"Unison Design" GSSL Finished! Pics inside

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sinestaraudio,

thanks for your comments!
the hum is really, REALLY inaudible even in total silence, let alone when audio is passing though the compressor. It doesn't need improvement. If I turn the volume up to the point where it becomes audible and press play, the room will explode and I'll go deaf. I guess that's pretty damn good noise floor.  :)
 
Good looking build.
I'm just starting a GSSL build myself and took interest in your change of the auto release resistors.

After studying it a bit myself, and looking at the schematic here:

http://www.ka-electronics.com/images/SSL/ssl_82E27.pdf

I'm drawing the conclusion that the lastest GSSL PCB is actually more true to the original design here than the GSSL Schematic.

Do you agree?
 
Thread revival ;D
I got back into modding after almost 9 months. Today I added the CRC board, really did a great job defeating the mains hum (which was audible at MAX makeup gain to begin with - got even better).

2cxdp9w.jpg


117v14l.jpg


f5d7it.jpg


2ztm3hc.jpg
 
hey, nice unit......

im bulding a gssl too......using dbx202c an the 2180 in the sidechain...

i read in a forum where they suggested to leave out the 10K res on the sidechain too.....

how do you did it, cant see that from the pix ????

 
Thanks! All the stuff I removed/changed are in the first post:

I did the following mods:

- Removed both 10k resistors from each VCA circuit (that is four resistors)
- Removed 68R resistor from each VCA circuit
- Removed 1M resistor from each VCA circuit
- Removed 47R resistor (pin4) from Sidechain
- Removed 47R resistor (pin4) from Turbo Board.
- Changed 3k9 resistor to 5k1 for each VCA circuit
- Changed the meter resistor from 2k to 4,7k (Behringer meter)
- Did the PSU mod which adds two 100nF/50V caps and a 1N4007 diode underneath the 79L12
- Changed 1000uF/63V caps to 2200uF/63V caps
- Switched 91k and 750k auto-release resistors in Control Board.
 
could somebody tell my why some users here switch the 91k  and 750k autorelease resistors on da control board ???

are values marked wrong on the control board ??????
 
Hi Stefanos!

Great build!

Could you explain how you exactly hooked up your SSC and Turbo board? I'm interested in how to wire just one SSC and Turbo board, but seeing different approaches on the forum.
And would you maybe post a schematic of your CRC board?

Thanks in advance!
 
theone23: Sorry for the late reply, I read they were marked wrong on the boards and need to be switched, some users do that, some don't. IIRC I put them according to the schematic. There is a possibility this depends on the board revision, not sure about that though.

tzman: I hooked the Turbo Board exactly the way the manual at expat audio describes the connections.

http://www.expataudio.com/diy/Turbo/TurboInstallationManual.pdf


As for the CRC board, I used SSLTech's schematic:

4fuxp2.png


Bridge Rectifier is the same that is used in the compressor board (1A/50V), caps are 470uF Electrolytics, resistors are 10R Metal Film. No magic here involved, either ;)
 
Thanks for your reply!

I misread your post, so I thought that you also had a SSC board installed.
Maybe you could help me out...
I found this picture about hooking up a Turbo board AND a SSC board. I think it's correct, but I think the L R wiring to the mainboard is reversed. As far as I can tell, the 47k resistor closest to the Left VCA is for the Right audio path and the 47k resistor the furthest from the Left VCA is for the Left audio path.

http://img263.imageshack.us/img263/4020/sscholgerwiring.jpg

Also, I think this one has the L R correct.
http://members.cox.net/capstanrecording/GSSL_PCB_SCmods.pdf

As opposed to:
http://picasaweb.google.com/barclaycon/GSSLSuperSidechainPCB#5185516904372762722

What to you think?
To be clear, this configuration would give the GSSL two modes: Gyraf, with SSC OR Turbo, without SSC

 
I see what you want, however, I can't help you since I don't have an SSC board. BUT you're likely to get all the help you need over in the GSSL Thread ( http://www.groupdiy.com/index.php?topic=47.0 ). If they can remotely troubleshoot a unit, they can definitely wire it too :)
 
I think I already got it, just going to hook it up and see what it does to keep the DIY spirit alive :).

Thanks for your answers!
 
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