Hairball Audio: 1176 Stereo Linking PCBs Support Thread

[mnats]

I tried signal tracing and it seemed to be an issue with one of my SPDT switches. I swapped out the switch and the problem persisted.

You drew a conclusion that proved to be incorrect. It would be more helpful if you posted the results of your measurements like moris did.

Before I try anything else, I want to make absolutely sure my wiring is correct. Please see the attached diagram.

Compare yours to the wiring shown in the Hairball document to confirm.

 

[DUDE GUY]

I tried signal tracing and it seemed to be an issue with one of my SPDT switches. I swapped out the switch and the problem persisted.

You drew a conclusion that proved to be incorrect. It would be more helpful if you posted the results of your measurements like moris did.

Before I try anything else, I want to make absolutely sure my wiring is correct. Please see the attached diagram.

Compare yours to the wiring shown in the Hairball document to confirm.

Hello again, mnats

I finally had a chance to do some measurements. I also triple checked my wiring and it is wired according to the Hairball document.

So just a reminder of where I'm at:

When I have both units linked with the TRS cable and both link switches enabled, unit 2 continues to show gain reduction and has audible compression, while unit 1 shows no gain reduction and has no audible compression. When I remove the TRS cable and leave the link switches enabled, I see gain reduction and hear compression on both units. I've tried three different TRS cables, but no change.

I hear audio at:

OUT
LOOP
IN
R201 (IN+OUT)
R202 (IN only)
R203 (IN only)
R204 (IN+OUT)
R205 (IN+OUT)
R206 (IN+OUT)
R208 (IN only)
C201 (IN+OUT)
C202 (IN+OUT)
A201 PIN1
A201 PIN2
A201 PIN3
A201 PIN6

I do not hear audio at:

LINK (when I remove the TRS link cable, I hear audio at LINK)
R207
R209
R316
R317
C301
C302
C203
A201 PIN4
A201 PIN5
A201 PIN7
A201 PIN8
A302 (ALL PINS)


Thanks for your help and I appreciate your patience.

-Kevin

 

[Piotr]

Hi to all of you !

Having built a stereo rotary version of the 1176 (Mnats boards) and trying to fit it with Hairball's stereo linking pcbs, I've run in the exact same issues stated by Ricothetroll. Stereo switch engaged nulled the ouput to almost nothing...

I've successfully rewired my unit using his drawing so big thanks to him for pointing me in the right direction and helping me understand the issue.

Here's the unit which still needs a little cosmetic work, but is calibrated and works as it should !

Thanks Rico !!!

Piotr.

 

[DUDE GUY]

I finally had a chance to do some measurements. I also triple checked my wiring and it is wired according to the Hairball document.

So just a reminder of where I'm at:

When I have both units linked with the TRS cable and both link switches enabled, unit 2 continues to show gain reduction and has audible compression, while unit 1 shows no gain reduction and has no audible compression. When I remove the TRS cable and leave the link switches enabled, I see gain reduction and hear compression on both units. I've tried three different TRS cables, but no change.

I hear audio at:

OUT
LOOP
IN
R201 (IN+OUT)
R202 (IN only)
R203 (IN only)
R204 (IN+OUT)
R205 (IN+OUT)
R206 (IN+OUT)
R208 (IN only)
C201 (IN+OUT)
C202 (IN+OUT)
A201 PIN1
A201 PIN2
A201 PIN3
A201 PIN6

I do not hear audio at:

LINK (when I remove the TRS link cable, I hear audio at LINK)
R207
R209
R316
R317
C301
C302
C203
A201 PIN4
A201 PIN5
A201 PIN7
A201 PIN8
A302 (ALL PINS)


Thanks for your help and I appreciate your patience.

-Kevin

Hello,

I'm really stumped here. Would someone mind helping me out?

I described my problem in the quote above and I provided a list of PCB pads where I heard and did not hear audio with my audio probe.

To add to that, I measured voltages across the pins of the IC's and ground.

Unit One (the 1176 with the issue):

--TL072
PIN1: 26.9V
PIN2: 26.9V
PIN3: 26.6V
PIN4: 0V
PIN5: 26.9V
PIN6: 22V
PIN7: 28.9V
PIN8: 29.6V

--TL071
PIN1: 158mV
PIN2: 26.9V
PIN3: 26.9V
PIN4: 1.3mV
PIN5: 158mV
PIN6: 26.9V
PIN7: 28.6V
PIN8: ??? (voltage continues to increase)

Unit Two (the 1176 that works fine):

--TL072
PIN1: 14.8V
PIN2: 14.8V
PIN3: 14.8V
PIN4: 0V
PIN5: 14.8V
PIN6: 14.8V
PIN7: 6.9V
PIN8: 29.7V

--TL071
PIN1: 155mV
PIN2: 14.8V
PIN3: 14.8V
PIN4: 0V
PIN5: 155mV
PIN6: 14.8V
PIN7: 29.7V
PIN8: ??? (voltage continues to increase)

From what I've read in the other posts in this thread, Unit Two seems to have the correct voltages (around 15V), while Unit One has an issue.

Any help would be greatly appreciated. Thanks very much, everyone.

-Kevin

 

[DUDE GUY]

OK, figured it out. I accidentally installed a 1k resistor where a 10k should be and vice versa (DUH). I'll proceed to kick myself for the rest of the night, although I am relieved. Thanks anyway everyone, always very helpful.

-Kevin

 

[jonathanmorbin]

Hi,

If there is anyone out there still looking at this thread i have a small problem i can't figure out. I have wired the boards as per the diagram and have all the correct voltages. I don't seem to be getting any audio where R206 and R205 Meet. The first buffer stage seems fine. I have audio in and out. But i have no input on the second buffer stage as mentioned. When i increase the input of one unit i get gain reduction on both units but as i move the other units input up it decrease the gain reduction on both. It doesn't seem to be summing the Control voltage correctly. I have tried new stereo link boards and still no joy. Can anyone give me any ideas?

 

[Janalex]

Quick question.  Which if any cables on the stereo link boards need shielding? I'm assuming in and out do. How about link and loop?

 

[robertoray]

Hi.
Really, i didn't understand how works the stereo linking PCB.
I will try to  the Ricothetroll wiring scheme that i've found in this thread.
But i'd like to place an external/internal sidechain switch, if it's possible.
And a stereo jack for ext. sidechain input.
Could someone tell me if I have attached a working wiring scheme?

 

[robertoray]

Quick question.  Which if any cables on the stereo link boards need shielding? I'm assuming in and out do. How about link and loop?

Hi Janalex,
I've the same questions.
But before i tried to understand the stereo link and compressor schematics because i can't found detailed info.
If i say something wrong, please correct me.
LOOP is an input where are connected the out of compressor-1(main board pad 15) bufferized and sent to OUT (for IN to the 2nd stereo link)
LOOP and IN(compressor-2 buffered out) are mixed together and sent to LINK
-------------------------------------
Switching in dual mode, looking at the Ricothetroll wiring scheme, we have the original connection, except LOOP it still connected to main board pad 15 and out pot.
I'm asking if will be better to disconnect this too when not used because we have 25k + 25 Kohm in the link board connecting the audio signal to the ground and the out pot is 250k ohm to the ground (250:50)
Has anyone observed signal lost adding this board, in particular connecting the loop wire?
In case, i will try.
In link mode the original audio signal from the out pot. to ratio pcb pad15 (then cross trough the gain reduction amp to control the output gain like sidechain) will be replaced by the mix (the common sidechain for both compressors)

This PCB is for LINK MODE, because we have a sidechain mix. But if we need for a general external sidechain?

A) we can use the link pcb buffer:  LOOP for ext. return and OUT to ratio pad 15.

B) the mixer like a buffer (obviously disconnecting theLOOP), using the IN like ext. return and LINK to ratio pad 15.
More simple if we would have the link  and ext sidechain features together, in this case we have one DPDT (dual/link) and one 3PDT (ext-int) switch.
And the ext. sidechain works only if the link switch is activated, but we have also dual or link mode in ext. sidechain, depend if we have mono or stereo ext. return.
in addition with this 3PDT switch we can disconnect the LOOP for ext. sidechain but also for the link switch when in dual mode position, if this could be a problem.

C) we don't need to have an input stage and we can connect the ext. sidechain return directly to ratio pad 15.
Any suggestion?

In the revD scheme, both Pad 15 and 17 to the output pot. have to be shielded.
So i think we need to shield this wires used just for sidechain, but connected directly to the pad 15:
-from output pot. to link switch
-from link switch to (ratio board) pad 15
-from LOOP to output pot.
-from LINK to link switch, i don't think, but by the way..
I was thinking to use 2 wires separately shielded for both LOOP and reduce possible crosstalk.
For LINK i think that connecting two LINK together or use one for two, it never mind, but only we don't need stereo ext. sidechain.
Seems that we have a mixer extra if we place the link boards in the same chassis.
We need the second board just for the input buffer.
However, near the link switch we can cut all grounds for avoid ground loops.
IN and OUT i think doesn't need to be shielded, it used just for sidechain... but by the way...

I would ask if it should be better connect the stereo link GND to c25 negative pole too or in any ground of the main PCB where we take the +30v rather than connect it to the IEC chassis ground.
And if i can take +30v from the blk output transformer pad, looks better.

 

[Jazzyseb]

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

Hi  everybody!
I've just finished my 2 Rev D builts with stereo link and the same  problems occuring to me, as to lowend about 2 years ago!
Dual Mono : everything works as it should!
Switch to Stereo: way too much compression is happening! :-(
Could this be the same issue? ( broken Opamp? )
I haven't an  osciloscope so i can't test it like lowend did...
Any other suggestions how to make sure the Opamps are the problem?
I'm quiet  sure i got all the wires right!
We'll i think i'm just going to order a 2nd pair of link Pcb's and see ...

Greetz
Jazzyseb

 

[weiss]

i wanted to add, that the link to the wiring guide is not working anymore

 

[Echo North]

i wanted to add, that the link to the wiring guide is not working anymore

Updated.

http://library.hairballaudio.com/datasheets/Stereo_Link_Wiring_Guide.pdf

 

[Fandangoita]

Hi, Mike, Hi mnats,  hi guys. Probably nothing new here, but i have built a stereo version of LN1176 rev J (Gyraf) rotary switch version and trying to link them using Hairball/Mnats stereo link pcbs. The limiters work perfectly in dual mode but not at atll when i switch to link. I trple checked the wiring dozen times and..nothing. No sound out except for a sort of almost silence distorted sound. Any advice? I am getting mad! Thanks!

 

[Echo North]

Hi, Mike, Hi mnats,  hi guys. Probably nothing new here, but i have built a stereo version of LN1176 rev J (Gyraf) rotary switch version and trying to link them using Hairball/Mnats stereo link pcbs. The limiters work perfectly in dual mode but not at atll when i switch to link. I trple checked the wiring dozen times and..nothing. No sound out except for a sort of almost silence distorted sound. Any advice? I am getting mad! Thanks!

Are they getting proper voltage?

Do you have the small link wire in place on the PCB by the labeling?

Mike

 

[Fandangoita]

Hi Mike. Yes on both questions. I've checked some previous posts here and it seems that there is an issue about connecting point 15 to volume pot streight from the main pcb and not from ratio pcb. Is that the solution?
Thank you

 

[Fandangoita]

Done! It works perfectly. Now i am looking forward to receive your matched four fets for a perfect stereo performance. Congrats to Mnats and Purple for the project and thanks Hairball for the totally killer deal selling this stereo link PCB  kit.
Just to make it clear, if you build a stereo 1176 clone rev J  (Gyraf project),  rotary ratio board, adding the  Hairball stereo link PCB,  you must consider that  lug1 volume pot must be connected streight to point 15 on main pcb and not on ratio pcb, just like on the draw found on this tread that i reposted in my previous post.
Happy stereo compressing!

 

[TheJetTek]

Anyone have insight on installing this kit on a Warm Audio WA76?? I've got everything wired up except I'm stuck on the whole "link to ratio pad 15" part… I have no idea where to make that connection on my units…. Any help, especially with a drawing, would be hugely appreciated.

Thanks guys!!!

 

[midwayfair]

TheJetTek: Use the picture Fandangoita posted.

I can't tell if the link document on Hairball's site is assuming that you're using the rotary PCB (which has pads for the output pot already on it) or just assuming that everyone would leave the connection from the output pot to the PCB in the wiring instructions, but the gist is that their diagram presumes that you're adding this to an existing build and not removing anything or touching any wires except the ones shown. It could probably be clearer in that document, though.

 

[elskardio]

Hi,

I've been trying to make the stereo link works for the past week and it's driving me crazy!
I have 2 perfectly working mono channels with 4 matched fets from Hairball Audio.
If I use the Pad 7 method to link, I get readings of +\- 1dB. So the fets looks pretty well matched. When I link using the Stereo Link PCB the readings are way off! +\- 8dB
My wiring is good and I read every post I could find on the forum but I can't find the solution and would really appreciated some help.  :-\
Here's a video of what happens when I link using the PCB.
https://vid.me/t24T

Thanks!

 

[darkus]

Hi all! Just installed the stereo link kit on my mnats rev D´s. Both sound great in dual mono, but when link engaged i get massive distortion and no compression! I guess the distortion is the output trafo saturating cause the output gets a dozen dB´s louder, but i cant get any gain reduction even if i crank the input all the way.

Dual mono, -5dB of gain reduction and output to daw is something like -12dB. When i engage link, no gain reduction and output to daw is +20 and distorted.

Anyone with a similar problem or solution, Mike perhaps?

EDIT: Problem solved, it was the cable connecting the units, so silly, works perfectly now.

-Markus