[sdiy] Help with Jupiter 8 clone

[Josh Nursing]

On Wed, Aug 3, 2022 at 1:23 PM Ben Stuyts <ben at stuyts.nl> wrote:

> The problem I see each and every time though, is that any noise generated
> in whatever is on the DC side, goes right back through the PSU and onto the
> mains supply lines.
>

Exactly. And that messes up all the audio chain response.

I have a sneaking suspicion the handful of people looking for citations or
sources have never even measured a thing themselves - high chance they
wouldn't even know how to measure nor what to look for -  nor do they know
anything about the inner workings of either SMPSes or the Linear Regulated
PSUs, and furthermore, know absolutely nothing about how power distribution
also plays a part in this, together with leakage currents.

I've done the work, compared Linear vs SMPSes with a DAC, both auditioning
and measuring. In fact, I can design an even better Linear PSU than the
originals in the vintage machines or even modern machines as I've spent
years investigating precisely this.

Some of it has been published, they could look it up with the measurements
there, but that would require I care about convincing these people. Let
them wallow in their fantasy world.

While Xpander/Matrix 12 are better at Synthesis architecture, it is the
OB-X, Xa and 8 which found favour with a lot of pros even with a more
limited architecture. Guess why that is despite the lesser architecture. I
bet they won't be able to find a reason now. Oberheim himself made a new
synth: it is a combination of the classics (X, Xa, 8) which had the Linear
PSUs and the more simple architectures. Let them try explaining that now...

Yes, a lot of machines use SMPSes. They really are a disservice to audio
quality, they will mess up your audio chain, as sure as a ballast-lamp or a
dimmer will do if it is anywhere in the same power distribution, as sure as
your computer's SMPS will also damage Sound Quality if it's in the chain.
If you can't do otherwise, at least use an AC-side filter (here again, I
designed and built my own), but try to ensure ports like USB are isolated
too.

Then people who know very little blame the filters... As if Curtis filters
were known to be bad in the past. Guess what happened between then and more
recently with these synths using those Curtis chips, albeit newer.

Where's the bass?
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