2 channel mixer build question

[Greenballs]

Hi all

I'm tinkering with the idea of building a two channel mixer for live use, based upon this project here:

https://sound-au.com/project205.htm

The mixer circuits run off a +15v/-15v power supply. I'm considering putting a compressor circuit (the AMZ Q&D compressor https://www.muzique.com/tech/2166.htm) just after the mic preamp section (before the EQ section), which runs off a +9v power supply.

My question is, is there anything I need to be mindful of when different power supplies producing different voltages are being used to power different parts of what would be the same circuit? A second question would be, can the AMZ comp run on +15v/-15v?

[antonis]

is there anything I need to be mindful of when different power supplies producing different voltages are being used to power different parts of what would be the same circuit?

As far as there is enough filtering (and DC blocking caps, of course..) there shouldn't be any problem..
(headroom is another kettle of fish..)

I stronly recommend LM317/337 voltage regulators implementation for +/- 15V..
https://sound-au.com/project05a.htm

A second question would be, can the AMZ comp run on +15v/-15v?

https://www.analog.com/media/en/technical-documentation/data-sheets/SSM2166.pdf

[Greenballs]

Excellent, thank you Antonis!

[ElectricDruid]

I strongly recommend LM317/337 voltage regulators implementation for +/- 15V..

Is there any advantage to using the variable LM317/337 regulators over the fixed LM7815/7915 versions? Aside from being able to tweak them to get *exactly* 15V, I suppose? (although the Rod Elliot circuit you linked to doesn't show any trims for the voltage that I could see).

[antonis]

Is there any advantage to using the variable LM317/337 regulators over the fixed LM7815/7915 versions?

!!! NOISE !!!

As many power supply gurus have stated (and personally verified): "Some 78XX ICs could be sold as noise generators"..

IMHO, mainly due to large ADJ pin and quiescent current, in relation with variable ones..
(but it's only a guess..)

[ElectricDruid]

!!! NOISE !!!

Do the datasheets reflect this? I don't think I've read them side-by-side, but it sounds like I should.

Thanks Antonis.

[antonis]

Do the datasheets reflect this?

Should they do and immediately be vanished by the marketing department..