[BUILD] 1176LN Rev D DIY

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hymentoptera said:
Yes, that seems fine. Assuming you have your + and - backwards. Should be one diode drop with the black (COM) lead on the cathode (stripe). We can rule out CR1 I think.

I think part of the trouble here is I don't know the terms well enough to communicate what I mean very well. When I said a drop 'from (-) to (+)' I meant measuring with the black (common) lead on the (-) end of the diode like you say.  Assembling the device was simple but there is a steep learning curve for troubleshooting!

Anyway, I appreciate you guys taking the time to help me with this. I'm out of town for a couple weeks and I'll pick this up when I'm back.
 
hymentoptera said:
A thing of beauty! Everything looks real professional (even the DIY heatsinks ;) ) and I just love these pics of the dual units inside! I hope it sounds as good as it looks. Thanks for sharing.  8)

Thank you! yes it sound incredible, very aggressive and dirty, i love it! A must have compressor!  :D

@JingleDjango

The lamp in the photo seem purple but it is dark red;  good luck with your DIY !
 
Here my check of voltages in DC on the pcb :

red= pdf 1176_VOLTS document
blue=my voltages

mesures_20150807.jpg


I see some problems but i want your expertise please ;)

Thanks
Baba
 
Hey, I managed to fix my problem with the meter its all working  but i have another problem now.

i'm at the 3rd stage of calibration, I have 1k going in at 0.775v and have my DDM at the output and I noticed my voltage at my output slightly bleeding off reducing by 0.01v per second.

So I went back to stage one of calibration to reset the Q bias now something funny is happening, the Bias trim pot  is acting strangely, Its controlling the meter (making it go back and forth depending on which way I tighten the screw) however the output signal is either fully on 2.775v or fully off it doesn't seem too allow me to set the 1dB drop

Have I done something wrong or have  I broke to Qbias trimmer?

I can upload a video if that help?

please can somebody help?
 
Hello,
i am at the first step of calibrating my compressor using the Hairball audio way.  The problem is that I'm not getting a voltage reading at the output xlr.

I have a signal and reading coming to the input xlr  (.775vac).

I measured the voltage to the input and ground pad on the board and with the input knob at 48 I'm getting 0v and at input 0 I'm getting .875 v. so it seems to be working to here.

I visually checked the wiring from the meter board and input transformer to the output and it is wired fine. 

I'm just not too sure what I should be looking for from here (i.e. what to test and what I should be seeing for readings).

I'm assuming that I shouldn't have the unit plugged in for this step and will not plug it in for testing unless someone recommends that I do so.

Thank in advance for any help.
 
milomofo said:
Hey, I managed to fix my problem with the meter its all working  but i have another problem now.

i'm at the 3rd stage of calibration, I have 1k going in at 0.775v and have my DDM at the output and I noticed my voltage at my output slightly bleeding off reducing by 0.01v per second.

So I went back to stage one of calibration to reset the Q bias now something funny is happening, the Bias trim pot  is acting strangely, Its controlling the meter (making it go back and forth depending on which way I tighten the screw) however the output signal is either fully on 2.775v or fully off it doesn't seem too allow me to set the 1dB drop

Have I done something wrong or have  I broke to Qbias trimmer?

I can upload a video if that help?

please can somebody help?
Did you check your jumpers I think you can take the meter right out of the equation by jumping it out
 
mgalimbe said:
milomofo said:
Hey, I managed to fix my problem with the meter its all working  but i have another problem now.

i'm at the 3rd stage of calibration, I have 1k going in at 0.775v and have my DDM at the output and I noticed my voltage at my output slightly bleeding off reducing by 0.01v per second.

So I went back to stage one of calibration to reset the Q bias now something funny is happening, the Bias trim pot  is acting strangely, Its controlling the meter (making it go back and forth depending on which way I tighten the screw) however the output signal is either fully on 2.775v or fully off it doesn't seem too allow me to set the 1dB drop

Have I done something wrong or have  I broke to Qbias trimmer?

I can upload a video if that help?

please can somebody help?
Did you check your jumpers I think you can take the meter right out of the equation by jumping it out

Hey, I fixed all the issues I was having, I had one cold solder joint on R17 which I believe was the culprit. My own stupidity and rubbish eyesight :p It works like a dream now .

The learning curve was steep with this one.

Thanks to everyone for helping and thanks Hairball for the amazing build!
 
mgalimbe said:
Hello,
i am at the first step of calibrating my compressor using the Hairball audio way.  The problem is that I'm not getting a voltage reading at the output xlr.

I have a signal and reading coming to the input xlr  (.775vac).

I measured the voltage to the input and ground pad on the board and with the input knob at 48 I'm getting 0v and at input 0 I'm getting .875 v. so it seems to be working to here.

I visually checked the wiring from the meter board and input transformer to the output and it is wired fine. 

I'm just not too sure what I should be looking for from here (i.e. what to test and what I should be seeing for readings).

I'm assuming that I shouldn't have the unit plugged in for this step and will not plug it in for testing unless someone recommends that I do so.

Thank in advance for any help.

ok because I'm impatient I tried the mats version of calibrating the Qbias and what I noticed is that my bias pot isn't doing anything so I probably overstressed it so my question now is if this bias pot is broken would that explain why I'm not getting a signal to the output xlr using the hairball method of calibrating the q bias?

time to order some pots!
 
milomofo said:
Hey, I managed to fix my problem with the meter its all working  but i have another problem now.

i'm at the 3rd stage of calibration, I have 1k going in at 0.775v and have my DDM at the output and I noticed my voltage at my output slightly bleeding off reducing by 0.01v per second.

So I went back to stage one of calibration to reset the Q bias now something funny is happening, the Bias trim pot  is acting strangely, Its controlling the meter (making it go back and forth depending on which way I tighten the screw) however the output signal is either fully on 2.775v or fully off it doesn't seem too allow me to set the 1dB drop

Have I done something wrong or have  I broke to Qbias trimmer?

I can upload a video if that help?

please can somebody help?

Bias should change the meter needle.  That sounds normal.  The trimmer is a 20 turn trimmer are you sure you're rotating enough to get to the drop?  You'll hear a light "click" when you reach the end of the trimmer.

Mike
 
mgalimbe said:
mgalimbe said:
Hello,
i am at the first step of calibrating my compressor using the Hairball audio way.  The problem is that I'm not getting a voltage reading at the output xlr.

I have a signal and reading coming to the input xlr  (.775vac).

I measured the voltage to the input and ground pad on the board and with the input knob at 48 I'm getting 0v and at input 0 I'm getting .875 v. so it seems to be working to here.

I visually checked the wiring from the meter board and input transformer to the output and it is wired fine. 

I'm just not too sure what I should be looking for from here (i.e. what to test and what I should be seeing for readings).

I'm assuming that I shouldn't have the unit plugged in for this step and will not plug it in for testing unless someone recommends that I do so.

Thank in advance for any help.

ok because I'm impatient I tried the mats version of calibrating the Qbias and what I noticed is that my bias pot isn't doing anything so I probably overstressed it so my question now is if this bias pot is broken would that explain why I'm not getting a signal to the output xlr using the hairball method of calibrating the q bias?

time to order some pots!

I doubt it's the trimmer. Even with a damaged trimmer you's see output.  Your signal is dying at some point likely do to a misplaced component, damaged component, or wiring.

Easiest way to check for signal is to use a DMM set to read AC volts.

Turn the attack pot to the GR off position. Set your input and output to mid rotation and your release fully CW.  Feed the unit a 1kHz, 0dB signal (0.775VAC).  Confirm you have 0.775VAC between input pins 2 and 3.  Now follow the signal using ground and you common reference point (where you put the black lead).  You can attach it to ground at the 0V/CT terminal at the PCB power supply.

Measure the VAC against ground at:

1. T-Pad input + (should be about half of 0.775)
2. T-Pad output +  (should be even smaller)
3. Input transformer primary + (should be the same as step 2)
4. Input transformer secondary + (getting smaller)
5. At the Input + terminal at the main PCB (should be roughly 0.06 to 0.09VAC)
6. C7 + pad (should be much larger now, around 2.0 VAC)
7. C7- pad (should be the same as  #6)
8. Blue wire on output transformer (should be a large VAC number)

Report back. That will help determine where the signal is dying.

Mike

 
Hairball Audio said:
mgalimbe said:
mgalimbe said:
Hello,
i am at the first step of calibrating my compressor using the Hairball audio way.  The problem is that I'm not getting a voltage reading at the output xlr.

I have a signal and reading coming to the input xlr  (.775vac).

I measured the voltage to the input and ground pad on the board and with the input knob at 48 I'm getting 0v and at input 0 I'm getting .875 v. so it seems to be working to here.

I visually checked the wiring from the meter board and input transformer to the output and it is wired fine. 

I'm just not too sure what I should be looking for from here (i.e. what to test and what I should be seeing for readings).

I'm assuming that I shouldn't have the unit plugged in for this step and will not plug it in for testing unless someone recommends that I do so.

Thank in advance for any help.

ok because I'm impatient I tried the mats version of calibrating the Qbias and what I noticed is that my bias pot isn't doing anything so I probably overstressed it so my question now is if this bias pot is broken would that explain why I'm not getting a signal to the output xlr using the hairball method of calibrating the q bias?

time to order some pots!

I doubt it's the trimmer. Even with a damaged trimmer you's see output.  Your signal is dying at some point likely do to a misplaced component, damaged component, or wiring.

Easiest way to check for signal is to use a DMM set to read AC volts.

Turn the attack pot to the GR off position. Set your input and output to mid rotation and your release fully CW.  Feed the unit a 1kHz, 0dB signal (0.775VAC).  Confirm you have 0.775VAC between input pins 2 and 3.  Now follow the signal using ground and you common reference point (where you put the black lead).  You can attach it to ground at the 0V/CT terminal at the PCB power supply.

Measure the VAC against ground at:

1. T-Pad input + (should be about half of 0.775)
2. T-Pad output +  (should be even smaller)
3. Input transformer primary + (should be the same as step 2)
4. Input transformer secondary + (getting smaller)
5. At the Input + terminal at the main PCB (should be roughly 0.06 to 0.09VAC)
6. C7 + pad (should be much larger now, around 2.0 VAC)
7. C7- pad (should be the same as  #6)
8. Blue wire on output transformer (should be a large VAC number)

Report back. That will help determine where the signal is dying.

Mike

Hi Mike Here are my findings

input xlr=.776vac
Tpad in+=.775vac (not half of input xlr)
Tpad out+=.276vac
Input trans. Pri +=.275
Input Trans 2nd+= .278
I have nothing on either pin(+or-) of c7.
nothing on blue wire of output transformer.
 
mgalimbe said:
I forgot to mention that I have .278vav at the input pad on the  main pcb

Check all of your components in the box labeled "Signal Preamp".  Make sure you have the R values right, like you don't have a 56K or 560K mixed up.  Check everything super close.

Check the DC V in that section against these values:
http://mnats.net/files/1176REVD_VOLTS.pdf

Mike

Mike
 
Hi again, pals.  I'm back at it, no closer to having this guy running yet. Going back over the build instructions, I see the note about the trim pots being vulnerable to breakage if you over-turn them. I don't remember reading this so I don't know if it was appended to the guide when the rev. A and rev D. guides were merged. Regardless, I would wager I've damaged R59 this way. Upthread it was suggested I turn it all the way in either direction to be sure it wasn't completely throttling the signal.

Anyway, troubleshooting and getting nowhere is starting to wear on my soul a bit. Since I bought two of these kits together, I've decided to go ahead on the second kit, take my experience with me from the first one and hope for the best. I'm wiring the thing up and I've come to the attack pot, with the film capacitor and resistor attached. Is there any reason I shouldn't solder the capacitor to the lug rivets rather than the lugs themselves? They appear to be electrically connected (i mean, part of the same lead altogether) and it's much easier to fit the cap. in here and have it stick. I'm attaching a picture to explain what I mean. Any thoughts?
 

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JingleDjango said:
Hi again, pals.  I'm back at it, no closer to having this guy running yet. Going back over the build instructions, I see the note about the trim pots being vulnerable to breakage if you over-turn them. I don't remember reading this so I don't know if it was appended to the guide when the rev. A and rev D. guides were merged. Regardless, I would wager I've damaged R59 this way. Upthread it was suggested I turn it all the way in either direction to be sure it wasn't completely throttling the signal.

You could pull it out and test it. Or if it's R59 just check your DC at pad 18 (vs ground). You should see a negative voltage (0 to -3) that changes when you rotate R59.
 
Here is my output pot. Using the rivet holes like I did with the capacitor on the attack pot makes for an elegant wiring I think.
 

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Okay, second unit is together. I want to calibrate it but there's something up with the output. 

Input signal is a 1kHz sine @ 0.767VAC (close as I could get to .775 in my DAW)
Between +/- on the output XLR the VAC is 15! So. . .

Following along with 1176REVD_VOLTS.pdf, everything is pretty close to what the diagram until Q6 where the collector reads 26.9VDC compared to 28.9VDC on the diagram.

Apart from that, everything is pretty close to what's shown in the diagram until Q11.
G lead reads -1.223VDC
S lead reads -1.169VDC
D lead reads 8VDC

Following that, Q11 and Q12 are out of whack. I centered all of the trim pots before installation if that's relevant, and tested all of the control pots. Tested every resistor on the way in.  Maybe a failed transistor? I'm not sure
 
JingleDjango said:
Okay, second unit is together. I want to calibrate it but there's something up with the output. 

Input signal is a 1kHz sine @ 0.767VAC (close as I could get to .775 in my DAW)
Between +/- on the output XLR the VAC is 15! So. . .

Following along with 1176REVD_VOLTS.pdf, everything is pretty close to what the diagram until Q6 where the collector reads 26.9VDC compared to 28.9VDC on the diagram.

Apart from that, everything is pretty close to what's shown in the diagram until Q11.
G lead reads -1.223VDC
S lead reads -1.169VDC
D lead reads 8VDC

Following that, Q11 and Q12 are out of whack. I centered all of the trim pots before installation if that's relevant, and tested all of the control pots. Tested every resistor on the way in.  Maybe a failed transistor? I'm not sure

Your output can be that high.  Did you rotate the output and try to get it to 0.775?

Mike
 
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