Flangelicious – A super-dooper flanger (Now in 2 versions!)

Posted by & filed under BBDs+Delays, Flanger, Projects, Stompbox stuff.

Flangers are generally regarded as one of the most complicated pedals to build. A typical design has tons of chips and lots of circuit elements. Flangelicious isn’t like that. By using a microprocessor to generate an LFO-modulated clock signal directly, we can get rid of a lot of the non-signal path stuff and add features whilst we’re about it. This gives us a much cleaner, simpler design for a flanger with a genuine fully-analog signal path. In fact, it can all be done with… Read more »

DIY 4 Second Digital Delay

Posted by & filed under BBDs+Delays, Projects, Stompbox stuff.

Recently I’ve been working on a four second digital delay with tap tempo and delay trails. There are lots of digital delay projects already, but the vast majority of them are based on the PT2399, which limits both the length of the delay and the sound quality.   A quick summary of the features: 0 → 4 Seconds of digital delay 12 bit/32KHz input, 16 bit/32KHz output Delay trails (tails) on/off Noiseless effect in/out bypass switching Momentary/latching feature on bypass… Read more »

Boss MT-2 Metal Zone pedal analysis

Posted by & filed under Distortion, Overdrive, and Fuzz, Stompbox stuff.

The Boss MT-2 Metal Zone distortion pedal is one of the most complex drive pedals there is, and has probably the most sophisticated (and least understood!) tone control circuit on any mass-market pedal. It’s also quite a divisive beast, with some loving it, and others hating it. It’s a great pedal for modifications – easily available, cheap, and rugged. This article is a technical analysis of the different stages in the pedal, finding out what each part does to the tone…. Read more »

Noise Reduction with Companders

Posted by & filed under BBDs+Delays, Chorus, Flanger, Projects, Stompbox stuff.

What’s a “compander”? It’s a simple way to make your circuit quieter! So how does it work? Let’s say we’ve got a fairly noisy effect, like a BBD. The basic idea is that you make quiet signals louder before you put them through the effect, and then you make them quiet again after the effect, and thereby make the noise quieter too. And that’s the clever bit! “Compander” is a compound of “Compressor” and “Expander”, since those are the two… Read more »

Investigations into what a BBD Chorus unit *really* does

Posted by & filed under BBDs+Delays, Chorus, Flanger, Stompbox stuff, Synth DIY.

I’ve been curious about Chorus for a while, since I’ve been working on and off with chorus design myself. There were a few things I didn’t understand, like what the relationshp is between the modulation LFO’s waveshape and the frequency modulation of signals going through the chorus. You’d think that if you use a sinewave to modulate the BBD clock, you’d get a sinewave modulation of frequency, right? Wrong! So what do you get? At this point, I realised that… Read more »

Useful design equations for the PT2399

Posted by & filed under Stompbox stuff.

The PT2399 datasheet gives some data showing the relationship between the resistor on pin 6, the clock frequency, and the delay time. Unfortunately, it doesn’t offer any design equations relating these three variables. So, can we derive some? Yes, we can! They’re all included here. First, a quick summary of what I’ve learned, if you want to cut to the chase: Delay msecs = (11.46 * Resistance KΩ) + 29.70 Delay msecs = (683.21 / Clock Freq MHz) + 0.08… Read more »