GSSL add-on help thread

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Dynamex1 said:
Is there any source in Europe, where i can get the CRC, Turbo and VU Meter Driver PCB´s ?
I know that Expat Audio offers them, but shipping is ~ 50% of the price for the Boards.

Hi Christian,
We don't have another distributor in Europe (our business is 2 people... the main one is me!)
There may be some folks on here with spares, but otherwise, you'll have to order from our website.

Our pricing is calculated directly from the USPS website + a small fee charged by the fulfillment company we use.

Thanks again

Dafydd
 
Hello good evening, I have rev12 pcb, everything is fine but I want the hpf filter to work better, I would also like to improve the stereo field of the unit, I have read with the expansion of the turbo pcb, this is fixed since it duplicates the tl072, tl074, add one more vac and add another hpf filter section.
So if I do this turbo boost, will it improve the stereo field of my unit as well as improve the feel of liberal bass in compression?
thank you very much.
 
Thanks Guion, so if I install turbo expansion, where would I have to get the cables from the HPF? rev12 main pcb? turbo pcb? or both with duplicate filter capacitors?
thank you very much
 
I don't really want sidechain, in my gssl I don't have the sidechain option installed, I want to duplicate the tl074 and vca sidechain circuit to improve the hpf, where would I have to insert these elements in the gssl rev12 pcb?
 
Hi,

i got a working compressor unit and hooked up a supersidechain mod from pcbgrinder.
The supply voltages at the sidechain ics are correct (+-15v). But im confused that i get 30V at both led outputs.

Due to no schematics of the ssc i need your help here.

Thanks so far



 
You referring to Meter LED ? Is that maybe because you are measuring across LED+ and LED- ? Try measuring from LED+ to ground and LED- to ground (e.g. negative probe to starground).
 
Script said:
You referring to Meter LED ? Is that maybe because you are measuring across LED+ and LED- ? Try measuring from LED+ to ground and LED- to ground (e.g. negative probe to starground).
Thank you Script!

Yep that was the cause - now i get +- 15V, but still pretty high for a LED.
 
15V, hmm. You soldered in the two resistors? Correct values? Should measure a bit lower (12V or 13V). Anyway, if LEDs are too bright, you can always stick another resistor on the wire in series (10K or so, maybe more). Or test with a higher resistance pot in series (100K or whatever), tune brightness to liking during daylight and at night, and then replace with fixed resistor. That's what I do with all my LEDs. I tend to like it less bright.
 
Script said:
15V, hmm. You soldered in the two resistors? Correct values? Should measure a bit lower (12V or 13V). Anyway, if LEDs are too bright, you can always stick another resistor on the wire in series (10K or so, maybe more). Or test with a higher resistance pot in series (100K or whatever), tune brightness to liking during daylight and at night, and then replace with fixed resistor. That's what I do with all my LEDs. I tend to like it less bright.

Yes 1k2 for Meter and 2k2 for In Led... i get the same readings before and after the resistors (+-15V).
Im using british push buttons DAPB400 with a 2V led and the meter  is a vintage meter s-500 with a 5-7v led.

im confused....
 
Script said:
Don't be. You have some cheap, generic LED lying around ? Try it, then measure.

For your vinatge meter (sure it's LED?), maybe try this:
https://ohmslawcalculator.com/led-resistor-calculator

I will test this later - maybe tomorrow... I think i also noticed some strange behavior with the sidechain settings... Gonna check all connections again and upload a video to make it easy...
 
By the way, where is the extern in position located viewed from the front panel left or right? And do i need to connect the sleeve (0V) of the sidechain input to case ground?
 
...ok i double, tripple checked every connection - everything is fine. Everything is wired up like it should be + I resoldered every joint on the sidechain board just be be sure that nothing is cold or weak.

- When im choosing OFF the signal is still beeing compressed and the make up gain isnt disabled like it should.
- I dont get any hearable or visible (compression meter) effects switching from 60 over to 200. I didn't adjust TM & TL so far
- The left channel  is louder an starts cracking from time to time even with no signal going through the device, no matter compression is on or not

I made some pictures of my device and certain parts ... Im using NE5532 AP at the SSC Board and NE5532/4 P at the main board...  VCAs are THAT 2180B

As i mentioned before the compressor was working without problems before i added the SSC

I also added a video of the cracking thingadingdong:
https://drive.google.com/file/d/1VmRJYle0RzG8W2naboFGjPYo9s8t8_Ip/view?usp=sharing

EDIT:
I did a test without the NE5532AP on the SSC board - it acts exactly the same without the opamps???!!!
The cracking thing first seemed to be gone, its still there but very low...
 






 
- When im choosing OFF the signal is still beeing compressed and the make up gain isnt disabled like it should.
Sounds like something in the switching logic is wrong, no ? Either on the SSC board or (my guess) the front sub board. Look at schematic and follow traces while checking for connectivity. You could also try and get the unit running without the relay switch on the SSC board first. I never used the SSC board relays at all. Rather, I took those relays and put them on a hardbypass board to switch from XRL IN to XRL OUT, which to me makes much more sense. Attached picture shows a dummy on an old board version with three cable connections for the gain pot, as well as two wire jumpers -- on my unit this works.
 

Attachments

  • GSSL_gain pot__ON jumper.jpg
    GSSL_gain pot__ON jumper.jpg
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TimKR said:
Thanks for your answer Script.

The relay works as it should, it switches the compression on/off. The wireing from front to ssc is also ok. Traces... there is nothing obvious...

Maybe its the main PCBs and i should solder the wir connections from both sides...

How about adjusting the resistor ls according to http://diy.fischerworks.com/gssl_vca.shtml

Im getting nuts already...


 
Going nuts ? Welcome to DIY  by the way.;) Maybe it's time to take a break.

Did you say your bypass switch didn't work but now it works ?
- When im choosing OFF the signal is still beeing compressed and the make up gain isnt disabled like it should
The relay works as it should, it switches the compression on/off.
What did you change ? Where was the problem ?

You said that the unit worked properly before you started modifying it ?

What is still a problem apart from the meter light ? The voltages you gave earlier seem fine. Check again, try with a cheap LED, connect, and it should be done.

The sleeve of a TRS jack for the EXT IN should be referenced (meaning 'connected') to ground or 0V (could be PCB board, case or even starground).. If not, it can introduce noise. Is that the crackling noise you mentioned ?
 
The yellow, orange and blue cables running from the main PCB underside to the filter board look like they do not connect properly on the main PCB. You should resolder them all. It's easier when you insert those cables from the top side and then solder on the underside cos that's where the traces are.
IMG-20210318-133917.jpg
 

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