Roland “Cross Mod” and “Metal Sync”– What do they actually do?
What do Roland’s “Cross Mod” or “Metal Sync” really do? There are quite few people asking this question on the internet, but no-one has much of an answer. Here’s a few forum discussions I found about...
View ArticleBuilding the Electric Druid pedals
This page collects together just the information you need if you’re intending to build one of the Electric Druid effects pedal/stompbox projects. For each pedal, you only really need the construction...
View ArticleA look at the TR-909’s noise generator
The TR-909 uses a hardware implementation of an LFSR as its noise generator. We’ve dealt with LFSR noise generators in a few other articles, but we’ve only looked at firmware implementations, so it...
View ArticleDesign a Eurorack “Vintage VCA” with the LM13700
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...
View ArticleMultimode filters, Part 2: Pole-mixing filters
Last time we looked at reconfigurable filters, filters that include switches to rearrange parts of the circuit during normal use. However, that’s not the only way to produce different responses from a...
View ArticleTwo StompLFO projects: Mini Tremolo
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...
View ArticleTwo StompLFO projects: Mod Delay
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...
View ArticleDesigning a classic OD-1/TS-808/SD-1 Overdrive
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 –...
View ArticleA “Graphic-wave” LFO
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...
View ArticleAnalogue Drums: Boss DR-110 Drum Machine
The Boss Dr Rhythm DR-110 was introduced in 1983 and was the second drum machine Roland had made under the Boss label, following the frighteningly basic DR-55 in 1980. It was also the last drum machine...
View ArticleDesigning a Slapback Echo pedal
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...
View ArticleAnalogue Drums: Korg KR-55
Let’s continue our deep dive into analogue drums with a look at something even earlier – the Korg KR-55. This is a preset drum machine from 1979. It uses a Read-Only Memory (ROM) to store patterns, but...
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