GSSL Relay Bypass Question

Hey guys, sorry for the double post.  I posted this a few days ago in the SSL Help thread but have yet to get a response so my GSSL is kind of at a stand still in this area.


I'm trying to add a relay bypass to my GSSL so in my searching I found this picture and it makes total sense to me except...



1: Would the xlr inputs run to both the relays and also the GSSL inputs?

2: If so, when bypassed wouldn't you see gain reduction because the GSSL would still be functioning except the audio out would be coming straight from the xlr ins?

3: It seems that it would make sense to take that schem and flip wherever it says "in" to "out" therefore the unit would actually be bypassed.  Does that seem more legitimate?

4: Where specifically (diagram of PCB if possible) would I get my power from for the relays?

5: Off topic but while I have you attention... Where might I be able to get my hands on those beautiful little hex nuts that the original SSL uses on the front panel?

I think that's it for now... just trying to wrap my head around this.

Thanks guys...

Taylor

I think normally bypass schems that I see uses two relays for chanel. You can see a schematic on Igors bypass PCBs here http://www.groupdiy.com/index.php?topic=29770 

ahhh... I looked at Igor's schem before but I guess that didn't fully click.  Shortly thereafter I found this picture and another similar to it so I figured this was the was most people were doing it.  I think I'm on the right track now.

Now I just need to figure out the best spot off of the PCB to draw the power...

Thank you,
Taylor

Maybe you can draw power from +12V to your reles (if they are 12V) but I dont know if your power supply can feed the extra power for the relays, you must do some maths I think. the 78L12 regulator can feed 100mA (says that on datasheet), I dont know how much need your relays. There are some omron 5GV-2 that need less power than others, standar draws like 50mA on 12V but there are High sensitivity ones that draws like 13mA... You can try to feed some relays with +12V rail and the others with -12V to compensate a little and not feed all from the same regulator... I dont know how much power the TL072s and TL074 opamps on board need, you must search... and must look your power transformer specs to know if it can do the extra

I prefer to keep relays on a seperate supply.  If you look at the standard power supply schematics most people use around here, like the SSLtechs psu or the JLM supply.  you can see that multiple supplies can be fed from a single transformer.  just add another bridge rectifier and move forward from there.

If you use the LM7812 datasheet (or whatever voltage works for your relays) there are only IIRC four parts.
for relays you don't have to use large smoothing caps, 10uf or 22uf are fine.

Anyhow, once you get the hang of it, you can knock out a relay supply on perfboard in about 10 minutes.
If you are etching yourself, just add that circuit to your relay bypass board and then you'll always know how to power your relays.

Kelly

Yes... its true, wold be easier to do a separate power supply, less problems asociated with posible interactions betwen relays and the main ssl board...

Thank you both, I guess it's time for more reading... haha.  I dedicate 2-4 hours per night around here at least just reading through posts.  Sometimes it doesn't lead me anywhere and other times I come out a little smarter.

Thanks again,
Taylor