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Musical Technology

This is a list of articles with teasers.  The headlines below are links to the full articles.

Vermona Synth Boards

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Posted under Musical Technology at . Last updated 2019-09-10 00:00.
Tags:artwork, hardware, instrument, KHW, synthesiser, Vermona, Synthesizer

In spite of the apparent quietness of the last few months, I’ve been working on synths in between other things; in particular on the Vermona. After the initial post, in the absence of any written technical information, I was planning to draw my own circuit diagrams. Actually I did some board drawings, because that’s easier when all you have are last year’s photos and enough space to sit. (happy emoticon)[1] A couple of weeks ago, this was complicated by my discovery of a new (I think) and rather great old manuals page at, which includes circuit schematics [2] for both versions of the Synth. The full update I was slowly working on will be rewritten in the light of the new information . . . but it will be better. For now, here are my drawings — with the component numbering brought into line with the schematics, as far as possible. (My earlier numbering was entirely arbitrary as there is no screening on the boards.)

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Korg MS-10 Notes

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Posted under Musical Technology at . Last updated 2022-06-02 06:39.
Tags:instrument, Korg, MS-10, synthesiser

MS-10s need no introduction, so — here’s one. Probably from about 1980 but I haven’t got it far enough apart to look for component dates.

front (on arrival)

This arrived in a purportedly Pro-Serviced state. In contrast to my many other gripes on the topic, I must note that it was well-packed, and arrived faster than the estimated earliest date. Also in near-perfect physical condition, which for me is a first, for a synth without a case. So would buy again? Maybe. It doesn’t even smell bad. No rotting food or wildlife, no decaying components, no decades of garage-storage and no undead tobacco. [1]

But I’d like to know what Pro-Serviced means. Perhaps that this time I’m paying someone to do the things I would normally do myself? This clearly doesn’t include cleaning, past a cursory wipe; there’s a lot of dust ingrained on the modwheel and at the back of the keys.

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Some Pipe and Register Measurements

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Posted under Musical Technology at .
Tags:history, organ, prime, typography

(Actually an update to a tangential note.)

I mused:

Are feet and Prime an English-language convention? Since this convention stems from pipe organs, were pipe organs all over Europe described in feet, in the past? . . . Have there ever been organs (or synths) described in cm? Or, were the Prime (′″) marks used with other pre-metric measurements?

From a survey of the web, it seems that different languages do use versions of the foot measurement to describe organ registers, but the Prime mark was not always used. e.g.:

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Notes from an Exploration of a Vermona Synthesizer

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Posted under Musical Technology at . Last updated 2017-03-29 10:42.
Tags:artwork, hardware, instrument, KHW, synthesiser, Vermona, Synthesizer

front elevation drawing

Back in the DDR days, before Vermona were reinvented as a purveyor of cool synthesiser and effects gear, they (or at least the brand) had already been a purveyor of moothies, organs, amps and effects to the people for decades, so far as the people were allowed such. But in the early 1980s they came up with an all-in-one synth, simply named the Vermona Synthesizer. (References to Vermonas below are to this model unless otherwise specified.) They were manufactured from 1983 to possibly as late as 1990, though I’ve not seen a definitive end date. [1] This page begins with me getting one. And recovering a few square feet of usable working space. Up on the table with it:

Vermona Synthesizer

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Polivoks Update

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Posted under Musical Technology at . Last updated 2022-01-02 00:00.
Tags:Formanta, instrument, Polivoks, repair, synthesiser, Поливокс, Форманта

Getting Further In

As mentioned in the last edition, it turns out that the steel shims holding the Polivoks’ rotary switch knobs on can fall out while the knob is being inserted. [1] They could in principle fall through to the base so you might be able to pick them out and finish what you’re doing. Alternatively they could get trapped on top of the main circuit boards, where they could potentially cause shorts, and you have to get the whole thing open again and try to remove the boards to find them. If they don’t fall out visibly, you don’t know where they are. (I do understand why some resort to glue.)

So, refer to the previous getting-the-case-off process. While shim-hunting, I also want to check the probably-failed reed switch, see what’s with the 2nd octave, and see whether there’s room for improvement on the key damping to reduce playing noise. I’ve commandeered a bit of table space . . . and floorspace. This isn’t going to make me popular if I’m not done by nightfall, so let’s go.


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Поливокс (Polivoks) Notes

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Posted under Musical Technology at . Last updated 2023-02-12 21:22.
Tags:Formanta, instrument, Polivoks, repair, synthesiser, Поливокс, Форманта

top front view, case open

Hey, got a Polivoks.

First, some points of nomenclature. I’ve had no occasion hitherto to consider it, but I now realise the correct English plural of Polivoks is Polivoksen. With that established, on the Polivoks:

  • Generator (Генератор) = tone generator = (audio frequency) oscillator = VCO.
  • Modulator (Модулятор) is mainly an LFO. (The control can select noise as well as periodic functions, so LFO would be incorrect . . . a less cumbersome term than Korg’s modulation generator.)
  • Glissando (Глиссандо) = portamento (a.k.a. glide).
  • Pedestal (Пьедестал) = sustain level.

I’ll use the Polivoks terms here, mostly.

This Polivoks was made in 1987, and came with lid, pedal and cables (5-pin and 3-pin DIN; don’t know what the 3-pin one was for . . . ). No power cable but has an IEC C-14 power socket mod. [1]

External Condition

Case: not great; sticky tape residues, heavily scraped and rather indented. So much for all the built like a tank guff. Built like a fake tank for to confuse the enemy, maybe. Sheet aluminium bends (like plastic, unlike steel) but doesn’t rebound. It seems to have had carry handles at either end; not sure if they were original, but gone now. The rubber feet on the underside are different sizes — presumably two were replaced at some point.


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