naa, it's not really that sensitive - the regular trimmer is workable
All things G1176 - the new "repost" thread.
- Thread starter orson whitfield
- Start date
Help Support GroupDIY Audio Forum:
Hi All, I'm trying to calibrate a 1176 that I just built, when switch to output VU the needle shakes a little but it does not mark a constant signal, also when the signal rises, you can hear the 1k tone through the current transformer, on ground position it seems to work correctly
any ideas?
any ideas?
gswan
Well-known member
Looks like your VU meter does not have internal rectifier diodes.
You can add germanium or schottky diodes in a full bridge configuration across the meter terminals to fix this.
You will need to recalibrate the gain reduction metering section to compensate for the extra Vf across the diodes.
You can add germanium or schottky diodes in a full bridge configuration across the meter terminals to fix this.
You will need to recalibrate the gain reduction metering section to compensate for the extra Vf across the diodes.
My Vu is from an otari, the terminals appeared with a sinusoidal, I thought that I would have to remove the diode bridge to make it work correctly positive and negative, right now it seems as if the vu meter can never move to the right, what I say makes sense ?
as mentioned earlier in this thread, make sure your meter reacts to AC in a correct way, with the correct series resistance. If your meter is DC, try adding a diode rectifier bridge to it - preferably germanium or schottky for decent precision
Thanks a lot, it was exactly that, now the VU meter seems to work fine and I have been able to calibrate it, but it seems that it is too quiet, could it be that I have used transistors with little gain? Or cables of the wrong thickness? it sounds nice actualy, but too quiet
I attached a video turning the insert on and off
I attached a video turning the insert on and off
too low gain shouldn't come from transistors (if they are right general type) or wireing
gswan
Well-known member
Did you take measurements of the gain of each amplifier stage? That will tell you which section has a problem. The first stage is around 30dB from memory and the second stage around 10dB.
No i , didnt, could you explain me how to do it exactly, its my first time doing something like this. (Is there somewhere where it is already explained?)
By the way i found information about lowering the value of r33 and reversing the transformer, but the diagram was down, could someone share that mod again?
Although in reality I suppose that my unit has another problem that I should solve before doing that mod
gswan
Well-known member
Have a look at the troubleshooting page in my 1176 notes web pages:
https://axtsystems.com/axtsystems/proj_1176.php
Thanks a lot!
Hi folks. Planning a stereo 1176 build - can I build the PSU only on one side and link them somewhere? ie stuff the PSU section only on board 1, omitting C23 to use as a bridge point to board 2, and mount C23 on board 2 instead? Or better just to build it up on both (I saw a post on here recommending that two PSUs helps decouple the boards)?
Or should I just buy an extra PSU board instead?
Or should I just buy an extra PSU board instead?
I'd say that it's best to build it as-is - that way we have this very-big thread of support. Changing it could open a whole new can of worms, grounding etc., but would depend on your ambition and skill level.
I used WIMAs for mine, as I and many others do for most projects. Panasonic would be another high quality alternative.
Orange Drops would be suitable as long as the voltage rating is correct, the capacitors will physically fit and the lead spacing is right.
Whether they’re worth it is up to you. Some people feel there is a difference in sound and it has been widely discussed in general.
Hello! My first post here. I just finished my first G1176 and is working fine, it is compressing.
The only issue I have is the VU meter is not stable when not passing audio in GR MODE. Sometimes is going lower then goes slowly up and then lower. If I set it at 0 it does not remain there, is like the voltage is constantly fluctuating. I am not a tech
but if anyone can help me I will troubleshoot.
Thank you all for this amazing group!
Gabriel
The only issue I have is the VU meter is not stable when not passing audio in GR MODE. Sometimes is going lower then goes slowly up and then lower. If I set it at 0 it does not remain there, is like the voltage is constantly fluctuating. I am not a tech
but if anyone can help me I will troubleshoot. Thank you all for this amazing group!
Gabriel
Does your gain fluctuate as well?
If not, could be contamination around meter jfet
or, if your supply voltages fluctuate, this will impact meter reading: check if meter error correlates with +30V/-10V supply voltage drift
/Jakob E.
If not, could be contamination around meter jfet
or, if your supply voltages fluctuate, this will impact meter reading: check if meter error correlates with +30V/-10V supply voltage drift
/Jakob E.
I checked with the MM at the 7824 i have a constant 29.6 V. At -10V point there is a fluctuation in voltage, between -8.8 to -9.4, what should I check more? Thank you!
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