GSSL HELP THREAD!!!

[Autophase]

Does anyone have the link for that rather handy GSSL roadmap, i've tried searching roadmap but cant find it.
Aslo, if I was to build another one but use PIO's for any caps in the audio chain, would i get a notable difference? Also are there any specific resistors that are better for audio? I would be interested to hear your oppinions

 

[Autophase]

Just finnished my ssl clone. I did somthing wrong with the power supply. I read -15v and 0v. The 7815 gets realy hot. I doesnt work. What do i need to do?

Gr, Pieter

Your trafo will have 4 secondary wires, basically 2 pairs of + & 0
What you need to do is combine a + from one secondary with the 0 of the other secondary. This combined wire goes to the middle of the 3 power connectors on your board.
The remaining 2 wires go to the outer 2 power connectors on the board.
I'm pretty sure  it doesnt matter which.

 

[ruckus328]

Do you have heatsinks on the regulators?  If not you should really put them on.  Did you probe the 7815?  And no +15V?  Are you getting +/-12V?  Most likely: You either 1) have it installed wrong, 2) overheated/fried your regulator.  3) Or it's possible it was just a bad chip.  4) You wired your transformer wrong.

 

[tgauge]

Hey everybody, I just finished my first GSSL (besides the front panel and cosmetics) and everything went very very smooth... Almost too smooth.  Plugged it in, tested the voltage points, dropped in the VCAs and passed a mix through it.  The compressor sounds amazing and is dead quiet.  I have only worked on SCA kits and a DIY Summer before this.  I was quite impressed.

Here's the issue: My right channel volume is about .5 decibel lower than the left.  Is there an easy solution to the problem?  I'm assuming that it's due to variance in the resistors or something of that nature.  I can always just adjust the track digitally once it's back in Pro Tools but I would much rather know what the issue is and how to solve it for my next build.

Any suggestions?  I searched all over for the answer and couldn't find what I was looking for...

Thank you to everyone for your help and the endless amount of data here.  I am so inspired to take on the next challenge.

Happy DIYing!

-Taylor

 

[Pieter001]

Thanks for the advise! I wired the trafo the wrong way. After i fixed it i read -15 and +15v. After a little time the +15v droped down to +0,72v. Do i need to replace the 7815 or is there some other problem?

 

[ruckus328]

Thanks for the advise! I wired the trafo the wrong way. After i fixed it i read -15 and +15v. After a little time the +15v droped down to +0,72v. Do i need to replace the 7815 or is there some other problem?

If it were me, I'd replace it to be on the safe side.  You may have damaged it, and it's not worth the $2-$3 to not replace it.  And heatsink them suckers, the cooler you keep them the better.  If you bend the regulators correctly, you can fit these guys on them right on the gyraf board.  They'll juuuuuuuust fit.

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=HS106-ND

 

[sonolink]

....guess you guys don't illuminate your meters....

I'm using a Simpson 1542 Edgewise VU meter for my Gssl with the Expat Vu meter Mod.
I would like to know how do you guys illuminate your edgewise meter? With LEDs? Are the Leds placed inside the meter? Behind?
Thanks in advance for all input and help
Cheers
Sono

 

[Pieter001]

@ruckus328, What do you mean by probe the 7815? Maybe i did something wrong with that to

 

[ruckus328]

@ruckus328, What do you mean by probe the 7815? Maybe i did something wrong with that to

I meant put a meter across it.  Right at the regulator pins.

 

[Harpo]

Here's the issue: My right channel volume is about .5 decibel lower than the left.  Is there an easy solution to the problem?  I'm assuming that it's due to variance in the resistors or something of that nature.  I can always just adjust the track digitally once it's back in Pro Tools but I would much rather know what the issue is and how to solve it for my next build.

Any suggestions?  I searched all over for the answer and couldn't find what I was looking for...

depending on when volume imbalance is happening,
volume imbalance in bypass/not compressing mode: easiest spot for a fix seems to be, replacing the 15K feedback resistors (between NE5532-pin 6/7) below and right next to the silkscreen label OUTPUT with a 10K fixed resistor in series with a 10K trimmer, wired as rheostat.
Volume imbalance while compressing the same signal: easiest spot for a fix seems to be, replacing the 1K resistors (between 'CV TO VCA'S' an audio-VCAs CV-in) right next to the DBX202 silkscreen outline with a 2.5K trimmer, wired as rheostat (between leftmost pin and the joined together rightmost and center pin of the trimmer).

 

[Pieter001]

Just replaced the 7815. Same thing happend again. First try i read -15 and +15. After some time the +15v droped down to +0.7v.

 

[gyraf]

Just replaced the 7815. Same thing happend again. First try i read -15 and +15. After some time the +15v droped down to +0.7v.

If the 7815 (like all 78/79 type regulators) gets too hot, it will power itself down. Maybe something is drawing too much current? Otherwise, mount a small heatsink to take some of the load off it's shoulders (make sure not to short to 7915's heat sink!)

Jakob E.

 

[Pieter001]

If i turn on the unit i read -15 and 0.7v. The 7815 is not that warm at this time. The first time i turn on the unit i read +15v.

 

[regularjohn]

....guess you guys don't illuminate your meters....

I've never used an edgewise meter, but when I add LED's to vintage meters I take them apart and drill a hole in the outer case.  The placement of the hole is something you'll have to decide.  Each meter is a little different and figuring out the best place to add the LED is up to you.
Insulate the legs of the LED, and secure it in place with strong tape.  Make sure it's not in the way of the needle movement.
Wire it up and watch it glow!

 

[Biasrocks]

If i turn on the unit i read -15 and 0.7v. The 7815 is not that warm at this time. The first time i turn on the unit i read +15v.

Perhaps you're drawing too much current through the +v rail,
IME just adding the meter LED comes very close to overtaxing the
positive rail in this design, that's using 202c's as the main VCA's and
2151's in the SC.

If you power additional boards, such as the turbo or SSC
you're probably over the current limit where the rail starts to sag.

What do you have hooked up to it?

Try disconnecting things to see if the PS stabilizes.

Mark

 

[Pieter001]

I hoocked up a SSC board. Don't use any meter led's. My bypass led works fine but the power led blinks when i turn on the unit. The power led didnt stay on. shall try to disconnect the SSC board tomorrow. Thanks for all your advise!

 

[Stagefright13]

Mine works fine with the ssc installed. And no heatsinks on the regulators to boot. The biggest problem on this board is solder joints. It is REAL easy to overlap. Try to build it as Gyraf suggested. THEN add options. I think many people want it all at once. Just build the GSSL! If you need to mod it then go ahead. Adding all this extra crap will get you A Lot of troubleshooting pain.

Just build it like Gyraf suggested. When it is working then mod it. You all want to add all these mods at the same time you are building. And most of you don't know which end of a screwdriver to hold. I am sorry if that was harsh. But the posts here reflect that.

Just build it stock. You can always put a stroker crank into an old Chevelle later. But if it doesn't start from the get go?

John

 

[regularjohn]

Just build the GSSL! If you need to mod it then go ahead.  

I definately agree with that.  I think people forget just how awesome of a compressor the gssl is when built properly.  There's soooo much buzz about these add on boards that newbies might think that the gssl on its own isn't that great.  That is definately NOT the case.  A comp that can do what the gssl does would be categorized as high end if it came from a name brand manufacturer.

In regards to the heatsinks on the regulators...I've never needed them, even with four additional add on boards run off the gssl's psu.

 

[sonolink]

I've never used an edgewise meter, but when I add LED's to vintage meters I take them apart and drill a hole in the outer case.  The placement of the hole is something you'll have to decide.  Each meter is a little different and figuring out the best place to add the LED is up to you.
Insulate the legs of the LED, and secure it in place with strong tape.  Make sure it's not in the way of the needle movement.
Wire it up and watch it glow!

Ok, so it goes "inside" the meter  8)
Thanks a lot Dustin  ;D

 

[j.frad]

[quote author=tgauge]
Hey everybody, I just finished my first GSSL (besides the front panel and cosmetics) and everything went very very smooth... Almost too smooth.  Plugged it in, tested the voltage points, dropped in the VCAs and passed a mix through it.  The compressor sounds amazing and is dead quiet.  I have only worked on SCA kits and a DIY Summer before this.  I was quite impressed.

Here's the issue: My right channel volume is about .5 decibel lower than the left.  Is there an easy solution to the problem?  I'm assuming that it's due to variance in the resistors or something of that nature.  I can always just adjust the track digitally once it's back in Pro Tools but I would much rather know what the issue is and how to solve it for my next build.

Any suggestions?  I searched all over for the answer and couldn't find what I was looking for...

Thank you to everyone for your help and the endless amount of data here.  I am so inspired to take on the next challenge.

Happy DIYing!

-Taylor
[/quote]

Hey taylor, I recently had 5dB offset on a gssl, turned out the two 27k (or 15k as sometimes written on the pcb) between the power transformer and the vcas had different values. That could be a starting point as they influence directly the level going to the vca inputs.
Hope it helps!

jules