TG1 - advice from any one who has built it...

[mrclunk]

I'll stop being a pussy and get on with it then!

 

[salomonander]

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

 

[r2d2]

wow 
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?

 

[Rob Flinn]

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.

 

[Rob Flinn]

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.

 

[desol]

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.

 

[Rob Flinn]

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.

 

[r2d2]

….  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 ?

 

[Rob Flinn]

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.

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

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.

 

[Michael Tibes]

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

 

[r2d2]

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

 

[Rob Flinn]

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.

 

[r2d2]

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  )

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

 

[weiss]

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?

 

[Rob Flinn]

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 ?

 

[weiss]

Did you match the diodes between channels ?

yes they are matched

 

[Ilya]

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.

 

[weiss]

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.

 

[Ilya]

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?

 

[weiss]

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.