via THeff on
this electro-music.com thread (audio there).
"I have finally gotten around to posting some info on a DIY ARP-2600 clone synth that I built the last three months of 2009. The ARP-2600 was always very intriguing to me. I guess it's a combination of the slide pots, cool graphics, and normalized patching that attracted me so much.
The word "clone" is used loosely here because there are a lot of differences from the original ARP-2600. One big difference is that it is modular and not one large front panel. I tried to maintain the orange, black and white graphics as close as possible.
I also tried to capture the original sound by cloning the oscillators (4027-1) and the filter (4035- Odyssey) very closely. The other modules, VCA, AR, ADSR, Ring Mod., Noise, S/H, and reverb use various other designs.
I have never had the privilege of actually playing the 2600, so I cannot verify the closeness of the sound.
The size and shape are a little different than the original because I used a case from a previous synthesizer that I built. The front panel speakers were not installed in order to fit everything in.
All three VCOs are like VCO #2 in the original 2600, meaning they all have Sine, Saw, Triangle, and Pulse waveforms available, including PWM. I also added sync to each like the Odyssey.
A separate VCLFO (a 4027-1 in LF mode) was added, in order to keep the other oscillators always available for audio use.
For the reverb I decided not to use springs and instead used the Spin Semiconductor FV-1 Reverb IC.
The 1/8" jacks were traded for 1/4" jacks out of preference.
More documentation about the synth will be coming in the near future, but for now here are some pictures and an MP3 recording that I made in December.
I have always loved the song "Frankenstein" by Edgar Winter, which was performed on an ARP-2600 in 1972. There is a cool YouTube video of Edgar Winter performing it.
The MP3 file enclosed is "Frankenstein" performed on the DIY ARP-2600 clone.
Here are the specifics:
Recorded using a MIDI file, sequenced with Cakewalk Sonar. I did not create the MIDI file.
All of the synth sounds were created with the DIY 2600. The drums, organ, and guitar were created with the Thomas Henry GM Voice (a Yamaha daughter card).
The filter sweep at 3:17 - 3:54 was manually created. I watched the Edgar Winter video many times to see how he did it!.
I would like to take this opportunity to thank Steve Daniels of Small Bear Electronics for special ordering the 1 meg slide pots needed for several of the modules. I could not find them anywhere and contacted Steve about them. He now stocks several values of the slide pots if you are interested, for very reasonable prices!
Regards, -Tim"
via Miguel
