GSSL HELP THREAD!!!

[Gustav]

need to buy pots

You bought a kit, and there are no pots?

Gustav

 

[thomasdf]

He means knobs I guess?

 

[Graph]

need to buy pots

You bought a kit, and there are no pots?

Gustav

No  50k linear pots and 3.8mohm resistor missing, but no problem, nothing i cant buy a few blocks from here. I have finished soldering nearly everything and rechecked every value/correct placement, when i finish the chassis i will test it

Thanks gustav for the kit, and Jakob for such a grear project

 

[Gustav]

need to buy pots

You bought a kit, and there are no pots?

Gustav

No  50k linear pots and 3.8mohm resistor missing, but no problem, nothing i cant buy a few blocks from here. I have finished soldering nearly everything and rechecked every value/correct placement, when i finish the chassis i will test it

Thanks gustav for the kit, and Jakob for such a grear project

I must have forgotten to pack the pots. I recently added the detented pots, so they are not packed when I pack a stack of kits anymore.

I really would feel best shipping them out to you.

Make sure to check the carpet for the resistor. I do make mistakes, but usually, they are universal (missing in one kit, missing in all), which means I am able to adjust from feedback if someone should be missing. I packed a huge pile of resistor kits for the GssL last year and haven't had feedback on missing items in that particular component bag.

Gustav

 

[Graph]

No problem, thanks anyways Gustav, i have already sourced a 3.9m resistor and 50k linear pots (it would take a month to deliver)

Next week i hope to have it finished inside its case, so i can post a pic of it

Bests

 

[turk sanchez]

.the only knob that does anything is makeup gain, and that only works when the unit is in bypass.

Then bypass switch is wired wrong. Re-check.

Jakob E.

...everything looks like it is wired correctly to my noob/colorblind eyes (I had a friend help w/the color of the wires). I usually label the wires w/tape and write the color on there.

Does anybody see anything I missed or did wrong? Thanks again, Jakob. I appreciate the help.

 

[TheBassgasm]

Hey guys.

I switched my latching 79L12 regulator for a new one today and the unit is passing audio in bypass now.  All +-15V & +-12V measuring poins (the ones printed on the PCB) show the right voltages.

Thing is, when I switch out of bypass, into compression, I get some very strange noise but no audio. When I turn the makeup pot CW there is a point at which the noise jumps right up to clipping my line input in my interface. When I defeat makeup in compression mode the unit passes audio and even does some strange compression. It sounds as if the gain reduction would be just all the way or nothing, but nothing in between. Does that help a little?

Looking at the schematics, I'd guess that there is something up with the TL072 or TL074.. Anybody got some advice?

I'd appreciate help very much!

 

[olebrom]

Send me a mail, Ill sort you out.

Gustav
[/quote]


Thanks!!! email sent. Eirik
[/quote]

Potentiometer recived   amazing service.  Thanks!

 

[turk sanchez]

edit/correction...I since discovered the answer to my own question ~ it does not matter the orientation of the DPDT switch. 

Old question below...

...does the bypass switch have specific pin-out? The mini-toggle on/on DPDT that comes w/the PCB Grinder kit (knx-2 switch ~ 3a/250vac).

Maybe I have the bypass switch wired "backwards"? Is that possible? Still no compression, makeup gain working in bypass mode only.

I have checked all the lines for resistance w/my meter ~ from switch to control PCB, and control PCB (via Molex cable) to main PCB. Everything seems good.

 

[TheBassgasm]

@turk: Well yes. It is a double throw switch. Make sure makeup is defeated when 'com' is switched to 'off'


@ all: I did some more troubleshooting today and found that the trim pot i put in for the gain reduction meter actually is a 50k, not a 5k one So I turned it down to 2kOhms and the meter is reading now!

Sadly I still wasn't able to solve my compression trouble. I searech this thread for my problem but didn't find anything helpful.

The funny thing is that the meter is reading quite normal. When I turn the threshold all the way up, the sound is clear and the unit doen't compress at all. But when I turn the thesh down a bit (Meter reading about 2-4dB compression) it sounds as if the compressor wasn't compressing but gating the signal when it exceeds thresh.. In heavy compression the signal disappears all together (as if gating).

Would anyone point me in the right direction or give me a hint on how to solve this? I'm stomped =(

 

[Gustav]

All +-15V & +-12V measuring poins (the ones printed on the PCB) show the right voltages.

try measuring voltages across all ICs (google:THAT2180 data sheet, 5534 data sheet etc for pinouts).

Gustav

 

[Gustav]

...does the bypass switch have specific pin-out? The mini-toggle on/on DPDT that comes w/the PCB Grinder kit (knx-2 switch ~ 3a/250vac).

Maybe I have the bypass switch wired "backwards"? Is that possible? Still no compression, makeup gain working in bypass mode only.

I have checked all the lines for resistance w/my meter ~ from switch to control PCB, and control PCB (via Molex cable) to main PCB. Everything seems good.

Switch looks fine on the picture. Would you mind posting a picture of your build, top and bottom, both main and control board?

Gustav

 

[turk sanchez]

Thanks, Gustav!

I'll take some pics in the morning sunlight tomorrow morning ~ I cut out the switch and ordered another one. At first I was going to try and clean the switch I have here (and re-wire it flipped around the other way), but when I tried to hold my solder tip to one of the lugs on the switch to remove the old wire, the whole tab just pulled right out (and ruined the switch).  This was the black wire in my picture of my switch. I think this is the "on" wire. Maybe this tab was bad the whole time and that was the problem?

I also see a mark #1 now by one of the pins...I had it wired "flipped upside down" where pin 6 was pin 1. I didn't think it made a difference with a dpdt (thanks for the tip, bassgasm). I figured I'd cut the switch out and re-wire it anyway. Can't hurt to try a new switch either way.

I'll post pics in the morning. Thanks, Gustav!!!

 

[turk sanchez]

...here are the pics, Gustav. Thanks again. I removed the Molex connector in the pics (so you can see the PCB better).

 

[turk sanchez]

...bottom main PCB

 

[turk sanchez]

...control PCB top

 

[turk sanchez]

...bottom of control PCB

Thanks for the help. I have a new switch on the way (should be here in a few days).

PS...My VU meter went dark (lights out) after the first power up. I had the wrong fuse in there for the first power up. It was a fast acting 250volt/250ma. I replaced it w/the correct 500ma, 250volt slow blow and having no problems w/that. Power supply is great. Ground is awesome everywhere I check. Passing signal fine and no noise.

Main issue is compression not working...only the makeup gain working in bypass mode. The gain sounds nice and clean though. I know I can't be that far off. Thanks for the help

 

[bernbrue]

Orientation of one of the THAT chips is wrong.
regards
Bernd

 

[Gustav]

Orientation of one of the THAT chips is wrong.
regards
Bernd

Great eye, Bernd.

And would account for the problem too, since its the side chain VCA, Turk.

Gustav

 

[turk sanchez]

...whoa! If that is the only problem, then that sure is an easy fix. I guess I might not have needed to cut out the switch. No big deal...new one shipped already.

Thank you SO much, bernbrue and Gustav!!

Any idea why the VU isn't lighting up (only lit up for a few seconds the first time).