hardware

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.)

the tubes

Some tubes from a newly arrived vintage radio, out for cleaning ... for about the first time since it was manufactured.  Arenʼt they shiny?  The story with these is the strange and wonderful alliance of thermionic valve technology and the Internet.

This set is a little over fifty years old.  (And I suspect there are people out there who could identify it from the tubes alone.)  One of the same model used to live in my parentsʼ house, humming away happily for nearly twenty-five years, until one day in the late eighties they said it had stopped working and would I look at it.

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.

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

another day another battery

Iʼve spent much of today trying to get my main workstation working.  This is a Mac G5 Dual-Processor machine.  I remember when they came out, actually I remember seeing a picture of one for the first time, a week or two before they were released ... someone was trying to sell one on eBay, and I thought, that looks interesting but I doubt itʼs a real Mac.  Then there was a flurry of technical ecstasy in the Mac Press, and I donʼt remember a single critical and informed article, but maybe I wasnʼt reading the right sites.  I did note one significant disappointment in the design – the thing which made the New-World G3 tower even better than the excellent PowerMac 9600/8600, the hinge-out motherboard, had been dropped.  Surprising, given the convenience it represented.  The board-at-the-back approach in the G5 looked likely to be less manageable than any Mac since the early Quadras.

G5 tower case open in 2010

A few years later I needed to upgrade my rather underpowered G4 (underpowered for the latest round of software updates, that is).  And so I obtained a secondhand G5 ... which was great in as much as it worked, it was visually striking, it has all these fans in separate cooling zones, and maybe as a result is actually noticeably quieter than the G4.  Today I notice it also has a lower maximum power rating.  But handling it is comparatively unpleasant, as the aluminium case is a lot heavier, and the handles are less comfortable.  Itʼs a minor issue but I did think it surprising, as I often do, when design updates result in poorer products.  Should we not record our successes and study them?

Intending to get to grips with the G5 technically, I attempted to disassemble it it – you know, as you do...

Advance H1 Notes

Advance H1 Audio Frequency Generator

This is a rather nice thing I laid hands on this week.  Itʼs a valve-based 15Hz–50KHz sine/square wave oscillator, probably made in 1958 [1].  It doesnʼt seem to have been refurbished, but for its age and intended use it looks in good shape.  Functionally?  Well ... weʼll see.

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