Friday, 16 August 2019

PE Minisonic VCF

I've finally got around to assembling a Eurorack  version of the Voltage Controlled Filter (VCF) from the Practical Electroncs magazine "Minisonic 2" Synth. The Minisonic was the start of my synth DIY journey, around 1979. While bits of my original Minisonic circuity are probably still around hiding in other equipment, the VCF "disappeared", so it's good to hear it again after about 35 years!
This is a diode ladder low-pass VCF and it will self oscillate, but only above 2KHz. It's designed to be 24dB/octave rolloff, but due to the circuit design it's less than this in practice.I think it has a relatively soft "bubbly" character.

I've added an internal white noise source, and gone for larger retro knobs.

This is a "one off" nostagia project, I'm not intending to market these.

Demo clip on Soundcloud (internal noise source then sequenced sawtooth wave - this is just the filter, nothing added):

Tuesday, 30 April 2019

100m-ish Audio Delay module

MN3208 (obtained from Banzai Musik) is now added to the list of tested BBD ICs for this module. The 2048 stage device provides sufficient delay to generate a "double tracking" or very short echo effect, but the delay is not long enough for a longer echo. MN3208 is fairly noisy.

Thursday, 21 March 2019

100m-ish Audio Delay panels are now in stock

I've just received a batch of lovely panels from Ben at ReSynthesis:

- This module is tested and works fine with the orinal MN3004 BBD IC (if you can find one!) or an MN3007 BBD IC.
- It's also tested and works fine with an MN3207.
- The current PCB batch needs a small mod to work with any MN32xx series BBD - I can make this mod for you if you request it when ordering.

I'm currently testing with a Coolaudio V3205D BBD IC (they are really cheap for a 4096 stage BBD). If anyone is contemplating trying to build the module using one of these, or an MN3005/MN3205 (4096 stage BBD) or MN3008/MN3208 (2048 stage BBD),  email me and I'll let you know how things are going.

Thursday, 7 February 2019

100m-ish Audio Delay update:

- Panels are currently in production (we have plenty of PCBs in stock)

- The module is now tested and working using an MN3207 (as well as MN3004 and MN3007).
- MN32xx series BBDs will need a small PCB modification/fix - see build doc.
- Build document updated (v1-1) on the "100m-ish Eurorack module" pages

Sunday, 20 January 2019

100m-ish Audio Delay
Testing using MN3004 and MN3007 BBD chips is now complete, and PCBs are now available (see "Pages", "100m-ish Eurorack Modules").