[sdiy] AES Meeting - Evolver

[Paul Maddox]

Hi,

> Please forgive me for the rather long post, but last night's AES meeting
> with Dave Smith was VERY entertaining and VERY informative.

shame it reads a little like an advert for dave....
And yes, I am a little disgruntled, I dont mind admitting that his evolver
took 5 or 6 of my Monowave customers, their loss...

> "I was amazed by how easy it was to get into all this. So many
manufacturers
> help you with application notes and things. Like the switcher. I had to
> design a switching power supply, all I did was copy stuff from ap notes.
> They say 'do this, use this part, lay out the board like this, and it'll
> work.' So I did that, and it worked!"

This is a good point, 99% of what you need is in the datasheets, the
hardpart comes in finding the part you want, and then managing to make all
the seperate parts fit together..

> The Evolver uses a wall wart for AC conversion. The benefits of this are
> 1) It's very easy to use the unit overseas. The wall wart works from
100VAC
> to 240VAC and includes three different plug adaptors. Dave has shipped to
> over twenty countries. About 40% of Evolvers are shipped overseas.

true, but lazy IMHO, the PSU in the Monowave is an auto sensing one, not
hard to find, and runs from 100Vac to 250Vac at anythign from 50hz to 60hz..

> 2) You don't have to apply for UL certification if you use a pre-approved
> wall wart. Apparently this is the main reason for their popularity.

This is the biggest point...

> Simple wave sequencing can be done with the two digital oscillators. Dave
> used the waves from the VS. New waves can be downloaded through SysEx,
> although there is currently no editor/converter program available.

and also you cannot control the waveforms via MIDI CC!!!!
Which you can with the Monowave, something that Sound-on-Sound chose to edit
out of the recent review, maybe because I dont have a history in the synth
industry like Dave.

> There are four sixteen-step sequencers that can run simultaneously. Each
one
> can control the pitch of a different oscillator! Unfortunately, the
> sequencers cannot control external equipment.

also, there is problems changing patterns/patchs relating to sequencer
timing.

> The sound chain goes DSP -> D/A -> Analog (VCO, VCF, VCA) -> A/D
> There are two feedback loops (with a tunable delay) that go from the A/D
> back to the D/A. These loops can also act as oscillators (great for
> Karplus-Strong stuff). Check the signal path at

a very good, and flexible sound chain, I have to admit..

> There are two ICs labled "Marion" in the Evolver. Apparently, these were
> designed by Doug Curtis for a Tom Oberheim project that never got off the
> ground! Dave says he has a source to fab new chips when these units run
out
> (in about a year and a half). He also mentioned briefly that Doug may be
> producing and reissuing some of the old Curtis chips again.

ahh, that explains a lot..
I read about the marion frame system, seemed like a superb idea, but it died
:-(

> One quote from Roger Linn that I thought was interesting. "I try not to
use
> any components that I can't get out of the Digi-Key catalog. They have a
lot
> of stuff in stock, you can get it in a day or two if you need it, and a
lot
> of times they can beat the price of the big distributors." All in all, I
> think we live in a GREAT time to be a Synth DIY geek!

except for the marion chip though?

If it sounds like I am being bitter, Im not. but its REALLY frustrating when
the industry ignores some designs and is pretty unwilling to help get a
small company off the ground, purely on the basis that the guy behind it has
no history in the industry. I wont go into details about my experiences,
lets just say that some people will delay things to help you in favour of
something else and will tell you lies about the reasons.
The whole thing has left me feeling very bitter towards the industry and
wondering if there is any point in doing further designs, commercial or
not..

Anyway, just my twopence worth...
please dont start a flame war, these are just the rantings of a very bitter,
small, synth company "one man in his house" to quote Dave.

Paul
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