technology

Vermona Synth Fault Requests

Message Received

Flavio, 2016-06-06

Hi there!

Thanks for your articles on the Vermona Synthesizer - I read entirely through the first part, went a bit too techy in the second article but still very interesting.

I got my Vermona Synthesizer a couple of days ago and Iʼm now facing two issue, which I hope you can help/suggest how to solve them.

First of all: for VCO 2 the register buttons donʼt remain pressed (none of them). I opened up the synth and I found out that the mechanism is somehow “stuck” in the “open” position (the position in which nothing gets blocked).

It can be seen in the difference to the VCO 1 register selectors: there, the right end of this longitudinal metal plate is in its “rest” or “inner” position, whereas for VCO 2 it can be seen that it is “out” and didnʼt get back (I donʼt know how to correctly describe, maybe I can show you pictures?!).

So of course, my question is: how do I repair this mechanical issue? I know itʼs only mechanical, because if I keep a register button pressed, VCO 2 is playing.

Second issue is the keyboard: as some keys were having “double triggers” or didnʼt trigger immediately, I took an eraser and tried to clean up what was accessible without removing any keys at all. I also moved the plated bars slightly a bit more left and then back right... now I got the lower 4-5 keys which play the same note (???) and all the others play ok but some of them are still not “clean” enough. What is your suggestion for this issue?

Thanks in advance and kind regards,

Flavio.

response

Well, sometimes I am a bit too techy.  Until itʼs the too techy bit you want.  Ignore the rest and let the search engines read it. :-)

(Iʼm writing these articles because I find it useful to record all the information I discover – less or more techy; and the interesting or entertaining thoughts that happen while looking; Iʼm publishing them specifically because I usually canʼt find the exact techy bit I want online, or anywhere else...)

Vermona Synth Update 1: Boards

(This is an update to Notes from an Exploration of a Vermona Synthesizer.)

In spite of the apparent quietness of the last few months, Iʼve 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 thatʼs easier when all you have are last yearʼs photos and enough space to sit. :-) [1]  A couple of weeks ago, this was complicated by my discovery of a new (I think) and rather great old manuals page at vermona.com, 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.)

MagSafe As It Should Have Been

(Or closer-to.)

(This is an update to “MagSafe – the Last Straw?”)

Since I last wrote on this topic Iʼve been living uncomfortably with my fourth Apple MagSafe PSU in a temporary-repair state; and many other things have been getting in the way, some of which have been much more interesting than fixing old PSUs.  But recently the (now, what, 18-month-old?) cable on Nº4 has shown additional signs of deterioration, requiring further bandaging.  Wonʼt last long.  So on to a full refurbishment of Nº2, which (including previous emergency repair) looks like this:

As the migrant plasticiser had almost completely evaporated when I took photos last year, there is no significant further deterioration, though a few flakes of sheath have fallen off.  The plan was:

“3. Whether or not (2) is successful, open up Nº2 and replace the whole cable.  I did look for something similar in the way of coaxial cable last year, unsuccessfully.  But I suspect this isnʼt necessary; itʼs just a DC power supply.  Ordinary 2-core flex should do – though all things considered I think Iʼll opt for heat-resistant.  Ideally this should include putting a socket in the adaptor, so the cable can be replaced if need be.  This will probably not look very elegant ... but nor does it in its existing state.”

So, to work.  Start with cutting.

Some Pipe and Register Measurements

(Anorak Adventures in Synthland 5)

(This is an update to a tangential note in Notes from an Exploration of a Vermona Synthesizer.)

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.:

Notes from an Exploration of a Vermona Synthesizer

vermona synthesizer drawing
(Anorak Adventures in Synthland 4)

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 Iʼve 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 Synthesiser front

Поливокс / Polivoks Notes

(Anorak Adventures in Synthland 2)

polivoks

Hey, got a Polivoks.

First, some points of nomenclature.  Iʼve 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 Korgʼs ‘modulation generator’.)
  • Glissando (Глиссандо) = portamento (a.k.a. ‘glide’).
  • Pedestal (Пьедестал) = sustain level.

Iʼll 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; donʼt 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 doesnʼt 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.

MagSafe – the Last Straw?

(This post is the long-promised update to A Disturbing Shade of Green.  I had intended to take update photographs of the adaptor previously bitched about, but had no decent working camera for a while.  Now I have camera and two adaptors worth a gripe, so here goes.)

This happened over the last 48 hours.

Apple L-tip Magsafe connector cable with a cracked sheath

In 2013, after a long spell of financial difficulty during which it wasnʼt an option, I replaced my laptopʼs sadly deteriorated MagSafe [4] power adaptor.  That adaptor (Nº2) went up on a high shelf in the interim.  And the new adaptor (Nº4) was good.  But early this year I noticed the onset of the same deterioration.  I might have blogged about it all the way through, but the last few months have been intense...

The progressive deterioration whilst in normal use of the new (c.2011 and on) cable for these adaptors seems to go like this:

Pages

Subscribe to RSS - technology