[BUILD] 1176 Rev F/G - new board, new transformer!

[ffarrell]

Hi all.

Where do you guys pull power from for the polit light on a dual 1176 ver. F?

Thanks
Fvf

 

[Echo North]

Hi all.

Where do you guys pull power from for the polit light on a dual 1176 ver. F?

Thanks
Fvf

Meter lamp?

Look through here:
http://www.hairballaudio.com/blog/resources/build-guides/wiring-your-compressor-

Bottom.

 

[ffarrell]

The power on pilot light. But I think I would just pull off the 30 volt leg and resistor it down like the meter lamp.  Im using a 6.3 volt guitar amp bulb. 

One other question on the 1176 F rev 1.2 board if I'm using the ic input and not the tranie should R5 be unpopulated? 

Thanks
Fvf

 

[Echo North]

The power on pilot light. But I think I would just pull off the 30 volt leg and resistor it down like the meter lamp.  Im using a 6.3 volt guitar amp bulb. 

One other question on the 1176 F rev 1.2 board if I'm using the ic input and not the tranie should R5 be unpopulated? 

Thanks
Fvf

Look like it should be left out.

 

[ffarrell]

Thank you

Fvf

 

[ffarrell]

If the tolorance of the resistors on this build are 5% can I use a 261k 1% in place of the 270k on the release pot?

Fvf

 

[Echo North]

If the tolorance of the resistors on this build are 5% can I use a 261k 1% in place of the 270k on the release pot?

Fvf

The original used 10%. You'll be just fine with that value.

 

[ffarrell]

The original used 10%. You'll be just fine with that value.

thanks

fvf

 

[ffarrell]

Ok, I want to finish this stereo 1176F  but a few more question please.

1.  Should I be using shielded cable from the stereo link PCB boards back to the output pots?

2.  Should I calibrate the unit before I add in the Stereo Link boards?

thanks
fvf

 

[ffarrell]

bump..

 

[Echo North]

Ok, I want to finish this stereo 1176F  but a few more question please.

1.  Should I be using shielded cable from the stereo link PCB boards back to the output pots?

2.  Should I calibrate the unit before I add in the Stereo Link boards?

thanks
fvf

1. Yes.
2. Up to you. SHouldn't mater unless the link boards are built wired/wrong.

Mike

 

[Olegarich]

Hey guys, I know this topic was noted posted in loing time, but still

I have problem with calibration. Actually it's the last step. Tracking adjustmen t.

I did everyt single step and all works well,
When Gain reduction is Off (Atack knob fully CCW) i read 10dbu on putput xlr
When gain reduction is on (Atack knob is CW) I read 0 dbu (0.77v)

My meter show me 1dbu drop when GR is turned on, and tracking adjustment trimpot is can't go any further. Trimpot is working for 100.

So basicly i wanted to ask is this can only be in the meter drive amp section? Cause i measure drop on xlr output but Meter not showing me this.

Thanks!

 

[Echo North]

Hey guys, I know this topic was noted posted in loing time, but still

I have problem with calibration. Actually it's the last step. Tracking adjustmen t.

I did everyt single step and all works well,
When Gain reduction is Off (Atack knob fully CCW) i read 10dbu on putput xlr
When gain reduction is on (Atack knob is CW) I read 0 dbu (0.77v)

My meter show me 1dbu drop when GR is turned on, and tracking adjustment trimpot is can't go any further. Trimpot is working for 100.

So basicly i wanted to ask is this can only be in the meter drive amp section? Cause i measure drop on xlr output but Meter not showing me this.

Thanks!

If the GR is happening, but you can't get the meter to match, you have an issue in the GR Meter Amp section.  Make sure you have a 2K pot in there and make sure your IC is inserted correctly or not dead.  Could also be a dead Q10.

Mike

 

[Olegarich]

Thanks MIke,

Yeah, it's compresion pretty well, GR is happening i hear it and i measure it on output.

I've changed different TL071, still the same, tried another FET, still the same. Definitely have 2K on zero adj and by the way that function works perfectly, problem with "Tracking adj" trimpot.  Maybe I'll try to resolder this part, it's not that much parts, so maybe I'll find what is broken. Thanks Mike,

 

[edgsil]

Hello,
I am  resurrecting a 1176LN Rev F/G based compressor which I purchased and built in 2013.  I'd like to recalibrate it, but can't find the videos of the calibration procedure that I followed back then.  The procedures that I found on the Hairball Audio website don't seem to cover the Rev F/G version.  If someone can point me to the correct version of the procedures, I would appreciate it.  Thank you.

 

[Olegarich]

Hey, Videos still there,

Hairball audio - Diy resource centre - build guides. In the bottom there is "Go to page" choose 2. Fet older version calibration.

 

[edgsil]

Olegarich,
Thanks for the response.  I saw those videos, but they seem to be referencing Rev D rather than Rev F/G.  I suspect the calibration steps are very similar, however the meter driver circuits are different (discrete transistor for Rev D, TL071 op-amp for Rev F/G) and there is a 3rd pot (null adj) in Rev D, as well as a jumper with R44.

So for performing the meter zeroing on my Rev F/G, do I simply remove any input signal, set the meter push button to "GR", and then adjust R55 (zero adj) for 0dB on the meter?  Or are there other steps involved?

Thanks again,
edgsil

 

[Echo North]

Olegarich,
Thanks for the response.  I saw those videos, but they seem to be referencing Rev D rather than Rev F/G.  I suspect the calibration steps are very similar, however the meter driver circuits are different (discrete transistor for Rev D, TL071 op-amp for Rev F/G) and there is a 3rd pot (null adj) in Rev D, as well as a jumper with R44.

So for performing the meter zeroing on my Rev F/G, do I simply remove any input signal, set the meter push button to "GR", and then adjust R55 (zero adj) for 0dB on the meter?  Or are there other steps involved?

Thanks again,
edgsil

There is no null adjustment needed.  You just do the GR calibration step for -10dB.

Mike

 

[edgsil]

Mike,
Got it.  Seems to be working fine.  Thanks.

 

[metacarple]

Hey,

So I've had a pre 2016 rev f/g for years now, working great. All of a sudden, a few years ago, a 60 cycle hum appeared. The hum occurs when the unit is on with no input or output connected (using a 0db 1khz sine wave with scope and just a scope). I can also hear it when its hooked up to a signal chain.  I have been all through the unit many times and re-flowed just about everything a few times at this point, dc voltage rails are good. I can't seem to track down this hum.... Nothing appears to be cracked nor do any joints seem to have come apart. Any information regarding troubleshooting this would be a great help, thanks!