FWD: AES Meeting - Evolver
2003-01-29 by Jeffrey D. McEachin
I got this on another list, thought you'd enjoy:
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>From: Tim Parkhurst <tparkhurst@...>
>To: synth-diy@...
>Subject: [sdiy] AES Meeting - Evolver
>Date: Wed, 29 Jan 2003 09:34:11 -0800
>Hello All,
>
>Please forgive me for the rather long post, but last night's AES meeting
>with Dave Smith was VERY entertaining and VERY informative. The Evolver is
>nothing short of revolutionary (IMHO) and learning more about it's innards
>was incredibly inspirational.
>
>Dave gave an informal, but very entertaining talk that covered several
>subjects including his new company, synthesizers in general, the design
>philosophy and genesis of the Evolver, and some guesses as to the future.
>Although I'll try not to waste bandwidth with all of my notes, here are what
>I thought were the highlights:
>
>*****Dave Smith Instruments:
>"I love being a one-man company. I work out of my house, I don't have a big
>office to pay for, and I don't have to argue with someone or go to marketing
>if I want to change something or add a feature."
>
>"The drawback of being a one-man shop is that it's lonely (laughs). That's
>why I call Roger (Linn) all the time to bounce ideas off him."
>
>"I really like feedback and things that are a little out of control."
>
>http://www.davesmithinstruments.com
>
>
>*****The synth industry:
>"25 years ago, one guy could do everything. Things were more 'hardware'
>oriented. Along came the DX7 and that era, and all of the sudden you needed
>very large investments in custom chips and lots of software. Now, things are
>coming back to the point where a one-man operation can work. I do web
>searches for parts and price quotes, download part spec sheets, I outsource
>the manufacturing, and all the PCB layout and software writing is done with
>relatively cheap tools that run on a fast, cheap PC."
>
>"I didn't want to do another retro analog synth. I wanted something with a
>LOT of personality. I didn't want to do another software synthesizer either.
>All the software synthesizers now seem to have a certain 'sameness' to them.
>Software is definitely the wave of the future, but it's just not the same. I
>wanted a neat little box to hold. I see a lot of room in the future to
>explore the combination of analog and digital hardware."
>
>"There are several problems with making a software synthesizer. For one, for
>every soft synth you sell, you give away ten (referring to piracy). Also,
>anyone who graduates from college can write a software synthesizer...and
>half of them are! And the biggest problem is the OS. You spend half your
>time porting to this OS and then that OS and this driver and that driver. A
>lot of times, software has problems that are completely out of your control.
>PCs crash, Macs crash, they all crash. (Holds up Evolver) This doesn't
>crash. It runs all the time, and it'll still run five or ten or twenty years
>from now."
>
>"There is NO way you could get everyone to agree on what should be included
>in a MIDI 2.0 spec. I don't think it will ever happen."
>
>*****Evolver:
>Notes: Dave uses Eagle for PCB layout, 18 series PIC micros (programmed in
>C), Analog Devices 2191 DSP programmed in fixed-point mode ("If I had it to
>do over again, I'd do it in floating-point," said Dave).
>
>"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!"
>
>The 48kHz coming off the CODEC was the biggest emission problem when doing
>FCC and CE testing. The Evolver had to go through twice, which ended up
>costing about six thousand dollars.
>
>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.
>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.
>
>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.
>
>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. Dave said he really didn't
>think anyone would want to use such a simple sequencer to control other
>stuff, but he's been surprised by how many people have asked for this
>capability. This will probably be added in the near future, as the firmware
>can be upgraded through SysEx.
>
>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
>
>http://www.davesmithinstruments.com/downloads/signal_flow.pdf
>
>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.
>
>There are NO TRIMMERS on the Evolver PCB! All analog trimming and tuning is
>done digitally. It is a VERY clean layout, and amazingly compact for what it
>includes. There is a picture on the Dave Smith Instruments web site for
>those who want to see.
>
>********************************************
>All in all, it was a very entertaining evening. The Evolver sounds AMAZING!
>Dave did demos with a single Evolver sitting on a desk. No keyboard, no
>outboard effects, nothing. It was hard to believe that all that sound was
>coming out of a single monophonic synth!
>
>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!
>
>Tim Servo
>"Imagination is more important than knowledge." - Albert Einstein