Patches and discussion for Ensoniq VFX family

--- In Ensoniq-VFX-SD@yahoogroups.com, "tijgersanni"
<m.c.breukink@...> wrote:
>
> --- In Ensoniq-VFX-SD@yahoogroups.com, Claus <clauzii@> wrote:
> >
> > And all the fuses are ok? (You probably checked allready..)
> > 
> > Claus,DK
> > 
> 
> Claus, thank you for your reaction
> 
> I have not checked all the fuses, but i will do that.
> I will also look at the circuit around chip 4051 with a scoop and a
> voltmeter.
>

Hi.
I had an "analog" problem with my previous SD-1/32 some years ago that
caused it to sound like the patch was being randomly modulated when it
wasn't. 

The SD multiplexes all it's analog input sources (mod wheel, pitch
wheel, etc) and then sends the multiplexed result to the A/D converter
chip. But note. It filters this multiplexed total through a Cap. prior
to being delivered to the A/D.  If this Cap. is faulty, then the A/D
gets sent all sorts of spurious values. I sent my SD-1 to the local
service agent (here in Australia), who had it for two months and
couldn't fix the fault. The chief tech at Yamaha (who had a look at it
as a favor) found it in 30 minutes!! He also provided me with this
explanation. (I'm no technician - you can probably tell). 

So I don't have a component ID because I don't have a circuit diagram,
(but try searching old postings, because I have posted this answer
once before...), but just look for the last Cap. prior to the A/D
Converter chip, you may well have your answer.  

good luck

Roger