Xpantastic!

Hello all, 

I guess everyone has seen the nos xpander VFDs on ebay: 

http://cgi.ebay.co.uk/Oberheim-X-pander-Matrix-12-VFD-display-Xpander-NOS_W0 
QQitemZ170303550830QQcmdZViewItemQQptZUK_Musical_Instruments_Pro_Audio_Synth 
esisers_CV?hash=item170303550830&_trksid=p3286.c0.m14&_trkparms=72%3A1688%7C 
66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318 

Handy part to have around as a spare part.
Still.. personally i think if your considering paying over £100 (current 
price is £100) for *1* spare VFD for your Xpander, then its well worth 
looking at the new replacement board that steve lenman is offering: 

http://www.lenham.clara.net/sound/obvfd.html 

My Xpander was the prototype for this board replacement, i asked steve to 
build it for me. 

It works really great. The replacement board uses VFDs that are still in 
production it looks and works the same. Its really good, really please with 
it. 

I had my Xpander fully recapped and its been great.. wish i could say the 
same about the few other analogue synths that i have now which seem to self 
destruct on a regular basis :( 

Cheers,
Rob. 

> 
> Hey Everyone, 
> 
> I have been helping folks fix their Xpanders / Matrix 12s for awhile 
> here. I can tell you that by far the most failed component is 
> electrolytic capacitors. A 2.2 uF @ 50V coupling capacitor is used 
> through out the analog voice boards. This capacitor will fail and 
> cause numerous voice problems from failed auto-tune to no sound. The 
> next part would be the encoders. Usually a good cleaning fixes this.
> Next would be the VFD displays which are very hard to find. Steve 
> Lanham is working on an upgrade for this one. 
> see:
> http://us.mc838.mail.yahoo.com/mc/compose?to=steve@... 
> 
> There have been a few cases of VCO ( 3374 ) and VCF filter chips ( 
> 3372 ) failing. Not impossible to find, but expensive.
> The DAC issue from Takis is the first I've seen of that part failing. 
> Many times things can be fixed by simply re seating ( pulling out and 
> putting back in ) the chips. This is easy on the Xpander because 
> every integrated circuit is in a socket.  Finally, many problems are 
> caused by cold solder joints. Simply re flowing the solder around the 
> suspect part can fix this. I always recommend doing this first
> before replacing parts. 
> 
> I personally have fixed my matrix 12 (owned since 1987) several times 
> This included cleaning the key contacts (typical of any keyboard) 
> Several of the before mentioned capacitors.  An analog switch chip 
> which had it's pin folded under at the factory. And finally, several 
> 74HC14 Schmidt trigger chips which debounce the encoders.   
> 
> Soon ( when time permits ) I would like to make a better list along 
> with part numbers etc. that we could all use to trouble shoot these 
> wonderful machines. I have been collecting capacitors/ battary etc.
> to recap mine.  
> 
> 
> BTW If you have any software issues/questions Tony C. is the man to 
> talk to, and PeWe is the best expert on sound design / functionality
> ( on nearly any synth ) I have ever talked to. Actually, all the 
> folks in this group are sharp characters ( they own xpanders :-)  
> 
> Best Regards 
> 
> Karl 
> 
>  
> 
>  
> 
>  
> 
> 
> --- In xpantastic@...m, Tony Cappellini <cappy2112@...> 
> wrote:
>>
>> Not really, but my gear is very under-used compared to most.
>> One voice is a little squirrly (occasionally). Karl was nice enough 
> to
>> point me to which cap typically goes bad that causes my symptoms. 
> Karl
>> is very knowledgable about the Xpander. 
>> 
>> I've wanted to recap my voice circuits, but haven't found someone I
>> will trust my Xpander with. 
>> 
>> For a long time that voice failed auto-tune now & then, but I 
> coulnd't
>> hear anything bad. Now I can hear it ;-)
>> I bought a bunch of spare parts a long time ago when they were easy 
> to find.
>>  
>> 
>> On 2/25/09, Simon G <playthefivetones@...> wrote:
>> >
>> >
>> > thanks for the info. if you don't mind me asking, has anything 
> failed on your xpander?
>> > 
>>
>  
>