Hairball Audio: 1176 Stereo Linking PCBs Support Thread

[earthsled]

Hi there.. Did it work? Thanks a lot! 

Yes, this wiring worked for me.

I also found that my unit needed a connection between audio ground and the chassis to function properly.

Cheers!

 

[JamesW]

Hi all  working my way through a dual build. Can the stereo link boards be powered direct from the power supply board? This will make a much neater wiring job.

Thanks

 

[Janzoulou]

@earthsled: Thanks !  8)

 

[germoju]

Hi,

My problem is when I switch it to be stereo, I have a the 2nd unit that has a (measured) gain reduction of about 2dB more than the first unit. My test procedure is : in dual mode, both channels are fed with the same signal (ch1 from the L output of my soundcard and ch2 from the right one), I scoped both signals at test point 2 - right after the input gain pot - to make sure both compressors are fed with the same signal, I then set the out pot in bypass mode to have unity gain in both units. Then I switch both units to GR and measure both outputs, and see that both gain reduction is the same. When I switch the link switch to link mode, I measure a 2dB difference between ch1 and ch2, that is to say there is a 2dB difference in gain reduction. Meters also display a 2dB difference between the two channels.

HI guys,

I got the same problem. I builded a Stereo Revision D. When I'm in Dual mode, the 2 compressors have the same compression.... But when switch to link mode, one of the copmpressor has a difference about 2 or 3 dB of compression...

Somebody has the same ? Somebody has fixed this already ?$

Thanks !!

 

[lowend]

Hello,

I finished 2x 1176 Revision A with the stereo link PCB. But I cant understand what happen. When I'm in Dual Mono mode, all is fine. Compression is normal etc.... But when I switch to stereo, Compression is very heavy !
I've made a video, please take a look : http://youtu.be/lybZ44KPct0

I hope someone has the same problem to get an issue ! Cause I really dont understand... I check all wires, voltage etc...

Thanks

 

[rainton]

sorry I can't help you but how did you get the UA Logo onto the frontpanel?
Looks really good and authentic!  8)

 

[Echo North]

Hello,

I finished 2x 1176 Revision A with the stereo link PCB. But I cant understand what happen. When I'm in Dual Mono mode, all is fine. Compression is normal etc.... But when I switch to stereo, Compression is very heavy !
I've made a video, please take a look : http://youtu.be/lybZ44KPct0

I hope someone has the same problem to get an issue ! Cause I really dont understand... I check all wires, voltage etc...

Thanks

Clean builds!

Do you have the link wire by the PCB link board writing installed?

 

[lowend]

Hello,

I finished 2x 1176 Revision A with the stereo link PCB. But I cant understand what happen. When I'm in Dual Mono mode, all is fine. Compression is normal etc.... But when I switch to stereo, Compression is very heavy !
I've made a video, please take a look : http://youtu.be/lybZ44KPct0

I hope someone has the same problem to get an issue ! Cause I really dont understand... I check all wires, voltage etc...

Thanks

Clean builds!

Do you have the link wire by the PCB link board writing installed?

Hi,

Sorry I dont really understand your question ...
To explain : I got a wire from Stereo PCB "link" to my switch.
I followed the instructions. When Stereo mode : "link" is connected to ratio pad 15, when dual mono : ratio pad 15 is connected to output pot.
I hope you can see , sorry for the picture quality...

 

[earthsled]

lowend: double check the orientation of the op-amps on your stereo PCBs -- these are easy to get backwards. 

 

[lowend]

lowend: double check the orientation of the op-amps on your stereo PCBs -- these are easy to get backwards. 

Thanks, but orientations are good

 

[Echo North]

You've followed this?

http://hairballaudio.com/guides/Stereo_Link_Wiring_Guide.pdf

your ins are connected to your outs?

Check that your PCB has +30 at the pad and voltages at the op-amp supply pins.  Make sure you have continuity to ground at the GND pad.

Mike

 

[lowend]

You've followed this?

http://hairballaudio.com/guides/Stereo_Link_Wiring_Guide.pdf

your ins are connected to your outs?

Check that your PCB has +30 at the pad and voltages at the op-amp supply pins.  Make sure you have continuity to ground at the GND pad.

Mike

Hi,

yes I followed the doc... Before I builded 2 pairs of Rev D with the same stereo link and it works
So I tested the stereo links cards with an oscilloscope and 1 kHz... I got a bad wave at some points...
As the TL071 and TL072 are plug with sockets pins,... I unplug them and test them with oscilloscope and 1 kHz... My TL071 has good wave... but TL072 has an uncorrected wave response.
So I think it's the problem.
I send my 1kHz in the card without TL072 and I good wave response everywhere...

So ! I have an other stereo link board kit, I change it and it works now. The issue was a bad TL072

 

[Echo North]

Send me an email and I'll get a replacement out to you.

Mike

 

[lowend]

Send me an email and I'll get a replacement out to you.

Mike

Done !
Thanks

 

[germoju]

Hi !

I builded a Stereo Revision D. When I'm in Dual mode, the 2 compressors have the same compression response.... But when switch to link mode, channel A has a difference about 2 or 3 dB of compression... and it's a little difference when I change the ratios...

Stereo link PCBs wiring is OK... IN of one go to OUT of the other etc. My 5457 are matched pair from HairballAudio...

Somebody had the same ? Somebody has fixed this already ?

Thanks !!

 

[Janzoulou]

Hello everybody... I am wiring now the Stereo-link board inside my dual 1176 REV A. One (maybe silly) question:

Referring to the graphic from ricothetroll on ratio-board pad17 and output-pot - pads staying empty??

Cheers and excuse if this question is stupid.. just want to be safe.

Ok... this one is solved. Now i got the same problem like germoju posted above... GR changes on one side around 2-3dB when the sidchain is linked via the Stereo-boards.. Anybody got an idea?

 

[Echo North]

Hello everybody... I am wiring now the Stereo-link board inside my dual 1176 REV A. One (maybe silly) question:

Referring to the graphic from ricothetroll on ratio-board pad17 and output-pot - pads staying empty??

Cheers and excuse if this question is stupid.. just want to be safe.

Ok... this one is solved. Now i got the same problem like germoju posted above... GR changes on one side around 2-3dB when the sidchain is linked via the Stereo-boards.. Anybody got an idea?

The link boards sum the side chain audio so both side chains see the same peaks.

You need to set both compressors to the same controls (input, output, ratio) then because of some tolerances with components you may need to tweak a control or two.  If they are way off if might be because you bought FETs a different times.  If you bought your FETs on the same order they should be reasonably matched.  You may want to send a test signal into one unit and test that you see the summed test signal in each unit.

Mike

 

[Janzoulou]

Thanks a lot for the response, Mike!

Yeah, you are absolutely right, i think. My 309 FET´s I actually did not buy in your shop.. i just forgot to order them and had to find them in a different place in Germany. Of course not matched ones... All the other parts were ordered in your store and mouser at once.... I will anyway order shortly a REV F kit at your place and then exchange the J309 with yours.

I tweaked around with the settings of course and reduced the output from on side at the end. The result is not accurate but for now I guess I have to live with that. I will also check the resistor - values in the corresponding area on the ratio and main board. Maybe there is some tolerance to get rid off?

Cheers again! Thanks again for the great support and everything else, making it possible to get those amazing kits Mike!!

Fredi

btw: when setting them up im stereo i do the following: I set everything in Dual-mode with the signal i want to compress, then put a 1kHz tone to check the compression etc is the same on both sides. then i link them. thats where I get a 2-3dB drop on one side.

 

[germoju]

Hi,

Yes I got 2x rev D inside and i buyed the Stereo kit on hairballlaudio. So I think FETS are matched by Hairball...
When I send a signal in one board, i can find it on stereo board but one is louder than the other.
The response is not the same between all ratio. Maybe i got a problem on my ratio boards ? But I dont think so,  cause in mono the response are the same with pots at same position etc.
The only components i'm not sure are the 3391 and 3708... Maybe they are not matched as it should.Thanks for your help Mike !

 

[Axelerator]

just a short q....is the stereo summing board out of the cuircuit while in dual mono mode  ?
(that is how i read the drawings here)
thank you
axel