GSSL HELP THREAD!!!

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

Ricardus

WILL SOLDER FOR FOOD
Joined
Dec 2, 2018
Messages
1,649
Location
No longer in NY and below the Mason Dixon line.
the threshold knob almost acts as if its working in reverse. when the knob is turned all the way counter clockwise the meter is buried at 20db and with it all the way clockwise its sitting at zero (with the attack on slow and the release on fast) If I put the attack on fast and the release on auto it changes to about 2db) Ive never see anything like this before and I have no idea where to even begin after checking the obvious.
Maybe it is in fact working in reverse because it's wired in reverse? Check that.

And maybe you need to look closer at the board with the switches and pots on it and make sure you placed all of the conponents in the right place. Also, IIRC there is a big loom of wires that goes between the motherboard and the switch PCB. Check to make sure all those wires are in the correct order.
 

atticus1872

Active member
Joined
Aug 12, 2021
Messages
37
Location
USA
I feel like you have to be measuring the voltages wrong at the 5532 and the 074 because those are exactly double the correct voltages. So I'm guessing you're measuring wrong and the voltages are correct.
Its a good possibility ill admit. Where should I be measuring voltages for 5532 & 074? If they are correct then what would be my next step in diagnosing?
 

atticus1872

Active member
Joined
Aug 12, 2021
Messages
37
Location
USA
Maybe it is in fact working in reverse because it's wired in reverse? Check that.

And maybe you need to look closer at the board with the switches and pots on it and make sure you placed all of the conponents in the right place. Also, IIRC there is a big loom of wires that goes between the motherboard and the switch PCB. Check to make sure all those wires are in the correct order.
Ill check it tonight and upload some images of it if i can get it to work. Ill report back and let you know, thank you for your help I greatly appreciate it!
 

richtrix

Member
Joined
Oct 14, 2015
Messages
7
Ok I've made progress!!! I looked over the PCB and don't know how I missed it before but I missed a tie next to the 47k resistor by the left vca... Plugged that hole and viola!!! It passes audio now!!! Woohoo!

All still is not good though. When I put the compressor button in the signal noticeably distorts and doesn't seem to respond to Threshold nor makeup gain. The only response from front panel (other than bypass button) I get is when I move the ratio to 10:1 the signal audibly lessens and the meter deflects to about 8db and just sits there. The meter does this whether there is signal or not. I can audibly hear the drop though. I verified all the ICs and caps are in the right place and orientation. I have the tie in on the control board that Jakob mentions everyone forgets next to meter output. I'm pretty good with soldering iron so no globs. I guess just start checking the resistors?? Would be nice for some additional voltage test points if anyone has any. THANKS
Greeting everyone! Since experiencing the above quoted issues I've not touched my GSSL project in 1.5 years. It saddens me but I clearly don't have the time/knowledge to try and troubleshoot it. I built it into the chassis of an old Mytek 20 bit converter that died after a long life. It fits perfectly and is much more compact than many other chassis you typically buy. Got all the really nice authentic buttons, knobs and VU meter. Don't know if any PCB components are bad. This is a PCBgrinder kit I put together. For symptoms you can read my posts. I'm selling the entire project. If you're good at troubleshooting you can have a basically fully assembled GSSL for pretty cheap. I bought the kit in 2016 so I don't even remember what it cost. I don't remember where I got the faceplate, VU meter and switches and knobs but I remember them costing a fair amount. I put a lot of time into it but can't seem to cross the finish line. Make me an offer. Only other thing that will be needed is one new screw hole on each side for the faceplate to fit the chassis as the top hole on each side doesn't line up with the holes for the old Mytek faceplate (see photos). Also interested if someone is willing to try and get it going for me I could pay you for your time! That would be preferred path but I can't have it on my desk jeering at me any longer.
 

Attachments

  • GSSL0.jpg
    GSSL0.jpg
    4.9 MB · Views: 0
  • GSSL1.jpg
    GSSL1.jpg
    8.4 MB · Views: 0
  • GSSL3.jpg
    GSSL3.jpg
    9.4 MB · Views: 0
  • GSSL4.jpg
    GSSL4.jpg
    2.2 MB · Views: 0
  • GSSL2.jpg
    GSSL2.jpg
    2.5 MB · Views: 0
Last edited:

atticus1872

Active member
Joined
Aug 12, 2021
Messages
37
Location
USA
Maybe it is in fact working in reverse because it's wired in reverse? Check that.

And maybe you need to look closer at the board with the switches and pots on it and make sure you placed all of the conponents in the right place. Also, IIRC there is a big loom of wires that goes between the motherboard and the switch PCB. Check to make sure all those wires are in the correct order.
Took a closer look at the board and the switches and pots. The components are all placed in the right spot and I inspected the 10 wires going from the board to the switch pcb and they are also in the correct location(s).
 

atticus1872

Active member
Joined
Aug 12, 2021
Messages
37
Location
USA
Pull up the spec sheets for both of those opamps and check the pinouts.
I checked to pin outs and from what I can tell I'm measuring in the correct spots but again correct me if I'm wrong since I'm new at this, on 5532 I'm checking pin 4 and pin 8 and on TL074 I'm checking pin 4 and pin 11. Let me know your thoughts. Thank you again for your help!
 

richtrix

Member
Joined
Oct 14, 2015
Messages
7
you posted into the wrong thread. "Want to sell "":belongs into black market
I put it here because this is where people interested in the GSSL hang out as well as because I was looking to see if someone wanted to help repair it. I just tried to put it in black market as you suggested. That page says I have insufficient privilege though. I am a white male, I am told this affords me all privileges so I can't make sense of this state of affairs.
 

JerryPbury

Well-known member
Joined
Jun 6, 2004
Messages
140
Location
Charlotte, NC
I put it here because this is where people interested in the GSSL hang out as well as because I was looking to see if someone wanted to help repair it. I just tried to put it in black market as you suggested. That page says I have insufficient privilege though. I am a white male, I am told this affords me all privileges so I can't make sense of this state of affairs.
😂
 

Script

Well-known member
Joined
Nov 27, 2008
Messages
1,881
Location
Japan
affords me all privileges
Weird humor -- better used sparingly around here. (But I get your frustration.)

If it was a kit, better build with all kit components as intended first !! Only then start swapping out for fancy whatevers in second step. -- Fancy switches have been the cause of many a headache (could read above).

Check ALL soldering in the sidechain with beeper for correct connectivity and , even more so, make sure there's no unwanted connectivity (globs/blobs). These boards/joints are tightly spaced -- just visual inspection does not suffice when unit's not working correctly at first fireup.

Also make sure your specific VCA is implemented correctly (could search for: Gssl VCA Matt Fisher).

Checking resistors -- sure, in the sidechain, and you missed one or two resistors elsewhere already.

Hope you will persevere.

(As for Black Market : there might be a minimum number of posts required to unlock, I think. Not privilege related, rather a protection against scam sellers).
 

petermontg

Well-known member
Joined
Dec 29, 2012
Messages
199
Location
Ireland
Just curious.....

Adjustable LPF shelf in the sidechain on top of the current HPF. With the current freq selection of the HPF selecting the FC and a +/- pot.

Ive borrowed another VCA compressor with one which I think is a great way to get the sidechain shape without over compressing it. Really fine adjustments of the sidechain.

Has it been done before I go and have a look at it and could I squeeze it in before the output of the super sidechain or best to put it on it's own board with its own buffers?

Best peter
 

Script

Well-known member
Joined
Nov 27, 2008
Messages
1,881
Location
Japan
If you have a supersidechain board, you could use the ext send and return to insert and test any kind of filter of your liking.

Do you mean adjustable HPF and adjustable LPF? Like two pots that create a bandpass and when overlap (i.e., LP is lower than HP) create a bandstop ?

I inserted a subboard into a gssl to convert from HPF to LPF. Somewhat useful -- depends. Thread is here:


Either way these are gssl add-ons.
 

petermontg

Well-known member
Joined
Dec 29, 2012
Messages
199
Location
Ireland
No external, it's an EQ shelf in the sidechain while the sidechain is functioning as normal.

So you would have the option to select your sidechain Freq ie 120hz the sidechain would act as normal. The shelf EQ would be ontop of this.

It doesn't seem to have been done.

I've had the lend of the Elysia alpha. If you look at the sidechain there is an option the EQ the sidechain. It sound great just for tightening things up without adding more compression.

From looking at the graph plots it just looks like a shelf +/- in the sidechain.
 
Top