Powering Gyraf 1176 and GSSL from the DC power of my Console Soundcraft TS12

[stuartpre]

Hi, and thanks for reading.

I have a pair of Gyraf 1176 and GSSL boards i'm looking at building (no probs done it before).

But this time I was thinking;

1. Can I run the Console rails of +-17 into the GSSL? Voltage drop of 0.7 per rail leaves +-16.3 Vin for the Lm7815/Lm7915...1.1V is the dropout voltage... so 200mV to spare..enough? Or can I connect post bridge rectifier? Any special approach required here..?

2. Can I run the +48 into the 1176? Do I use a rail splitter here for 24 0 24?  Any suggested circuits..?
I guess current is the issue...? Not sure on the PSU spec here, (no known schematic yet..)  it is called 'Soundcraft - Large Console PSU' no numbers I can see, I have two of these supplies connected as intended by manufacturer (Main and Auxillary).

3. Is there a better way? Or another way (apart from using the transformers..) Can I double the +-17V and use that for 1176? Any suggested circuit?

The console is a Soundcraft TS12

The spare panel in center console that could have been automation looks a good place to build these pairs of comps in, nice and close to power distribution and room under the hood for pcbs and of course the panel is for knobs and meters...

Thanks for reading.

 

[radardoug]

No, its a bad idea. The 48 volt supply in particular is not a high current supply. And transformers for power supplies are cheap. Just buy a standard case and build it in that.

 

[Bo Deadly]

You shouldn't need to regulate the Soundcraft supply further. It should have good regulation already. You could add a simple RC filter and maybe a choke if you're worried about noise one direction or the other. More generally, regulator's like LM317 require several volts so your +17 would end up being more like +14. TL783 requires >10V over the target voltage.

Personally I would just make your project outboard using whatever the usual enclosures are because otherwise you're basically binding the project to this particular console. Do you really want to do that?

If the answer is still "yes", then you really just need +24V for the 1176. Otherwise you can regulate down from -17 to -10V for the 1176 negative rail and the GSSL should be just fine with +-17 (taking care about op amps used). To make +24, you cannot regulate down from 48V because a) the supply is probably not designed to provide that much current and b) your regulator will get very hot. If the Soundcraft also has a high current lower voltage supply, you could use a DC/DC converter to make +24V.

But for it to actually work, you would probably need to be very careful about grounds. You could end up introducing noise where there was none. There are lots of good material around about grounding. It's covered here regularly. Improper grounding is probably the #1 cause of noise issues in pro-audio.

 

[s2udio]

No, its a bad idea.

This............

 

[stuartpre]

ok, 3 x bad idea. cool. thanks.