DIY Eurorack Cabinet

I had this small shelf I wanted to turn into a rack for a while: I had to figure out a way to hold the faceplates in the middle. A few pieces of wood used for baseboards will do the trick. I first have to find the right order for the few modules I’ve done so far..From left to right,…
Read more

Small Stone Clone mod part2: Univibing

The first mod will be getting this “Univibe” hack: http://www.lynx.net/~jc/pedalsSmallStone.html The idea is to emulate the “Univibe” effect using the four CA3080 OTAs on the clone, getting both flavors.As explained in the link I must add another set of caps plus a switch per 3080.Fortunately my breadboard build had just the physical space need to throw 4 caps and four…
Read more

Electro-Harmonix Small Stone Clone rework

It’s been a while since I wanted to rework my Small Stone clone aka the Piedrita by Tonepad. This is still on a breadboard but it works well and it’ll be easy to start messing with those 6.8nF caps when there’s no solder involved. Right now here is how it looks and sounds like:

BB BP-1 Filter

Next on the list is building great filters, both resonating High and Low Pass, voltage control is a must if I want this to integrate further on a CV controlled system. I found this great component manufactured by Alfa and distributed by Electric Druid: the AS3320, a clone of the CEM3320 as featured in the Sequential Pro-One and the Oberheim…
Read more


I just put together all the units I’ve been building. I just sticked the SSS sequencer, the PT39 delay, the 3080 Phaser, the Grand-Mixer, the 808 Kick Clone and the Nano-B synths onto a piece of plywood. Here is how it sounds through my iPhones mic and Youtube audio encoding.

CA3080 4 Stages Phaser

I just love Electro-Harmonix phasers such as the Small Stone or the Electric Mistress.. I found these schematics to build a Small Stone replica using the CA3080 Operational Transconductance Amplifiers: http://www.tonepad.com/project.asp?id=11 The build on a breadboard looks like this: And the sound is great, here’s a demo using a great song by Adrian Nation, Five Fingers Rapid:  

Delays lays lays

My my first effect build I wanted to do a delay so I went and shopped around for designs. I found some cool ones there, based on the cheap PT2399: http://www.diystompboxes.com/smfforum/index.php?topic=60662.0 http://www.tonepad.com/getFile.asp?id=98 And here’s the PT2399 specs sheet: http://www.princeton.com.tw/Portals/0/Product/PT2399_1.pdf I build two different designs from very simple to a bit more sophisticated. The first has only a time control and…
Read more

The OP-HPF High Pass Filter

I wanted to have an Isolator-style high pass filter device to play with. I found this design at https://www.eeweb.com/blog/circuit_projects/20hz-to-200hz-variable-high-pass-filter that uses a very common op-amp, the TL072. And there I found the design for a 555-driven negative voltage generator, needed for the TL072: https://www.allaboutcircuits.com/projects/build-your-own-negative-voltage-generator/ The only case I got is that Walkers biscuits box. Well English. I punched two holes to mount a rotary…
Read more