Welcome to
PATCH
HELL
The Jim Patchell Synthesizer D.I.Y. Web Page
This website was first posted in December of 1998.
Last updated January 17,++
Welcome to my do it yourself analog synthesizer page. It is a bit more
than that, but this is the primary purpose. I have been building my own
analog synthesizers since 1974. I originally started building the
circuits that John Simonton (Paia) published in radio
electronics, and I started right in on trying to improve on them. My
first wholly scratch built synth was completed in 1978, and I guess you could
say I started out big. It was a four voice polyphonic synth. The
keyboard scanner was originally implemented using my Polymorphic 8813.
Soon, I changed over to using the 6504 micro processor.
I stopped for a while, right around 1990, partly because of
the nice digital synthesizers that were available then, and even nicer ones now
I have to admit (I love my Nord Modular), and also, because no
body seemed to care about analog any longer, let alone, building one
yourself. That has all changed now. Interest in analog synths is
back up, and now that I have been introduced to the Internet, I have found out
there are a lot of other people out there who share my interest.
Things are a lot different now than they were. It seems that finding the custom chips from CEM and SSM is very difficult. And besides, I don't like to design circuits that use parts that may become unobtainium. It costs a lot of money to make a PCB, I don't want to have to throw them away because I can't get parts.
I have started to design a new set of modules. This projects is now pretty much complete. There are still a few things that need to be fleshed out, but it is now a fully working synth. Hopefully, soon, I will be able to do a piece with it.
Plus, I hope to restore some of the old equipment I built a long time ago. I have three synths and a vocoder that are full of spider webs.
Some of the other things you will find on this website are lots of C code. One of my current projects (as of April 2010) is that I am attempting to write an ACTION! cross compiler for the Atari 800 computers. This also involves the use of Anagram, a Parser Generator. It was quite a challenge to write the parser, and I am pretty proud of the fact that I managed it despite the fact I have lost most of my eyesight back in September.
I am still praying for the return of my eyesight, along with my very loving wife, and many of my friends. But life goes on. My next project will involve making a softcore for the 6502 (like we need another one).
You will also find things lke real time operating systems, recipes for glutan free food, pictures of cats, paintings, music. etc.
Everything I am creating will be open source.
Electrical
Engineering Resources
Synth Module Boards
Intrerfacing the Spartan 3 Starter Kit to an Atmel
STK500/501 to make a Digital Synthesizer
Pacific South West Synthesizer DIY Meet on June 10, 2006
The Start of the DSM1 Digital Synthesizer Module
Pacific Southwest DIY Meet 2004 Photos
Pacific Southwest DIY Meet 2003 Photos
Synth Modules
For Sale
Parts For Sale
The Jim Patchell Verilog and VHDL Archive
The Jim Patchell Gluten Free Webpage
Building Odd Musical Instruments
New
Marion
Systems MS68K Single Board Computer
The love of my life
Here are some photos from early outings I had with Noni...Now, on the first two, you will note, I did not take any pictures of Noni...I am not exactly sure why that was. These were pretty early dates...and I was still not exactly sure how Noni felt about me...I just don't know...:-)
A
Day at the Botanic Gardens
A
day at the Zoo
Well, in case somebody didn't know...I now have a very lovely young lady in my
life. Noni Kimbel and myself are getting
married on December 30, 2006 at the First Presbyterian Church in Santa Barbara,
California. The Christmas party was very important. Because of my
work, I was not able to go north to Seattle to celebrate the holidays with my
family. The Kimbels were very gracious in
sharing the day with me. Little did any of us know that a mere six days latter our two families would be joining. It was on
December 31, 2005 that I proposed marriage to Noni.
Christmas Party 2005 with the Kimbels
Christmas
Day 2005 with the Kimbels
It was, however, 10 days latter
that I go the answer...
Noni Says Yes
And about two months after that Noni finally got her
ring.
Noni's 50th Birthday
Contents:
Secrets
of the OTA
Spindle
Controller and Spin Stand
My
First Synthesizer Project
Old Data
Sheets
Synth
DIY FAQ web page
Protel
PCB Utilities
Polyphonic
Synthesizer Boards
Control
Voltage
Splitter
Roland
MT32 firmware mods
Transistor
vbe
matcher
Seven Segment Decoder Pal
My
Home Studio
Voltage Controlled
Vocal Filter
Experiments
Archives of some old
drawings and
articles(new)
DIY
Digital Synthesizer page
Paia 8700
SMB-1
Synth Module Board
Old
VCO Circuit
Midi
To Relay Controller
Midi Light Dimmer
Midi to CV interface
Do
It Yourself Tips
Restoring
one of my old Homebuilt Synthesizers
Links
Do It Yourself Mixers
Microprocessor
Page
Tau
Synth Circuits
Power Supply Tips
Use full Components for
Synthesizers
TX816
Editor for Atari ST computer
Bell Labs Voice
Synthesizer
Picture of Various Things
pictures of my home made
electronic
equipment
Don't
you
hate it when people post pictures of themselves
The
Family Piano
My
Work
Room
Manuals
Schematic and owners manual for the Korg Poly 800
My Music
This is a collection of some of my music. I am a Joplin fan, so that is what I tend to do.
1. The Strenuous Life by Scott Joplin(mp3 3.5M)
2. The
Entertainer by Scott Joplin (MP3)
3. Elite
Syncopations by
Scott Joplin (MP3)
4. The
Cascades by Scott
Joplin (MP3)
5. The
Chrysanthemum by
Scott
Joplin
6. The
Great Crush
Collision
March by Scott Joplin (MP3)
7. Maple
Leaf Rag by
Scott Joplin
(MP3)
Equipment used
(sorry, old recording, no
SYNTH
DIY in this one):
Yamaha
TX816, Yamaha TX81z, Yamaha FB-01, Kawai K1r, Oberheim XK controller,
Yamaha
SPX90, Teac 40-4, Art 2408, Marantz PMD430. Digital Mastering
was
done on
an Echo Layla. Midi Sequencing Atari Mega ST4 running Cubase
2.0.
The Literary Section
Books
I have read
Stories
I have written
Santa Barbara Atari Computer Enthusiasts (SBACE)
Yep, I own Atari Computers.
Recreating the ACTION! compiler for the Atari.
Read all about mine and the Atari Club
Atari ST Files
Model
Railroading
South
Coast
Society of Model Engineers
Model
Railroad
Union
Pacific
Transportation Innovation
Anyway, all for now. Hope to hear from you all.