GSSL HELP THREAD!!!

[guitarguy12387]

Hey guys!

I'm building a GSSL with turbo and 2 SSC boards.

I'm worried about powering the relays directly from the 15v rails... seems i remember seeing posts saying to be careful loading these rails on a GSSL...

Anyone have any thoughts/experiences?

Thanks!

 

[radiance]

Hey guys!

I'm building a GSSL with turbo and 2 SSC boards.

I'm worried about powering the relays directly from the 15v rails... seems i remember seeing posts saying to be careful loading these rails on a GSSL...

Anyone have any thoughts/experiences?

Thanks!

AFAIK, powering stuff from the 15V rails is ok. Just don't use the 12V cause they're used for the reference voltage for the VCA's.

 

[guitarguy12387]

Cool! Thank ya, sir!

Few other questions about the dual SSC/turbo setup:

1. Do i just tie the External sidechain's (on the SSC boards) together in parallel to the jack?

2. What is the use of having send for the sidechain? (I am assuming this is a send for the sidechain, and not a return for the External sidechain, right?)

Hopefully it is clear what i am asking. Thanks so much, again!

 

[Hank Dussen]

1: yes

2: the 'send and return' is an insert. So you could, for example, insert an EQ without having to split the original signal.
Appearantly most people don't connect the send but it could be usefull in live situations.

 

[guitarguy12387]

Ohh i see! I was under the impression it was something different. Okay, that makes sense!

Thanks alot.

 

[guitarguy12387]

Got another...

For the Com-off-on-potA-potB pads on the SSC boards.... which SSC do i connect to?

I probably don't even need relays on both SSC boards, do i??

If it helps, i'm going off the drawing at the bottom of this thread:
http://www.groupdiy.com/index.php?topic=35450.0

 

[Hank Dussen]

nope, you need only one relay (and everything else on the left side of the board).

 

[guitarguy12387]

Okay cool! Thats what i figured...

So i just take the COM-OFF-ON-POTA-POTB pads from the SSC WITH the relay and leave those on the other SSC unconnected, right?

 

[Stagefright13]

Thanks Gyraf for the GSSL! I use it A lot. Today I had some time and was playing with it. Here is a sample with a plain GSSL with the sidechain board. I used it on the master buss from a straight mix for smooshing. Thanks again!!!

www.stagefrightrecords.com/gssl.mp3

 

[pietro_moog]

hi guys!
i built a Gssl with SSC and Turbo boards. 78L12 and 79L12 weren't enough so i switched to 7812 and 7912.
i powered and the 2 10R resistors that bring down 15V to 12V burned.
why?  does those 2 require more power so the 1/4 W resistors were not enough?

thanks guys

 

[radiance]

hi guys!
i built a Gssl with SSC and Turbo boards. 78L12 and 79L12 weren't enough so i switched to 7812 and 7912.

How did you conclude they're not enough?

i powered and the 2 10R resistors that bring down 15V to 12V burned.
why?  does those 2 require more power so the 1/4 W resistors were not enough?

thanks guys

Something is sucking a lot of 12V current, maybe a short somewhere. Having upgraded your 12V regulators was probably too much for the current limiting 10R resistors. Those should be 1/4 watt btw.

 

[pietro_moog]

thanks, i didn't understand your first sentence.
you upgraded 12v voltage regulators and did conclude too that 1/4 W is not enough (i mean the 10R resistors) ?
i concluded that because mines burned. the circuit was working before i changed them, and i changed them because i did not have enough power.
i have 2 W ones, so i'll try those..

 

[radiance]

Sorry , I ment to say: How did you conclude they're not enough?

Circuit should run fine as is. You don't need to upgrade the 12V regulators or use 2W 10R resistors.

What exactly do you mean with "I had not enough power"?

 

[pietro_moog]

that has been suggested me a few pages/weeks before.
i without SSC and Turbo, the comp was working fine.
with SSC in,the leds were a bit weaker, but everything was fine.
with SSC and Turbo in, leds were dead but the comp was fine.
it has been suggested me that i had too much ics on 79L and 78L, and those two were working HOT, i mean 100 degree hot (celsius).

i don't know..

 

[regularjohn]

The SSC should be pulled from the 15V rails, so it should have no impact on your 12V rails.
The turbo is drawn from the 12V rails, so I'd check there first.

 

[pietro_moog]

yeah, but the turbo board was working fine before!

WTF!!!!
there something so wrong in my GSSL. i put 2W resistors on the rails and they burned!!
is it even possible?
the comp was working fine before switching VR on +/- 12V..
i'm wondering: does the 7812 and the 7912 have the same pinout of ,respectively, the 78L12 and the 79L12?
because that was the only substitution i i did!!

hey guys, do you have a SSC and a Turbo boards on your Gssl? did you substitute the 12V VRs? did your 10R resistors got burned?

 

[pietro_moog]

i'm not sure, but i could have done a mistake in wiring the 7912.
gonna check

 

[Harpo]

yeah, but the turbo board was working fine before!

WTF!!!!
there something so wrong in my GSSL. i put 2W resistors on the rails and they burned!!
is it even possible?
the comp was working fine before switching VR on +/- 12V..
i'm wondering: does the 7812 and the 7912 have the same pinout of ,respectively, the 78L12 and the 79L12?
because that was the only substitution i i did!!

hey guys, do you have a SSC and a Turbo boards on your Gssl? did you substitute the 12V VRs? did your 10R resistors got burned?

facing the flat/labled side, the 78L12 has the pins reversed, compared to the 7812. Have a look at the regulators datasheet (watch out some manufacturers have the pins for in/gnd/out numbered in a different order).
Using the 7812/7912, make sure the regulators heatsinks don't touch eachother (the 7812 has gnd connected to this tab, the 7912 has input voltage connected to this tab).
You don't need a higher wattage resistor for normal operation. With Turbo, this +/-12V only connects to 2 sidechain VCAs, 2 TL074, 1 TL072 and 1 LED. The filterboard is powered from the +/-15V rails.

 

[pietro_moog]

mmm.. i see, i didn't check yet, but, could all this happened because i screwed this 2 VRs on the chassis?
in the case, could some insulating tape on the back of VRs be enough to stop all this?

 

[Harpo]

mmm.. i see, i didn't check yet, but, could all this happened because i screwed this 2 VRs on the chassis?
in the case, could some insulating tape on the back of VRs be enough to stop all this?

Your regulators bolted to your conductive case without isolation will burn your forementioned 10R resistor. Use isolation kits (mica, grease and isolation washer) for both regulators, else the 79xx will short the negative rail to gnd and the 78xx will cause a ground loop. No need for heatsinking these 12V regulators with this connected load. If you have other circuits connected to these rails (meter illumination, cigarette lighter, charger for your mobile phone, .. ;D) this might be different.