[sdiy] EKO Stradivarius

[Rutger Vlek]

Thanks, great suggestion!

Op zo 27 mrt. 2022 20:05 schreef Jean-Pierre Desrochers <jpdesroc at oricom.ca
>:

> Hi Rutger,
>
> For the first ‘connected’ tests you could run your power cord in series
> with a 25 watts or lower wattage bulb.
> If there is a short (which I believe there is) the bulb will lit brightly
> to show excessive current draw but preventing any damage
> to the shorted circuit. Then you can go further to spot the offending
> short..
>
>
>
> *De :* Synth-diy <synth-diy-bounces at synth-diy.org> *De la part de* Rutger
> Vlek via Synth-diy
> *Envoyé :* 27 mars 2022 13:12
> *À :* SDIY List <Synth-diy at synth-diy.org>
> *Objet :* [sdiy] EKO Stradivarius
>
>
>
> Dear list,
>
>
>
> for reasons of knowledge (and instrument) preservation, and out of
> enthusiasm I wanted to share some info on my current restoration project. A
> few months ago I saw an ad listed on internet for an Eko Stradivarius,
> which I didn't know, and by the looks of it assumed it to be a cheap/cheesy
> kind of organ. I remember skipping over it, thinking "that's one heck of a
> pretentious name for an instrument". Shortly after that I was watching this
> documentary on Italian synth industry:
> https://www.youtube.com/watch?v=FZ-sVujDlS8 and was amazed at the sounds
> of some of the more obscure Italian machines (I owned a few less obscure
> Italian instruments but was never impressed with them). It brought me back
> to the Stradivarius, and after seeing a short video of it, I realised it
> was an amazing sounding string ensemble, easily on par with (and
> technically very similar to) the first version of the Solina. Luckily, the
> instrument was not yet sold, and I managed to buy it at a very decent
> price. Optically, it is in a very good condition, even the original lid was
> still there (despite the tolex no longer sticking to some of its corners),
> and it was fully functioning!
>
>
>
> Arriving back home, I opened it up, wondering what to find inside. The
> first, and best surprise was: a service manual with full schematics
> stitched to the inside of the case! Since this instrument is so rare and I
> could not find any technical info online, I decided to scan and share it
> with you (assuming that any legal restrictions are long overdue). EDIT:
> attatchment turned out too big for this list, so available on request and
> submitted to synfo.nl.
>
>
>
> Internally, the instrument seems to be in fully original state, including
> a gigantic amount (126!) of electrolytics that are probably several decades
> beyond their expected life, but show very little sign of leakage or
> bulging. I wondered, since there are so many, if I could leave them in
> place, but decided to replace them as I want to give this instrument a much
> longer life. Many of them are axial capacitors, by the way, which are much
> harder to come by these days (especially when you want a decent brand). I
> was wondering how others go about this? Replacing them with radial versions
> could mean more physical stress to the legs of the radial ones. Would that
> be a problem?
>
>
>
> After finishing my shopping list for capacitor values I took a brief
> glance at the power inlet, wiring and fuse holder, which generally looked
> tidy except for mains insulation that was stripped back a little too far to
> my taste, leaving bare copper to be fairly close to the metal casing. I
> almost decided to go for lunch, but then thought a quick check of the fuse
> couldn't harm, even though the instrument was working fine, so I expected
> no problems... well aaaarggh! Glad I checked, because I found an example of
> the worst kind of electronics practice: aluminium foil wrapped around a
> burned-out fuse, creating a bypass for it without any current limitation
> whatsoever. After seeing that I was glad I had decided against using the
> instrument much, until at least all PSU electrolytics were replaced. Also,
> I'm curious what will happen to a newly inserted fuse at the proper rating,
> if there's a hidden malfunction that will trigger it.
>
>
>
> Rutger
>
>
>
>
>
>
>
>
>
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