GSSL HELP THREAD!!!

[spoontex]

Hello,

I've just finished my GSSL build and I do some tests. I notice that one channel compress more than other. I upload a video. Center, Left Out and Right Out. You will see the difference.

Anybody can help me?

Thanks.

 

[Script]

Have a scope? Or feed a steady tone into both channels and then measure AC with your DMM to see where left and right deviate.

 

[spoontex]

Have a scope? Or feed a steady tone into both channels and then measure AC with your DMM to see where left and right deviate.

Steady tone.

Right Out: 0,145V
Left Out: 0,082V

I've traced with the two out opamps, and also the same readings.

 

[Script]

Need to trace all the way from input to output.

 

[spoontex]

I've check the input opamps, and I see a lot of difference between pins 2 and 6.

 

[spoontex]

SOLVED.

I made a mistake with one resistor. I solder 2.2K instead 22K.

Thanks.

 

[MiamiBoy]

After a lot of sweat & tears, too much $$$$$$$$ spent, im finally done.

For the dbx 202C VCA's, I'm still not a 100% sure if the "resistor change" I made, is accurate.
It's not documented very well. All I did was to add a couple of "50K trimmers" and 1M resistors below it.
The two trimmers are soldered to the bottom side of main-pcb.
I drilled some hole to the bottom enclosure, so I have access from underneath with a screwdriver to the trimmers.

Ive added a 5K trimmer for Meter sensitivity.

And added heatsinks to 7815 & 7915 regulators. Very much recommended!

For the HPF* i've added 2 goldpins, and shorted it with a plastic-covered jumper.

I've used an L shape aluminum profile for mounting on the "switch/pot knobs", and mounted that on the bottom enclosure. Courtesy of damien thanks

I've also added a "voltage selector switch" for 115V & 230V needs.
Thank you so much Harpo, for getting me started by drawing the diagram. If it wasn’t for you, I wouldn’t have got this far. I am so much wiser on electronics now, because of you.

The meter I initially bought, had blue LED lights, because I chose blue LED for the pushbuttons.
Unfortunately, I didn't like the blue tint the meter had, it was dull & very dimmed, it looked cheap. So I switched it out for a white LED instead. Much better!

Details on the SuperSide Chain & Turbo mod can be found her

I haven't hooked up the CRC board, as I haven't felt the need. My unit is 100% hum free.
The free space in the middle is made for a perhaps later mod: The Cavendish mod, courtesy of Expat Audio.

 

[FowleyK]

Hey,
ordered the kit and im pretty much new to soldering. after starting with the 1k resistors i wondered if i use too much solder, resulting in pins that are very close to each other starting to connect with each other. would greatly appreciate a look at this and your opinion if i should be bothered.

 

[MiamiBoy]

It doesn’t look like it’s too much. But it doesn’t look good either, sorry.

The solder should cover the spots in a dome shape. Yours looks like they been smothered.
Maybe the tip of your solder iron is too big?!
It looks like you haven’t used enough actually. But there’s a lot of resin flux left (the dark stuff), contra how little solder you’ve used.

Look how I do it

 

[FowleyK]

thanks alot, i tried before a test solder kit and it looked like what you did. i dont know what went wrong, perhaps i screwed my soldering tip as it seems not to transfer enough heat to the pin and wire for the solder to melt into.

 

[MiamiBoy]

Perhaps yea.. if your soldering iron have a temperature control, try to aim for around 250 degree celcius as minimum.

For soldering on PCB bords, you need a small chisel tip iron (pencil style tip) instead of of a standard round tip chisel.

I would recommend the the Hakko T18-D16 which is a 1.6mm tip. These are expensive, but very high Japanese quality.
It's worth it though, especially if you're gonna continue to do some more work in the future.

The solder you choose, should also be a thin type. I recommend Kester #245, it's a no clean, lead-free type, size 0.031 diameter. Mouser part# 24-6337-8800 -also expensive, but it's the very best. But you still need to use isopropyl alcohol to clean up after, as you'd do with all other types.

And finally, I've spent hours on YouTube watching How To Solder videos before I began. You'll learn a lot there!

 

[FowleyK]

Thank you, watched quite some videos now. using a chisel tip and i can't help but feel the pcb is the issue here, i was soldering a test kit on a green board and i can easily solder or desolder pins there with 350 degree celsius or use desolder wick which easily sucks up anything, while on the black gssl board i need to increase the tip temperature to 380 degree until anything barely starts happening and even then the solder has trouble connecting with the pins and wants to flow onto the the tip instead. i have used 400 degrees now on that board to solder as smoothly as on the green test kit.

 

[MiamiBoy]

Im sorry, I don’t know how to help you. Maybe the black pcb has some issues, therefore making the solder hard to stick. I believe Gustav is still selling the classic green pcb’s. Good luck

 

[pelagos]

Mains and Transformer wiring check

Hi there

just finishing of this build and was wondering is someone may do a quick check on my mains -> switch -> transformer -> PCB wiring?

See attached images for reference

Mains input live/neutral goes to switch -> transformer blu-blu connected here (I assume it matters not which goes to which as they are both blue?) then from here the the black/yellow go to centre connection on PCB and red and orange either side (once again assume it does not mater what way the red and orange go)

Many thanks in advance

 

[Gustav]

Remove the secondaries from the PCB.

Attach probes to secondaries.

Set meter to read AC.

Power up, check voltages.

Gustav

 

[gyraf]

black/yellow go to centre connection on PCB and red and orange either side

yup, from the description on the transformer this is right

 

[pelagos]

Remove the secondaries from the PCB.

Attach probes to secondaries.

Set meter to read AC.

Power up, check voltages.

Gustav

Thanks will do

yup, from the description on the transformer this is right

thanks very much

 

[Clbraddock]

Im building a GSSL style compressor (it's not GSSL exactly, but is very similar and my problem is in the side chain rectifier which is identical). With threshold clockwise I get pure DC coming out of the rectifier. With threshold counterclockwise (i.e. lower) I get up to .29VAC coming out of the side chain rectifier (higher threshold settings make it worse). Any idea what could cause this?

 

[gg85]

Hey guys, wondering if anyone might be able to help with some weird SC issue I have. With no audio (no cables are even plugged in) to my gssl, when I turn the threshold the meter pins. It starts off slowly but once it gets to a certain point it just maxes and I can't seem to figure it out. I've tried swapping the VCA and ICs and still getting the same issue.

 

[gyraf]

shorts in the cable/connection/soldering to the frontpanel pcb?