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

[salomonander]

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

 

[salomonander]

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?

 

[salomonander]

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.

 

[etheory]

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.

 

[salomonander]

thanks a lot i really appreciate it! best

 

[31cc7]

The left channel on my DR-ZEN2 sadly died. There is no output signal, however, the gain reduction needle correctly reacts to the incoming signal. If I switch to THD mode and turn the input to the max I'd hear some of the input, but very faint and distorted.
Everything looks okay, no evidence of burnt parts or cold solder joints. I removed and checked power transistors (2N4898 and 2N4910 and they are fine). I checked two other transistors near those and they are fine too.
I also checked the output transformer and it is fine.
I noticed that 2N4898 gets noticeably hotter than the same one on the working channel.
I am also not sure what could have caused it.
I am writing maybe someone had similar problem and can recall it.
Worst case scenario I will have to pull parts one by one and test them, probably starting with semiconductors.
If I find the fault I will definitely update.

 

[31cc7]

I couldn't find anything so I started staring at the board... Then I found a little scratch just next to the power transistor mounting hole. That scratch was the ground and it seems like as time passed somehow connection from transistor was created and it was shorting to ground and not passing signal through. I put a plastic washer underneath the transistor and it now works fine!
Can't find other explanation 

 

[maxwall]

Seems I see a lot of very overlooked simple mistakes that make this project difficult for builders. Understandably,  diy'ers get too rushed to finish the TG out of shear excitement and make simple errors along the way , in the end, becomes really difficult to locate once the board is populated.  It can be a overwhelming job to back track and track down the culprits and effects on emotional distress can keep your troubleshooting efforts in the blind.

I'm not exempted, done my share in the learning process.

Those output transistors 2N4898/4910 should be slightly raised off the board with short standoffs, heatsink ,and mica insulator to keep them cool and happy. You will also get  better s/n too.

Trying to run Lukes ( etheory ) spice file in LTSpice version XVII with text file extension renamed to .asc  It comes up with some errors - no potentiometer found . When I run the simulation it does not recognize any of the transistors. Is there a library that needs to be loaded for the components ? Thought the library for these simple transistors would already be there. When I try to save the file it tells me that all components will be erased, another strange error. What the .......

 

[etheory]

Trying to run Lukes ( etheory ) spice file in LTSpice version XVII with text file extension renamed to .asc  It comes up with some errors - no potentiometer found . When I run the simulation it does not recognize any of the transistors. Is there a library that needs to be loaded for the components ? Thought the library for these simple transistors would already be there. When I try to save the file it tells me that all components will be erased, another strange error. What the .......

I've attached the potentiometer model as a .zip of the .asy and .sub files.
When you've downloaded the Potentiometer.txt file, rename it to Potentiometer.zip, then uncompress it.
As for the transistors, any model will do.
There are BC109 and BC177 models all over the internet.
I provided the file completely as is, I didn't intend it to work unless you were capable of editing files yourself.
If anyone needs specific help, please let me know.

 

[etheory]

Downloaded the .txt file and renamed it to  ".zip but 7zip ( my utility ) does not recognize it as a compressed file.  Usually it will give me the option to extract the file.

That's weird, I just tried it then myself and it worked perfectly?

Also , how do you load a transistor profile into LT Spice , is there a online resource guide or tutorial recommended.

In your install in C:/ you will find a file called "C:\Program Files\LTC\LTspiceXVII\lib\cmp\standard.bjt", you can add models to it directly.

I used these ones:

.MODEL BC109B NPN(Is=7.049f Xti=3 Eg=1.11 Vaf=59.59 Bf=381.7 Ise=59.74f Ne=1.522 Ikf=3.289 Nk=.5 Xtb=1.5 Br=2.359 Isc=192.9p Nc=1.954 Ikr=7.807 Rc=1.427 Cjc=5.38p Mjc=.329 Vjc=.6218 Fc=.5 Cje=11.5p Mje=.2718 Vje=.5 Tr=10n Tf=438p Itf=5.716 Xtf=14.51 Vtf=10)

.MODEL BC109C NPN(Is=7.049f Xti=3 Eg=1.11 Vaf=28.14 Bf=677 Ise=7.049f Ne=1.38 Ikf=96.23 Nk=.5 Xtb=1.5 Br=2.209 Isc=250.3p Nc=2.002 Ikr=10.73 Rc=1.433 Cjc=5.38p Mjc=.329

.MODEL BC177 PNP(Is=336.7f Xti=3 Eg=1.11 Vaf=55.46 Bf=154.4 Ise=412.1f Ne=1.429 Ikf=.2994 Nk=.7028 Xtb=1.5 Br=3.99 Isc=1.03n Nc=1.958 Ikr=9.726 Rc=1.833 Cjc=11p Mjc=.2223 Vjc=.5 Fc=.5 Cje=33p Mje=.3333 Vje=.5 Tr=10n Tf=847.7p Itf=2.198 Xtf=23.26 Vtf=10)

.MODEL BC177B PNP(Is=336.7f Xti=3 Eg=1.11 Vaf=55.46 Bf=154.4 Ise=412.1f Ne=1.429 Ikf=.2994 Nk=.7028 Xtb=1.5 Br=3.99 Isc=1.03n Nc=1.958 Ikr=9.726 Rc=1.833 Cjc=11p Mjc=.2223 Vjc=.5 Fc=.5 Cje=33p Mje=.3333 Vje=.5 Tr=10n Tf=847.7p Itf=2.198 Xtf=23.26 Vtf=10)

.MODEL BC178A PNP(Is=336.7f Xti=3 Eg=1.11 Vaf=44.61 Bf=187 Ise=336.8f Ne=1.459 Ikf=.2059 Nk=.5081 Xtb=1.5 Br=4.068 Isc=1.121n Nc=1.953 Ikr=10.05 Rc=1.86 Cjc=11p Mjc=.2223 Vjc=.5 Fc=.5 Cje=33p Mje=.3333 Vje=.5 Tr=10n Tf=845.5p Itf=1.701 Xtf=19.04 Vtf=10)

.MODEL BC178B PNP(Is=336.7f Xti=3 Eg=1.11 Vaf=30.75 Bf=271.9 Ise=2.821p Ne=1.925 Ikf=.2462 Nk=.5416 Xtb=1.5 Br=3.009 Isc=1.753n Nc=2.075 Ikr=8.143 Rc=1.803 Cjc=11p Mjc=.2223 Vjc=.5 Fc=.5 Cje=33p Mje=.3333 Vje=.5 Tr=10n Tf=846p Itf=1.546 Xtf=18.27 Vtf=10)

.MODEL BC179A PNP(Is=336.7f Xti=3 Eg=1.11 Vaf=44.61 Bf=187 Ise=336.8f Ne=1.459 Ikf=.2059 Nk=.5081 Xtb=1.5 Br=4.068 Isc=1.121n Nc=1.953 Ikr=10.05 Rc=1.86 Cjc=11p Mjc=.2223 Vjc=.5 Fc=.5 Cje=33p Mje=.3333 Vje=.5 Tr=10n Tf=845.5p Itf=1.701 Xtf=19.04 Vtf=10)

.MODEL BC179B PNP(Is=336.7f Xti=3 Eg=1.11 Vaf=30.75 Bf=271.9 Ise=2.821p Ne=1.925 Ikf=.2462 Nk=.5416 Xtb=1.5 Br=3.009 Isc=1.753n Nc=2.075 Ikr=8.143 Rc=1.803 Cjc=11p Mjc=.2223 Vjc=.5 Fc=.5 Cje=33p Mje=.3333 Vje=.5 Tr=10n Tf=846p Itf=1.546 Xtf=18.27 Vtf=10)

.MODEL MJE3055 NPN(Is=457.5f Xti=3 Eg=1.11 Vaf=50 Bf=156.7 Ise=1.346p Ne=1.34 Ikf=3.296 Nk=.5961 Xtb=2.2 Br=7.639 Isc=604.1f Nc=2.168 Ikr=8.131m Rc=91.29m Cjc=278.7p Mjc=.385 Vjc=.75 Fc=.5 Cje=433p Mje=.5 Vje=.75 Tr=1.412u Tf=37.34n Itf=35.68 Xtf=1.163 Vtf=10 Rb=.1)

.MODEL MJE2955 PNP(Is=66.19f Xti=3 Eg=1.11 Vaf=100 Bf=137.6 Ise=862.2f Ne=1.481 Ikf=1.642 Nk=.5695 Xtb=2 Br=5.88 Isc=273.5f Nc=1.24 Ikr=3.555 Rc=79.39m Cjc=870.4p Mjc=.6481 Vjc=.75 Fc=.5 Cje=390.1p Mje=.4343 Vje=.75 Tr=235.4n Tf=23.21n Itf=71.33 Xtf=5.982 Vtf=10 Rb=.1)

 

[etheory]

Hey electrochronic,

Fire me a PM with your e-mail address, and I'll just e-mail through whatever you need.

There's definitely no issue with the .txt to .zip conversion as I've tested it a few times.

Sending you the file via email directly should fix the issue.

As for permissions issues, I've not experienced any of those issues in Windows 10, though I do remember very early on changing some permission setting that fixed everything. Let me take a look and I'll see if I can tell you what that was.

Sorry it's given you such grief.

 

[dogears]

I downloaded, ran it, it works fine. I didn't have the library for the potentiometer, but it's easy enough to replace with fixed resistors and adjust as necessary.

Thanks etheory for sharing.

 

[maxwall]

I downloaded, ran it, it works fine. I didn't have the library for the potentiometer, but it's easy enough to replace with fixed resistors and adjust as necessary.

Thanks etheory for sharing.

Dogears, did you run simulate command ? what were your results ?  Do you  need to run the simulate command at all  ? What version of LTSpice ?  I did note that the potentiometer file is not included , its text profile just needs to be added to the standard.bjt  file to get recognized, but have'nt found a profile for it yet.


Any details , this is the first time using this program I'm no veteran with it , its not working as described.  I'd sure like to get this thing running properly.

After a generous offer , It appears etheory is not available to help thru emails , no response , two attempts already. Sent to gmail. PM box is full too.  I was going to send the log file errors , but decided to add to this post for convenience.

How do you edit the file for the transistors that are missing ( already used a text editor Wordpad  , copy , paste , saved file with same file name extension) ?  copied and pasted verbatim etheory's earlier post of LTSpice transistor profiles.

The transistor profiles ( listed earlier ) are in the file and saved ( standard.bjt ) , but when running simulate command in the program , all the errors start logging on execution as if it does not recognize any of the transistor profiles.  I assume you need to run simulate to see voltages, current and other running characteristics , yes ?

What version of LTSpice is being used ?
What editor , or how do I properly edit the text file with the component profiles in them so they are recognized by LTSpice.

any help appreciated

Error log below , generated by LTSpice

"Thanks etheory for sharing."

 

[dogears]

You need to have models for the transistors and diodes referenced in the schematic - that's why it says "unable to find definition of..."
An alternate way to do what he did is to create a text file called "models.txt" and copy+paste the .model lines into it.  Save that in the same directory as  you're running the .asc file from. Then you need to run the command ".include models.txt".

Delete the potentiometers and replace them with fixed resistors.

Everything else should work as-is.

 

[etheory]

After a generous offer , It appears etheory is not available to help thru emails , no response , two attempts already. Sent to gmail. PM box is full too.  I was going to send the log file errors , but decided to add to this post for convenience.

"Thanks etheory for sharing."

Sorry mate, lemme clear out my PM box for you.
As for e-mail, your e-mails must have somehow gone to my spam folder, let me check for you.

I'm sorry you are having so many issues. What you described is exactly what you should do, I have no idea why it's not working for you since it's not normally this difficult.

 

[etheory]

Sorry electrochronic, I've checked my spam folders and my inbox, and I have no record of you e-mailing me.
You should be able to PM me now however.

 

[maxwall]

Sorry electrochronic, I've checked my spam folders and my inbox, and I have no record of you e-mailing me.
You should be able to PM me now however.

etheory
I sent another email (gmail), maybe it works this time. left a link in message

Dogears
I'll give that a try and get back with result.

thanks for the quick replies.

Reference page :  https://rb.gy/8bir8y

P.S. - Bruno2000 , where the heck are you or how the heck are you ?

 

[Rogy]

P.S. - Bruno2000 , where the heck are you or how the heck are you ?
[/quote]

Joe Neil AKA Bruno2000 has left us, I am afraid...

https://www.proaudiodesignforum.com/forum/php/viewtopic.php?f=11&t=961

 

[Rogy]

I stumbled upon this thread and thought I'd share my experience with this build...

First of all, I built the 51X-version of this project. It worked straight away, but required some calibration.

*About the Hold control:
As reported by Salomonander, the Hold control can sometimes have too big a range.

The TG1 is originally designed to have a Hold range of -10dB<>+10dB, so 20dB gain range max.
Mine had +26dB gain range on the Hold  and acted funny at the highest Hold setting as well.

I simply measured the voltage at the Hold pot wiper that gave me the lowest Gain setting, and the voltage that gave me 20dB above that. I then limited the Hold range by adding a resistor (1K1) from 0V to the bottom of the Hold pot, and setting the Hold trimmer.
In my situation, the Hold control wiper originally had a range of 0<>+10V corresponding to 26dB of gain change.
After my mod, the Hold control wiper has a range of 0,95V<>9,5V corresponding to 20dB of gain change.

About the Hold control's 0dB position: it's simply the position where the gain is 10dB above minimum and 10dB below maximum. In my build the Hold's 0dB position is at 2PM.

Hope this helps...

Best regards,
Rogy

 

[maxwall]

P.S. - Bruno2000 , where the heck are you or how the heck are you ?


Joe Neil AKA Bruno2000 has left us, I am afraid...

https://www.proaudiodesignforum.com/forum/php/viewtopic.php?f=11&t=961

Rogy ,  thanks for letting me know about Joe ,  I suspected something but it was already too late and I could not get in contact since all I had was his phone # and email, and no replies.  I never thought to call the Studios, and I did'nt want to disturb since I knew he had a busy schedule with the mobile truck he ran. I never thought the worst. Now. I'm really struck down.

I put up a remeberance page on my website , late I admit , but never too late.  He certainly deserves to be remembered. Wow , I am constantly reminded how life can get cut short in a instant.

A picture with Joe  :  https://rb.gy/hb4e0e


Dogears I can't figure out how to invoke the .include command , the help topic within the LTSpice is horribly written and does not cite a example in a clear and easy to follow format - well this is my first time with it, but still the help file is not helpful.

"Syntax: .include <filename>

This directive includes the named file as if that file had been typed into the netlist instead of the .include command. This is useful for including libraries of models or subcircuits.

An absolute path name may be entered for the filename. Otherwise LTspice looks first in the directory %HOMEPATH%\Documents\LTspiceXVII\lib\sub and then in the directory that contains the calling netlist and finally in the list of directories listed in the Library Search Path.

No file name extension is assumed. You must use ".inc myfile.lib" not ".inc myfile" if the file is called "myfile.lib"