Title link takes you to Yusynth DIY. You will find information on known DIY manufacturers and a ton of custom designs. The following is an example of some of what you can expect. via sequencer.de."The ARP4072 filter equipped mostly the famous ARP2600 semi-modular synthesizer. I always wanted to build one. In the first place I gave a try to the EFM VCF7b. After correcting some PCB design errors I found this filter was sounding real great.
Eventually, I designed my own version of this filter. I have included in the design an input buffer stage and an ouptut buffer stage. The output buffer stage is also used to compensate the loss of low frequencies that is generally observed at high resonance in 24db/octave filters such as the famous Moog ladder. Curiously enough, neither Bob Moog nor Alan Ron Pearlman cared to compensate for this loss. This is strange knowing that it is quite a simple modification. Such compensation was introduced by Roland for the filter of their nowadays very sought after TB303!
On the two boards I built of this filter I obtained pure sinewave auto-oscillation at high resonance within the range 20Hz-20kHz, for the first board, and within the range 60Hz-20kHz for the second board. My design uses japanese dual transistors (2SA798). Because people may have difficulties to source 2SA798 I have also designed a PCB to use regular PNP transistors (BC557), however I have not tested this second design yet."
Well, just to make things clear, this is all about SDIY, I do not sell modules and do not build modules for others. The aim of my site is to share my passion and experience in building analogue synths.
ReplyDeleteCheers
I have much respect for your work and efforts. I know from experience it's not easy work.
ReplyDeleteHowever, I'm completely confused when it comes to your recent Minimoog filter.
If it's a "clone" of a circuit, why change almost everything?
The filters of many Moogs used transistor arrays, opamps, 15 volt supplies, etc, but the Mini filter didn't. It sounds the way it does for many reasons and other Moog filters (micro, prodigy, source, etc) don't sound so much like a Mini for these reasons. The sonic 6 is actually very close to a Mini filter though.
Remember, Moog was already using tranny arrays in their oscillators.
They *could* have changed their filter too and saved some bucks.
But they didn't for a reason.
They don't sound as good.
So, no slam on your hard work, but you just built a filter far closer to other Moog models really.
Why not just buy the original parts?
Tranny matching isn't that difficult :)
Ok Kevin, "clone" is not the right word, let's say filter à la MiniMoog...
ReplyDeleteAnd yes tranny matching is not that difficult, it's just boring.
Cheers
Glad someone else isn't afraid to put bigger knobs on the Frequency controls. ;-)
ReplyDeleteKnobs are out. Levers are in. Levers with big Wico joystick balls on the end.
ReplyDeletehell yes, we want more levers!
ReplyDelete