I recently saw an advert for the new EHX Slapback Echo reissue pedal and thought it was a cool little thing and would make a nice project. The original pedal came out in 1978 and was about as simple as it could get. There was one “Blend” knob to mix the straight and delayed signal, and […]
I was exchanging a few emails with a customer recently, and they suggested designing a chip that allowed you to define an LFO shape with a set of controls – obviously sliders would be perfect for something like this, like a Graphic EQ for LFOs! The idea was that you’d have some waveform sliders, plus […]
First, a quick history of overdrive pedals. Boss got the ball rolling in 1977 with the OD-1, one of the first pedals in their now-famous “compact” series, and the first proper “overdrive” pedal – before that, they were all called “Fuzz” or “Distortion”. This pedal was part of the three releases that started the series, […]
I’d like to share a couple of things I’ve had kicking around on my desk for a long while. The first one was a simple optical tremolo, and for this second StompLFO project, we’re going to use the StompLFO to apply modulation to a PT2399 delay. This is actually very simple to do! PTWobble, StompLFO […]
I’d like to share a couple of things I’ve had kicking around on my desk for a long while. They also show a couple of ways to use vactrols. One is a simple optical tremolo, presented below, and the other is a modulated delay effect. StompLFO Optical Tremolo One very simple way to produce a […]
The LM13700 is a bonafide classic synth chip, plus it’s cheap and *still* available decades after it was originally introduced. Ok, it’s no longer the state of the art, and its noise and distortion figures are pretty poor, but that’s actually a part of its charm. It’s definitely got that “vintage sound”. So let’s have […]
Replacing the LM3914/LM3915/LM3916 with a PIC Most designs you see for audio level LED bargraph displays use the LM3914/LM3915/LM3916 series chips that are no longer made. However, the chips are simple, so we can replace them with a PIC and build a nice LED bargraph driver on a single chip. So why do you need this thing? […]
For this post, I’d like to take you through the process of designing a pedal, from initial idea to completed PCB and pedal. Everyone has their own way of doing this, so I thought it might be interesting for people to see the way that I work on something like this. Pedal (or Synth) design […]
There was a discussion on the SynthDIY mailing list recently about how the early digital drum machines like the LinnDrum or the Oberheim DMX used to change the pitch of drum sounds by simply changing the sample rate. They literally just played the samples back faster or slower, exactly like speeding up or slowing down […]
Here’s something slightly different! Is it an LFO? Is it an envelope generator? Well, it’s a bit of both. It produces a one-off event like an envelope generator, but it has a selection of waves more like an LFO. It works by producing a single “ping” when triggered. A ping is like a mini-envelope. The […]
