The Kool-Verb

This is a simple but nice sounding reverb based on the FV-1 dsp chip. Lots of low pass filtering gives a nice washy sound. You can adjust from a small room to a large hall.  The unit provides about a 75/25(dry) max reverb. Anything more than that is useless. Check out the stomp amp demo for how it sounds…same reverb, but just with just one fixed room setting.

The switch mode power supply keeps the current down to 30mA so you can use a battery if desired. You can use a linear regulator and it will work great, but then the current consumption doubles.

The schematic:


built into a 1590b case:

kool verb



The PWM Squeazal revisited

I have enjoyed my PW modulated compressor and decided to make a feedback(the original was feed forward) version with improved attack and shorter decay response. The result is excellent – I love this version. I use a Zetex current monitor IC as a full wave rectifier and this lets me really speed up the attack. So the response is super fast, very low noise, very low distortion, and very large dynamic range.


SchematicPWM COMP1_2_4

Link to design files: