I’ve often seen it said online that the LM13700 is just two CA3080’s in one package. Even by one of the co-designers! While it’s almost true, it’s not exactly right, and the little differences are sometimes important, so I thought we could take a look at what the differences are. Luckily we have schematic diagrams for […]
The Jupiter 4 was Roland’s first polysynth in 1979. Given that the Prophet 5 had been released the previous year, Roland were definitely playing catch-up, and the design looks notably less “modern” than Sequential’s game-changing instrument. Nonetheless, the Jupiter 4 is well thought of and sounds great, with a character of its own. It’s the […]
We’ve recently started stocking Alfa’s clone of the famous old Roland IR3109 filter chip. This is the chip that was inside a ton of Roland synths, including the SH-101, Jupiter 6 and Jupiter 8, Juno 6/60 and even the Juno 106, although in that case it was hidden in a potted module! I thought it’d […]
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 it has no processor, unlike the Boss Dr. Rhythm we looked at. Consequently the digital side of this […]
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 […]
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 that Boss made before the Dr Rhythm series moved onto digital samples. The Linn Drum (LM-2) was released in […]
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 […]
