by: Majestic12 on February 18, 2013, 02:21:25 PM
Okay - I feel like this maybe the dumbest question I have asked on this board...  Is the switch for the Iron/Bypass/Clean is a SPST?  I am planning on going with the 1:1/Trafo Bypass setup - although I will add the iron later.  How would a SPST switch accomplish 3 things?!  Or do you sacrifice hard bypass by having iron/no iron switching?  I've looked over the various BOMs, Bypass Schem and Bypass Versions PDF and I am as confused as ever!  Time for lunch I guess...

Thanks!

The bypass schematic is somehow confusing. You need a 3 position ON-OFF-ON switch to have  iron, opamps and real bypass.
Title: Re: TG1 - advice from any one who has built it...
Post by: JdJ on February 18, 2013, 02:42:31 PM
Thanks guys!
You can build with opt out stage and use Clean or Bypass position on switch, Iron will work after you add transformers

Exactly my plan - glad it should work.

The bypass schematic is somehow confusing. You need a 3 position ON-OFF-ON switch to have  iron, opamps and real bypass.

See?  I knew I was missing a simple explanation! :P

Cheers!

Josh
Title: Re: TG1 - advice from any one who has built it...
Post by: r2d2 on February 21, 2013, 08:03:01 PM
hi
i attached some bc214 datasheet (partial)
include the motorola that seem to be wrong ,
(don't confuse the motorola bc214 with bc214L)

image 1- motorola bc214 "wrong" pins order

(http://imageshack.us/a/img10/2907/1bc214motorolawrongdoc.jpg)


somebody have checked about right pins order ?
peace!

ps
motorola semiconductors email not found
any info about is welcome.  ;)

Maybe you already got asked this but did you use the right version of the BC214 ?  There are 2 different pin outs for this transistor.  The pcb has the ebc pins marked.  If you bought the BC214L (I think) then the pin outs will be wrong & you will need to turn them round.

If you have the right ones then please ignore the above !

You can check the V's on the transistors in a basic way by checking that there is around 0.6v between base & emitter.   But this may not hold true for all configurations.
Title: Re: TG1 - advice from any one who has built it...
Post by: r2d2 on February 21, 2013, 08:06:22 PM
image 2- motorola bc214 "old" doc pins order


(http://imageshack.us/a/img820/3465/2bc214motorolaolddocok.jpg)
Title: Re: TG1 - advice from any one who has built it...
Post by: r2d2 on February 21, 2013, 08:07:24 PM
image 3-  Unknowed  bc214 old datasheet

(http://imageshack.us/a/img266/1374/3bc214olddoc.jpg)

Title: Re: TG1 - advice from any one who has built it...
Post by: r2d2 on February 21, 2013, 08:08:03 PM

image 4- fairchild  bc214LC pins order (hope right)

(http://imageshack.us/a/img195/1742/4bc214lcfairchild.jpg)
Title: Re: TG1 - advice from any one who has built it...
Post by: baadc0de on March 01, 2013, 06:54:55 PM
One interesting problem for the crowd here, maybe someone has any ideas..

Sometimes, when excessive low frequency information is in the input (such as from a preamp when recording a kick drum or direct bass guitar) and the gain reduction is set to a slow enough attack and quite a bit of makeup, the TG1 starts smoking R77. Could the output transistor pair be somehow to blame? I don't know enough about transistors, but say if one of them faults into being a straight line for a time?

It all works out if I power it off for some time. The output transistors are not heatsinked, maybe I should do that?

Thanks!
Title: Re: TG1 - advice from any one who has built it...
Post by: warpie on March 03, 2013, 05:28:19 AM
One interesting problem for the crowd here, maybe someone has any ideas..

Sometimes, when excessive low frequency information is in the input (such as from a preamp when recording a kick drum or direct bass guitar) and the gain reduction is set to a slow enough attack and quite a bit of makeup, the TG1 starts smoking R77. Could the output transistor pair be somehow to blame? I don't know enough about transistors, but say if one of them faults into being a straight line for a time?

It all works out if I power it off for some time. The output transistors are not heatsinked, maybe I should do that?

Thanks!

Ha! welcome! You're not alone. I've been mentioning this problem for quite a while but unfortunately it looks like a mystery :)

http://www.groupdiy.com/index.php?topic=37400.msg512287#msg512287
http://www.groupdiy.com/index.php?topic=48297.msg617261#msg617261

I'm pretty sure it's not a heat problem as I'm using heatsinks on the transistors. What transistors do you use?
What wattage is the 56ohms resistor? Do you have good heatsink on the PSU regulators?

In my case a 2watt resistor with a BIG heatsink on the regulators gives me a maximum of around 40C which I suppose it's OK.

Still though, I don't know what causes it.  ::)

Good luck and let me know. It's been my nightmare for more than two years now  ;D
It'll be good if other people can report too.
Title: Re: TG1 - advice from any one who has built it...
Post by: bieckmusic on March 03, 2013, 12:13:30 PM
Quick question - do you'all think a utc a-20 would be a good candidate for the output transformer.  The data sheet says it can be a 600 pri and 600 sec.  I'm running my unit 1:1 per Uncle Festers docs...

any thought?

Lovin this thing on Drum rooms and guitars, I think I'm using it too much   :)


Title: Re: TG1 - advice from any one who has built it...
Post by: baadc0de on March 03, 2013, 01:28:47 PM
Great to know it's not that uncommon...!

I have for now put two philips BC capacitors (1000uF) in antiseries, which gives about 500uF of capacitance but blocks DC both ways. I'll let you know if it helps any.. the output transistors are NOS Motorola ones from electrochronic as are the rest of transistors.

The reason to put in another capacitor - a fake bipolar one - is because in the previous configuration it smoked not only R77 but also a winding on the output transformer (which now reads open). So this is more intended to protect the trafo. If anyone came to a solution to this, please let me know!

One interesting problem for the crowd here, maybe someone has any ideas..

Sometimes, when excessive low frequency information is in the input (such as from a preamp when recording a kick drum or direct bass guitar) and the gain reduction is set to a slow enough attack and quite a bit of makeup, the TG1 starts smoking R77. Could the output transistor pair be somehow to blame? I don't know enough about transistors, but say if one of them faults into being a straight line for a time?

It all works out if I power it off for some time. The output transistors are not heatsinked, maybe I should do that?

Thanks!

Ha! welcome! You're not alone. I've been mentioning this problem for quite a while but unfortunately it looks like a mystery :)

http://www.groupdiy.com/index.php?topic=37400.msg512287#msg512287
http://www.groupdiy.com/index.php?topic=48297.msg617261#msg617261

I'm pretty sure it's not a heat problem as I'm using heatsinks on the transistors. What transistors do you use?
What wattage is the 56ohms resistor? Do you have good heatsink on the PSU regulators?

In my case a 2watt resistor with a BIG heatsink on the regulators gives me a maximum of around 40C which I suppose it's OK.

Still though, I don't know what causes it.  ::)

Good luck and let me know. It's been my nightmare for more than two years now  ;D
It'll be good if other people can report too.
Title: Re: TG1 - advice from any one who has built it...
Post by: warpie on March 03, 2013, 08:04:08 PM
Yes, let me/us know please.
I'm pretty sure we are not they only ones who have this issue.  ;)
Title: Re: TG1 - advice from any one who has built it...
Post by: JdJ on March 05, 2013, 02:49:58 PM
Yes, let me/us know please.
I'm pretty sure we are not they only ones who have this issue.  ;)

And it looks from your other post that this DC/hot resistor occurs with an output transformer as well as without one correct?

Title: Re: TG1 - advice from any one who has built it...
Post by: warpie on March 05, 2013, 03:07:06 PM
Yes, with or without transformer. Also, with transformer, it occurs both with gapped and ungapped.

EDIT: Speaking of transformers, am I right to think that an ungapped transformer will be more appropriate for this project?

Title: Re: TG1 - advice from any one who has built it...
Post by: JdJ on March 07, 2013, 05:38:29 PM
EDIT: Speaking of transformers, am I right to think that an ungapped transformer will be more appropriate for this project?

That's my understanding, but if you have a bunch of DC on the output before the OT perhaps a gapped would be better?
Title: Re: TG1 - advice from any one who has built it...
Post by: dirty1_1garry on March 12, 2013, 05:21:42 PM
Hi
While my TG in process want to ask you. What is the switch LIM/THD?! What it does?)
Title: Re: TG1 - advice from any one who has built it...
Post by: baadc0de on March 12, 2013, 06:05:50 PM
Hi
While my TG in process want to ask you. What is the switch LIM/THD?! What it does?)

Disables the side chain, thus turning compression off, but leaving the rest of the circuit in the audio path. Similar to 1176's off setting, where the input and output amps are still in circuit and can be overdriven, but no GR is happening.
Title: Re: TG1 - advice from any one who has built it...
Post by: SLB on March 20, 2013, 07:41:40 PM
wow. Thats a pretty big disparity. Looks like Igor went up from an 82k to 100k. Definitely see the 8.2k

Fo sho.  I'm not qualified to actually determine what effect the difference would have - or even posit a guess for that matter...  anyone else?  All of the other values in that area of both schems seem the same.  I wonder if it is intentional or a mistake?  I'd think if Igor changed it for the 500 version it was intentional...

I'm gonna leave the 82k's I already soldered in there stay until I hear differently...

The reason R47 is 82K and not 8.2K is because the attack switch was added which was not part of the original circuit. The switch has 10 resistors that are in parralel with R47 and you get the following values.

(http://www.ladislavbrezovnik.com/diy/TG12413/TG12413_attack_times.png)

As you can see position 7 is 8.19K which is the same as the original.

And the release times.

(http://www.ladislavbrezovnik.com/diy/TG12413/TG12413_recovery_times.png)

Regards,
Brezo
Title: Re: TG1 - advice from any one who has built it...
Post by: SLB on March 20, 2013, 07:57:14 PM
Here is a picture of my build. I'm waiting on a couple of components and then it's calibration time. I think I have worked out what the calibration procedure is and if I'm right I'll post it here.

(http://www.ladislavbrezovnik.com/diy/TG12413/TG12413.png)

Regards,
Brezo
Title: Re: TG1 - advice from any one who has built it...
Post by: baadc0de on March 22, 2013, 01:27:07 AM
Very Snazzy brezo. Looks righteously good! Which transformers and transistors are you using in the output section & have you found any abnormalities like me and warpie are having?
Title: Re: TG1 - advice from any one who has built it...
Post by: SLB on March 22, 2013, 06:12:01 PM
I'm still deciding on transformers but will most likely be going with the Carnhill VTB 2281 for in and outputs. That way I'll have +6dB in and out but most importantly input as the comp needs a decent level to get it working. On the flip side you play with AOT 3 and 4 to change the threshold of the comp mode and AOT 5 and 6 for limit mode.

I'm using 100% original semiconductors as per 1969 schematic.

I'm only doing preliminary testing at the moment with no transformers, OP amps configured for +6 in/out  and output going to headphones as I would not want to destroy my Apogge converters if something went wrong. The compressor sounds great, no unbelievably good.

Now my thoughts on the resistor that keeps burning out is that because you are driving a low impedance output of the transformer primary more current is need to for a given dB level. I have no problem with resistor temp at the moment a I'm driving a high impedance load. Does the resistor burn out only when you have the iron switched in. I have been smashing the unit with dance music (big bass) for hours now with no issues.

I'm also using a 10K lin hold pot and R115 jumped.

More details to come as I finish off this project.

Regards,
Brezo.
Title: Re: TG1 - advice from any one who has built it...
Post by: SLB on March 23, 2013, 06:00:40 PM
Hi desol,

your inbox if full and I can't PM you.

I designed the panel myself and got DIY racked to make it for me. I have the design as a pdf in http://www.ladislavbrezovnik.com/diy/TG12413/ (http://www.ladislavbrezovnik.com/diy/TG12413/) as well as other info.

Regards,
Brezo
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on March 23, 2013, 07:24:45 PM
Thanks! I hadn't noticed!
Title: Re: TG1 - advice from any one who has built it...
Post by: SLB on March 26, 2013, 02:11:32 AM
Here are my AOT resistor settings.

AOT1 620r
AOT2 not used
AOT3 47K
AOT4 not used
AOT5 3K
AOT6 510r (Make the unit work limit more in limit mode)
AOT7 33K
AOT8 68K
AOT9 10r
AOT10 not used

Time for some audio samples. I have attached a track that I’m recording of a mate’s band. It’s only drums and guitar at the moment. I have the TG12413 on the drum bus. The drums where recorded in a room not much bigger than a bedroom.
This is done without transformers as I have not ordered them yet.

http://www.ladislavbrezovnik.com/diy/TG12413/audio_samples/The_Gate_%28TG12413%29.mp3 (http://www.ladislavbrezovnik.com/diy/TG12413/audio_samples/The_Gate_%28TG12413%29.mp3) With Compression

http://www.ladislavbrezovnik.com/diy/TG12413/audio_samples/The_Gate_%28No%20Comp%29.mp3 (http://www.ladislavbrezovnik.com/diy/TG12413/audio_samples/The_Gate_%28No%20Comp%29.mp3) Without Compression

I'm using a 25-0-25 30VA power transformer with the powersupply PCB that came with the boards with no trouble. The main PCB draws 80mA and the Bypass PCB with relays in draws 42mA. So a total of 122mA per channel.

Regards,
Brezo
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on March 26, 2013, 08:10:16 PM
Nice sound quality...they need to work on their timing tho...they're all over the place.

Compressor sounds good.

Title: Re: TG1 - advice from any one who has built it...
Post by: SLB on March 29, 2013, 06:15:59 AM
Here is some only drums samples.

Drums TG Out http://www.ladislavbrezovnik.com/diy/TG12413/audio_samples/Drums%20TG%20Out.mp3 (http://www.ladislavbrezovnik.com/diy/TG12413/audio_samples/Drums%20TG%20Out.mp3)
Drums TG In http://www.ladislavbrezovnik.com/diy/TG12413/audio_samples/Drums%20TG%20In.mp3 (http://www.ladislavbrezovnik.com/diy/TG12413/audio_samples/Drums%20TG%20In.mp3)
Drums TG In Hard Limit http://www.ladislavbrezovnik.com/diy/TG12413/audio_samples/Drums%20TG%20In%20Hard%20Limit.mp3 (http://www.ladislavbrezovnik.com/diy/TG12413/audio_samples/Drums%20TG%20In%20Hard%20Limit.mp3)

Regards,
Brezo
Title: Re: TG1 - advice from any one who has built it...
Post by: haima on March 29, 2013, 06:25:14 AM
Thanks Brezo - so rare that people actually post samples from their DIY gear.

The TG1 definitely hardens up the attack of the drums in a useful way. I think it would also be really great in parallel on drums, or on just room mics etc... really seems like it will be a useful mix tool. Can't wait to find the time to finish mine!
Title: Re: TG1 - advice from any one who has built it...
Post by: SLB on March 29, 2013, 06:38:48 AM
It's great on the room mic as well. It's also good on individual drums. I had the attack set to 8mS and the recovery set to 47mS with the HPF set to 80HZ to let more of the kick through. This is the best compressor I've built because it is a creative tool not just a mix tool. Another awesome compressor I built is a modded RS124. It has amazingly quick attack and release times for a variable mu tube comp. Info Here. http://www.ladislavbrezovnik.com/diy/RS124/ (http://www.ladislavbrezovnik.com/diy/RS124/)

Regards,
Brezo
Title: Re: TG1 - advice from any one who has built it...
Post by: alexc on March 29, 2013, 06:43:56 AM
Way, way nice SLB   ;D

And thanks for your descriptions of the aot and other less obvious things.
I'm going to be doing my one soon and I think you helped!

Cheers

AlxC
Title: Re: TG1 - advice from any one who has built it...
Post by: SLB on March 29, 2013, 06:50:24 AM
I never thought I would get the TG to work as it is the most complicated transistor build I've done, but it worked first go thanks to festers great PCB. I am very happy with the results. I'm still waiting on the output vol switches, once they arrive I'll take some detailed pics. If you run into any issues I'll do my best to help.

Regards,
Brezo
Title: Re: TG1 - advice from any one who has built it...
Post by: warpie on March 29, 2013, 07:01:05 AM
BTW, what fuse do you guys use for a single unit?
Title: Re: TG1 - advice from any one who has built it...
Post by: SLB on March 29, 2013, 07:04:34 AM
500mA for 240V mains.
Title: Re: TG1 - advice from any one who has built it...
Post by: SLB on March 29, 2013, 07:07:02 AM
I also made a recall sheet to suit the case I made but you should be able to use it. http://www.ladislavbrezovnik.com/diy/TG12413/TG12413%20Recall%20Sheet.pdf (http://www.ladislavbrezovnik.com/diy/TG12413/TG12413%20Recall%20Sheet.pdf)

Regards,
Brezo
Title: Re: TG1 - advice from any one who has built it...
Post by: warpie on March 29, 2013, 07:09:53 AM
Thanks SLB. Is that for a single unit that draws around 125mA?
I'd think that a slow blow 250mA at 240V would be sufficient? Or maybe not?  :)
Title: Re: TG1 - advice from any one who has built it...
Post by: SLB on March 29, 2013, 07:14:46 AM
The mains fuse is to protect the power transformer not the circuit. The fuse would have to very small to protect the circuit but big enough not to blow on the in rush current when you first turn the power on.

Regards,
Brezo
Title: Re: TG1 - advice from any one who has built it...
Post by: warpie on March 29, 2013, 07:28:19 AM
So for a dual unit you double the value, don't you (ie. 1Amp at 240V) ?
Title: Re: TG1 - advice from any one who has built it...
Post by: SLB on March 29, 2013, 07:40:07 AM
500mA is for the 25-0-25 30VA transform I used. Bigger VA bigger fuse as the transformer can supply more curren on the secondaries.

Regards,
Brezo
Title: Re: TG1 - advice from any one who has built it...
Post by: warpie on March 29, 2013, 07:46:34 AM
I see.. So in my case (25-0-25 50VA) the fuse needs to be of a higher value.
Thanks  :)
Title: Re: TG1 - advice from any one who has built it...
Post by: peskado on April 11, 2013, 03:22:03 PM
Hi
almost finished build and have question about hold
somebody know how calibrate hold with trim(100k) on attack board?
Title: Re: TG1 - advice from any one who has built it...
Post by: SLB on April 13, 2013, 03:03:05 AM
What gauge are you using?
Title: Re: TG1 - advice from any one who has built it...
Post by: SLB on April 13, 2013, 03:07:10 AM
I have attached a photo of the main PCB using all original transistors and HS2501 diodes.
Title: Re: TG1 - advice from any one who has built it...
Post by: peskado on April 13, 2013, 03:43:40 AM
Hi
My build with Modern kit from Frank, (1N751A,BC184C,BC214)
Im use 21step switch for Hold
Now i'm try to understand how calibrate Hold
Do you have same value for AOTs on two boards?
on my board AOT1 have difference 100ohm(330 and 430ohm) it ok?
Title: Re: TG1 - advice from any one who has built it...
Post by: SLB on April 13, 2013, 04:00:19 AM
Go back one page and you will see the AOT values I used. I used the same values for both PCBs.
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on April 13, 2013, 06:51:43 PM
But, I'm assuming your supposed to do the actual AOT procedure...rather than just using given values. Wouldn't the values change with different component choices?

I like that you used original components. Nice. I have original HS2051's, etc as well. I'd like to acquire the transistors tho...and the odd value capacitors. I really have to get on this build...it's been sitting a long time.
Title: Re: TG1 - advice from any one who has built it...
Post by: SLB on April 13, 2013, 07:06:16 PM
You are correct. I will post the setup procedure when I get soon.
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on April 13, 2013, 07:40:29 PM
Great!
Title: Re: TG1 - advice from any one who has built it...
Post by: SLB on April 13, 2013, 08:25:28 PM
This is the setup procedure I came up with by reading festers instruction and studying the schematic.

Set up procedure.

1. Make sure you have +28Vdc and -28Vdc on the power supply PCB.

2. Set the +20Vdc on test point TP+20 by adding in resistors on JP1, JP2 and JP3 as required.

3. Set the -20Vdc on test point TP-20 by adding in resistors on JP4, JP5 and JP6 as required.

4. Install resistor in AOT10 so that the dc voltage on the collector of VT5 and VT6 are the same.

5. Set unity gain. Set HOLD and OUTPUT to 0 and switch the compressor side chain out by selecting THD. If you have the correct 2.5mA FS meter it should read zero, if not adjust the 100K trim pot until it does. Apply 0dBu (0.775V) 1KHz sine wave to input and measure the output on a oscilloscope or DMM. You need to adjust AOT1/AOT2 so that you get 0.775V at the output.

6. Set distortion without compression. Set HOLD to +10, OUTPUT to 0 and switch the compressor side chain out by selecting THD. If you have the correct 2.5mA FS meter it should read +10. Apply 0dBu (0.775V) 1KHz sine wave to input and measure the output on a distortion meter and select a resistance for AOT7/AOT9 that gives you the lowest distortion reading.

7. Set distortion with 20dB of compression. Set HOLD to +10, OUTPUT to 0 and switch the compressor side chain in by selecting LIMIT. If you have the correct 2.5mA FS meter it should read +10. Apply 1KHz sine wave to input and increase the voltage so that you have 20dB of gain reduction as indicated on the meter. If you have the correct 2.5mA FS meter it should read -10. Measure the output on a distortion meter and select a resistance for AOT8 that gives you the lowest distortion reading.

8. AOT3/AOT4 adjusts the compressor threshold. This is a matter of taste. I left mine standard.

9. AOT5/AOT6 adjusts the limiter threshold. This is a matter of taste. I set my unit to limit harder by changing the resistors to suit.

If you don’t have a distortion meter (like me) use the standard values. When I set my TG12413 up I did so with the bypass PCB disconnected. That way the test signal is going straight into and out of the compressor without being boosted or attenuated the OP amps or transformers.

Here are the values I used.

AOT1 620r (Unity Gain)
AOT2 not used
AOT3 47K (Compressor Threshold standard value)
AOT4 (Compressor Threshold not used)
AOT5 3K (Limiter Threshold standard value)
AOT6 510r (Limiter Threshold, make the unit limit more in limit mode)
AOT7 33K (Distortion without compression, standard value)
AOT8 68K (Distortion without compression, standard value)
AOT9 (Not Used)
AOT10 10r (DC voltage on the collector of VT5 and VT6 are the same)

I have also attached the procedure as a pdf.

Regards,
Brezo
Title: Re: TG1 - advice from any one who has built it...
Post by: Majestic12 on April 15, 2013, 01:11:25 AM

2. Set the +20Vdc on test point TP+20 by adding in resistors on JP1, JP2 and JP3 as required.

3. Set the -20Vdc on test point TP-20 by adding in resistors on JP4, JP5 and JP6 as required.


What exactly do you mean with "resistors as required" at JP1, JP2 etc. ?
Title: Re: TG1 - advice from any one who has built it...
Post by: baadc0de on April 15, 2013, 05:18:15 AM

2. Set the +20Vdc on test point TP+20 by adding in resistors on JP1, JP2 and JP3 as required.

3. Set the -20Vdc on test point TP-20 by adding in resistors on JP4, JP5 and JP6 as required.


What exactly do you mean with "resistors as required" at JP1, JP2 etc. ?


JP1..6 are headers that can be jumped or not. Depending on how many you jump or have open, output voltage changes. So you just get 6 jumpers and put them in one by one, measuring inbetween. When it hits the desired voltage at test point, you win :)
Title: Re: TG1 - advice from any one who has built it...
Post by: SLB on April 15, 2013, 05:33:16 AM
Please see attached picture for better explanation. This is a simple voltage regulator circuit and by adding resistance in parallel you are controlling the base voltage of the transistor which is part of a voltage divider. Think of it as a variable voltage divider. I'm no expert but thats how I see it.

1. Start with only JP1 and JP5 link in.
2. Make sure you have +28Vdc and -28Vdc on the main power connections.
3. Measure dc voltage on -20V and +20V test points.
4. If voltage is out add another link and check voltage.
5. Repeat process until voltage is close to 20V.

Regards,
Brezo
Title: Re: TG1 - advice from any one who has built it...
Post by: dirty1_1garry on April 22, 2013, 03:07:53 PM
Hello TG's guys!

In the final process of assemble the mother board.
I bought vintage semi kit from Frank that contains BC109 and BCY71. I done a HFE measurements all of them with multimeter.
I know that some of VT's should be paired, so that was my main purpose - find a pairs. But if I know hfe of all VT's may be anyone know some secret:
at what places it could be more suitable to use VT's with less hfe and where with more hfs?!  :o
Title: Re: TG1 - advice from any one who has built it...
Post by: dirty1_1garry on April 26, 2013, 10:54:29 AM
Anybody... anybody?  :o
Title: Re: TG1 - advice from any one who has built it...
Post by: warpie on April 26, 2013, 11:03:33 AM
I know that some of VT's should be paired,

which VTs should be paired?
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on April 26, 2013, 11:06:45 AM
This is the setup procedure I came up with by reading festers instruction and studying the schematic.

Set up procedure.

1. Make sure you have +28Vdc and -28Vdc on the power supply PCB.

2. Set the +20Vdc on test point TP+20 by adding in resistors on JP1, JP2 and JP3 as required.

3. Set the -20Vdc on test point TP-20 by adding in resistors on JP4, JP5 and JP6 as required.

4. Install resistor in AOT10 so that the dc voltage on the collector of VT5 and VT6 are the same.

5. Set unity gain. Set HOLD and OUTPUT to 0 and switch the compressor side chain out by selecting THD. If you have the correct 2.5mA FS meter it should read zero, if not adjust the 100K trim pot until it does. Apply 0dBu (0.775V) 1KHz sine wave to input and measure the output on a oscilloscope or DMM. You need to adjust AOT1/AOT2 so that you get 0.775V at the output.

6. Set distortion without compression. Set HOLD to +10, OUTPUT to 0 and switch the compressor side chain out by selecting THD. If you have the correct 2.5mA FS meter it should read +10. Apply 0dBu (0.775V) 1KHz sine wave to input and measure the output on a distortion meter and select a resistance for AOT7/AOT9 that gives you the lowest distortion reading.

7. Set distortion with 20dB of compression. Set HOLD to +10, OUTPUT to 0 and switch the compressor side chain in by selecting LIMIT. If you have the correct 2.5mA FS meter it should read +10. Apply 1KHz sine wave to input and increase the voltage so that you have 20dB of gain reduction as indicated on the meter. If you have the correct 2.5mA FS meter it should read -10. Measure the output on a distortion meter and select a resistance for AOT8 that gives you the lowest distortion reading.

8. AOT3/AOT4 adjusts the compressor threshold. This is a matter of taste. I left mine standard.

9. AOT5/AOT6 adjusts the limiter threshold. This is a matter of taste. I set my unit to limit harder by changing the resistors to suit.

If you don’t have a distortion meter (like me) use the standard values. When I set my TG12413 up I did so with the bypass PCB disconnected. That way the test signal is going straight into and out of the compressor without being boosted or attenuated the OP amps or transformers.

Here are the values I used.

AOT1 620r (Unity Gain)
AOT2 not used
AOT3 47K (Compressor Threshold standard value)
AOT4 (Compressor Threshold not used)
AOT5 3K (Limiter Threshold standard value)
AOT6 510r (Limiter Threshold, make the unit limit more in limit mode)
AOT7 33K (Distortion without compression, standard value)
AOT8 68K (Distortion without compression, standard value)
AOT9 (Not Used)
AOT10 10r (DC voltage on the collector of VT5 and VT6 are the same)

I have also attached the procedure as a pdf.

Regards,
Brezo

Nice!  Thank you.
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: dirty1_1garry on April 27, 2013, 04:39:20 AM
I know that some of VT's should be paired,

which VTs should be paired?

I heard about this paired VT's:
VT5 - VT6
VT13 - VT14
VT18 -  VT19
Title: Re: TG1 - advice from any one who has built it...
Post by: warpie on April 27, 2013, 06:00:51 AM
I heard about this paired VT's:
VT5 - VT6
VT13 - VT14
VT18 -  VT19

thanks :)
I probably missed that..

Title: Re: TG1 - advice from any one who has built it...
Post by: late on May 04, 2013, 03:47:40 PM
I cant find info about R115. As i understand it is needed when using hold switch. How to find right value for R115?
Title: Re: TG1 - advice from any one who has built it...
Post by: SLB on May 04, 2013, 04:06:51 PM
From Festers build docs.

Original units were transformerless, and used HOLD control (10k lin pot).

Fester's clones can be built either with input pot or hold control.
Actually, HOLD control gives better s/n ratio, less unwanted distortion,
and closer to original units sound.
10k lin potentiometer used in EMI units, gives control range more than 40db.
To get more precision in range of +/-15 db gain,
5k log pot connected in series with 5k resistor can be good option.
To get precision steps, possible to use switch,
however, you'll need to connect 10k pot and measure its value at every step,
because control voltage depends on zener diodes used.
1n751a is very close substitute to HS2051.
Optional 100-200k /HOLD trimer can be installed on front pannel
board to adjust both channels for precision "0" at the same position
of HOLD control. It connected in parallel to HOLD and "shifts" its "center".

I jumped R115 and used a 10K lin pot and it works perfectly.

Regards,
Brezo
Title: Re: TG1 - advice from any one who has built it...
Post by: late on May 07, 2013, 09:20:14 PM
Thanks SLB. What transformers people have used? I've looked sowter, edcor and carnhill transformers. Carnhill VTB9071 input and VTB2280 output for 1:1 setup. Should work well? Sowter is more expensive and maybe is edcor too cheap or are they good?
Title: Re: TG1 - advice from any one who has built it...
Post by: jplebre on May 12, 2013, 06:19:08 PM
Hey guys, just confused about something
A lot of people seem to have trouble with the hold switch, Since this is 10 resistors for 11 positions (position 1 is 0ohm)  and is 10k linear, shouldn't it be 1k resistors per step?

1- 0
2- 1k
3- 2k
4- 3k
5- 4k

- 6- 5k -

7- 6k
8- 7k
9- 8k
10- 9k
11- 10k

?
Title: Re: TG1 - advice from any one who has built it...
Post by: late on May 12, 2013, 06:53:36 PM
Hey guys, just confused about something
A lot of people seem to have trouble with the hold switch, Since this is 10 resistors for 11 positions (position 1 is 0ohm)  and is 10k linear, shouldn't it be 1k resistors per step?

1- 0
2- 1k
3- 2k
4- 3k
5- 4k

- 6- 5k -

7- 6k
8- 7k
9- 8k
10- 9k
11- 10k

?

Hi

http://twin-x.com/groupdiy/displayimage.php?album=325&pos=4

Hold values are marked on that schematic file.
Title: Re: TG1 - advice from any one who has built it...
Post by: jplebre on May 13, 2013, 01:44:57 AM
Hi Late!! Ty!! I thought I had downloaded everything from that page.

Hmmm These values look more like Log ladder to me and do explain why Rob Flinn said he could only get to 9.67k earlier this post.
What did people go with for the 10k hold option?

@Late, I'm going edcor for input, VTB2280 for o/p. I've used Edcors on my LA2A's and they are pretty good, specially for the price!!!
R115 is either jumped for 10k hold or 5k for 5k hold.

Cheers
J

Title: Re: TG1 - advice from any one who has built it...
Post by: late on May 15, 2013, 04:29:50 AM
Is it possible to use 21step switch? And can i use 10k pot with it if i have did hold fix for the panel pcb. Or do i need remove that fix?
Title: Re: TG1 - advice from any one who has built it...
Post by: peskado on May 15, 2013, 04:41:50 AM
im used 21 step for hold
20 x 499ohm
Title: Re: TG1 - advice from any one who has built it...
Post by: jplebre on May 15, 2013, 05:29:42 AM
im used 21 step for hold
20 x 499ohm

I might upgrade to that at some point. Too expensive as it is at the moment.
Title: Re: TG1 - advice from any one who has built it...
Post by: jplebre on May 15, 2013, 05:30:34 AM
Is it possible to use 21step switch? And can i use 10k pot with it if i have did hold fix for the panel pcb. Or do i need remove that fix?
the fix is for hold - either Pot, 11 position or 21. Just break off the PCB and replace.

Title: Re: TG1 - advice from any one who has built it...
Post by: peskado on May 15, 2013, 06:10:08 AM
im used uraltone)
Title: Re: TG1 - advice from any one who has built it...
Post by: late on May 15, 2013, 06:44:50 AM
So step 1 is 0ohm and everyone from 2-21 are 499ohm?
Title: Re: TG1 - advice from any one who has built it...
Post by: peskado on May 15, 2013, 07:06:24 AM
yes, 2-21 499ohm, total 10k
Title: Re: TG1 - advice from any one who has built it...
Post by: jplebre on May 15, 2013, 07:11:44 AM
That's why I was confused as the other values you said earlier was more of a  logarithmic aproach - when it should be linear.

I'm populating Igor's PCB with the suggested values on the schematic, and I got a few lorlins where I'm populating with 10x 1k and I'll try both see what feels better.
Title: Re: TG1 - advice from any one who has built it...
Post by: late on May 17, 2013, 12:55:18 PM
Original unit uses 21 position hold switch? I tried to google but can't find what values.
Title: Re: TG1 - advice from any one who has built it...
Post by: jplebre on May 17, 2013, 04:39:28 PM
original uses pot I belive
Title: Re: TG1 - advice from any one who has built it...
Post by: late on May 17, 2013, 04:54:48 PM
original uses pot I belive

First 1969 version uses switch. But can't find what kind switch.
Title: Re: TG1 - advice from any one who has built it...
Post by: jplebre on May 21, 2013, 03:33:53 PM
Right guys need a bit of help here. I'll try to write it so you can teach me how to fish, rather than just blurb out an answer.

Both channels populated at same time. Voltages check @supply points, jumpers done so +20 is reading +20, -20 is reading -20.30 (very close for both channels).

Symptom: both channels have a huge drop in level, of about 20 dB if hold set to 0 and O/p set to 0. O/p to +10 and hold to +10 will almost bring the signal to "level).

I traced the signal through the pad where it drops aprox. 9dB. (eg. a .750v signal drops to .230 ish). Signal reacts to hold changes on TPC and B. tracing the signal to the S3 pad it never boosts the 9dB it should in VT9.
But maybe I'm doing it wrong. Where should the signal get boosted? at collector of VT10, VT9 or VT8?

So signal reaches S3 at 222v or lower.

With no signal present, the voltages match the dribbles done by igor on the "resharpened cooking recipe" schematic (+-1v in some places).

Hold is a 9.4v measure at point 6 of the jumper. But this drops in level as hold goes down. I thought that that was a constant potential and only the wiper should change the voltage?

Any help would be grand!
Title: Re: TG1 - advice from any one who has built it...
Post by: jplebre on May 22, 2013, 03:47:38 AM
To make things more interesting - seems gain is kept on THD mode.
So issue either on sidechain (Aot1?? earlier? can't really tell how to troubleshoot this as it's a feedback compressor) or Vt8/VT10/VT9 issue?

Ideas? :)
Title: Re: TG1 - advice from any one who has built it...
Post by: imo on May 22, 2013, 06:03:12 PM
hello,
I am finally getting my TG1 500 going. There are a few differences with the 500 from the rackmount, but fundamentally is the same.
I am good on my +20 points, and my VT4-5 are balanced. The unit seems to be working properly. I am having a weird issue with the relays however. They are set to default to bypass, but when i short the "bypass" switch to pull the circuit in, the switch still stays in bypass. I can hear the relay clicking a little, but it doesn't seem to throw the switch. I have temporarily pulled them out of circuit to check the rest of the unit, and from what i can gather it is working properly. I am able to see the affects of adjusting hold, input output, etc.
Before is start tearing this thing apart, does anyone have any obvious points to check?
the lm317 seems to be working, but the measurements seem quite off. 16vDC at input, adjust is -11.55, and out is -5v
I am using a 3.9k resistor as the adjust. Also i have tried replacing both the .1cap and the 4148 diode. When i first replaced the diode i briefly had -16v on both sides, but now i am back to -11.55 on cathode side and 16 on anode.. are my 4148's faulty, or does this sounds like the 317?
Thanks
Ian
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on May 22, 2013, 06:22:57 PM
Is the relay coil resistance greater than 700 Ohms?
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: Harpo on May 22, 2013, 06:25:35 PM
the lm317 seems to be working, but the measurements seem quite off. 16vDC at input, adjust is -11.55, and out is -5v
I am using a 3.9k resistor as the adjust. Also i have tried replacing both the .1cap and the 4148 diode. When i first replaced the diode i briefly had -16v on both sides, but now i am back to -11.55 on cathode side and 16 on anode.. are my 4148's faulty, or does this sounds like the 317?
I am not building this unit, but from schematic the LM317 is not set up as a voltage regulator but for a [1.25Vref/3K9]=0.32mA constant current regulator. 0.32mA won't operate your relais coils, so this 3K9 is way too high.
Title: Re: TG1 - advice from any one who has built it...
Post by: jplebre on May 22, 2013, 06:27:02 PM
shouldnt the LM317 be positive? not negative?
Title: Re: TG1 - advice from any one who has built it...
Post by: late on May 22, 2013, 06:57:53 PM
Anyone have used Hairball 8020 meter?

To adjust the metar, use 500R-1k 10turn pot in parallel. But how?
Title: Re: TG1 - advice from any one who has built it...
Post by: jplebre on May 23, 2013, 01:52:15 AM
Anyone have used Hairball 8020 meter?

To adjust the metar, use 500R-1k 10turn pot in parallel. But how?

You needed to have another pot in paralell so you could compensate the amperage, as well as some place to put the meter in series to see if you are actually going for 1mA

Found post here: http://www.groupdiy.com/index.php?topic=37400.msg653727#msg653727

Edit2: haven't done it yet. I'm busy for the next few weeks so I'm hoping week after next one I get to do this.
Title: Re: TG1 - advice from any one who has built it...
Post by: jplebre on May 23, 2013, 02:05:38 AM
OK new developments on my issue - more info on what the problem actually is:
It seems all is fine but the compressor is compressing signals at -2dBu. If I actually feed a sine wave to a signal under -25dBFS (on my sound card, callibrated for -20dBfs) there's no loss

Now, before I thinker with anything, could someone please confirm if this is this normal?
If it's indeed an issue I'm thinking it's probably a calibration issue: either with AOT 3/4, 5/6 (it does make a difference in the overal level if I'm in limit or compression) or unity gain with AOT1,2?

I'm more inclined to think AOT3/4 5/6 because When switching to THD, all is good (no loss no matter what level) so I'm guessing it's either around VT9 (make up stage on signal path) or something related with the sidechain.

Also, if someone could confirm this based on experience with chandler/original/festers:
- when using Hold, the top of the potentiometer changes voltage as well. SHould it remain fix at 10v and only the wiper change voltage?
- Hold control not doing much. (note: i don't have the meters working yet, so I can't actually see. But by hear, only the last 3 steps really do a difference).
- Original attack time speed quite slow (both on Lim/Comp mode?)

Compression is sweet. If you are holding off building this guy don't as it's pretty "special"

If you guys could help confirm the above would be a great help on the troubleshoot process :)

Thanks
Title: Re: TG1 - advice from any one who has built it...
Post by: imo on May 23, 2013, 03:29:16 AM
yes, thanks Harpo. I couldn't find any ref on the relay and had way too big of a resistor in there.
I have the relays working. I have the voltages straight at all the test points on the main board. I did notice however that the current on the negative side of the 24v rail is low. I measured 120mA on the +24 side, but only about 55mA on the -24 side. This is with only the main board hooked up. No AC signal
the 4898 is B 19.9 E 20.4 C 9.3
The 4910 is B .6 E 0 C 9.3
the voltages seem right with the emiitter of 4910 at ground, and the base .6v above it. I just wanted to double check before i went any further.
Thanks
Ian
Title: Re: TG1 - advice from any one who has built it...
Post by: jplebre on May 27, 2013, 05:18:28 PM
I want to ask if everyone has cracked the code on:
Quote
1). +/-20v
JP1...6, TP+20v, TP-20v
2).Unity gain
Initial gain is set by AOT1,2
3).Distortion w/o compression
minimum distortion adjustment AOT 7,9
4).Distortion at 20dB GR
distortion under hard compression adjusted by AOT8/10, usually 10R is fine
5).Com threshold
Com threshold adjustment: AOT3,4
6).Lim threshold
Lim threshold set by AOT5,6.
7).Check: reqresp, max gain, min gain, S/N, timeconstants.


I've been PM'ing several members and my feeling - either because they admited or from their "I guess so" or "I think that" is that the above is not straight forward.
There are members here that said that they went around in circles adjusting. Now, I'm having a bit of a hard time even understanding where to start as some things - even w Igor's description - don't make much sense to me.

I would love if it got to the point where we could maybe do some sort of a meta post on this ;) where everything get's explained a bit better.

You all know my problems on this. Signal get's dropped to -6VU if the i/p signal is higher than that. Hold does very little except for the last few steps - every other step seems to simply bring signal further down. On Limiter mode, the signal is slightly higer (by about 4dB) than the -6VU on compress. On THD mode the signal keeps a consistent level.

Now, here's the bits that are hazy:
2) Unity gain - but AOT1,2 is on the sidechain. So how exactly does it impact on gain?
on my example, disabling sidechain (THD mode) is ok signal wise, but compression engaged the level is way too low. No gain make up is present on VT9 (which should be happening according to EMI docs
So what is this? a make up? an offset for the threshold?

3) distortion w/out compression. does this mean common mode rejection?

5) 6) Thresholds.
But what should these be set to? 0vu? +4? +10? -10????
Am I understanding correctly that the Hold would be slamming the quiescent amplification forcing the signal to hit the threshold?

I'm struggling to understand what the unit should be doing, therefore struggling to know how to troubleshoot :P

Am I alone?

Title: Re: TG1 - advice from any one who has built it...
Post by: late on May 28, 2013, 10:49:10 AM
LL1540 is compatible with 10k:10k configuration? Just need use 12k resistors.

Like here is suggested connections:
http://www.lundahl.se/pdf/1540.pdf

jblebre: I also would like to know more about that calibration procedure.
Title: Re: TG1 - advice from any one who has built it...
Post by: jplebre on May 28, 2013, 11:49:28 AM
the document you have states that each primary is 610 and each secondary is 800ohms
Not sure this would do if you are going for 10k:10k input for 1:1 gain i/p - o/p solution
Title: Re: TG1 - advice from any one who has built it...
Post by: jplebre on May 30, 2013, 06:05:57 PM
Should the nominal +10vDC (near R115*/R63, "live" end of hold pot) stay put?
Looking at the schematic, seems like it should remain +10vDC regardless of the position of the wiper for hold control, but then again there is some sort of feedback to the base of VT20 so I'm not sure.

Can someone confirm if the 10vdc should remain fixed or vary depending on the position of the hold pot?


EDIT: following Fester's TG fix, there's an extra cut that needs to be done. The trimmer resistor side "1" goes to the 270ohm resistor. This needs to be cut as well.
I can now measure a fixed 9.7v ish on the hold circuit, regardless where the wiper is. The wiper now does it's thing correctly.

The CV voltage seems to be fixed at about 5v. Shouldn't it follow the hold control?

Thanks
Title: Re: TG1 - advice from any one who has built it...
Post by: imo on June 05, 2013, 12:13:44 AM
I consider it a small miracle, but i have a somewhat working 500 series TG1. I agree that we should aggregate some standardized setup procedures. I have the right voltage as per Igor's notes. I've also got my meter going (used a 1mA meter) but beyond that I'm trying to decipher the original schematic with voltages(hard to see) to see if everything is in line. Right now the only thing jumping out to me as out of line is this: i have 13vDC on the top of the hold pot where it should be 10. The 500 series has both an input pot and a hold pot(as well as a hold trimmer). I've been messing with the trimmer/pot combo to see what effect it had, but still somewhat unsure.
Igor's instructions are pretty cloudy. He says to set unity gain with the hold control in the middle(doesn't mention anything about the 10k hold trimpot). and to move the hold control around until you get unity(with AOT1 trim). That seems pretty loose..Is this really the way you calibrate this unit?

Any setup comments, general comments about the circuit would be VERY welcome!
Title: Re: TG1 - advice from any one who has built it...
Post by: jplebre on June 05, 2013, 02:24:58 AM
if it's anything like the rack unit, the hold trimmer should be set to one of the sides. so it doesn't add parallell resistance.
You can use this trimmer to match for stereo operation.

Where are the documents for the 500 series? it might shed some light on the issues I'm having
Title: Re: TG1 - advice from any one who has built it...
Post by: imo on June 05, 2013, 04:22:03 AM
Here are where the files are: https://drive.google.com/folderview?id=0B9HeCk99hJfqYXRyTWppcjJIVm8&usp=sharing

So, I've been tearing this thing back apart, trying to properly calibrate it. In one of the many dismemberments, i have done something...Not exactly sure.
I am able to see a signal all the way to the input of C21/R65, which is the collector of the output transistors(4898 and 4910). the voltage is dropping to around .7vDC, which is down from 9-10(which is where it should be). The obvious sign is that the transistors are blown, right? I checked them with my transistor checker and they both check fine though. ?????
I was going to order the MJE2955TTU and MJE3055TTU, but these are only available in to-220. would this do with good heatsinks?
Everything was working previously, so i am assuming they must have sourced too much current and died?
I guess i'm looking for a confirmation before i desolder for the 4th time<g. Any ideas?
Thanks
Ian

I had them mounted originally with mica insulators underneath. There is a solid connection to the collector through the screws
Title: Re: TG1 - advice from any one who has built it...
Post by: imo on June 05, 2013, 11:40:49 PM
I have another question regarding the meter:
I was able to set up my 1mA meter via the diagram. I used a 2k resistor in series to the positive terminal of the meter, and then the 200r trimmer and 22r resistor. I was able to trim the meter to full scale deflection at 2.4mA. In circuit the meter is barely registering at any settings. My schematic has a 200r trimmer already installed with the 22r. Do I measure my test rig and then set the trimmer for the same resistance that i am getting at FSD?
Thanks
Ian
Title: Re: TG1 - advice from any one who has built it...
Post by: jplebre on June 06, 2013, 12:03:37 PM
My schematic has a 200r trimmer already installed with the 22r.

If it already has it, then that's it. You just need the total "right" resistance in parallel to the meter.
But I have to say it wasn't enough that. I need to try what igor said on another post "To adjust the metar, use 500R-1k 10turn pot in parallel."
Title: Re: TG1 - advice from any one who has built it...
Post by: imo on June 06, 2013, 03:07:53 PM
I figured it out. I had to temporarily strap a 2k onto the anode side of the diode that is across the meter. I also put a 200r trimmer across the meter in parallel with the 200+51r that is already there. I was able to get the right current at about 42r. Ill keep the trimmer in for now. Its a bit clunky, but it works
I'm trying to get an idea of the range of the hold pot. I am seeing from about 2v to 5.6v on the CV depending on the throw. Anyone see anything similar?
Title: Re: TG1 - advice from any one who has built it...
Post by: jplebre on June 06, 2013, 03:55:35 PM
.3v to 5.8v

However, I followed rev2 schematic for igor where the values are logaritmic. So my -10 would actually be much lower than a linear 10k pot.
I'm also having trouble with my signal (almost 20dB) so might not be right.
Title: Re: TG1 - advice from any one who has built it...
Post by: jplebre on June 06, 2013, 04:59:10 PM
IMO, thanks for the link. There were pics of the callibration procedure that really helped out!

I noticed Igor's quote on:
t_g, t_e are approx. 3.2V RMS, same amplitude (+/-1%)


Now, on my unit, they are at abou 3.3v RMS same amplitude, but they are out of phase.

Any ideas if this is normal and I am mis interpreting Igor's sentence. If it's not normal, ideas on how this could happen?

J
Title: Re: TG1 - advice from any one who has built it...
Post by: baadc0de on June 08, 2013, 11:18:27 AM
Great to know it's not that uncommon...!

I have for now put two philips BC capacitors (1000uF) in antiseries, which gives about 500uF of capacitance but blocks DC both ways. I'll let you know if it helps any.. the output transistors are NOS Motorola ones from electrochronic as are the rest of transistors.

The reason to put in another capacitor - a fake bipolar one - is because in the previous configuration it smoked not only R77 but also a winding on the output transformer (which now reads open). So this is more intended to protect the trafo. If anyone came to a solution to this, please let me know!

One interesting problem for the crowd here, maybe someone has any ideas..

Sometimes, when excessive low frequency information is in the input (such as from a preamp when recording a kick drum or direct bass guitar) and the gain reduction is set to a slow enough attack and quite a bit of makeup, the TG1 starts smoking R77. Could the output transistor pair be somehow to blame? I don't know enough about transistors, but say if one of them faults into being a straight line for a time?

It all works out if I power it off for some time. The output transistors are not heatsinked, maybe I should do that?

Thanks!

Ha! welcome! You're not alone. I've been mentioning this problem for quite a while but unfortunately it looks like a mystery :)

http://www.groupdiy.com/index.php?topic=37400.msg512287#msg512287
http://www.groupdiy.com/index.php?topic=48297.msg617261#msg617261

I'm pretty sure it's not a heat problem as I'm using heatsinks on the transistors. What transistors do you use?
What wattage is the 56ohms resistor? Do you have good heatsink on the PSU regulators?

In my case a 2watt resistor with a BIG heatsink on the regulators gives me a maximum of around 40C which I suppose it's OK.

Still though, I don't know what causes it.  ::)

Good luck and let me know. It's been my nightmare for more than two years now  ;D
It'll be good if other people can report too.

Turned out to be a nasty short in the output transistor wiring, that occured only under certain (thermal??) circumstances.
Title: Re: TG1 - advice from any one who has built it...
Post by: imo on June 09, 2013, 01:55:01 PM
I think i am having a similar issue with my unit. I am having occasional dropouts that seem to be the output transistors shutting down.
The 500 series is pretty tight for space. Still trying to find a heatsink solution. Right now i have both the transistors off the board with a couple of washers and a nut. That helps a bit and stopped them from shutting down so easily. This is what made me earlier think that i had blown them. I think they were sourcing too much current, and i am now seeing this occasionally when i turn up the hold control all the way up. Is anyone using the TO220 versions of these transistors? I am thinking in this design i could heatsink them better, but it seems that the TO3 is physically a better solution for current and heat.
Title: Re: TG1 - advice from any one who has built it...
Post by: dirty1_1garry on June 11, 2013, 01:49:51 PM
Hello TG's guys!

Could anyone of you post voltages on all T_* points of TG schematic with 0.775V input signal?!
Really need to compare!
Title: Re: TG1 - advice from any one who has built it...
Post by: jplebre on June 15, 2013, 02:00:32 PM
Hello, can someone raise their hands if they got a rack version 1.2 (fester unlimited) working just by populating boards and doing the hold fix?
Of the lack of starting looking at traces on PCBs, I tried everything but the signal is dead quiet and can't for the life of me figure this thing out :P

Title: Re: TG1 - advice from any one who has built it...
Post by: warpie on July 04, 2013, 05:49:10 AM
So, the last few days I've been reading about different types of amplifiers and by checking the schematic I can't figure what class this circuit is  :o

Looks like Class A but is it really?

Any idea?  :)
Title: Re: TG1 - advice from any one who has built it...
Post by: etheory on August 06, 2013, 07:15:54 PM
I've just completed an LTSpice simulation of the entire circuit, as I prepare to build mine at some point soon (crosses fingers).
The simulation works perfectly (as I guess you'd expect).

The process and discoveries I've made during simulation I am hoping will help me to choose the right AOT resistors (the descriptions I've read and found so far are OK, but they don't truly help me understand what the circuit it really doing).
However I'll share anything I find and write a very thorough description of exactly how to choose the AOT resistors, a detailed calibration procedure and an even more comprehensive description of how the circuit works than I've seen so far.

What I didn't realize before was that essentially the main gain element is a long-tailed npn pair with a pair of zeners in each of their collectors.
The tail current is varied, which changes the current through the zeners, hence changing their resistance, hence changing the gain of the stage.

In a way this shares a lot topologically with something like a diode-based VCF like the EMS Style VCF's - which I wasn't expecting at ALL.
I think the way the original schematic is drawn partially obscures this fact, but if you lay it out slightly differently, it's clearer that this is how it works.

Very cool.

Anyone have a preference for the 600:600 output transformer to use? I was looking at edcor/carnhill but if there is something that really shines here I'd love to know!
Title: Re: TG1 - advice from any one who has built it...
Post by: etheory on August 07, 2013, 07:55:02 PM
Crazily enough, the simulation not only works and compresses, but reveals a LOT about the circuit operation.
I'll write up something soon once I "calibrate the simulation".

I am still surprised at how similar the circuit is to a synthesizer VCA.
I expected some crazy magical circuit design, but it really is pretty simple stuff!

I think replacing most of the AOT resistors for trimmers is probably a really good option too.
Title: Re: TG1 - advice from any one who has built it...
Post by: haima on August 07, 2013, 08:40:36 PM
This is VERY cool etheory! Keep us posted :)
Title: Re: TG1 - advice from any one who has built it...
Post by: etheory on August 08, 2013, 08:58:05 AM
Looks like Class A but is it really?
Any idea?  :)

I take it you are specifically talking about the output amplifier correct?

It is "Class A" (whatever that is) in my definition if the transistors don't turn off throughout a full cycle of a sinewave.
I mean, it gets funky when you talk A/B cause things are kind of off and kind of on, yadda yadda.

By my loose definition, yes, this is Class A, up until it outputs around +-9V into 600ohms at which point the waveform initally clips asymmetrically, and then rather abruptly top and bottom, at which point the output transistors start looking more like they are conducting in Class B for the tiniest portion where they share the waveform duties, then the entire thing falls into a screaming clipping heap around +-11V. Not that outputting those sort of voltages before clipping is anything to scoff at. It's a pretty cool amplifier design, and seems to perform very very nicely on the simulator.

This is all very hand-wavy, but, long story short, it kinda sorta basically is Class A, yes.
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on August 08, 2013, 09:34:54 AM
I've just completed an LTSpice simulation of the entire circuit, as I prepare to build mine at some point soon (crosses fingers).
The simulation works perfectly (as I guess you'd expect).

The process and discoveries I've made during simulation I am hoping will help me to choose the right AOT resistors (the descriptions I've read and found so far are OK, but they don't truly help me understand what the circuit it really doing).
However I'll share anything I find and write a very thorough description of exactly how to choose the AOT resistors, a detailed calibration procedure and an even more comprehensive description of how the circuit works than I've seen so far.

What I didn't realize before was that essentially the main gain element is a long-tailed npn pair with a pair of zeners in each of their collectors.
The tail current is varied, which changes the current through the zeners, hence changing their resistance, hence changing the gain of the stage.

In a way this shares a lot topologically with something like a diode-based VCF like the EMS Style VCF's - which I wasn't expecting at ALL.
I think the way the original schematic is drawn partially obscures this fact, but if you lay it out slightly differently, it's clearer that this is how it works.

Very cool.

Anyone have a preference for the 600:600 output transformer to use? I was looking at edcor/carnhill but if there is something that really shines here I'd love to know!

Thanks for doing all of this work.  It's going to inspire me to dust off my boards, heat up the iron, and put some together.
Best,
Bruno2000

Title: Re: TG1 - advice from any one who has built it...
Post by: Biasrocks on August 08, 2013, 11:20:52 AM
Anyone have a preference for the 600:600 output transformer to use? I was looking at edcor/carnhill but if there is something that really shines here I'd love to know!

I ended up using a 1166 type transformer with a step up, works a treat.

Hairball has one.

http://www.hairballaudio.com/shop/product_info.php?cPath=24&products_id=63

Regards,
Mark
Title: Re: TG1 - advice from any one who has built it...
Post by: late on August 09, 2013, 01:14:49 PM
What is standard value for AOT7?

In Igor's docs it is 3.3k but SLB said that it is 33k.

I get +27,5 and - 27,6 from my psu, is it ok? Or do i need get it closer 28?
Title: Re: TG1 - advice from any one who has built it...
Post by: late on August 10, 2013, 11:21:53 AM
One more thing. Can i calibrate vu meter that way?

Send 1khz 0.775v to TG1 and switch it to THD mode. Then trim with 100k trim that the output is same.

Then trim vu meter with 22R and 200R trim that it shows "0". Like in this picture.
http://i50.tinypic.com/wv4vu8.jpg

Does this works?
Title: Re: TG1 - advice from any one who has built it...
Post by: etheory on August 11, 2013, 07:13:03 PM
What is standard value for AOT7?

Forgive me if you know this already, but each AOT resistor specified in the circuit would have a different "standard" or, better put, "starting" value.
I found some info in Igor's docs about what he generally uses for these, but it's supposed to be based on measurement.

I get +27,5 and - 27,6 from my psu, is it ok? Or do i need get it closer 28?

Those values are within 2% of what they should be. That's pretty close if you ask me, I'd say you are fine.
Title: Re: TG1 - advice from any one who has built it...
Post by: jplebre on August 12, 2013, 05:40:54 AM
etheory, maybe you can help me.
I have a bit of a signal drop. unit works almost as it should but signal is down by about 20dB. I don't seem to have the make up after the gain reduction transistor pair.

VT8, VT10 have signal on their bases, but the collector of VT9 only see's noise on scope.

What should the voltages be around this area?

Or maybe if you have any other idea why there's such a big drop in signal I'm all ears :D
Title: Re: TG1 - advice from any one who has built it...
Post by: etheory on August 12, 2013, 05:18:30 PM
etheory, maybe you can help me.
I have a bit of a signal drop. unit works almost as it should but signal is down by about 20dB. I don't seem to have the make up after the gain reduction transistor pair.

VT8, VT10 have signal on their bases, but the collector of VT9 only see's noise on scope.

What should the voltages be around this area?

Or maybe if you have any other idea why there's such a big drop in signal I'm all ears :D

VT9 is basically a current source for VT8 and VT10, so it will have a pretty small signal as a voltage, but be providing around 1.6mA of current.
Check the voltage across R27, the 12K resistor, is it around 20V?
Check that R23 and R26 are 3.3K
Check that R22 and R25 are 7.5K
You should see a small audio signal across R22 and R25 and about 6V of difference across them.
Title: Re: TG1 - advice from any one who has built it...
Post by: late on August 18, 2013, 05:54:47 PM
I have weird thing. If send audio to channel 1, same signal comes out from channel 2 a little bit. I thing it come by ground some how. What is wrong?
Title: Re: TG1 - advice from any one who has built it...
Post by: jplebre on August 19, 2013, 04:54:33 AM
I have weird thing. If send audio to channel 1, same signal comes out from channel 2 a little bit. I thing it come by ground some how. What is wrong?
Are you sharing the main board power?
you should be linking pSU -> main board -> input board
not PSU-> main board -> main board

play with trafo placement. In some units it's enough for crosstalk not sure on this one.

picture of the beast's guts?
:)
Title: Re: TG1 - advice from any one who has built it...
Post by: late on August 19, 2013, 07:52:40 AM
Yes sharing. Now i broke it a little more, shieetjh!! Clean mode wont work anymore. ROP5 burned and maybe relays. Will send pics after i get it fixed.
Title: Re: TG1 - advice from any one who has built it...
Post by: late on August 22, 2013, 04:57:27 PM
Working again. But the second channel compressing/distort way more. Here is the clip. Hold is 10 and attack/release fastest possible.
https://dl.dropboxusercontent.com/u/20579799/TG1.mp3
Title: Re: TG1 - advice from any one who has built it...
Post by: late on October 09, 2013, 03:30:47 PM
Noticed that popping stops when hpf is switched to 40Hz or so. But can't understand what doing this.
Title: Re: TG1 - advice from any one who has built it...
Post by: thomasdf on October 10, 2013, 05:00:11 AM
I'd like to dive into the building of one of those lovely comp, as I am looking for something colored to put across my mixbus with gentle compression (4dB max). I need to start reading this thread carefully :)
Can someone give an approx overall cost of the build?

Many thanks in advance

Thomas
Title: Re: TG1 - advice from any one who has built it...
Post by: bieckmusic on October 10, 2013, 11:37:45 AM
Hi Thomas,

I love my T G clone!  I don't have transformers installed yet just the 1:1 ratio with IC's per uncle festers notes. 

I purchased the vintage transistor set from Electrochronic, he was very helpful as it's not the easiest build. 

All in I've got about a $1000 into the project, with mirrored vintage style meters, etc...  $80 for a pair of stepped output switches.  My PCBS didn't come with a power supply so i used a Sontec power supply which seems to work fine.

Title: Re: TG1 - advice from any one who has built it...
Post by: thomasdf on October 11, 2013, 06:09:08 AM
Hello
Thanks for your fast answer. That project is a bit more expensive than what I thought (even if I don't necessarily mirrored VU's)... I'll think about it twice. Since I love that comp I'll probably end up building it, but I have a few other piece of gear that I need to take care of first.

Best,

Thomas
Title: Re: TG1 - advice from any one who has built it...
Post by: late on November 07, 2013, 03:19:07 PM
Anyone knows what can cause this
https://dl.dropboxusercontent.com/u/20579799/TG1.mp3

Weird because it stops when set hpf on like 40hz. T_G and T_F are about 5.00v on working channel when hpf off. Bad channel jumping so much that my multimeter shows overload. But when i set hpf 40hz or so then it shows about 5.00v. Anyone have idea what can do this?

Title: Re: TG1 - advice from any one who has built it...
Post by: bieckmusic on November 07, 2013, 09:03:17 PM
sounds like a cool techno remix... sorry couldn't resist.  just wondering, did you do Igor's TG fix mod?
Title: Re: TG1 - advice from any one who has built it...
Post by: late on November 08, 2013, 11:12:45 AM
sounds like a cool techno remix... sorry couldn't resist.  just wondering, did you do Igor's TG fix mod?

Yes. Have tested both channels with same cables and front panel pcbs.
Title: Re: TG1 - advice from any one who has built it...
Post by: Biasrocks on November 09, 2013, 10:40:54 AM
Anyone knows what can cause this
https://dl.dropboxusercontent.com/u/20579799/TG1.mp3

Weird because it stops when set hpf on like 40hz.

DC offset somewhere?

Mark
Title: Re: TG1 - advice from any one who has built it...
Post by: late on November 11, 2013, 05:16:18 PM
I disconnected R3 and R11 so the sidechain was out. Then i soldered them back and it worked well. After 5min it started do that old problem again. Maybe the problem is in sidechain section. But i cant understand where.
Title: Re: TG1 - advice from any one who has built it...
Post by: jplebre on November 11, 2013, 05:39:42 PM
I disconnected R3 and R11 so the sidechain was out. Then i soldered them back and it worked well. After 5min it started do that old problem again. Maybe the problem is in sidechain section. But i cant understand where.
quick question, sorry to hijack your thread
disconnecting R3 and R11, would it give nominal gain through the audio path?
I'm asking this because I'm having terribly low o/p and can't really figure out why.
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on November 11, 2013, 05:49:50 PM
Could someone post a diagram of the "Hold" switch with values for the 5k r/log option?
Thanks!
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: e.oelberg on November 11, 2013, 05:56:55 PM
as far as I remember this ( I built my unit 2 years ago) you can't just use stepped switches. You have to build one and measure every step on the second running signal to get a working stereo unit.

Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on November 11, 2013, 06:02:08 PM
as far as I remember this ( I built my unit 2 years ago) you can't just use stepped switches. You have to build one and measure every step on the second running signal to get a working stereo unit.

Sounds like a plan, but I've got to start with the first switch and have the starting values, but don't know which way they go.
There's also that 100k trimmer across the whole thing.
Thanks for your help!
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: etheory on November 12, 2013, 12:49:23 AM
I've just discovered that in their infinite stupidity Australia Post has returned my meters and hundred of dollars worth of original TG parts for my build to America where I bought them from, without contacting me with any of the 3 required notices of delivery, or managing to find the perfectly filled out address on the package.

Now I will have to wait around 3 months minimum to even know if the package is still available as it is returned via carrier pigeon to sender.

Very very upset since I was sooooo looking forward to getting to this build.

Having said all that, massive thanks to Frank and Bruno2000 for helping me out with finding all the bits. I just hope one day soon I can get them to actually built it  :(
Title: Re: TG1 - advice from any one who has built it...
Post by: jplebre on November 12, 2013, 04:03:59 AM
Hi Bruno

I built it with log values but I'm not happy with the result. Most of the more drastic stuff happens towards the end of the spectrum but the clicks are too far apart to make use of it. By the time it starts to get into the distorting/very coloured range, you have one click at the beginning of that range and then all the way up (smashing).

I have an issue with the gain recovery bit (VT9 section) so it MIGHT be why.

But I am going to swap the hold for a linear, as the original schematic says handwritten and barely visible.

Anyway values are:
330
390
470
620
750
910
1k1
1k8
2k


There's some discussions about this earlier.

Igor also installed a 100k trimmer. This is crucial to get both sides to match!

Cheers
J
Title: Re: TG1 - advice from any one who has built it...
Post by: e.oelberg on November 12, 2013, 04:09:11 AM
I don't know if you need stepped control here. If the unit is in stereo mode, compression is anyway linked and you can set it pretty good with a pot. Stepped output is useful though
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on November 12, 2013, 09:24:27 AM
Thank you both for your replies!  I have the option of Igor's stock 12 position switch in the r/log mode, or a 24 position switch configured as a 10k pot.  Looks like I'll have to try each.
On Igor's switch board, which resistor goes in position #1, the 330r or the 2k?
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: late on November 12, 2013, 11:54:22 AM
I disconnected R3 and R11 so the sidechain was out. Then i soldered them back and it worked well. After 5min it started do that old problem again. Maybe the problem is in sidechain section. But i cant understand where.
quick question, sorry to hijack your thread
disconnecting R3 and R11, would it give nominal gain through the audio path?
I'm asking this because I'm having terribly low o/p and can't really figure out why.

Yes.
Title: Re: TG1 - advice from any one who has built it...
Post by: late on November 23, 2013, 10:55:08 AM
Got my tg1 working but still sounding difference. This is in comp mode. Ch1 gives more output and not so limited. Vt13,14 gives differences but same bc184 or bc109 pair gives different result in both channels. Very hard to get matched channels?

https://dl.dropboxusercontent.com/u/20579799/Tg1_Ch1.mp3
https://dl.dropboxusercontent.com/u/20579799/Tg1_Ch2_Broken_Before.mp3

---
Ch2 D6 was bad. Now it work and have good transistors in vt13 and 14. What transistors must be selected, just vt13,14?
Title: Re: TG1 - advice from any one who has built it...
Post by: etheory on November 24, 2013, 05:04:48 PM
In theory, since this design lacks a lot of feedback to help correct for component tolerance differences, unless you match each of the long tailed pairs, you will get a bit of variation.
The most important LTP to match, are the two NPN BJT's sitting below the zener diodes.

Also, matching the zeners is crucial. Distortions and offsets are governed entirely by the balance of the main voltage controlled attenuator section compromising the NPN LTP and the 4 x zeners.
The better this match, along with trimming the currents through each side to be as equal and opposite as possible, will give the best performance.

At least that's what the simulation tells me.
Title: Re: TG1 - advice from any one who has built it...
Post by: trampo on December 20, 2013, 11:17:31 AM
Hi All

I have completed my TG using the original 2501 diodes and original transistors etc and although the unit works great, I cannot calibrate it for unity gain.

Can anyone confirm that by having the hold and the gain makeup in the central position I should get unity gain on the main board?

If I inject  a 1K signal at .707V I am getting around .450V out!

Any help would be much appreciated.

Trampo
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on February 10, 2014, 02:56:29 PM
Well guys,

it's the new year and I've decided to try my luck again with the TG1 doorstopper / boat anchor that I have stashed away in hopes of some time getting it together..

Anyway, the +- 20V points are good as are the +- 28V and the signal is entering the board, however it gets beat up in the process..

This is a spectrograph power cycle of the board.. first you have a nice healthy signal coming through the relays and when you switch it on through the opamp input, look at the spectrograph. There's a click, some weird harmonics (weak weak signal). The other click and healthy signal is of course when I switch it off and relays click the signal back. I can only get this weak signal if I turn compression on (THD off) and take HOLD to the rightmost extreme (which puts the VU to above +10 on sintech's VU scale).
(http://dl.dropbox.com/u/12679166/TG1/TG1_on_off.png)

These are the oscilloscope scans of the testing points on the PCB:

T_A
(http://dl.dropbox.com/u/12679166/TG1/TP_A.png)

T_B
(http://dl.dropbox.com/u/12679166/TG1/TP_B.png)

T_C
(http://dl.dropbox.com/u/12679166/TG1/TP_C.png)

T_D
(http://dl.dropbox.com/u/12679166/TG1/TP_D.png)

T_E
(http://dl.dropbox.com/u/12679166/TG1/TP_E.png)

T_F
(http://dl.dropbox.com/u/12679166/TG1/TP_F.png)

T_G
(http://dl.dropbox.com/u/12679166/TG1/TP_G.png)

T_H
(http://dl.dropbox.com/u/12679166/TG1/TP_H.png)

T_J
(http://dl.dropbox.com/u/12679166/TG1/TP_J.png)

T_K
(http://dl.dropbox.com/u/12679166/TG1/TP_K.png)

I could use some help debugging this, as it's way over my head, all these transistors and how it works together. Just so to repeat, symptoms are extremely low output signal and high distortion.

I know this is an old post, but what was the fix for this?  I have a similar problem.
Thanks in advance!
Best,
Bruno 2000
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on March 03, 2014, 04:23:14 PM
I disconnected R3 and R11 so the sidechain was out. Then i soldered them back and it worked well. After 5min it started do that old problem again. Maybe the problem is in sidechain section. But i cant understand where.
quick question, sorry to hijack your thread
disconnecting R3 and R11, would it give nominal gain through the audio path?
I'm asking this because I'm having terribly low o/p and can't really figure out why.

Did the low output get fixed?  I'm having the same kind of problem.  Seems like I'm missing about 15dB of gain in "THD" mode.
Thanks!
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: trampo on March 04, 2014, 04:34:17 PM
Are you getting unity gain with the compressor in?

I have managed to get mine to work at unity gain by lowering the value of R19 and R21, the downside is it now does not follow the voltages written on the original schematic.

Not sure if I am boosting earlier on in the circuit to make up for loses later on?

A friend of mine worked out that the impedance of the diodes would cause this to happen, maybe different batches of diodes would not need this mod.

However the unit now works as you would expect and sounds fantastic.

Trampo
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on March 04, 2014, 05:08:26 PM
Are you getting unity gain with the compressor in?

I have managed to get mine to work at unity gain by lowering the value of R19 and R21, the downside is it now does not follow the voltages written on the original schematic.

Not sure if I am boosting earlier on in the circuit to make up for loses later on?

A friend of mine worked out that the impedance of the diodes would cause this to happen, maybe different batches of diodes would not need this mod.

However the unit now works as you would expect and sounds fantastic.

Trampo

Thanks for the suggestion! 
My situation is that in the sidechain OUT (THD position), I cannot get unity gain through the unit with the HOLD control at mid position.  I am using a 10k linear switch, with R115 (?) shorted out.  From the input to the output it's about 15 dB down. 
The output section is giving me the appropriate 14dB of gain with the output switch centered, so that's not the issue
If I raise the value of AOT1 to 3k9, increasing the CV, I can get unity, but then the metering is messed up.
Lowering the values of R21 and R23 does pretty much the same thing from a different side, although I don't know what it would do to the metering.
This weekend I am going to try some different brand Zeners (D1, D2, D3, D4) and see what change that makes.
I think that it's really interesting that some folks have gotten their units to work well, but others have this gain loss problem.
Please chime in if you have thoughts or suggestions!
Thanks!
Best,
Bruno2000
Anyone else out there have suggestions?
Title: Re: TG1 - advice from any one who has built it...
Post by: jplebre on March 05, 2014, 05:50:50 AM
no but im really interested if you do find anything :)
Title: Re: TG1 - advice from any one who has built it...
Post by: muffy1975 on March 08, 2014, 12:42:58 PM
Guys,


i'm trying to match some zeners for the TG .


I am using this JIG and 1n751 diodes.

Am i looking for four diodes with the same voltage when switched  between 1K and 50K or just four that react in the same way?

Hope you can help me here.

Thanks in advance

Michael
Title: Re: TG1 - advice from any one who has built it...
Post by: late on March 09, 2014, 07:07:01 AM
I am almost ready with my tg1 but second channel have distortion. Anyone have an idea what can do this?

Sample:
https://dl.dropboxusercontent.com/u/20579799/TG1.wav
Title: Re: TG1 - advice from any one who has built it...
Post by: muffy1975 on March 09, 2014, 07:23:39 AM
Does the poormans variant work as described here?

Me thinks not.

I can't get the relays to switch over. Omron 24V 1A G5V-2-1H

The LED is on when in bypass ( position on the switch ) and the LED is off when IN???

Getting +/-24V. getting all the correct voltages arouns the two pcbs.

If i hard wired the 604 to the input xlr and hardwire the output of the main pcb i get the unit working and compressing.

Just can't get the I/O board and its relays to work.

Is the in out switch supposed to be a spdt as stated?


Anyone know about this?


Michael
Title: Re: TG1 - advice from any one who has built it...
Post by: trampo on March 31, 2014, 07:37:45 PM
Ok so I have now built both the original rack version and the 500 series version with slightly different results.

The rack version I used all original components including the hs2051 diodes and have low output, about 6dB down, which isn't to much of an issue if I wire the output transformers to +6dB.

The 500 series is from Igors kit and I can get unity gain with no problem.

So far the only differences I can see are:-

A0202s are H333
BCY 71 and BC109 are the BC184 and 214s
2.4mA meter with the 1mA and compensation circuit
hs2051 with 1n751 diodes

In theory none of the above should make much of a difference, however I with a number of others are experiencing low output on the rack version.

If anyone has any suggestions as to any measurements or comparisons I could make between the 2 units we may be able to get to the bottom of the issue.

Trampo 

Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on March 31, 2014, 10:51:13 PM
Ok so I have now built both the original rack version and the 500 series version with slightly different results.

The rack version I used all original components including the hs2051 diodes and have low output, about 6dB down, which isn't to much of an issue if I wire the output transformers to +6dB.

The 500 series is from Igors kit and I can get unity gain with no problem.

So far the only differences I can see are:-

A0202s are H333
BCY 71 and BC109 are the BC184 and 214s
2.4mA meter with the 1mA and compensation circuit
hs2051 with 1n751 diodes

In theory none of the above should make much of a difference, however I with a number of others are experiencing low output on the rack version.

If anyone has any suggestions as to any measurements or comparisons I could make between the 2 units we may be able to get to the bottom of the issue.

Trampo

I am doing some extensive testing of my TG units to try and figure out this gain issue that a lot of us are having.  It would help me a great deal if you could measure the current that the meter is measuring.  Just put a DVM on its 2mA current range IN SERIES with the meter and its conversion network.  What I'm interested in is that value with NO INPUT SIGNAL, and the HOLD switch / pot in the center, and at each extreme.  I also need to know if you used the 10k linear, or the 5k r/log pot plus the 5k resistor on the board for the hold control.
Thanks so much for any reply.  I hope to have a fix soon.
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: trampo on April 01, 2014, 03:26:54 PM
Ok so I have now built both the original rack version and the 500 series version with slightly different results.

The rack version I used all original components including the hs2051 diodes and have low output, about 6dB down, which isn't to much of an issue if I wire the output transformers to +6dB.

The 500 series is from Igors kit and I can get unity gain with no problem.

So far the only differences I can see are:-

A0202s are H333
BCY 71 and BC109 are the BC184 and 214s
2.4mA meter with the 1mA and compensation circuit
hs2051 with 1n751 diodes

In theory none of the above should make much of a difference, however I with a number of others are experiencing low output on the rack version.

If anyone has any suggestions as to any measurements or comparisons I could make between the 2 units we may be able to get to the bottom of the issue.

Trampo

I am doing some extensive testing of my TG units to try and figure out this gain issue that a lot of us are having.  It would help me a great deal if you could measure the current that the meter is measuring.  Just put a DVM on its 2mA current range IN SERIES with the meter and its conversion network.  What I'm interested in is that value with NO INPUT SIGNAL, and the HOLD switch / pot in the center, and at each extreme.  I also need to know if you used the 10k linear, or the 5k r/log pot plus the 5k resistor on the board for the hold control.
Thanks so much for any reply.  I hope to have a fix soon.
Best,
Bruno2000

I am using the 10K linear pot in both cases.

I will have at look at this over the weekend and post the results as soon as i have them.

Also one thing I have noticed is that the sintech meters have 0 in the center, however the original EMIs have 0 slightly offset and Igor quotes "Set unity gain with AOT1 trimpot; meter reading should show 0db (55% of full scale).
For differerent meters types scale can be different.
If needed, move a bit HOLD pot."

Trampo

 
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on April 01, 2014, 11:35:03 PM
Ok so I have now built both the original rack version and the 500 series version with slightly different results.

The rack version I used all original components including the hs2051 diodes and have low output, about 6dB down, which isn't to much of an issue if I wire the output transformers to +6dB.

The 500 series is from Igors kit and I can get unity gain with no problem.

So far the only differences I can see are:-

A0202s are H333
BCY 71 and BC109 are the BC184 and 214s
2.4mA meter with the 1mA and compensation circuit
hs2051 with 1n751 diodes

In theory none of the above should make much of a difference, however I with a number of others are experiencing low output on the rack version.

If anyone has any suggestions as to any measurements or comparisons I could make between the 2 units we may be able to get to the bottom of the issue.

Trampo

I am doing some extensive testing of my TG units to try and figure out this gain issue that a lot of us are having.  It would help me a great deal if you could measure the current that the meter is measuring.  Just put a DVM on its 2mA current range IN SERIES with the meter and its conversion network.  What I'm interested in is that value with NO INPUT SIGNAL, and the HOLD switch / pot in the center, and at each extreme.  I also need to know if you used the 10k linear, or the 5k r/log pot plus the 5k resistor on the board for the hold control.
Thanks so much for any reply.  I hope to have a fix soon.
Best,
Bruno2000

I am using the 10K linear pot in both cases.

I will have at look at this over the weekend and post the results as soon as i have them.

Also one thing I have noticed is that the sintech meters have 0 in the center, however the original EMIs have 0 slightly offset and Igor quotes "Set unity gain with AOT1 trimpot; meter reading should show 0db (55% of full scale).
For differerent meters types scale can be different.
If needed, move a bit HOLD pot."

Trampo

Yes, I noticed the slight issue with the meter, but the question is the actual current going through the diodes, and how to achieve the gain appropriate structure.  I have one channel with modern high hfe transistors, and a second with "vintage" low to medium hfe.  Both channels measure about the same current, and they both have the same gain issue using the 1N751 diodes.
Thanks for your time to do measurements!
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: Winetree on April 02, 2014, 02:53:55 AM
Quote
Ok so I have now built both the original rack version and the 500 series version with slightly different results.

Trampo, Are you talking about Igor's TG-500 series compressor?
Title: Re: TG1 - advice from any one who has built it...
Post by: trampo on April 02, 2014, 06:14:07 AM
Quote
Ok so I have now built both the original rack version and the 500 series version with slightly different results.

Trampo, Are you talking about Igor's TG-500 series compressor?

Yes, it is the full kit including all components.
Title: Re: TG1 - advice from any one who has built it...
Post by: trampo on April 03, 2014, 06:03:01 PM
Ok so I have now built both the original rack version and the 500 series version with slightly different results.

The rack version I used all original components including the hs2051 diodes and have low output, about 6dB down, which isn't to much of an issue if I wire the output transformers to +6dB.

The 500 series is from Igors kit and I can get unity gain with no problem.

So far the only differences I can see are:-

A0202s are H333
BCY 71 and BC109 are the BC184 and 214s
2.4mA meter with the 1mA and compensation circuit
hs2051 with 1n751 diodes

In theory none of the above should make much of a difference, however I with a number of others are experiencing low output on the rack version.

If anyone has any suggestions as to any measurements or comparisons I could make between the 2 units we may be able to get to the bottom of the issue.

Trampo

I am doing some extensive testing of my TG units to try and figure out this gain issue that a lot of us are having.  It would help me a great deal if you could measure the current that the meter is measuring.  Just put a DVM on its 2mA current range IN SERIES with the meter and its conversion network.  What I'm interested in is that value with NO INPUT SIGNAL, and the HOLD switch / pot in the center, and at each extreme.  I also need to know if you used the 10k linear, or the 5k r/log pot plus the 5k resistor on the board for the hold control.
Thanks so much for any reply.  I hope to have a fix soon.
Best,
Bruno2000

I am using the 10K linear pot in both cases.

I will have at look at this over the weekend and post the results as soon as i have them.

Also one thing I have noticed is that the sintech meters have 0 in the center, however the original EMIs have 0 slightly offset and Igor quotes "Set unity gain with AOT1 trimpot; meter reading should show 0db (55% of full scale).
For differerent meters types scale can be different.
If needed, move a bit HOLD pot."

Trampo

Yes, I noticed the slight issue with the meter, but the question is the actual current going through the diodes, and how to achieve the gain appropriate structure.  I have one channel with modern high hfe transistors, and a second with "vintage" low to medium hfe.  Both channels measure about the same current, and they both have the same gain issue using the 1N751 diodes.
Thanks for your time to do measurements!
Best,
Bruno2000

Here are some initial measurements:-

Rack version 0 (center) 1.2mA going down to 0 and up to 3.6mA (with sintech meter)
If i then plug the same meter into the 500 series version (and remove the extra pot and resistor) I get the same results with the current but this does not effect the gain.
I have 2 other 1mA full scale meters and the results vary in terms of current and therefore alignment but does not affect the gain.
Not sure this sheds anymore light on the problem!
Let me know what else to measure, I have both units here and would like to help in solving this problem.

Regards

Trampo
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on April 04, 2014, 09:12:57 AM
Ok so I have now built both the original rack version and the 500 series version with slightly different results.

The rack version I used all original components including the hs2051 diodes and have low output, about 6dB down, which isn't to much of an issue if I wire the output transformers to +6dB.

The 500 series is from Igors kit and I can get unity gain with no problem.

So far the only differences I can see are:-

A0202s are H333
BCY 71 and BC109 are the BC184 and 214s
2.4mA meter with the 1mA and compensation circuit
hs2051 with 1n751 diodes

In theory none of the above should make much of a difference, however I with a number of others are experiencing low output on the rack version.

If anyone has any suggestions as to any measurements or comparisons I could make between the 2 units we may be able to get to the bottom of the issue.

Trampo

I am doing some extensive testing of my TG units to try and figure out this gain issue that a lot of us are having.  It would help me a great deal if you could measure the current that the meter is measuring.  Just put a DVM on its 2mA current range IN SERIES with the meter and its conversion network.  What I'm interested in is that value with NO INPUT SIGNAL, and the HOLD switch / pot in the center, and at each extreme.  I also need to know if you used the 10k linear, or the 5k r/log pot plus the 5k resistor on the board for the hold control.
Thanks so much for any reply.  I hope to have a fix soon.
Best,
Bruno2000

I am using the 10K linear pot in both cases.

I will have at look at this over the weekend and post the results as soon as i have them.

Also one thing I have noticed is that the sintech meters have 0 in the center, however the original EMIs have 0 slightly offset and Igor quotes "Set unity gain with AOT1 trimpot; meter reading should show 0db (55% of full scale).
For differerent meters types scale can be different.
If needed, move a bit HOLD pot."

Trampo

Yes, I noticed the slight issue with the meter, but the question is the actual current going through the diodes, and how to achieve the gain appropriate structure.  I have one channel with modern high hfe transistors, and a second with "vintage" low to medium hfe.  Both channels measure about the same current, and they both have the same gain issue using the 1N751 diodes.
Thanks for your time to do measurements!
Best,
Bruno2000

Here are some initial measurements:-

Rack version 0 (center) 1.2mA going down to 0 and up to 3.6mA (with sintech meter)
If i then plug the same meter into the 500 series version (and remove the extra pot and resistor) I get the same results with the current but this does not effect the gain.
I have 2 other 1mA full scale meters and the results vary in terms of current and therefore alignment but does not affect the gain.
Not sure this sheds anymore light on the problem!
Let me know what else to measure, I have both units here and would like to help in solving this problem.

Regards

Trampo

Current through the meter should equate to a change in gain. 
Attached is a chart of my measurements for one channel.  The other channel is almost identical.  Measurements taken with 1N751 diodes, batch #1.
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on April 04, 2014, 09:15:02 AM
Here's my test setup.
Cell phone camera, ugh!
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: trampo on April 06, 2014, 01:34:43 PM
Attached are the measurements from both my rack version and my 500series version. Whilst testing I noticed a difference between the units at test point H, so I have included these with both the DC and AC voltages at point H.

Hope this helps

Trampo
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on April 06, 2014, 03:25:08 PM
Attached are the measurements from both my rack version and my 500series version. Whilst testing I noticed a difference between the units at test point H, so I have included these with both the DC and AC voltages at point H.

Hope this helps

Trampo

Nice, thank you!  I'll study this.  You said test point H, do you mean test point E?
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: trampo on April 06, 2014, 05:32:01 PM
Apologies, yes I did mean test point E, also it was with compression in.

Trampo
Title: Re: TG1 - advice from any one who has built it...
Post by: trampo on April 10, 2014, 04:47:34 PM


I have taken the sidechain from the 500 series and wired it into the rack version and I can now achieve unity gain on the rack version!

The next thing to try is hard wiring the hold and all font panel controls to see if we have another problem with the front panel pcb.

Has any one got any thoughts on Hfe gain of the transistors?

Any other suggestions welcomed.

Trampo
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on April 11, 2014, 09:33:34 AM


I have taken the sidechain from the 500 series and wired it into the rack version and I can now achieve unity gain on the rack version!

The next thing to try is hard wiring the hold and all font panel controls to see if we have another problem with the front panel pcb.

Has any one got any thoughts on Hfe gain of the transistors?

Any other suggestions welcomed.

Trampo

Hoping to study your data this weekend. 
What Zener diodes are you using?
Thanks!
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: trampo on April 11, 2014, 07:07:58 PM
The fairchild 1n751a, I have also tried the HS2051 and some unknown old stock with no manufacturer on the band. They all performed pretty much the same in terms of gain, they just had a different  compression curve.

The 500 series came with 8 matched 4.7V zeners again these performed pretty much the same in both units.

Trampo
Title: Re: TG1 - advice from any one who has built it...
Post by: muffy1975 on April 12, 2014, 06:07:57 PM
I wanted to make more TGs racks for my studio so i copied very closely the Igor layout.

RE : IGORS PCB of the TG comp :- Painstakingly I went through the schematic ( Igor's ) and  Igors PCB and they both were/are  100% correct as a match for each other,  apart from the already disclosed info about the rack's HOLD problem.

There are a few tiny variations from IGOR's to the original 1969 schematic ;  around the 1UF caps in the side chain but i guess you guys already know that.

HFE of transistors would have to be on the lower side. 600 HFE would be high for original transistors no? I have used BC549C and 559C and I have matched all mine for around 450HFE.

Thing sings.

Interested to know if there was any measurable difference between zener diode brands!


Also, what is the word on the BCY34 substitute? has everyone just gone PNP whatever on this one and put in a bc214 bc213 etc?

Michael
Title: Re: TG1 - advice from any one who has built it...
Post by: dogma on April 16, 2014, 09:37:47 PM
So is this project going to be brought back from the dead? Be a real shame - don't suppose anyone knows where to source some boards do they?
Title: Re: TG1 - advice from any one who has built it...
Post by: muffy1975 on April 18, 2014, 07:02:59 AM
does anyone know if there is a real world difference between BC549c and BC184C ,(  both NPN with similar specs/HFE  )  and BC559C and BC214 , both PNP with similar specs and HFE.

Unless i'm missing something these things are interchangeable.

The original TG did not use BC184s and BC214s.

Is there something magical about these transistors?


regards


Michael
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on April 21, 2014, 12:25:19 PM
This is Tanner guarding the different Zener diodes we've tried.
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: trampo on April 21, 2014, 07:12:19 PM
I have been doing a few more comparisons between the two units and it turns out I made a mistake connecting the side chain from one unit to the other. After correcting this they do actually perform the same.

I have also realized that the 500 series unit also has its output transformer wired with 6db of gain to achieve unity gain.

Can anyone else confirm how they have their output circuits wired?

Did the diodes tested help with any gain issues?

Trampo
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on April 21, 2014, 08:12:17 PM
This is mostly to Trampo, but others can ride along as well.

With the 1N751 diodes and the component values listed, the closest I was able to get to unity gain was 16 dB down.  I could change some R values and raise the gain, but that messed up all of the other current readings, and the meter was wrong.

It's interesting that the 500 series has the transformer wired 1:2.  So far I have found one 5V1 diode type that can get within 6 dB of unity gain and has really nice compression curves, spaced just like they ought to be with each click of the switch.  After all of the diodes I have tried, I will probably try a few more, then call it a day and use a 1:2 output transformer myself with a 1:1 input.  Those output transistors can easily drive a 150r load.

Another observation was that there were a couple of diodes that did better with the gain situation (I think within 3 dB or so), but at extreme ends of the hold control (I'm using the 10k switch), they either caused a great deal of distortion, had a significant jump in decreased gain, or oscillated.  There were also some diodes that exhibited a second "knee" about 8-10 dB above the first knee, i.e. at -8 dB the ratio was 2:1, and at 0 dBm it changed to 4:1 and showed an obvious second "knee" on the graph.

I plan on sharing my test results with whomever is interested, but I've got to catch up on some Honey Dos before I get any more shop time.  :)

Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: muffy1975 on April 22, 2014, 05:38:29 AM
Hey,


will you tell us which 5v1 zeners you found to perform the best in the TG circuit?

kind regards

Michael
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on April 22, 2014, 09:50:11 AM
Yes, I'll share all of my info, but first I need to run a couple more tests to verify operation.  I'm also going to try the 5k r/log switch plus 5k fixed configuration.
Below is a graph of input level vs. output level (not A-A frequency response like it says at the top) for each of the 23 positions of the 10k hold switch.  This graph was made with a 1:2 Carnhill output transformer.  I'm pretty happy with the curves, and although I can't do any critical listening in my shop (yet), so far I'm very happy with the sound.
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on April 22, 2014, 09:54:19 AM
Not to bore you with more home movies, but here's a "zoomed in" graph showing the nice 2:1 ratio with the hold switch set at "0".  Note the cursors, input +3dBu, output +1.492dBu also input +10dBu, output +4.785dBu.
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: trampo on April 28, 2014, 07:59:51 PM
Really interesting study. I have also tried a couple of different diodes, but not to the same detail. The second knee you discovered would probably explain why I seem to get nice compression up to a certain level and then above this level the meter goes off the scale, making it very hard to achieve even compression.

What is also conclusive is that 1n751s are not all the same. I had problems with a few 1n751 diodes with low gain, if i remember correctly the worst was the silver motorola 1n751s and by far the best were the fairchild 1n751s. Is this because we are using the diodes for a different purpose other than their intended use?

Now i am happy that the output transformer needs to be wired 1:2 I will also conduct some listening tests with a few diodes including the original HS2051s and report back.

So... can we conclude that the gain problem is down to the diodes?

Trampo
Title: Re: TG1 - advice from any one who has built it...
Post by: Biasrocks on April 28, 2014, 09:32:04 PM
So... can we conclude that the gain problem is down to the diodes?
Trampo

No, the problem is that the limiter is surrounded by transformers in the console it came from. You need the 1:2 boost on the output transformer.

Mark
Title: Re: TG1 - advice from any one who has built it...
Post by: trampo on April 29, 2014, 04:25:22 AM
So are you saying that with diodes that have up to 15dB of gain loss we should make that up with the appropriate transformer, or should we choose a diode with 6dB of loss and make it up with a 1:2 output transformer?

Trampo
Title: Re: TG1 - advice from any one who has built it...
Post by: Biasrocks on April 29, 2014, 10:49:38 AM
So are you saying that with diodes that have up to 15dB of gain loss we should make that up with the appropriate transformer, or should we choose a diode with 6dB of loss and make it up with a 1:2 output transformer?

Trampo

I used the original NOS diodes in my build and have no issues with gain makeup.

No idea how substitutions would effect that.

Mark
Title: Re: TG1 - advice from any one who has built it...
Post by: etheory on May 02, 2014, 10:02:26 PM
If you have one left over, would you be able to post an IV curve for it if you have a curve tracer?
I'd be very curious to see a comparison of IV curves amongst the different diodes people have used to see what effect we might be able to garner from that.
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on May 13, 2014, 09:55:39 AM
Sorry for the tease, but no follow-through.  I've been a little distracted recently.

The best diodes I have found so far are the Fairchild 1N5231B.  They are very quiet, they produce nice compression curves, and they sound punchy.  They do, however, lose 6dB of gain through the circuit, so I make that up with a 1:2 output transformer. 

The batch of diodes that I tested was from DigiKey, but Mouser has them also.  Out of the 100 I bought, I found 6 pairs that were +/- 1mV at all three current tests that I use (10mA, 1mA, 0.2mA).  When I get time, I am going to run some automated sweeps from 10mA to 0.05mA of the final contenders of my shootout, plus some of the ones that really suck.

Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: trampo on May 14, 2014, 06:10:28 AM
I have some of the original hs2051s, might be worth including these in the sweep test?
Just PM me your address and I will send them over.

Trampo
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on May 14, 2014, 09:33:41 AM
I have some of the original hs2051s, might be worth including these in the sweep test?
Just PM me your address and I will send them over.

Trampo

Outstanding!  Thank you!
PM sent.
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: Bonsaimaster on May 22, 2014, 09:50:31 AM
Anyone have the BOM for the Fester PSU for the TG?

Thanks
Bonasimaster
Title: Re: TG1 - advice from any one who has built it...
Post by: Bonsaimaster on May 31, 2014, 08:11:46 PM
Anyone have the specs on the transformer for the TG power supply?
Title: Re: TG1 - advice from any one who has built it...
Post by: trampo on June 01, 2014, 10:37:30 AM
All of the documentation is here.

http://twin-x.com/groupdiy/index.php?cat=10333

Trampo
Title: Re: TG1 - advice from any one who has built it...
Post by: Bonsaimaster on June 02, 2014, 02:14:45 PM
Looked thru those documents can find the input and output transformer specs but not the power transformer.
Title: Re: TG1 - advice from any one who has built it...
Post by: peskado on June 02, 2014, 07:25:45 PM
2x25v 50va
Title: Re: TG1 - advice from any one who has built it...
Post by: drask on June 11, 2014, 10:35:11 AM
Hi Guys,

What do I have to check if R84 on the main PCB is burning when I turn on the uni?

Thanks
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on June 11, 2014, 10:42:12 AM
C7,C121
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: drask on June 11, 2014, 10:47:55 AM
C7,C121
Best,
Bruno2000
Thanks
And in the case they're good?
Could it be VT26 or 25?
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on June 11, 2014, 11:29:13 AM
C7,C121
Best,
Bruno2000
Thanks
And in the case they're good?
Could it be VT26 or 25?

Probably not.  Burning out that resistor indicates a catastrophic short to agnd of the junction R67, R73, C7, C101 side of the resistor.  Check for solder bridges.
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: drask on June 11, 2014, 12:13:35 PM
C7,C121
Best,
Bruno2000
Thanks
And in the case they're good?
Could it be VT26 or 25?

Probably not.  Burning out that resistor indicates a catastrophic short to agnd of the junction R67, R73, C7, C101 side of the resistor.  Check for solder bridges.
Best,
Bruno2000

Problem Solved :) Thanks.
You were right. C7 was reversed
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on June 11, 2014, 12:16:51 PM
C7,C121
Best,
Bruno2000
Thanks
And in the case they're good?
Could it be VT26 or 25?

Probably not.  Burning out that resistor indicates a catastrophic short to agnd of the junction R67, R73, C7, C101 side of the resistor.  Check for solder bridges.
Best,
Bruno2000

Problem Solved :) Thanks.
You were right. C7 was reversed

Congrats!  Happy to help.
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on November 03, 2014, 05:08:39 PM
Ever wonder why the 40 Hz and 80 Hz settings on the HPF sounded the same?  It's because C110 and C108 are swapped (mis-labeled) on the switch board, that's why.
Best,
Bruno200
Title: Re: TG1 - advice from any one who has built it...
Post by: Biasrocks on December 01, 2014, 12:36:26 PM
Ever wonder why the 40 Hz and 80 Hz settings on the HPF sounded the same?  It's because C110 and C108 are swapped (mis-labeled) on the switch board, that's why.
Best,
Bruno200

Thanks for that Bruno. I rarely use that feature but it gives me something to do when I have it on the bench next time.

Mark
Title: Re: TG1 - advice from any one who has built it...
Post by: late on December 28, 2014, 09:12:29 PM
I have working unit in dual mode but stereo link is problem. When switch stereo link on right channel drops 2db. What can do this?
Title: Re: TG1 - advice from any one who has built it...
Post by: trampo on January 02, 2015, 07:02:48 AM
I had a similar problem, and although I could not get the unit spot on I did manage to get it within 1/2 a dB.

I found that carefully matching the diodes and the threshold between the 2 channels got the unit closer.

Whilst in dual mono compression mode, try inserting a low level sine wave into both channels (this level needs to start below the threshold), then increase the level of the sine wave until compression starts and check that both channels start compressing at the same level. If not adjust the AOT3 and 4 resistors until they match. Do the same in limit mode and adjust AOT 5 and 6.

I found it easier to replace the AOT resistors with trimpots .

Good luck

Trampo
Title: Re: TG1 - advice from any one who has built it...
Post by: Bonsaimaster on February 01, 2015, 10:59:02 AM
Ok I am setting off to start this project. Have the major parts together. Some questions. I will break it up in sections.

Bypass -  I am using 1:1 input and 1:1 output transformers (I have the Black boards Version 2)
1. C31-C38 are labelled .1uf on the boards. In the BOM that I have they are required to be 47nf-0.33uf. Which one is correct?
2. I see that there are C2 anc C3 but no mention on the BOM. Do I used them on the board? Values?
3. Are both 1N4004's installed or just one? One is unlabelled. Or do I just populate was is in the pic? 
4. Do my connections look ok? Pic included.
5. What do I use in CZ and DZ and RZ?
6. There is a unlabelled capacitor next to the unlabelled diode. Do I populate? Value?
Title: Re: TG1 - advice from any one who has built it...
Post by: Bonsaimaster on February 01, 2015, 11:12:58 AM
Motherboard

1. There are two unlabeled parts one resistor and one capacitor near the power connectors. What are these values?
2. Do I populate R47 with a 82K resistor?
3. Values for AOT?
A.O.T. 8 = not used
A.O.T. 10 = 10R
aot1 = 330R
aot2 = not used
aot3 = 47k
aot4 = not used
aot5 = 3k
aot6 = not used
aot 7  = 3.3k
aot 9 = 68k

Where are the meters connected to the board via CV?


LORLIN Switches should they be shorting or non-shorting?

Switches
BYPASS is a SPDT ON-OFF-ON?
FAST/SLOW is a SPDT ON-ON?

LIN/COMP is a DPDT ON-ON?
LIN/THD is a DPDT ON-ON?

 I have the original HS2051 diodes.
 
I will have extra diodes after my build that I will sell if anyone is interested.
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 02, 2015, 10:39:40 AM
Does anyone have the threshold fix details ready to hand.  I'm searching back through the thread & links seem to be broken.
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 09, 2015, 09:10:01 AM
Quote
1. There are two unlabeled parts one resistor and one capacitor near the power connectors. What are these values?
2. Do I populate R47 with a 82K resistor?
3. Values for AOT?
A.O.T. 8 = not used
A.O.T. 10 = 10R
aot1 = 330R
aot2 = not used
aot3 = 47k
aot4 = not used
aot5 = 3k
aot6 = not used
aot 7  = 3.3k
aot 9 = 68k

this is detailed further back

Quote
Where are the meters connected to the board via CV?

Yes
Quote
LORLIN Switches should they be shorting or non-shorting?

Not sure it makes much of a difference.  Would probably use a shorting for the gain make up.


Quote
Switches
BYPASS is a SPDT ON-OFF-ON?
FAST/SLOW is a SPDT ON-ON?

LIN/COMP is a DPDT ON-ON?
LIN/THD is a DPDT ON-ON?

Yes


Title: Re: TG1 - advice from any one who has built it...
Post by: Bonsaimaster on February 09, 2015, 11:21:29 AM
Thanks for the answers. A couple of more then I will be able to wire it up. I am using the LL1540 transformers and there is some suggestion to use 12K resistors for asymmetric input amplifier. Not sure if I understand this. Has anyone else use these transformers and can suggest wiring? Also would like to know the values used in CZ and RZ. Second, I am luck enough to get the Fester PSU board with the kit. I understand the connections from it to the motherboard. It has a couple of labels I don't understand if anyone can help.

G1
G2
G3
~G
~25
~1

I am using an Antek AS0528 with to 28V and not sure how to connect.

Thanks again in advance.

Bonsaimaster
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 09, 2015, 04:02:28 PM
Quote
Thanks for the answers. A couple of more then I will be able to wire it up. I am using the LL1540 transformers and there is some suggestion to use 12K resistors for asymmetric input amplifier. Not sure if I understand this. Has anyone else use these transformers and can suggest wiring? Also would like to know the values used in CZ and RZ.

I have no idea about your transformers because I've not used those specific ones.  CZ & RZ form a zobel network, which damps down ringing from the transformer.  These values are specific to the particular transformer used.  You will need to find them yourself.   If you inject a square wave & look the secondary of the transformer you quite often see overshoot on the leading edge.  CZ & RZ kill this.  I think if you search on the forum you will find how to determine values, if not Google will have the answers.



I am luck enough to get the Fester PSU board with the kit. I understand the connections from it to the motherboard. It has a couple of labels I don't understand if anyone can help.

G1
G2
G3
~G
~25
~1

I can't remember what these points do.  However I would guess that the G1, G2 etc are grounds.  Maybe you could buzz these points out with a meter.  See if they are connected to ground.   I think the points with ~ in front of them are likely to be a.c points where you might connect the mans transformer.  Again a meter can determine if the connect to the diodes that form the bridge rectifier.

Quote
I am using an Antek AS0528 with to 28V and not sure how to connect. .

 I ASSume that the AS0528 is your mains transformer.   Does it have dual secondaries  or a single centre tapped secondary ?
Title: Re: TG1 - advice from any one who has built it...
Post by: Bonsaimaster on February 16, 2015, 07:48:03 PM
Dual secondaries.
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 17, 2015, 05:00:19 AM
Dual secondaries.

You connect the + of one of the secondaries with the - of the other.  That becomes you   centre tap which connects to ~G.  The other 2 wires connect to either side of the bridge rectifier.  Look at diagram 9 on this page.  The bridge rectifier in this instance is D1-D4.  I think either side for you is ~1 & ~25.  But not having the box in front of me to check, I suggest that you check it out with a meter.

It is quite important to make you centretap pair a + of one secondary & a - of the other.  If you don't you will get through a lot of fuses and/or possibly damage the transformer.
Title: Re: TG1 - advice from any one who has built it...
Post by: Bonsaimaster on February 23, 2015, 08:43:43 PM
Anyone know what the minimum requirements are for the power transformer for the IGOR PSU? I am trying to fit everything in a 2U rack space. Can I use a 32V 25VAor a 30V 30VA?
Title: Re: TG1 - advice from any one who has built it...
Post by: Majestic12 on February 25, 2015, 10:48:43 AM
Anyone know what the minimum requirements are for the power transformer for the IGOR PSU? I am trying to fit everything in a 2U rack space. Can I use a 32V 25mA or a 30V 30ma?

30mA max current is way too less to power the unit. Do you mean 25 or 30VA instead?
Title: Re: TG1 - advice from any one who has built it...
Post by: Bonsaimaster on February 25, 2015, 08:40:29 PM
Sorry yes 30VA
Title: Re: TG1 - advice from any one who has built it...
Post by: Bonsaimaster on March 07, 2015, 08:45:37 AM
Ok got 28V from the power supply. Looking to connect to main board and start the calibration. Will add jumpers to get 20V. Any advice after that?
Title: Re: TG1 - advice from any one who has built it...
Post by: Bonsaimaster on March 07, 2015, 11:31:45 PM
Ok got 20V on the board with one jumper. Hope everything else goes ok. Using 1:1 Lundahl transformers on input and output and a 10k Lin pot for hold with the jumper on R115.
Title: Re: TG1 - advice from any one who has built it...
Post by: Bonsaimaster on March 14, 2015, 10:10:55 PM
Anyone using the 1517 Lundahl transformer for output. I am trying to find the RZ and CZ for the zobel network with no luck. Unfortunately, I don't have a scope. Also in looking at the 1:1 and 1:1 bypass it states to OMIT J8 yet on the schematic it looks like it is needed.

Last stupid question. How are people powering the lamps on the VU meters.

Thanks again!
Title: Re: TG1 - advice from any one who has built it...
Post by: Bonsaimaster on March 15, 2015, 08:48:39 PM
Got everything up and running. This is an incredible f**king compressor. OMG! Outstanding. Thanks for everyone for answering the stupid questions. all worth it!
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on March 27, 2015, 11:00:57 PM
Would you be able to post some helpful points/remarks for anyone planning on building this unit Bonsai? It's been long on my list. Have most everything needed for it but the case. Cheers.
Title: Re: TG1 - advice from any one who has built it...
Post by: Bonsaimaster on March 27, 2015, 11:20:48 PM
Yes have lots of advice or problems that I had that I would love to share. I found it very difficult to get solid info when builiding this unit.  I however am no electronics expert. I am a musician who loves great sound. I build these units to use creatively. So technical data may be lacking.

Tell me how you  plan to build the unit ie transformer or not. I will post details tomorrow.
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on March 28, 2015, 10:03:11 AM
Transformers and opamps, I think. I do like the aggression of the chandler unit.

Title: Re: TG1 - advice from any one who has built it...
Post by: Bonsaimaster on March 28, 2015, 10:25:38 PM
Ok so first I got all the parts from electro chronic. Great guy, has all of the necessary parts, also does the testing. Worth the money to get the critical parts from him.

I always find that a picture is worth a thousand words and helpful with basic questions. I can send pics if you want.

PSU

I used the Igor PSU. I have the BOM if you need it. Inputs to the PSU were not easy to decipher until I got the schematic. Was able to connect to the transformer with that info.

Used a Hairball audio transformer for the 1176. Avel Lindberg 2X25 30VA dual primary/secondary toroidal power transformer.

Works great, no problem. Almost went with a larger transformer but space was limited in a two-space rack.

I would most likely build it with a deeper case and a 3U case next time around.

Relay board

I guess there were two versions of this. The instructions on what to populate are wrong. Again, the schematic was helpful in getting the right connections. However, the schematic is not the clearest. I am a noob with schematics so take that with a grain of salt. I populated the boards using pictures of others builds and matching up with available info. I was missing some basic connections when reviewing the schematics.

I am using Elcor transformers 1:1 input and output. Finally figured out that RZ and CZ are the Zobel network. These are different for different brands of transformers. Never knew what this was. I have no way of testing the transformers so I am going to populate RZ and CZ on the bypass board based on Elcor's recommendations.

I used DIMM sockets also for the relays on the relay board.

Motherboard
I sourced the HS2051 diodes for the build. They were expensive, but I hope made the build easier. Installed DIMM sockets so I could remove them easily. I tried to match the diodes I had but they were all so close that I don't think it makes any difference. I think they are military parts so the variation is very small. I had to purchase more than I needed to build the unit.

There are some unlabeled resistors and caps on the board. I trusted the schematic for these values and seemed to work. Did not populate R47.

Installed heatsinks on VT28 and VT29. 

During the 20V calibration only need one of the jumpers on the - and + sides.

I also used cut DIMM socket connectors for the AOT resistors.

I used these resistor values for AOT resistors. I have not had the AOT resistors calibrated.
AOT1 620r (Unity Gain)
AOT2 not used
AOT3 47K (Compressor Threshold standard value)
AOT4 (Compressor Threshold not used)
AOT5 3K (Limiter Threshold standard value)
AOT6 510r (Limiter Threshold, makes the unit limit more in limit mode)
AOT7 33K (Distortion without compression, standard value)
AOT8 68K (Distortion without compression, standard value)
AOT9 (Not Used)
AOT10 10r (DC voltage on the collector of VT5 and VT6 are the same)

Selector boards
I used the Limit "FIX" and that seemed to work well. Don't know what it did but it worked. I also used a 10k Linear pot for the limit. Did not use a switch.  R115 was then jumped. I think the two channels may match better with a pot.

One of the capacitors on the HPF are switched. Again the schematic is right and the board is wrong. This is from Bruno 2000. Ever wonder why the 40 Hz and 80 Hz settings on the HPF sounded the same?  It's because C110 and C108 are swapped (mis-labeled) on the switch board, that's why.

Used a ON-OFF-ON for the bypass switch. It is IRON-BYPASS-CLEAN. Clean being the compressor engaged without the transformers. All other switches are ON-ON. Used an ON-OFF for Link switch.

Wiring of the unit was very time consuming. There are many connectors and crimping the molex connectors can get aggravating. There were two times where a good connection was not made.  Be careful with the  connections from the PSU to the motherboard and then to the bypass board. I accidentally wired the second board wrong.

Connecting the link switch was wiring the LNK1 on each board to a switch. Shorting the switch allows for the unit with the greatest inputs in each control to be the control board.

The one problem is I am having trouble getting the lamps to light on the VU meters. BTW I have the Sifam meters. I have connected the VULED+ and VULED= from the bypass board. I get +28V and -28V from each but no light on meter. The lamp on the meters are 24V. Not sure of the problem. I know the only problem, I should be happy.




Title: Re: TG1 - advice from any one who has built it...
Post by: Patrick from Davis on March 28, 2015, 11:07:42 PM
Two questions:
1.  How deep was the enclosure that you used?

2.  On the Iron-Bypass-Clean, is the clean unbalanced?  I could probably figure this out by digging in the docs, but I was hoping a simple question would be faster.
Thanks,
Patrick

Title: Re: TG1 - advice from any one who has built it...
Post by: Bonsaimaster on March 28, 2015, 11:13:39 PM
11 inches. 14 would be better.

Not sure about the outputs without the transformer. I assume they are unbalanced.
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on March 29, 2015, 03:21:33 PM
Still digging out from some personal issues, but I'll try to help as I successfully completed my unit, and it sounds really fine.  I am by no means an expert, but I have some nice test gear, and was able to look at multiple waveforms and Voltages simultaneously.
First, I could NEVER get the unit to put out unity gain without doing some extreme things to values.  My solution was a 1:2 output transformer, and that works.
Second, I modified the bypass board so that the "electronically balanced" option on the bypass switch used the chip input, but the output is going through a big honkin' Jensen 123 transformer.  The switch works like this, up position, Zutt input transformer, Carnhill output.  Mid position hardwire bypass ("bypass-I don't believe in it"). Down position chip balanced input, output through Jensen 123.  Additionally, I used a by-color LED so that up showed red, and down showed blue (the blue is TOO bright.  Gonna have to fix that).  I need to add that the "Festoon" (?) lamps for the meters draw a LOT of current.  That combined with switching 6 (?) relays required a MUCH larger power transformer than I thought.  The result was regulator starvation hum until I changed it out.
One of the "tricks" I discovered the hard way is that the differential transistor pairs need to be matched along with the diodes.  I went through more than 20 types, and measured over 1000 diodes.  I set up an "automated" test procedure with my AP DCX-127 that would step the diodes, and then imported the measurements into a database program, then sorted to find matches.  Out of 100 diodes (that's how many I usually bought of one type), I could get 8-10 pairs that were really close matches.
More later.
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: Biasrocks on March 29, 2015, 03:51:29 PM
This is how I went as well, much nicer sounding with transformers on the in and out. I went with a 1:1 vintage Sowter on the inputs and a EA1166 on the output wired 200:600.

I also modified the FB resistor (3K3 iirc) to apply a 6db boost which I placed on a toggle switch on the front panel. This allows the gain knob to run mostly in a more central position and affords some additional gain if needed.

First, I could NEVER get the unit to put out unity gain without doing some extreme things to values.  My solution was a 1:2 output transformer, and that works.
Bruno2000

Mark
Title: Re: TG1 - advice from any one who has built it...
Post by: Bonsaimaster on March 29, 2015, 04:25:43 PM
Are you drawing power for the Festoon lamps from the VULED- and VULED+ or wiring another way. Would the LED versions of the lamps draw less current?

Bonsaimaster
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on March 31, 2015, 09:22:42 AM
Are you drawing power for the Festoon lamps from the VULED- and VULED+ or wiring another way. Would the LED versions of the lamps draw less current?

Bonsaimaster

I believe that I wired the meter lamps in series including a series resistor directly across the bridge of the regulator board.  I like the warm glow of under-Voltaged incandescent lamps.  LED lamps will draw significantly less current.  YMMV
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: Majestic12 on May 07, 2015, 10:31:41 AM
Since it's now almost impossible to get the suitable 2.4mA meters for this built (especially if you want mirrored ones), I first tried to use an opamp converter to use standard VU meters, but calibrating was very difficult. The solution is a small circuit around an Attiny85 that uses a lookup table to convert the incoming signal to the correct voltage values for VU meters.
It is also very easy to "mirrow" one meter,  I only need to print out one inverted meter scale.
The ballistics are a bit slower than on the correct mA meter, but I'm not really concerned about that :)

(http://i62.tinypic.com/30vc5fd.jpg)

Here's a video of the buffer in action:

https://www.youtube.com/watch?v=Ip_s31CcbPQ&feature=youtu.be
Title: Re: TG1 - advice from any one who has built it...
Post by: drask on November 18, 2015, 05:31:26 PM
Hi there !
Trying to figure out a gain difference between the two canals.
By measuring and testing, I sorted out that T_E has quite a big difference.
Any idea what I can change ?
Should be around VT16 VT17 ?

Thanks guys !
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on November 18, 2015, 05:42:57 PM
Hi there !
Trying to figure out a gain difference between the two canals.
By measuring and testing, I sorted out that T_E has quite a big difference.
Any idea what I can change ?
Should be around VT16 VT17 ?

Thanks guys !

Do you mean "channels"?
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: drask on November 18, 2015, 07:23:15 PM
Do you mean "channels"?
Best,
Bruno2000
Hi Bruno,

Yes ! Sorry french took over.
I can't figure out where the difference come.
I think it's around that point T_E.

Any idea?
thanks !
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on November 18, 2015, 08:00:02 PM
I don't have the schematics in front of me, but will get back to you tomorrow.  If you disable the cv do you get the same gain through both channels?
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: drask on November 18, 2015, 08:13:23 PM
I don't have the schematics in front of me, but will get back to you tomorrow.  If you disable the cv do you get the same gain through both channels?
Best,
Bruno2000
What do you mean by disabling the CV?

Thanks !
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on November 19, 2015, 10:07:30 AM
I don't have the schematics in front of me, but will get back to you tomorrow.  If you disable the cv do you get the same gain through both channels?
Best,
Bruno2000
What do you mean by disabling the CV?

Thanks !

It helps if VT13 and VT14 are fairly close hfe match.  Switch the comp in / thd switch to thd, eliminating the audio feed to the side chain, then measure the AC Voltage at T_F and T_G.  Should be 0.  Then measure the DC Voltage at T_E.  Should be the same for both channels.  I'll check the actual Voltages on mine this weekend. 
Best,
Bruno200
Title: Re: TG1 - advice from any one who has built it...
Post by: drask on November 19, 2015, 11:15:45 AM
It helps if VT13 and VT14 are fairly close hfe match.  Switch the comp in / thd switch to thd, eliminating the audio feed to the side chain, then measure the AC Voltage at T_F and T_G.  Should be 0.  Then measure the DC Voltage at T_E.  Should be the same for both channels.  I'll check the actual Voltages on mine this weekend. 
Best,
Bruno200
I'll try that and I'll be back to you ! Thanks Bruno200
Title: Re: TG1 - advice from any one who has built it...
Post by: drask on November 25, 2015, 03:03:37 PM
It helps if VT13 and VT14 are fairly close hfe match.  Switch the comp in / thd switch to thd, eliminating the audio feed to the side chain, then measure the AC Voltage at T_F and T_G.  Should be 0.  Then measure the DC Voltage at T_E.  Should be the same for both channels.  I'll check the actual Voltages on mine this weekend. 
Best,
Bruno200

Hi Bruno,
Finally got time to take some time.
So here the Voltage I get.

The problem is on the Channel A. Don't have unity gain in comp Modo.

                Channel A                             Channel B
Ref     | Comp | THD                          | Comp | THD   
T_G    | 0,90     | 1,62                          | 1,55    | 1,55
T_F     | 2,37     | 1,74                          | 1,67    | 1,73
T_E     | 0,62     | 0,62                          | 0,62    | 0,62

Thanks !
Title: Re: TG1 - advice from any one who has built it...
Post by: Biasrocks on November 25, 2015, 04:51:23 PM
Have you checked you output pot for the correct values?

Mark


The problem is on the Channel A. Don't have unity gain in comp Modo.

                Channel A                             Channel B
Ref     | Comp | THD                          | Comp | THD   
T_G    | 0,90     | 1,62                          | 1,55    | 1,55
T_F     | 2,37     | 1,74                          | 1,67    | 1,73
T_E     | 0,62     | 0,62                          | 0,62    | 0,62

Thanks !
Title: Re: TG1 - advice from any one who has built it...
Post by: drask on December 03, 2015, 03:41:34 AM
Hi Mark,

Yes I checked the output again this morning, and the values are correct.
Another lead ?

Thanks !
Jay
Have you checked you output pot for the correct values?

Mark
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on December 03, 2015, 10:29:38 AM
What are your readings at T_B & T_C?
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: drask on December 06, 2015, 02:00:36 PM
What are your readings at T_B & T_C?
Best,
Bruno2000
Here my readings

T_B    | 10,47   | 10,21
T_C    | 10,41   | 10,22

thanks!
Title: Re: TG1 - advice from any one who has built it...
Post by: Joe_caithness on February 28, 2016, 08:51:50 AM
Can anyone confirm the ratios of the comp/limit?
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on February 29, 2016, 12:19:34 PM
Has anyone even built one of these that works properly and sounds correct? I've heard the chandler on youtube and Sintech's white EMI units on youtube and they sound pretty awesome on drums. That's a sound I'm after.

Has anyone figured out the de facto calibration procedure? ...instead of just the default values given?  I have a stereo pair of these with all the stuff(original HS2051's), etc...but IGOR's build notes seem a bit complicated(too many options imo). I wanna build it...but I don't know if I could handle it. :) I still have doubts about this build.
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on February 29, 2016, 12:34:18 PM
Has anyone even built one of these that works properly and sounds correct? I've heard the chandler on youtube and Sintech's white EMI units on youtube and they sound pretty awesome on drums. That's a sound I'm after.

Has anyone figured out the de facto calibration procedure? ...instead of just the default values given?  I have a stereo pair of these with all the stuff(original HS2051's), etc...but IGOR's build notes seem a bit complicated(too many options imo). I wanna build it...but I don't know if I could handle it. :) I still have doubts about this build.

I built one, and it sounds fantastic.  I have had it up against a Chandler, and an original EMI.  It is MUCH more flexible than a Chandler, and sounded pretty much the same as the EMI.    There ARE a lot of options, and I could not get mine to calibrate exactly as Igor's instructions, but I have a pretty good test bench, and calibrated everything to my satisfaction.
YMMV
BTW, you should consider the PYE on your drum bus as well.......
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on February 29, 2016, 12:42:42 PM
It helps if VT13 and VT14 are fairly close hfe match.  Switch the comp in / thd switch to thd, eliminating the audio feed to the side chain, then measure the AC Voltage at T_F and T_G.  Should be 0.  Then measure the DC Voltage at T_E.  Should be the same for both channels.  I'll check the actual Voltages on mine this weekend. 
Best,
Bruno200

Hi Bruno,
Finally got time to take some time.
So here the Voltage I get.

The problem is on the Channel A. Don't have unity gain in comp Modo.

                Channel A                             Channel B
Ref     | Comp | THD                          | Comp | THD   
T_G    | 0,90     | 1,62                          | 1,55    | 1,55
T_F     | 2,37     | 1,74                          | 1,67    | 1,73
T_E     | 0,62     | 0,62                          | 0,62    | 0,62

Thanks !

Check all circuitry around VT13 & VT14.  Make sure they are matched for hfe.
Maybe swap VT13 & VT14 with the channel that works, and see if the problem follows the transistors.
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on February 29, 2016, 12:56:06 PM
Bruno did you built yours with everything? DOA's, input/output transformers, etc? I listened to an Igor build a while back and was somewhat unimpressed.The unit sounded kinda muffled and small(overly crushed)...instead of 'big and powerful' like the Chandler and EMI samples I've heard.

.

Has anyone even built one of these that works properly and sounds correct? I've heard the chandler on youtube and Sintech's white EMI units on youtube and they sound pretty awesome on drums. That's a sound I'm after.

Has anyone figured out the de facto calibration procedure? ...instead of just the default values given?  I have a stereo pair of these with all the stuff(original HS2051's), etc...but IGOR's build notes seem a bit complicated(too many options imo). I wanna build it...but I don't know if I could handle it. :) I still have doubts about this build.

I built one, and it sounds fantastic.  I have had it up against a Chandler, and an original EMI.  It is MUCH more flexible than a Chandler, and sounded pretty much the same as the EMI.    There ARE a lot of options, and I could not get mine to calibrate exactly as Igor's instructions, but I have a pretty good test bench, and calibrated everything to my satisfaction.
YMMV
BTW, you should consider the PYE on your drum bus as well.......
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on February 29, 2016, 01:07:49 PM
Full build for me.  Zutt input transformers, Carnhill outs.  My "clean?" option was the opamp balanced input, but a large 80% nickel core Jensen output tranny instead of the opamp.  Some folks like the "vintage" transformers better, some folks like the opamp/Jensen better.  If you want to send some samples to me (.wav files), I'll run them through, and send them back.
Best,
Bruno2000

Bruno did you built yours with everything? DOA's, input/output transformers, etc? I listened to an Igor build a while back and was somewhat unimpressed.The unit sounded kinda muffled and small(overly crushed)...instead of 'big and powerful' like the Chandler and EMI samples I've heard.

.

Has anyone even built one of these that works properly and sounds correct? I've heard the chandler on youtube and Sintech's white EMI units on youtube and they sound pretty awesome on drums. That's a sound I'm after.

Has anyone figured out the de facto calibration procedure? ...instead of just the default values given?  I have a stereo pair of these with all the stuff(original HS2051's), etc...but IGOR's build notes seem a bit complicated(too many options imo). I wanna build it...but I don't know if I could handle it. :) I still have doubts about this build.

I built one, and it sounds fantastic.  I have had it up against a Chandler, and an original EMI.  It is MUCH more flexible than a Chandler, and sounded pretty much the same as the EMI.    There ARE a lot of options, and I could not get mine to calibrate exactly as Igor's instructions, but I have a pretty good test bench, and calibrated everything to my satisfaction.
YMMV
BTW, you should consider the PYE on your drum bus as well.......
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on February 29, 2016, 02:45:34 PM
Sure. I'll send you a pm in a few days. Maybe send a decent stereo kit and mix.

D.
Title: Re: TG1 - advice from any one who has built it...
Post by: Bonsaimaster on May 03, 2016, 02:01:04 PM
Anyone using Carnhill VTB2281 600:600 output transformer and know the Cz and Rz values they used? 

Thanks
Bonsaimaster
Title: Re: TG1 - advice from any one who has built it...
Post by: duantro on June 05, 2016, 03:02:58 PM
Anyone using Carnhill VTB2281 600:600 output transformer and know the Cz and Rz values they used? 

Thanks
Bonsaimaster
I was wondering the same question with the outputs that I was going to use, a pair of Freed 32035 600:600.
I suppose finishing the build and measuring is the only way to go, if no one has values for these. I didn't find anything from Google.
Title: Re: TG1 - advice from any one who has built it...
Post by: Bonsaimaster on June 06, 2016, 05:34:15 PM
I am not sure why this is a complicated question. I know measuring is the way to go but personal experience would help.

Bonsaimaster
Title: Re: TG1 - advice from any one who has built it...
Post by: duantro on June 12, 2016, 07:02:28 PM
I got my point to point power supply buttoned up and working. A few more switches to wire up and almost ready to test if it will hold the magic black smoke. These molex connectors take a while to connect!
Hey Bonsaimaster, how did you end up with the vu lamp connection? Are you using the Sifam 2.4 mA meters also?  Do you still have extra HS2051's? If so, shoot me a pm and Let me know what you have, and how much you'd like for them.
Title: Re: TG1 - advice from any one who has built it...
Post by: duantro on June 14, 2016, 02:55:52 PM
Got everything wired up. Upon power up my r77 gets very hot. I've got a short or bad wiring somewhere. I'll keep looking to see if I can find it.
Edit: ok, I think I've found it. The unmarked cap on pcb (c3), I had mistakenly put in a resistor! :o  Must have gotten it confused with the unmarked resistor in the same area. Looks like that solves it.
Title: Re: TG1 - advice from any one who has built it...
Post by: duantro on June 15, 2016, 06:49:57 PM
PSU putting out 27.7v. Main Board 20v test points are looking good with 1 jumper. However, I'm not getting signal out of it. It's dead Silent. Meters move when I boost the test signal So it is getting signal to some parts of it.. Opa604 voltages are only 21v. It looks like I have a 3k05 instead of a 3k5 in r91 and r92! I'll switch those tomorrow and see if it helps any. 24v on Relays drop down to 18.4v when energized. Is this too low? I tapped into my VU LED+ for my festoon bulbs and sent the ground of the bulbs to case. This wouldn't be causing any issues , would it?

Edit: after putting in 3k5's, I've got 24 V on relays. Still measures 18.4v at relay side of r110 when switch is in iron.

Edit: I figured I would check the output transistors, since I had wrong component in c3 and likely messed something up here.
vdc measurements
The 2n4898 =  B 20.42 (r75), E 19.72 (r74), C 0(t_op).
 voltage drop  diode test =  B to E  .268     B to C .531

The 2n4910 = B .648 E 0 C 0
voltage drop diode test  B to E .516    B to C .516

The transistor tests were done in circuit. Does it look like I need a new 2n4898?

Back to tracing signal...
I'm sending  a  .775vac at 1khz.
While using a home made  audio signal tracing pen (one that connects injected signal to a speaker), I'm getting signal at the "in" connector on relay pcb that heads to the main board with opamps and iron settings.   It progressively drops down as I continue on in the circuit.
I am getting a faint (.084vac) audio signal at r100. after that it disappears. Not sure where to look here. Can anyone suggest things to check?
Title: Re: TG1 - advice from any one who has built it...
Post by: Spencerleehorton on June 18, 2016, 04:52:35 AM
Then 0.6v emitter/base rule of thumb on transistors looks like your 2N4898 is faulty.
Other than that I haven't looked any further.

Spence.
Title: Re: TG1 - advice from any one who has built it...
Post by: duantro on June 18, 2016, 09:13:21 AM
Then 0.6v emitter/base rule of thumb on transistors looks like your 2N4898 is faulty.
Other than that I haven't looked any further.

Spence.
Thanks Spence,
That's what I thought. I'll get some more and see what that does.
Edit: just noticed that this is reply 666. This beast is sure to sound evol once I get it working!!
Title: Re: TG1 - advice from any one who has built it...
Post by: duantro on June 20, 2016, 04:03:26 PM
Well crap, I pulled the 2n4898 and it measures good voltage drop out of circuit. Must be something in line that was altering the reading. I was really hoping it was faulty so my bad trouble shooting skills could be put to an end.  Is the 2n4910 base voltage not quite high enough to cause conductance thru the collector the issue?  Can anyone suggest where to check that would be causing the transistors to read 0v on the collectors? I've triple checked all of the values/ polarity of components and voltage drop/ orientation of transistors in this area. I'm about to lose my mind!
Edit: How high of an ac audio signal should I be seeing at these base junctions?  ...or anywhere prior to here, so I can find where I'm dropping signal.
Title: Re: TG1 - advice from any one who has built it...
Post by: duantro on June 22, 2016, 07:20:58 PM
Another day after I've came back in from the ledge, contemplating whether  to throw this thing off, jump off, or both.  I've checked ALL of the resistor values once again. No mysteries here. Ac audio Signal seems to oscillates after vt1 (32vac-0)
Here is a voltage chart I put together to see if it makes any sense.
Title: Re: TG1 - advice from any one who has built it...
Post by: Bonsaimaster on June 23, 2016, 01:31:26 AM
Do you have the schematic? I had an oscillation problem and traced it to a blown VT28. Included it here. Sometimes time away from a project brings clarity. Don't give up!
Title: Re: TG1 - advice from any one who has built it...
Post by: duantro on June 26, 2016, 01:37:00 AM
While going over the "sharpened" (but still blurry)  original schematic I think I  realize that I have my bcy34 in the wrong spots. I have them in vt 26 in stead of vt 27! Man trying to keep all of the cross referenced and original transistors straight has been a task. Hopefully this will sort out my problem.

Edit: oh hell yes, it is working now!! This thing sounds freaking awesome! Time to calibrate!
Looks like  everything is pretty close with the standard AOT values, besides not looking at distortion calibration yet. Also I am getting .395vac on output,  with a .775 vac input signal. I think others had this also and opted for a 1:2 output transformer and output amp options  to compensate.  I used 1k resistors on a 11 position lorlin switch for the hold, and am going to change them out for the values listed on festers schematic. As is, not much  happens until the last few positions.
Title: Re: TG1 - advice from any one who has built it...
Post by: duantro on July 02, 2016, 04:24:17 PM
I have Marinair T1448's on the input, wired 10k:9k6. I'm going to try these as 9k6: 2k5 and see how it sounds.
Here are the spec's that  I've found for them:

Marinair T1448
This is a line bridging transformer. Designed specifically to isolate equipment with previously unbalanced input arrangment, this transformer may be inserted without serious loss of level.
10k/2k5 : 9k6/2k4 ( 2 x 5k : 2 x 4k8 windings )
Secondary load: 9k6 (rated)
Input impedance: 10k
voltage ratio-insertion loss:1dB
Frequency response (600ohms source, 9k6 load): +/-0,3dB (20Hz-15kHz and -0,5dB at 20kHz
Distortion: <0,1% (above 40Hz) and < 0,01% (500Hz-10kHz)
Squarewaves: No overshoot, no ringing,
Title: Re: TG1 - advice from any one who has built it...
Post by: Ilya on July 28, 2016, 12:39:52 PM
Has anybody of you guys got an original PDF from Winston? Any chance I can get a copy?
Title: Re: TG1 - advice from any one who has built it...
Post by: chefducuisine on July 30, 2016, 08:21:17 AM
I have the documentation of Igor's version if that helps.
You can see mine here: http://groupdiy.com/index.php?topic=63350.0 (http://groupdiy.com/index.php?topic=63350.0) (Scroll down a bit).
Title: Re: TG1 - advice from any one who has built it...
Post by: skeeler87 on July 30, 2016, 11:08:50 AM
Does anyone know where I can get boards for this? Would love to give this one a shot!
Title: Re: TG1 - advice from any one who has built it...
Post by: chefducuisine on July 30, 2016, 11:40:59 AM
Boards are not available at the moment but member electrochromic is planning to do some in the future:
https://sites.google.com/site/diypartsstore/catalog/pcb-transistors-op-amps-pots (https://sites.google.com/site/diypartsstore/catalog/pcb-transistors-op-amps-pots)
Title: Re: TG1 - advice from any one who has built it...
Post by: Spencerleehorton on August 07, 2016, 06:12:59 PM
Anyone know where I can get hold of these pcbs?

Regards

Spence.
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on August 09, 2016, 02:56:26 PM
These boards are long gone.  Unavailable for over a year.
Title: Re: TG1 - advice from any one who has built it...
Post by: Spencerleehorton on August 09, 2016, 03:09:04 PM
Isn't it time for someone to make some more then?
I only have the facility to make single sided boards, is there any printouts or anything layout wise?

Regards

Spence.
Title: Re: TG1 - advice from any one who has built it...
Post by: mrclunk on August 11, 2016, 12:00:36 PM
There isn't any layouts avaliable.
Igor was smart making black PCBs, you can't scan them to make copies :) I tried before stuffing mine.
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on August 11, 2016, 12:06:05 PM
There isn't any layouts avaliable.
Igor was smart making black PCBs, you can't scan them to make copies :) I tried before stuffing mine.

Don't be so sure..........
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: mrclunk on August 11, 2016, 12:34:54 PM
There isn't any layouts avaliable.
Igor was smart making black PCBs, you can't scan them to make copies :) I tried before stuffing mine.

Don't be so sure..........
Best,
Bruno2000

Haha, you tease!
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on August 11, 2016, 02:08:45 PM
id take a pair for sure
Title: Re: TG1 - advice from any one who has built it...
Post by: duantro on August 11, 2016, 11:18:07 PM
Isn't it time for someone to make some more then?
I only have the facility to make single sided boards, is there any printouts or anything layout wise?

Regards

Spence.

Pm me spence.
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on October 09, 2016, 04:22:08 PM
Well, I've spent the last few days going over Igor's TG build trying to make sense of how he has everything laid out, etc. I'm assuming that originally, one just drove input into the unit and there was no input pot. I'd like it more like the original so....that's fine (I wouldn't mind having some kind of 'boost' switch that makes it more chandler-ish...but I suppose that's besides the point at the moment. Sourcing the 20uf radial caps seems difficult. Gotta figure out how to match HS2051's. There's a lot of attack/release settings on the unit...and the times aren't listed in the documentation. I know the original was meant to mimic the Fairchild. Hmm...regardless, I'd like to have them on the front panel cause it's nice to know the setting one's on. Panel is nearly done apart from the timings:

Looks good so far I think! Quite a bit of work actually getting everything lined up, etc. Wonder if it'll ever see the light of day? :)
(http://i700.photobucket.com/albums/ww10/desol777/Frontpanel.jpg) (http://s700.photobucket.com/user/desol777/media/Frontpanel.jpg.html)

Still need to get the nice Elna switches and something good for the hold control. The 'hold fix' seems simple enough. I have one power supply board for it and I'm pretty sure it'll handle two channels. I think I remember asking Igor at the time. One thing I haven't figured out is why the arrows point different directions on the two power supply clips? Not using the options board, so that cuts down on some costs and time. It's a sort of puzzle figuring this one out, but it is fun!
Title: Re: TG1 - advice from any one who has built it...
Post by: duantro on October 17, 2016, 01:25:50 AM
Looks good Desol. I sourced 20uf caps on eBay. If you look back in this thread, or in the build docs, there is a jig described to match the hs2051's or equivalents.
This thing sounds sweet.
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on October 17, 2016, 01:13:05 PM
Nice. Thanks Duantro. I did find some 20uf caps on ebay...but they seem to be mostly only available in larger axial packages.

I like matching parts to the board print, lead spacings, etc...if I can. I've wondered at time why Igor chose radials in this spot instead of axial's, which most of the 20uf's seem to be.  Glad you're happy with yours!

Title: Re: TG1 - advice from any one who has built it...
Post by: duantro on October 17, 2016, 01:27:39 PM
Nice. Thanks Duantro. I did find some 20uf caps on ebay...but they seem to be mostly only available in larger axial packages.

I like matching parts to the board print, lead spacings, etc...if I can. I've wondered at time why Igor chose radials in this spot instead of axial's, which most of the 20uf's seem to be.  Glad you're happy with yours!
That  sounds like the 20uf's that I found. They are pretty big. Yeah, it is interesting that it was designed this way.
Title: TG1 - advice from any one who has built it...
Post by: electrochronic on November 23, 2016, 02:27:20 PM
In case your after boards and meters , I'm still working on this project , the main signal board and power supply gerbers are done. Don't ask me for gerbers, I wont give them out. Still have the front panel switch board gerbers to complete. Should'nt take long , but I been saying this for the past two years. It took almost this long to get the meters since Sifam was under corporate re-structuring. The Sifam meters are in stock now at my web page, just working on the pcb boards. I am also working on some more affordable meters for those on a tighter DIY budget. All pictured at my web page link.
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on November 23, 2016, 07:01:37 PM
Why don't you guys use 22uF caps.   They are well within tolerance and easy to get.  Electrolytic caps have poor tolerance.
Title: Re: TG1 - advice from any one who has built it...
Post by: Spencerleehorton on November 24, 2016, 08:59:28 AM
I'm looking forward for this project to be completed, I've got a fair bit of the components together now, I might have a go at doing my own pcb first and see how turns out.

Anything else to report?
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on November 24, 2016, 09:39:52 PM
Why don't you guys use 22uF caps.   They are well within tolerance and easy to get.  Electrolytic caps have poor tolerance.

Hey Rob. I don't enough about design and didn't want to assume whether it would or wouldn't affect anything circuit wise. I figured Igor would know details like that and so chose to specify that exact value. If it in fact doesn't change anything, then that solves the problem....cause they are basically impossible to find.
Title: TG1 - advice from any one who has built it...
Post by: electrochronic on November 25, 2016, 03:19:27 AM
Yes, Rob is correct in saying a 22uf cap would sub in for a 20uf . In fact , most of these caps have up to a 20% tolerance from rated /stated capacitance , just measure a few and you will see first hand. You could probably get away with using a 33uf in there if you did'nt have 22uf in your stash.

Tip

Incidentally , a error exists at C108 & C110 on the hpf 2x6 rotary switch board , it's reversed . C108 should be 22nf and C110 should be 33nf . Maybe this is already a known issue , not sure.  credit to B2k

Also, quite a few problems with builders having signal problems using 1n751 diodes in the Zener bridge. Best to go with a 1-2% tolerance 5.1v Zener in this location.  The BOM suggests the use of  1n751 diodes but It depends on the manufacturer and date code.  Vishay or Fairchild seem to be good choices, if you can't source the elusive HS2051's
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on November 25, 2016, 08:30:55 AM
You MUST hand select the diodes.  Buy 100 and test them all.  You can find 4 pairs that are that are REALLY close.
My $0.02.
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on November 25, 2016, 12:00:36 PM
Thank you guys for the helpful information.
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 02, 2017, 11:22:00 AM
hey guys,
im just populating my boards. i really like to use original coupling caps. but those 4.7uf tfm wimas are impossible to find. is this a value that one could vary? i can get 3.3uf or 6.8uf....wouldone of these do as a replacement for the 4.7uf caps? cheers
Title: Re: TG1 - advice from any one who has built it...
Post by: mrclunk on February 02, 2017, 11:38:11 AM
i used these
http://uk.farnell.com/panasonic-electronic-components/ecqe2475jf/cap-film-pet-4-7uf-250v-rad/dp/1744798
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 02, 2017, 11:54:28 AM
i used these
http://uk.farnell.com/panasonic-electronic-components/ecqe2475jf/cap-film-pet-4-7uf-250v-rad/dp/1744798

thanks mate. i really want to stick to the wima tfm though. i have some sort of capacitor fetish :) if anyone knows if 3.3uf or 6.8uf will do please let me know. otherwise i can get 2.2uf and will run two of them in parallel
Title: Re: TG1 - advice from any one who has built it...
Post by: mrclunk on February 02, 2017, 12:17:55 PM
Not 100% but isn't that just an output coupling cap? Don't have the schematic but larger should be fine.
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 02, 2017, 12:37:25 PM
Not 100% but isn't that just an output coupling cap? Don't have the schematic but larger should be fine.

thats what i was thinking - but im really  too dumb to tell :) yes its a coupling cap. on the input though.....
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 04, 2017, 07:55:00 AM
ps: i did find some 3.3uf and 1.5uf which should add up nicely. now im  struggeling to understand the bypass pcb. maybe im missing some information? i cant seem to find out how to actually trigger the relais. is there any wiring diagram for how to implement the "iron,byp,clean" switch? thanks a lot
Title: Re: TG1 - advice from any one who has built it...
Post by: Majestic12 on February 04, 2017, 03:45:04 PM
You have to look at the schematic. The 3 way bypass switch consists of two pairs of relais. One does hard bypass from input to output. The second arrangement of relais switch between transformer or IC input and output stage.
Title: Re: TG1 - advice from any one who has built it...
Post by: Strawtles on February 05, 2017, 02:38:06 AM
Hello, what's the best input transformer for this compressor?
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 05, 2017, 07:55:19 AM
Hello, what's the best input transformer for this compressor?

as far as i know its a 10K:10K when used with a 600:600 output iron. see the attached document.
the original emi input trafos in the threads beginning are looking like sowters. im using gardners in and out.
oh - and cheers majestic!
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 05, 2017, 01:56:28 PM
as far as i know its a 10K:10K when used with a 600:600 output iron. see the attached document.
the original emi input trafos in the threads beginning are looking like sowters. im using gardners in and out.
oh - and cheers majestic!

I'm using Gardners too.   Nice to keep the unit British ;)
Title: Re: TG1 - advice from any one who has built it...
Post by: duantro on February 05, 2017, 02:05:02 PM
I'm using Marinair's t1448's  on the inputs
Title: Re: TG1 - advice from any one who has built it...
Post by: Gearsix on February 05, 2017, 02:08:14 PM
I have used Lundahl LL1540
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 05, 2017, 03:37:28 PM
I'm using Gardners too.   Nice to keep the unit British ;)

i love gardners. problem is, they do not show up anymore. im using some weired version on the input. its black and much smaller than the regular ones.  its still listed under the proper octal types in the data sheet. nr MU7570. its black and small (not much bigger than the actual octal socket) i have MU7524 on the output. not finished yet. anyone have experience with the small black gardners?
im not sure if they are a MU7530 in a smaller package or a cheapout version - they weight half.....:)
Title: Re: TG1 - advice from any one who has built it...
Post by: Strawtles on February 05, 2017, 11:29:32 PM
Thank you.
Someone has compared the difference between a transformer and an opamp to balance the input of this circuit?
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 06, 2017, 03:12:46 AM
i love gardners. problem is, they do not show up anymore. im using some weired version on the input. its black and much smaller than the regular ones.  its still listed under the proper octal types in the data sheet. nr MU7570. its black and small (not much bigger than the actual octal socket) i have MU7524 on the output. not finished yet. anyone have experience with the small black gardners?
im not sure if they are a MU7530 in a smaller package or a cheapout version - they weight half.....:)

I like Gardners a lot too. 

I'm using the big silver ones on input & the small black ones on output.   I never had a problem with the smaller ones.    They work great.   I have a stash of both types for future projects .
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 06, 2017, 03:14:04 AM
Thank you.
Someone has compared the difference between a transformer and an opamp to balance the input of this circuit?

I built one with an op amp input and a carnhill output.  Sounded very nice.
Title: Re: TG1 - advice from any one who has built it...
Post by: Strawtles on February 06, 2017, 03:56:36 AM
Thank you Rob
What opamp/circuit have you  used ?
I'd like to try this solution
I'm interested mostly in balancing the input ... the circuit adds his colour, so I don't think it is really necessary an input transformer to increase it
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 06, 2017, 12:42:37 PM
Thank you Rob
What opamp/circuit have you  used ?
I'd like to try this solution
I'm interested mostly in balancing the input ... the circuit adds his colour, so I don't think it is really necessary an input transformer to increase it

I think I used an OPA604 as suggested by Igor.  You're right in that a lot of the vibe comes from the circuit.  If one  does the chandler type circuit I think the transformers would make a much bigger difference since from what people say the input transformer is saturating quite a lot.
Title: Re: TG1 - advice from any one who has built it...
Post by: Strawtles on February 06, 2017, 12:49:13 PM
Rob, do you have this circuit?
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 06, 2017, 06:02:00 PM
Which circuit ?
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 06, 2017, 07:35:56 PM
Strawtles - this might help:
Title: Re: TG1 - advice from any one who has built it...
Post by: Strawtles on February 06, 2017, 11:45:26 PM
Thank you Salomonander but I'd need the OPA604 input schematic
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 07, 2017, 05:49:20 AM
Try that.  I seem to remember using jumpers instead of the relays in places.   It took some head scratching to get it all working because you want half of one varient & half of another working at the same time.
Title: Re: TG1 - advice from any one who has built it...
Post by: Strawtles on February 07, 2017, 07:43:50 AM
Thank you Rob, I'll try to take away what I don't need  :)
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 13, 2017, 01:42:56 PM
does anyone know the value for "CZ" on the bypass board? right next to the big molex header.... i cant find the info. im using 1:1 transformers. cheers

ps: also wondering if this willrun with 2520 opamps or only 990 types.....
Title: Re: TG1 - advice from any one who has built it...
Post by: Majestic12 on February 13, 2017, 02:02:39 PM
does anyone know the value for "CZ" on the bypass board? right next to the big molex header.... i cant find the info. im using 1:1 transformers. cheers

ps: also wondering if this willrun with 2520 opamps or only 990 types.....

The zobel capacitor and resistor depends on the kind of transformer you're using. If the datasheet does not specify a suitable zobel network you can only measure the frequency response and adjust the value to compensate any high frequency bump.

The opamps will run on the same voltage as your power supply. If you are using +-24V it will burn out any opamp that runs on lower voltages (2520 and similar).
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 13, 2017, 02:26:35 PM
thanks majestic.
im using old gardners 600:600 on the output. i dont think there is an offficial recommandation. could you maybe give some rough ballpark values? i would not really know where to start honestly.....
good to know about the opamp. thanks a lot!
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 13, 2017, 05:44:10 PM
thanks majestic.
im using old gardners 600:600 on the output. i dont think there is an offficial recommandation. could you maybe give some rough ballpark values? i would not really know where to start honestly.....
good to know about the opamp. thanks a lot!

Put a square wave through the unit, the look on a scope to see if theere is any ringing happening.  If there isn't you don't need a zobel network.  If there is do some searching & you will find out how to get the right value.  it's a bit trial and error but not difficult.
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 15, 2017, 12:30:30 PM
thanks rob!
ok now maybe for a stupid question.... my frontpanel gives me the option of iron/bypass/clean. i honestly do not care for  transformerless option. although it would be a lot of work - could i have a chandler/emi choice instead? i know id need different transformers but have some carnhills anyways. i guess id need some extra relays to re-configure the input/hold pot but that should be possible.

the only differences are pot arrangement (and value) plus the transformers right? does anyone know which pot chandler used on the tg1? and which carnhills for in and out?

thanks a lot and sorry if this info was already posted....
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 15, 2017, 02:44:24 PM
thanks rob!
ok now maybe for a stupid question.... my frontpanel gives me the option of iron/bypass/clean. i honestly do not care for  transformerless option. although it would be a lot of work - could i have a chandler/emi choice instead? i know id need different transformers but have some carnhills anyways. i guess id need some extra relays to re-configure the input/hold pot but that should be possible.

the only differences are pot arrangement (and value) plus the transformers right? does anyone know which pot chandler used on the tg1? and which carnhills for in and out?

thanks a lot and sorry if this info was already posted....

VTB 9045 on input  VTB1148 on output.  You could probably do this, but you will have to work it out for yourself because I don't think anyone has done this.
Title: Re: TG1 - advice from any one who has built it...
Post by: bruno2000 on February 15, 2017, 03:59:14 PM
thanks rob!
ok now maybe for a stupid question.... my frontpanel gives me the option of iron/bypass/clean. i honestly do not care for  transformerless option. although it would be a lot of work - could i have a chandler/emi choice instead? i know id need different transformers but have some carnhills anyways. i guess id need some extra relays to re-configure the input/hold pot but that should be possible.

the only differences are pot arrangement (and value) plus the transformers right? does anyone know which pot chandler used on the tg1? and which carnhills for in and out?

thanks a lot and sorry if this info was already posted....

Chandler uses Carnhill mic pre XF on input.
Best,
Bruno2000
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 15, 2017, 06:14:17 PM
VTB 9045 on input  VTB1148 on output.  You could probably do this, but you will have to work it out for yourself because I don't think anyone has done this.

cheers. im well aware that i will be alone on this :) but it should not be too complicated. anyone know what pot value chandler used on the input?
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 15, 2017, 07:35:33 PM
cheers. im well aware that i will be alone on this :) but it should not be too complicated. anyone know what pot value chandler used on the input?

10k log
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 15, 2017, 07:47:25 PM
10k log

cheers...
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 24, 2017, 12:58:07 PM
...and im back :)
slightly insecure about the hold control. in order to be less confused i re-drew the shematic as to what i think is right for an emi type unit. could anyone be so kind as to take a look? is the pots wiper shorted with one side? thanks a lot
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 24, 2017, 02:40:04 PM
...and this for chandler?
 
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 28, 2017, 04:50:59 PM
can anyone be so nice and comment on my drawings? are they correct? cheers
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 28, 2017, 06:27:24 PM
They look very nice, but I don't have time to check them.  Sorry.
Title: Re: TG1 - advice from any one who has built it...
Post by: Ilya on March 18, 2017, 09:48:57 AM
Has anybody have any HS2051 spares left? I'd like to buy some. Preferably the ones that give the unity gain.

As a side note, has anybody actually measured the curve of these zeners?
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on April 03, 2017, 01:04:08 PM
...i think im missing an important piece of information. does anyone have the TG_FIX.rar file? i cant find it anywhere for download and need the information. cheers
Title: Re: TG1 - advice from any one who has built it...
Post by: Ilya on April 03, 2017, 01:10:31 PM
Here you go.
Remove the ".txt" from the extension to make it a proper RAR archive.
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on April 03, 2017, 01:32:22 PM
cheers mate. i whish i could help you with the diodes but the only source i knew had barely enough for me. if i find another source ill let you know.
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on April 03, 2017, 03:34:48 PM
gosh this is a tough one for me. i cant use the pcb since my frontpanel is drilled differently (so all switches are on breadboard) and my freaking adhs makes it really tough for me to sort this out. i might be wrong but i think the schematic is drawn wrong in this section.  i tried to make sense of it, redrawing the schematic once again. it would be great if anyone without adhs could chime in and correct me if im wrong.  i drew for a 1:1 emi unit with 10k lin hold. but why is this 270ohms resistor in there? its not in the original schematic.

thanks a lot
Title: Re: TG1 - advice from any one who has built it...
Post by: Ilya on June 30, 2017, 01:03:24 PM
I've got a problem with 1N751A zeners from Central Semi.  In the batch that I received from Mouser all zeners are very noisy. When I replace these with another zeners, everything is fine, but with 751A the unit is a noise machine. Has anybody had anything like that?
Title: Re: TG1 - advice from any one who has built it...
Post by: fripholm on June 30, 2017, 03:53:26 PM
When I replace these with another zeners, everything is fine, but with 751A the unit is a noise machine.

What type are the other Zeners and did the unit work as expected with these?
Title: Re: TG1 - advice from any one who has built it...
Post by: Ilya on June 30, 2017, 04:02:51 PM
What type are the other Zeners and did the unit work as expected with these?

Don't remember which ones, got them in local store. I'm getting  roughly -76dBFS self noise vs -35dBFS with 751A. Unit works as expected, but I get a bit of CV on the signal and can't get rid of that no matter what. Going to tinker a bit more.
Title: Re: TG1 - advice from any one who has built it...
Post by: fripholm on June 30, 2017, 04:48:58 PM
I'm getting  roughly -76dBFS self noise vs -35dBFS with 751A.

Wow, -35dBFS is a lot! I thought my units were noisy but they're far from that. At unity gain from input to output I'm getting about -85dBFS, which translates to roughly -72dBu.

I'm using Multicomp 1N751A from Farnell. They are dirt cheap and I had my six matched pairs after testing about 30 pieces.
Title: Re: TG1 - advice from any one who has built it...
Post by: Ilya on July 01, 2017, 12:20:07 PM
Wow, -35dBFS is a lot! I thought my units were noisy but they're far from that. At unity gain from input to output I'm getting about -85dBFS, which translates to roughly -72dBu.

I'm using Multicomp 1N751A from Farnell. They are dirt cheap and I had my six matched pairs after testing about 30 pieces.

Yeah, this is absolutely unusable. Besides, central zeners are much more expensive.

Do those Multicomp zeners give unity gain or are you using an 1:2 trafo at the output?
Just put an order for a boatload of those zeners, 2 wks leat time though...
Title: Re: TG1 - advice from any one who has built it...
Post by: fripholm on July 02, 2017, 05:34:45 AM
Do those Multicomp zeners give unity gain or are you using an 1:2 trafo at the output?

When calibrated correctly, the compressor stage should have a gain of about +14dB when not compressing - which it has in my case. The output stage provides even more gain, so a 1:1 OPT is more than enough.
Title: Re: TG1 - advice from any one who has built it...
Post by: Ilya on July 02, 2017, 06:37:53 AM
When calibrated correctly, the compressor stage should have a gain of about +14dB when not compressing - which it has in my case. The output stage provides even more gain, so a 1:1 OPT is more than enough.

Well, going through the gain staging of this compressor, and following the notes (~V and dB, written in the original schematics), I would argue that this device requires step-up on the output because it looses around 4 dB. If you look at the output of the VT10, it shows -19.2 dB (~0.085V). After VT10 it goes to the unity gain buffer (VT11/VT12) and to the output attenuator S3. Output stage is designed to have 14 dB gain with the S3 set to 0. Doing simple math: -19.2dB+15dB=-4.2dB. This is almost exactly the figure I'm getting on the output if I set all the levels according to the notes in the schematic.

I wonder where your unit is getting those extra 4 dB. What are the signal voltages on your D2 and D4 anodes? It should be -26dB (~0.039V) with input signal at -0.8dB (~0.707V)
Title: Re: TG1 - advice from any one who has built it...
Post by: fripholm on July 02, 2017, 08:27:54 AM
Sorry, didn't want to add to any confusion. I was going by my own version of the PCB which is slightly different and was designed to give more gain in the output stage (amongst other changes).  :-X
Title: Re: TG1 - advice from any one who has built it...
Post by: Ilya on July 18, 2017, 05:09:30 PM
Got the Multicomp 1N751 zeners from Farnell today. I'm not impressed with the curves at all - they are all over the place and the actual knee is very different from piece to piece. But there's good news as well - they are not as noisy as the ones I've got from Mouser.

With these zeners the signal drops dramatically. I estimate a loss of around 12-16 dB. I suppose (I'm almost sure) this is because they have a rather sharp IV curve. I've managed to find some original zeners as well, but they haven't arrived yet. I have some ideas that may help to bring the gain back to unity with current zeners. Going to play a bit more with this guy until the NOS parts arrive.
Title: Re: TG1 - advice from any one who has built it...
Post by: Randyman... on July 27, 2017, 10:36:28 PM
So, I have a full TG1 kit still sitting in the box with nice AML transformers and all.  Time has gotten the better of me, and between that and a lack of cunning schematic decoding skills and the "Test in situ" type values for this build, I'm looking for a brave trustworthy soul that would be willing to assemble it for a generous fee.  Any takers or leads?  Please PM or email from my profile.

I wish I had more time!!!  I'd prefer to spend my time using this gear in the studio with what little free-time I have these days  ;D

Carry on - Thanks!  8)
Randy V.
Title: Re: TG1 - advice from any one who has built it...
Post by: moltenwok on August 05, 2017, 10:57:16 PM
Hmmm interesting-could be the missing link. I do have an original RS168 here to compare
Title: Re: TG1 - advice from any one who has built it...
Post by: moltenwok on August 05, 2017, 11:33:06 PM
Here she is
Title: Re: TG1 - advice from any one who has built it...
Post by: jplebre on March 17, 2018, 07:32:22 PM
I think I'm about ready to give up on this.

My first DYI acceptance of failure. I just don't have time for this. and this is a £1k door stopper that I have lying around.

Anyone wants it, come make me an offer https://groupdiy.com/index.php?topic=68538.msg872305#msg872305 :)

Title: Re: TG1 - advice from any one who has built it...
Post by: willbart on March 21, 2018, 04:32:20 PM
Hi
Just bought a TG1 clone, with no Link.  I've got a few 2-in/2-out line transformers here, can I use one of these?

I'm not really sure where I'd take the link from either, I don't suppose anyone could give me some ponters could they?

Many thanks!
Title: Re: TG1 - advice from any one who has built it...
Post by: Ilya on March 21, 2018, 05:11:00 PM
Hi
Just bought a TG1 clone, with no Link.  I've got a few 2-in/2-out line transformers here, can I use one of these?

I'm not really sure where I'd take the link from either, I don't suppose anyone could give me some ponters could they?

Many thanks!

You don't need transformers for linking. In the schematic there's a special link connection. You need to connect link points between the compressors and you're good to go.
Title: Re: TG1 - advice from any one who has built it...
Post by: willbart on March 22, 2018, 01:59:22 PM
You don't need transformers for linking. In the schematic there's a special link connection. You need to connect link points between the compressors and you're good to go.

Thanks Ilya
I didn't build this myself, dont have a schematic - have attached a pic of one of the channels - there are a few unused points, can't see one marked Link. I've found an old circuit diagram but can't find an obvious place.
Any ideas?

Also, as well as a normal link, I was hoping to fit an 'emphasis' pot on each side to fade between the sidechains so one can be independently controlled by the other.
Would this work as I'm imagining? I'd have to break the circuits at the link point, then insert the pots there. 
The link switch would just bypass the faders.

Thanks
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on June 07, 2018, 01:44:00 PM
hey,
finally finishing this up. help me out here.... did igor mess up on the opamp holes - or am i stupid? my opamp sockets wont fit the pcb.... i have the standard sockets from capi and the holes are too small....... cheers
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on June 07, 2018, 02:20:48 PM
Sometimes I wonder if the parts Igor had access to were different than mainstream components we normally see here. lol

Just based off of when I was putting the parts list together for this project. Weird lead spacings, diameters, etc for parts that didn't seem to be available or make sense. One of the things that kept me from actually building this up...
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on June 07, 2018, 05:13:21 PM
Sometimes I wonder if the parts Igor had access to were different than mainstream components we normally see here. lol

Just based off of when I was putting the parts list together for this project. Weird lead spacings, diameters, etc for parts that didn't seem to be available or make sense. One of the things that kept me from actually building this up...

so im not stupid! thats great news :) cheers
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on June 07, 2018, 05:50:45 PM
If you look at some of Igors pics you can see he uses  quite a lot of Military surplus parts.  I believe that they are plentiful in Israel.
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on June 08, 2018, 09:26:38 AM
If you look at some of Igors pics you can see he uses  quite a lot of Military surpus parts.  I believe that they are plentiful in Israel.

I knew something was off, or on, whichever way you want to look at it. I was like, 'how is he getting 20uf radial capacitors?' lol

I couldn't source those from anywhere but china at the time I think. I believe they were approx 8mm diameter.
Title: Re: TG1 - advice from any one who has built it...
Post by: mrclunk on June 14, 2018, 06:15:38 AM
I've 4 channels of this half built...
Will get back to them one day.
Did anyone ever work out why the output transistors were burning up?
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on June 14, 2018, 01:19:49 PM
I've 4 channels of this half built...
Will get back to them one day.
Did anyone ever work out why the output transistors were burning up?

I built a couple of these and never had any issues with the output transistors ..................
Title: Re: TG1 - advice from any one who has built it...
Post by: mrclunk on June 15, 2018, 07:13:00 AM
I'll stop being a pussy and get on with it then!
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on June 20, 2018, 09:27:45 PM
alright so i finished wiring this beast up. what a massive pain in the butt!
im too dumb to finish though... maybe one of you can be kind enough to help me out.
so i've got my +-28v lines and sifam meters that ask for 24v. i lack the electronic skills to figure out what to do. please help :)
can i connect it like the bypass led (insertig it between +-28v with a 10k resistor)? the sifams already have a high watt 1k resistor soldered to the led. thanks a lot
Title: Re: TG1 - advice from any one who has built it...
Post by: r2d2 on June 28, 2018, 06:43:49 PM
wow  :o
what a project….
it seem really not friendly for not very expert tech…  :'(

checked most of pages and the docs pack at twin-x
and :
am i wrong or there are headaches for all tastes ?
wrong parts details , partial / incomplete info , etc…

really nobody that have finished a working  51x version
have  docs like some kind of "travel diary" / building guide (at least with the most useful info)
right parts required list , in-out transformers options ,
calibration , etc.. ?
cheers
ps
any source for pot knobs as on attached image?
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on June 29, 2018, 04:58:31 AM
alright so i finished wiring this beast up. what a massive pain in the butt!
im too dumb to finish though... maybe one of you can be kind enough to help me out.
so i've got my +-28v lines and sifam meters that ask for 24v. i lack the electronic skills to figure out what to do. please help :)
can i connect it like the bypass led (insertig it between +-28v with a 10k resistor)? the sifams already have a high watt 1k resistor soldered to the led. thanks a lot

Do the sifam meters have led's or festoon bulbs which are about an inch loong and tubular ?   Maybe a pic would help.  You aren't really giving all the information needed to answer your question.
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on June 29, 2018, 07:32:23 AM
am i wrong or there are headaches for all tastes ?
wrong parts details , partial / incomplete info , etc…

Not really.  I have built 2 working examples of this project & have a 3rd one on the way.  The information is there, it's just not handed to you on a plate like quite a few of Igors projects, & you need to think through what you do.
Title: Re: TG1 - advice from any one who has built it...
Post by: desol on June 29, 2018, 07:42:24 AM
Not really.  I have built 2 working examples of this project & have a 3rd one on the way.  The information is there, it's just not handed to you on a plate like quite a few of Igors projects, & you need to think through what you do.

Maybe you could elaborate on a few things you think people need to think through on this project Rob? I still have my complete(unbuilt) set here.

Just thinking off hand, I was confused by the power wiring. Each board has 2 power connectors I think, as well as the power supply board? Pwr1 &Pwr2? The i/o board also has a power connector. All the power connectors on the boards have arrows pointing different ways. I just assumed they all paralleled off of the main supply? Cheers.
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on June 29, 2018, 07:55:32 AM
Maybe you could elaborate Rob on things you think people need to think through on this project. I still have my complete(unbuilt) set here. Just thinking off hand, I couldn't even figure out the power wiring scheme. Each board has 2 power connectors I think, as well as the power supply board? Pwr1&2?

I found everything is in the documentation with a bit of studying.  I don't think there's anything much to figure out with the PSU connections.   There are probably 2 sets of power connections so you have more than one place you can connect the power &/or you can diasy chain the power from one channel to another if you are doing a stereo set with 2 boards next to each other.  On the PSU board it is probably so you can connect to each of 2 boards.

The i/o boards are a bit tricky to figure out, but not impossible with a bit of experimentation.    This is mainly because there are so many options.     e.g op amp in/trafo out, op amp in/out, trafo in opamp out.   trafo i/o & switchable op amp i/o.    I did one version with trafo & op amp i/o switchable, & in reality I don't notice massive differences.   I did another one that was op amp in & trafo out.   I'm half way through another which I haven't quite decided on.   The i/o boards have regulators on them to knock the +&-28v down to (I think) +&-24v for relays & op amps, but if you used lower voltage op amps you could use different regs.    However with Igors docs, it is possible to figure out what you need.
Title: Re: TG1 - advice from any one who has built it...
Post by: r2d2 on June 29, 2018, 08:53:38 AM
….  This is mainly because there are so many options.     e.g op amp in/trafo out, op amp in/out, trafo in opamp out.   trafo i/o & switchable op amp i/o.    …...
and this is so cool ( many i-o options )

and something like a wiring / setting guide as made for the PPR vari mu comp and many others too
will be a very great help,
(for not very expert tech)

but only who have finished a working unit can give the info about ,

cheers

ps
are the pcb for the 51x version
still available somewhere ?
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on June 29, 2018, 09:57:26 AM
Quote
and this is so cool ( many i-o options )

Well in my experiences it doesn't make massive differences to the sound & it makes it difficult for peopl like yourself to figure out how to hook it up.

Quote
and something like a wiring / setting guide as made for the PPR vari mu comp
will be a very great help,
(for not very expert tech)

but only who have finished a working unit can give the info about ,

Yes, I can understand that, but I think Igor wanted people to learn from the process of building, & having aa paint by numbers approach doesn't get people thinking about things.

cheers

ps
Quote
are the pcb for the 51x version
still available somewhere ?

Igor disappeared about 4 years ago so unless someone else brings something out like this you will have to find them used.
Title: Re: TG1 - advice from any one who has built it...
Post by: Michael Tibes on June 29, 2018, 10:00:23 AM
and this is so cool ( many i-o options )

and something like a wiring / setting guide as made for the PPR vari mu comp
will be a very great help,
(for not very expert tech)

The wiring was actually pretty well documented by Igor, though it might be confusing at first because of all the possible options. The calibration not so much though, I believe it really requires understanding the provided documents and all the information that came to light during the initial consolidation phase. Or was there ever a calibration document that I missed?

Michael
Title: Re: TG1 - advice from any one who has built it...
Post by: r2d2 on June 29, 2018, 10:49:37 AM
The wiring was actually pretty well documented by Igor, though it might be confusing at first because of all the possible options. The calibration not so much though, I believe it really requires understanding the provided documents and all the information that came to light during the initial consolidation phase. Or was there ever a calibration document that I missed?

Michael
Thanks Rob for info !!!

about docs " pack" i found a :
"rev 2 - 10th may"
and a :
"rev 2 -10th may fixed"
but seem not differences , anybody know what is related to " fixed " ?
(the cable wires / jumpers on main pcb ? )

about calibration i found here some page back a doc called "TG12413 SET UP procedure"
that seem a calibration "notes" , but still not understand it ,
check attached

any chance for a "summ" doc that include info about :
- power supply : rack version 28v and 51x (500) 24v ( ? ) and related connections,
- input output stages : ic - transformers options and related modifications if required ,
- transistors type and replacements :  unfortunately among all the documents included inside the various "docs packs" , not found a page with included a "summ" info related ,

cheers
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on June 29, 2018, 11:06:04 AM
Sorry I don't know anything about the 500 version.   Also I haven't built a TG for some time now, so without going through everything I can't help you.  Basically I don't have the spare time.   I'm pretty sure that all the info  needed was on this thread or in the docs.   I do remember faffing around with the i/o board a bit to configure how I wanted.
Title: Re: TG1 - advice from any one who has built it...
Post by: r2d2 on June 29, 2018, 11:58:12 AM
So really thanks Rob !

…...I'm pretty sure that all the info  needed was on this thread or in the docs.  ….
… probably "yes" ,
but 39 pages  near to 40 , to read with deep attention too…
what a "waste"  : (    
( it require more time than build a full working unit  :o )

ok the Igor is "lost" (forever ?)  somewhere in his (better? ) interests… ( Amen )

then no 1 person motivated with direct ($$$) interest to follow the developments,
put together and update a "Meta build guide" (as for many other projects available here)
or write a "summ" paper with the "essentials" info to know ,
(as wrote on the post above )

….waiting something from the sky...
(….sound like a famous / infamous song title..  ;D  )
cheers
Title: Re: TG1 - advice from any one who has built it...
Post by: weiss on July 09, 2018, 06:55:18 PM
The output volume with my tg1 on one channel is slightly louder compared to the other. What would be the easiest way to fix that so i can match the output switches?
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on July 10, 2018, 04:25:45 AM
The output volume with my tg1 on one channel is slightly louder compared to the other. What would be the easiest way to fix that so i can match the output switches?

Did you match the diodes between channels ?
Title: Re: TG1 - advice from any one who has built it...
Post by: weiss on July 10, 2018, 06:16:20 AM
Did you match the diodes between channels ?

yes they are matched
Title: Re: TG1 - advice from any one who has built it...
Post by: Ilya on July 10, 2018, 10:30:54 AM
If the level mismatch is not large (1-2 dB), you can trim it out with AOT resistor in the GR section (don't have the schematic at hand, so can't tell you which AOT exactly). It sets the idle current of the zeners, so it should work for small level adjustment.
Title: Re: TG1 - advice from any one who has built it...
Post by: weiss on July 10, 2018, 01:27:59 PM
If the level mismatch is not large (1-2 dB), you can trim it out with AOT resistor in the GR section (don't have the schematic at hand, so can't tell you which AOT exactly). It sets the idle current of the zeners, so it should work for small level adjustment.

Thanks Ilya! Do you mean AOT1,2 for Unity Gain ? It's max. 2dB.
Title: Re: TG1 - advice from any one who has built it...
Post by: Ilya on July 10, 2018, 02:00:01 PM
Thanks Ilya! Do you mean AOT1,2 for Unity Gain ? It's max. 2dB.

Yes, those AOTs. They are good for small adjustments, and if your zeners are not that well matched (between the corresponding pairs of stereo channels) this might not do the trick. But it's a good starting point. I'd check compression curves after gain matching.
How close are your zeners matched? What did you use for matching?
Title: Re: TG1 - advice from any one who has built it...
Post by: weiss on July 10, 2018, 07:32:53 PM
Yes, those AOTs. They are good for small adjustments, and if your zeners are not that well matched (between the corresponding pairs of stereo channels) this might not do the trick. But it's a good starting point. I'd check compression curves after gain matching.
How close are your zeners matched? What did you use for matching?

I bought the device from a member here, no idea how close..
I use the trimmers (hold calibration) behind the front panel to make the channels equally loud but only in dual mode. As soon as I enable 'link‘ it is off again for about 0.4 dB. The funny thing is, if i turn the hold switches CW the output level deviation increases.
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 11, 2019, 08:06:51 AM
hey there,
i really hoped i would not have to bump this again - but i do. i took a long break from this and finally wired and fired this thing up. most things work as they should, but the hold control does not do what its supposed to. maybe one of you has an idea. i had to wire all switches by hand since the pcb did not fit my frontpanel and im pretty sure i messed up somewhere in there.

when fully engaging the hold switch (i used a 1x12 switch) the unit works  as i would it expect to. but when lowering the hold, the level drops and the vu meter shows increased reduction (regardless of input level). it still compresses - but only the spikes above the static reduction shown on the meter.  when no signal is applied at the input and hold fully deengaged, the vu meter reads full reduction which then dops the further i engage the function. this also happens in thd mode.

anyone have an idea? i was confused regardig wiring the hold switch since igor released that "tg fix"  document and the original shematic seemed wrong. i did redraw the shematic accordingly. but maybe i did that wrong? i'll attched my version of the shematic to this post. the hold schematic is at the bottom right. maybe someone could be so kind and take a look? maybe i redrew it incorrect. ill attach the emi shematic too.

if ayone has an idea where i might have messed up - any help would be apprecited. im scratching my head. i most likely shorted something that is not supposed to have a connection. but what ? :)

thanks!

ps: could a reversed or broken D12 explain the behaviour?
        R115 is jumped
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 11, 2019, 09:00:29 AM
this is the original emi shematic:
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 11, 2019, 10:52:05 AM
just noticed that the lower the signal i feed - the more compression i get :(
Title: Re: TG1 - advice from any one who has built it...
Post by: Ilya on February 11, 2019, 01:28:33 PM
Well, until I saw your last message I was going to say that that's the correct behavior.
When you turn the hold one side you get higher output level and more compression. When you turn the hold another side you get less output level and less compression. You last message puzzles me though. I can't understand how you can get more compression by lowering the level.
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 11, 2019, 01:47:02 PM
Well, until I saw your last message I was going to say that that's the correct behavior.
When you turn the hold one side you get higher output level and more compression. When you turn the hold another side you get less output level and less compression. You last message puzzles me though. I can't understand how you can get more compression by lowering the level.

hey thanks for the rely. maybe its correct after all? but it behaves so akward. when i disengage the hold pot, the meter reads full reduction and i hardly get any signal going through..... is that normal?

ps:  yes, the reduction gets a lot more obvious when i lower my input signal. half the signal input and every kick drum seems to trigger the unit more than before.

ps2: my fast/slow switch seems to affect the release and attack both. is that normal?
Title: Re: TG1 - advice from any one who has built it...
Post by: weiss on February 11, 2019, 01:51:36 PM
hey thanks for the rely. maybe its correct after all? but it behaves so akward. when i disengage the hold pot, the meter reads full reduction and i hardly get any signal going through..... is that normal?

ps:  yes, the reduction gets a lot more obvious when i lower my input signal. half the signal input and every kick drum seems to trigger the unit more than before.

ps2: my fast/slow switch seems to affect the release and attack both. is that normal?

seems to be normal
the fast / slow has influence on the two settings
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 11, 2019, 01:55:06 PM
seems to be normal
the fast / slow has influence on the two settings

thanks, just to clarify: yes (normal) in regards to "ps2" (fast/slow) or my entire issue? cheers
Title: Re: TG1 - advice from any one who has built it...
Post by: weiss on February 11, 2019, 02:01:37 PM
it is normal if you pull the hold pot completely to one side, that more compression appears and therefore levels change, on the other hand if you engage the fast/slow switch, it affects both, release and attack time constants.

i quote from the manual

Quote
The Hold control RV1 is a 10K linear potentiometer. It is fed through R63
from the point which is decoupled from the +20V supply by R45, 016, and which
feeds the collector of VT17 and the emitter of VT21. This results in the upper end
of the Hold control being at about +10V. The potential from the slider is connected
via D12 to the junction of D11 and R47. Thus the Hold control sets a potential
below which the effective control voltage cannot fall. This detennines the increase
of gain with falling signal level, and henoe controls the amount of compression or
Iimiting.

The earthy lead from the Recovery switch is taken to the slider of the Hold
control so that the discharge of C18 is exponential to the potential on the slider.

Terminal 36 is connected to a ganging switch. When this is switched to the
‘gang’ position this terminal is connected to the corresponding terminal of the
limiter in the other channel of the stereo pair. In this condition both units are
controlled by whichever control voltage is higher, and the Recovery controls should
be set to the same setting.
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 11, 2019, 02:31:27 PM
hey weiss,
thanks a lot. ill study what you have attached. i always need a little longer for this :) but there is certainly something wrong. when i feed a low signal i can clearly hear the attacks triggering the compressor in my signal. i hope i explain it right ... but i can hear the impulses that are supposed to feed the compressor mixed in with my signal on the xlr outs. that cant be right. i need to figure this out. most likely a short somewhere.
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 11, 2019, 02:32:39 PM
What you describe sounds normal to me.  WHen you operate the hold control the meter displays a static level & any compression that goes on is superimposed on that static level.

It is worth saying that this compressors controls are weird & it  drives differently to any other compressor I have.   I   
Title: Re: TG1 - advice from any one who has built it...
Post by: weiss on February 11, 2019, 02:33:37 PM
hey weiss,
thanks a lot. ill study what you have attached. i always need a little longer for this :) but there is certainly something wrong. when i feed a low signal i can clearly hear the attacks triggering the compressor in my signal. i hope i explain it right ... but i can hear the impulses that are supposed to feed the compressor mixed in with my signal on the xlr outs. that cant be right. i need to figure this out. most likely a short somewhere.
maybe there is a bleed somewhere? did you already check for continuity where there shouldn't be?

What you describe sounds normal to me.  WHen you operate the hold control the meter displays a static level & any compression that goes on is superimposed on that static level.

It is worth saying that this compressors controls are weird & it  drives differently to any other compressor I have.   I

that is true indeed. you have to get used to it. not straight forward like an ssl
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 11, 2019, 02:35:27 PM
maybe there is a bleed somewhere? did you already check for continuity where there shouldn't be?

thats what im about to do. if you happen to have an idea where to look first, go ahead - im a noob :)
or hold on - doesn't a compressor work with reversed phase somehow? (such a noob) could i have messed tis up by wiring my sidechain reversed?
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 12, 2019, 01:32:37 PM
ok so since i did not know what to do i simply went through the test voltages found in the original shematic.
and i certainly have wrong voltages. most of them are fine. except for VT5 and VT6 and the surrounding negative voltages. collector of VT5 should be -26V (testpoint T_B on Igor) and emitter of VT6 should be -10,7V. now collector of VT5 gives me +10,5V and emitter of VT6 is +6,5V. im having no negative voltages there. im also getting these 6,5V on the diode D5 (across meter) instead of -16,8V. no meter connected.

so now im lacking the basic electronics skills. what could prevent that negative voltage from happening? where is it created? am i looking for a broken transistor around VT5 & VT6?
Title: Re: TG1 - advice from any one who has built it...
Post by: Ilya on February 12, 2019, 01:43:53 PM
These negative numbers around that part of the circuit are NOT voltages. It's signal level at that point.
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 12, 2019, 03:02:36 PM
These negative numbers around that part of the circuit are NOT voltages. It's signal level at that point.

thanks. but are you certain about this? except for that part of the schematic, all other test numbers show up for  me in dc on my multimeter. cant be coicidence...
or do you mean all numbers missing a V for voltage?
Title: Re: TG1 - advice from any one who has built it...
Post by: Ilya on February 12, 2019, 04:25:50 PM
Yes I am. I traced the signal through my unit and got those values (or pretty close to them).

Edit: generally, all numbers with dots before them are AC signal voltage, most "-xxx" numbers are dBu values of the signal. In the sidechain there are some DC voltage readings, but in the input section it's almost everything AC.
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 14, 2019, 11:19:18 AM
it works after all!!
gosh what a massive pain in the butt. i did draw the schematic wrong. the auto release caps were connected to the wrong side (they need  to be joined with  R107 instead of R106 -  rest as on my schematic). plus i had a short on one of my release switches. but now both channels work as they should.

it might be a stupid question after having all these issues. but could anyone think of a simple mod that would turn the hold switch into a regular threshold? no more messing with the level or vu meter? i'd much prefer that honestly.
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 14, 2019, 01:07:09 PM
it might be a stupid question after having all these issues. but could anyone think of a simple mod that would turn the hold switch into a regular threshold? no more messing with the level or vu meter? i'd much prefer that honestly.
If you have Igors documentation it explains how to do this jumpering etc on the i/0 board.
Title: Re: TG1 - advice from any one who has built it...
Post by: weiss on February 14, 2019, 01:08:41 PM
it works after all!!
gosh what a massive pain in the butt. i did draw the schematic wrong. the auto release caps were connected to the wrong side (they need  to be joined with  R107 instead of R106 -  rest as on my schematic). plus i had a short on one of my release switches. but now both channels work as they should.

it might be a stupid question after having all these issues. but could anyone think of a simple mod that would turn the hold switch into a regular threshold? no more messing with the level or vu meter? i'd much prefer that honestly.

I'm glad you figured it out!
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 14, 2019, 06:37:15 PM
If you have Igors documentation it explains how to do this jumpering etc on the i/0 board.

hey,
i do have all the documents. but not really an idea on how to go about it. could you maybe elaborate. i do know where everything goes on the boards - i lack the engineering knowledge.
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 14, 2019, 07:56:47 PM
hey,
i do have all the documents. but not really an idea on how to go about it. could you maybe elaborate. i do know where everything goes on the boards - i lack the engineering knowledge.

I think you use a pot connected to where it says i/p pot (instead of jumpering the pads) on the i/o board & leave out the hold pot, but as with all Igors projects he doesn't give you it on a plate.  The 3 that I have built have all been EMI versions so I don't know for sure.   However read the attached folder (part of his documentation) & it may convince you that it is better to keep the hold control like the EMI version rather than the Chandler version wth the input pot.
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 18, 2019, 07:42:16 AM
I think you use a pot connected to where it says i/p pot (instead of jumpering the pads) on the i/o board & leave out the hold pot, but as with all Igors projects he doesn't give you it on a plate.  The 3 that I have built have all been EMI versions so I don't know for sure.   However read the attached folder (part of his documentation) & it may convince you that it is better to keep the hold control like the EMI version rather than the Chandler version wth the input pot.

thanks Rob,
actaully i knew about that option. it only works with 1:2 transformers and im using 1:1 - no intend of changing that. i was thinking of a threshold in a 33609 fashion. just threshold with no effect on volume or the vu meter. but i guess that would be its own little project :)
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 18, 2019, 08:42:53 AM
Maybe you could connect the 1:1 transformer to the op amp input & make the op amp have a 2x gain to get your level right.

Or do away with the input transformer & use an op amp input.   The first one of these I built you could switch betweenvintage Gardeners transformers i/o & op amp i/o.   I found that the characteristic sound was the pretty similar either way.  I think a lot the vibe comes from the electronics.  One version I built had a Neve style o/p transformer with an op amp input, another had op amp in with Jensen output tranformer, they both sounded very nice.   All of these boxes sound good.
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 18, 2019, 09:40:11 AM
Maybe you could connect the 1:1 transformer to the op amp input & make the op amp have a 2x gain to get your level right.

Or do away with the input transformer & use an op amp input.   The first one of these I built you could switch betweenvintage Gardeners transformers i/o & op amp i/o.   I found that the characteristic sound was the pretty similar either way.  I think a lot the vibe comes from the electronics.  One version I built had a Neve style o/p transformer with an op amp input, another had op amp in with Jensen output tranformer, they both sounded very nice.   All of these boxes sound good.

thanks mate,
ill just keep it as it its. my transformers sound super nice and i dont want to mess with that. now three things im wondering about

- im using 1:1 trafos and have the option to switch between trafos and opamp (opa640). now when switching to the ic version the output is unbalanced. could i balance it by modding the second (now empty) opamp slot on the bypass board?

- my opamp signal is slightly louder. plus im feeling as if i loose a little bass. how can i adress that?

- when switching between comp in / hardware bypass i get some clicks - anything i could do about it (like diodes around the relais)?


thanks a lot
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 18, 2019, 12:54:14 PM
- im using 1:1 trafos and have the option to switch between trafos and opamp (opa640). now when switching to the ic version the output is unbalanced. could i balance it by modding the second (now empty) opamp slot on the bypass board?

I think output isn't unbalanced. I think it is ground compensated, which is good.

Quote
- my opamp signal is slightly louder. plus im feeling as if i loose a little bass. how can i adress that?

Use some eq before or after TG ?

Quote
- when switching between comp in / hardware bypass i get some clicks - anything i could do about it (like diodes around the relais)? 

The bypass board already incorporates back e.m.f diodes for the relay coils.


thanks a lot
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 19, 2019, 08:56:44 AM
hey guys,
i do need help after all. my weired parasitic effects are back - it seems to depend on calibration. please let me try to explain my issue again:

first off, i think i have the wrong meter? https://www.don-audio.com/Sifam-AL20-6-7-Retro-VU-Meter-Set
anyways thats what i use - but the problems happen with the meter detached as well.

so when i feed no signal and have hold on 0, the needle lingers somewhere in the middle - just about where the original emi meter might have had its 0 marking.
when i fully engage hold, the needle goes down - past 0 on the meter and everything goes bollocks (past the 0 marking). the unit still works with good volume inputs. but when i feed the same signal quieter, the compressor seems to get overtriggered by any little peak reaching the threshold. backing off one position on the hold fixes the issue. as does increasing the input signal.
also, when i go to full hold (needle goes past 0) and back off a step - the needle jumps - then settles again. doing the same thing a step further down doesnt cause the needle jump. so everything with full hold and low input causes issues.

now i am able to cure this by playing with aot1, aot3 and aot5. all of them seem to have an effect on my needles position in full hold position. i trimmed aot1 to not allow the needle past 0 in THD and full hold. and aot3 and aot5 making sure the needle does not go past 0 in limit and hold full. but during this calibration the needle also got jumpy around the 0 mark. still - seems to work now that i set positions that are not past 0 on the meter.

but is this normal behaviour? or do i have a ghost in my system and just found a lucky calibration position?



Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 21, 2019, 10:04:28 AM
ill just keep talking to myself here.... maybe someone replies after all :)
now first of all i get the jumpy meter with no in or output connected. its just in the circuit. when i try to get the needle to 0 on full hold it starts jumping up from 0 and back down. i can varie the lenght of the "jump" by the release switch. so its something triggering the sidechain falsely. also my 10v voltage on the hold switch gets jumpy on max hold.

now another issue im having is that i cant adjust the voltage between VT5 and VT6... which might cause the entire problem.
i am capable of adjusting AOT7 therefore matching the basesupply on VT5 & VT6. this gets the collector voltage to almost the same - but AOT 10 shows no effect at all on T_B and T_C.

matching the base volatges via AOT7 actually cures the needle jumping! but why does AOT 10 not allow me to fully match this (resistance from AOT10 to 20v rail moves correctly)?
any ideas? could my initial zener matching be too bad and responsible for all this?

thanks a lot!

another thing im wondering and need to clarify is the set up procedure. step 5 says:

set unity gain. Set HOLD and OUTPUT to 0 and switch the compressor side chain out by selecting THD. If you have the correct 2.5mA FS meter it should read zero, if not adjust the 100K trim pot until it does. Apply 0dBu (0.775V) 1KHz sine wave to input and measure the output on a oscilloscope or DMM. You need to adjust AOT1/AOT2 so that you get 0.775V at the output.

now, with a 5k linear switch and R115 being 5k for my hold - where would my "Hold 0" be as to referred in the set up? to the far left or in the middle position?
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 21, 2019, 12:17:57 PM
Quote
set unity gain. Set HOLD and OUTPUT to 0 and switch the compressor side chain out by selecting THD. If you have the correct 2.5mA FS meter it should read zero, if not adjust the 100K trim pot until it does. Apply 0dBu (0.775V) 1KHz sine wave to input and measure the output on a oscilloscope or DMM. You need to adjust AOT1/AOT2 so that you get 0.775V at the output.

now, with a 5k linear switch and R115 being 5k for my hold - where would my "Hold 0" be as to referred in the set up? to the far left or in the middle position?

Think you need to look at the bit that says "switch the sidechain out". To me this means setting the thd control so no compression is happening ?
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 21, 2019, 12:43:20 PM
yes sidechain is out. but since the hold position still determines the output level in thd mode (at least on my unit) its crucial to know if igor referred to 0 as fully ccw or center dent of a hold pot as on the vintage units.... i think he means center of a 10k pot. but then where is this on my 5k switch & 5k resistor setup?

i dont get it. "Apply 0dBu (0.775V) 1KHz sine wave to input and measure the output on a oscilloscope or DMM. You need to adjust AOT1/AOT2 so that you get 0.775V at the output." how would AOT1 have any effect on the output level in THD mode when this grounds the entire sidechain? at least on my unit AOT1 has no effect on output level in THD the hold control does.
Title: Re: TG1 - advice from any one who has built it...
Post by: Ilya on February 21, 2019, 01:25:42 PM
how would AOT1 have any effect on the output level in THD mode when this grounds the entire sidechain? at least on my unit AOT1 has no effect on output level in THD the hold control does.

These set the amount of current through zeners. So yes, they affect overall signal level both in THD and compressor modes.
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 21, 2019, 01:28:52 PM
The way I see it is AOT 1 & 2 affect the way VT23 & VT24 behave which the C.V output comes from.   The C.V output is never disconnected from the audio part of the amp.   Therefore it should have an effect on the level.
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 22, 2019, 05:08:18 PM
Thanks Rob,
i have tow question that might lead to something:

- my hold pot actually changes my main +-20V lines. by .05V  is that ok?

- the control voltage at AOT1 acutally reaches negative values (-0.2V) - thats on full hold. whenever it reaches these minus
   values things go bad. when i dial back the hold from a negative (full hold) control voltage the needle jumps. when i dial it back
   from the slightest (almost full hold) positive control voltage the needle dials back normal. are negative control voltages  ok?

-  i just found that i have a BCY71 in VT27 position. the original schematic asks for a BCY34. Igor used a 214 and i thought it
    would be ok to use BCY71. but maybe its not ?

thanks!
Title: Re: TG1 - advice from any one who has built it...
Post by: Rob Flinn on February 22, 2019, 06:00:38 PM
Maybe the bcy 71 has a different pin out ?  I thnk Igor uses a BC214C.  The "C" is important because a BC214 without the "C" has a different pin out.
Title: Re: TG1 - advice from any one who has built it...
Post by: xarolium on February 25, 2019, 04:29:41 AM
Wow, -35dBFS is a lot! I thought my units were noisy but they're far from that. At unity gain from input to output I'm getting about -85dBFS, which translates to roughly -72dBu.

I'm using Multicomp 1N751A from Farnell. They are dirt cheap and I had my six matched pairs after testing about 30 pieces.

Hi there,

I'm experimenting exactly the same issue. More or less -36dBFS of background white noise with 1N751A Central Semiconductor Zener Diode.
Does anybody experiment other 5.1V zener Diode like BZX55C5V1, 1N5231A, TZX5V1D to get better S/N ratio ?
It seems that Central Semiconductor Zener are very noisy, what about others manufacturers like On semiconductor or Vishay ?

Your help are welcom ;)
Title: Re: TG1 - advice from any one who has built it...
Post by: fripholm on February 25, 2019, 05:47:48 AM
Does anybody experiment other 5.1V zener Diode like BZX55C5V1, 1N5231A, TZX5V1D to get better S/N ratio ?

As you've quoted, I was using Multicomp 1N751A from Farnell in both of my units which did not produce excessive noise. But I wanted to see if even this could be improved and have since tried 1N5231B TR from Mouser (Central Semi) in my stereo unit and the noise floor has dropped almost 3dB compared to the 1N751A.

So you should try different brands to see if that helps the noise. At 0,116 Euros for a diode (when you buy 100) you're not losing too much ;)
Title: Re: TG1 - advice from any one who has built it...
Post by: xarolium on February 25, 2019, 05:54:19 AM
As you've quoted, I was using Multicomp 1N751A from Farnell in both of my units which did not produce excessive noise. But I wanted to see if even this could be improved and have since tried 1N5231B TR from Mouser (Central Semi) in my stereo unit and the noise floor has dropped almost 3dB compared to the 1N751A.

So you should try different brands to see if that helps the noise. At 0,116 Euros for a diode (when you buy 100) you're not losing too much ;)

Thank you for your reply. I think i will try 1N5231B and BZX55C5V1 from vishay.
Do you know if all those 5V1 Zener diode have the same curve response ? or do you notify a difference response time between 1N751A and 1N5231B ?
Title: Re: TG1 - advice from any one who has built it...
Post by: fripholm on February 25, 2019, 07:37:47 AM
The timing of the compression is controlled by the sidechain - the type of diodes shouldn't affect this. The compression knee and/ or distortion behaviour might change a bit from type to type but in my case I didn't notice anything different.
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on February 25, 2019, 10:10:03 AM
hey guys,
i think my jumpy needle and weired artefacts are gone by replacing VT27 with a BCY34. need to do some more testing but so far the unit behaves a lot better.
still, im nowhere near unity gain with my hold in the middle (went back to a 10k switch) and thd selected.  i might have to try different zener diodes too. at the moment im using silver motorola 1n751a.
Title: Re: TG1 - advice from any one who has built it...
Post by: Undos on February 27, 2019, 05:57:57 AM
Hi

I have spare Original Fairchild 1N751A Zeners from my TG Limiter built which I recently put up on the black market. They worked great in my unit, when matched. I haven't noticed any noise or gain problems.
Shoot me a message when interested.
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on March 02, 2019, 01:08:47 PM
i tried some 1n751 by RND today - matched them perfectly and ended up in a sea of noise. dont use these!!

i still can not set  AOT10 for adjusting the collectors for VT5 and VT6. the trimmer just doesnt do anything. when measuring resistance it does its job fine. i can measure 0-20ohms to the +20v line but the collector voltage doesnt change a bit :(
AOT7 has an effect on it but nothing on AOT10. any ideas?
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on March 03, 2019, 07:55:15 AM
i think its time to throw the towel. i just dont get this thing working as it should . without a reference im lost.
now, is there anyone who could help me here in the eu? anyone with a working unit, that could maybe troubleshoot one board for me? i dont have a fortune left - but i can pay. i invested too much to give up on this. any help is appreciated. cheers
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on March 05, 2019, 05:35:18 AM
ok - i dont get any feedback. darn im too late with this build. perhaps someone can still try to answer me some questions:

- should AOT10 have an effect with no input signal and no compression?  or is this AOT just working under hard compression?
   my AOT10 just doesnt do anything. i can balance with AOT7 but AOT10 has no effect. then again this AOT is wired compreletly
   different than in the original schematic.

-could my problems stem from low hfe from my transistors? im just running out of ideas and my hfe is rather low. they are all around 180-250 hfe. all pairs  are matched.

- i have an extra ground wire running to the psu from my starground. is this the way to go, or should the psu receive its ground
  via the mounting screws only? did you guys connect your PE cables?

- my 10v going to the hold switch do not stay constant. it varies between 10v (0 hold) and 9,6v (full hold). is this ok?
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on March 05, 2019, 09:01:53 AM
to state my problem again:
full hold does bad things. the needle gets jumpy and the compressor over sensitive. when switching from full hold to a lesser position the needle jumps and i hear a click. the unit also gets slightly hummy with full hold. when im in THD mode the last step on the hold switch gives me a big gain increase compared to the others. i also hear that click in THD mode when i switch back from full hold. and lots of the parts (everything around VT5 & VT6) make my vu needle jump when touching them with my test probe (not earthed just going to my fluke). this doesnt happen in any other hold position.

also the voltage going from VT3 and VT2 to the sidechain kind of flips in the last hold setting.
they always stay around -9v. but on full hold the voltages mess up. collector of VT2 goes to -6v while collector of VT3 goes to -12v. i can somewhat balance this out by AOT7. the needle gets a more stable then - but its still not right. removing the zener diodes keeps the voltage stable even on full hold.

and no effect from AOt10 nor unity gain with hold in the middle.

PS: actually AOT10 does a tiny bit. when hold is fully off it does +-0.3Vdc. with hold in the middle it does +-.01 and nothing with full hold.
Title: Re: TG1 - advice from any one who has built it...
Post by: etheory on March 07, 2019, 07:54:24 AM
Due to popular demand, please find attached a working LTSpice simulation of the TG1 compressor for educational reference.
I gave this model to previous forum member Bruno2000 in order to help him debug his build.

It might be useful for people to play with and get an idea about the voltages and currents to expect at various points in the circuit.

If for whatever reason this is inappropriate, please, by all means, remove this post.

I hope it helps some people!

Change the extension to .asc to load it in LTSpice.
Title: Re: TG1 - advice from any one who has built it...
Post by: salomonander on March 07, 2019, 08:15:25 AM
thanks a lot i really appreciate it! best