[sdiy] switching supply for synth use. also using TTL for synths

[anthony]

So I have two switching supplies that each put out 5V/3.5A , 24V/1.8A, 
+15V/0.5A & -15/0.3A. They came from very high quality early 90's vintage 
RGB scanners. I figure with all of that analog circuitry in there the 
supplies must be at least a little bit better than an old PC supply (which 
from scrounging I can tell you vary WIDELY in quality of manufacture). I 
like them because they are very compact and have a long slender shape rather 
than a squat box, which is perfect for my application. They also actualyl 
look pretty cool compared to you average PC PSU. The make is Touch 
Electronic Co., LTD.

My other more important question: is +15/0.5A & -15V/0.3A big enough for an 
MS-50 sized monosynth? I'll be using mostly JFET opamps, but I will also be 
using a few 3080's and some NE5532's and uPC4574's and 4558's. I could use 
both of them I suppose but that will start to take up space.

I suppose I could also chaneg the design for some of the things so that they 
use TTL or HCMOS circuitry and use the 5V supply.

I also thought about just using it for a "dirty" supply and making a bigger 
linear supply since I do have 5 40V-CT transformers, but I had them 
ear-marked for something else... (which involved using 4 in parallel so I 
guess I couls use the 5th one...).

OR I could modify the +/-12V supply to be another +/-15V supply.

This sort of brings me to my next question. I was really wondering why you 
don't see a lot more synt circuitry using TTL? I knwo CMOS has its analog 
uses and that's probably the biggest reason why nowadays since HCMOS uses 
very little power. I have some 74HCT4046AE's that I thought would make good 
clocks for MN3207's, but that's not s synth circuit per se. What I was 
really thinking about was all of the 74S163 and 74LS161 counters that I 
have. Not to mention 74123 and the 74121 and the 74221... you get the idea. 
I have a lot of 7406's too which would make interfacing it all together 
easy. That and the 4049's and 4009UB's that I have.