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

[bruno2000]

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

 

[drask]

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 !

 

[bruno2000]

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

 

[drask]

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 !

 

[bruno2000]

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

 

[drask]

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

 

[drask]

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 !

 

[Biasrocks]

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 !

 

[drask]

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

 

[bruno2000]

What are your readings at T_B & T_C?
Best,
Bruno2000

 

[drask]

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!

 

[Joe_caithness]

Can anyone confirm the ratios of the comp/limit?

 

[desol]

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.

 

[bruno2000]

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

 

[bruno2000]

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

 

[desol]

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

 

[bruno2000]

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

 

[desol]

Sure. I'll send you a pm in a few days. Maybe send a decent stereo kit and mix.

D.

 

[Bonsaimaster]

Anyone using Carnhill VTB2281 600:600 output transformer and know the Cz and Rz values they used? 

Thanks
Bonsaimaster

 

[duantro]

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.