A piece of musical history is the Maplin 4600, a DIY electronic music synthesizer from the 1970s. The design was published in an Australian electronics magazine and sold as a DIY kit, and [LOOK MUM NO COMPUTER] got his hands on an original Maplin 4600 that he refurbishes and puts through its paces.
The Maplin 4600 is a (mostly) analog device with a slightly intimidating-looking layout. It features multiple oscillators, mixers, envelope generators, filters, and a complex-looking patch bay on the right hand side that is reminiscent of a breadboard. By inserting conductive pins, one can make connections between various inputs and outputs.
Internally the different features and circuits are mostly unconnected from one another by default, so the patch board is how the instrument is “programmed” and the connections made can be quite complex. The 4600 is one of a few synthesizer designs by [Trevor Marshall], who has some additional details about on his website.
The video (embedded below) is a complete walk-through of the unit, including its history, quirks, and design features. If you’d like to skip directly to a hands-on demonstrating how it works, that begins around the 10:15 mark.
Synthesizers have a rich DIY history and it’s fascinating to see an in-depth look at this one. And hey, if you like your synths complex and intimidating, do yourself a favor and check out the Starship One.
Surely not Maplin as in the ill fated UK hobbist electronics chain?
That was my first thought too. Apparently it IS the same Maplin. Wikipedia’s pretty useless on the topic, but I found this article with scans of the original construction booklet, which has Maplin’s original logo and Essex address on the back cover:
https://www.matrixsynth.com/2025/03/maplin-4600-synthesiser-full.html
Before they diversified into selling tat in high street shops, Maplin used to be a fairly respectable electronics component supplier for hobbyists and small businesses. They had a range of kits too, and published a magazine with plans and discussions. Quite a few of the kits were very well designed (I still use the bench power supply I built 40 years ago for example). Picking up the latest telephone book sized catalogue from WHSmiths used to be a highlight for many hobbyists in 1980s UK.
Maplins catalogue, Argos catalogue, Thompsons Local directory… ephemera of the 80s, now vanished like tears in the rain. And don’t get me started on Marathon bars or the shrinking, rampant cost inflation, and reformulation of Creme Eggs…
Their kits were by Powertran and included power amps and mixers as well as synthesizers and audio FX units, usually with in tandem with construction articles in ETI magazine
Nice find! Thanks for sharing the link.
The very same, Maplin used to be incredible when it was owned and run by enthusiasts with fewer than 10 shops across the UK.
Then they began to expand so came to the attention of the vulture capitalists and the original owners were gone so the rest is history.
Yes, the high point of my visits to Southend was the Maplin’s shop
I wonder if circuit design would tolerate an analog mux hooked up to the patch bay. Then the connections could then be controlled by a computer, tablet, or smartphone. That would be a really cool collaboration between old tech and new tech.
Certainly doable with an AD75019. I’ve used this chip for guitar effects loop switching and since it accepts +/- 12V signals should be fine for the 10V of an analog synth.
Oh, since the 4600 synth of the article has a 22×22 matrix, you would need 4 of these chips. Oops. Hope that Analog Devices still sends out samples?
More actual electronics, views of the interior etc, and a calmer presenter in the repair video https://www.youtube.com/watch?v=PkotWnKwaPM
Ahh, makes me wish I had kept my 99% complete build of one of these, it was one my first major electronics builds (FAR cheaper than any commercial synth I could afford at the time) The quality wasn’t that bad, the better one was the Elektor design, but a much more expensive build as I remember getting close to the cost of the commerial korg machines of the time.
I do remeber the funky pin matrix patch board was especially fun to play with …
On this side of the pond we had PAIA kits but you’d have to go the shack or order from one of those thick catalogues. I looked at one of those for someone that built it but it did not work. Everything looked good but all the 1/8 inch jacks were hot and ground reversed. Once fixed I got a chance to enjoy it for a while.
If this is your interest, musicfromoutterspace(dot)com used to have a lot of seemingly high quality and free designs on their website. I love this stuff, but have zero music ability, so…. not sure if that web site is still up or not though, just remember it from a few years back.
Looks very like the French Synthétiseur Coupigny …