[sdiy] SSB Banana polysynth

[Tom Wiltshire]

Yes, it had occurred to me too that it simply might not have been economic to mess about with it, even for a fairly simple fix. I don’t know what these things fetch(ed) but the CEMs were certainly worth plenty. If the outside was beat-up too, it might have looked impossible to make any sort of sense out of spending hours on it.

We’ll see, I guess.

Thanks for the documents - that’s a *lot* more than I had before.

Tom

==================
       Electric Druid
Synth & Stompbox DIY
==================

> On 25 May 2018, at 15:59, chris <chris at chrismusic.de> wrote:
> 
> In december, Kenny Balys told AH that he has some dox on the Banana,
> see his message quoted below
> 
> The reason it was stripped may have been simply that it wouldn't fetch
> as much as an Oberheim or a bunch of CEMs (Ok, that may have been before
> the Alfa chips). But then, maybe it *did* have problems.
> 
> Chris
> 
> 
> 
> On Fri, 25 May 2018 15:07:57 +0100 Tom Wiltshire <tom at electricdruid.net>
> wrote:
> 
>> Does anyone have any documentation for this beast? Or know much about them?
>> 
>> Specifically, I’m interested in how the voice Pitch CVs are generated. From the era, I’m guessing DAC->4051->S&H, but I haven’t even seen the main board, let alone the schematics, so it’s real guesswork.
>> 
>> I’m trying to help a customer debug one. They’ve got one that was stripped of CEMs, so they’ve put Alfa chips in it. First thought was that the Alfa chips are either faulty or not totally compatible, but it doesn’t look or sound like that to me. I suggested that there must have been a reason someone gave up on repairing it and stripped it of valuable parts, and that we should find that reason.
>> 
>> Tom
> 
> 
> 
> On Tue, 19 Dec 2017 04:24:49 +0000 Kenny Balys <kenny at beatkamp.com> wrote:
> 
>> 
>> I put near everything I have on the EEH Banana together. This material 
>> is all in German and includes the MIDI instructions.
>> 
>> The schematics are very casual and do not bother to describe things like 
>> decoupling and the specifics of the front panel & keyboard assembly. 
>> Still, everything is there that one would need.
>> 
>> http://www.beatkamp.com/downloads.shtml
>> 
>> PS: I will shortly be hand building a MIDI board for my Banana. This 
>> involves a simple daughter board tethered to the Z80 CPU socket (the CPU 
>> moves to the daughter board). This also requires a new EPROM image 
>> (kindly provided by a helpful list member).
>> 
>> I am particularly excited to try the Banana split mode where half the 
>> keyboard controls the inner synth and the other half, an external synth. 
>> Cool! Hope it works.
> 
> 
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