Xpantastic!

My tech fella, Mr. Mikko Köykkä replied as follows:

---
Electrically any 2-bit binary encoder should work. Recommended
resolution is 20 - 30 pulses per turn to preserve the original touch
of the knobs. Encoder wiring may vary, so you may need to cross-wire
pins 1 and 3.

Shaft diameter is 6 mm and minimum length measured from the PCB bottom
12 mm. Holes on the Matrix-12 board are slightly too big for
replacement encoders, so it's important to use a suitable washer and
an extra sleeve that fills the gap nicely. Also it may be necessary to
drill a small guide hole just above the big hole to make encoders fit
perfectly.

http://www.its-like-that.com/radiokorjaamo/encoder1.jpg
http://www.its-like-that.com/radiokorjaamo/encoder2.jpg
http://www.its-like-that.com/radiokorjaamo/encoder3.jpg
---

Honestly, I'd let him operate my guts as well. :-D

-P.

--- In xpantastic@yahoogroups.com, "shire03@..." <shire03@...> wrote:
>
> Hi All,
> That Rotory Encoader Up/Grade fix sounds really interesting.
> Yes, Please post all the gory details. Also please do post any 
> Failure / Fix you come across. I am constantly keeping a list of 
> Fixes. I compile them and post it from time to time. 
> If it's OK with the moderator I'll put it in the database.
> 
> - Karl  
> 
> 
> 
> --- In xpantastic@yahoogroups.com, "mursupeppe" <petri.alanko@> wrote:
> >
> > Hi and thanks for the links.
> > 
> > I happen to know the deep mud I'm in and so I just recently bought two Xpanders (one beyond repairs, the other should be fine), just to find out whether there's anything worth scavenging. Again, I'll let you know if and what.
> > 
> > > Up to now, I never had a blown 3374 in my Xpander,- but I´m on the 
> > > waitlist for 3374 @vintage planet for years and like many others are.
> > > CEM3372 are much easier to find.
> > 
> > I've heard people tell this about their 3374s, but after cross-checking I really have to admit that one of them is really broken. The other one's outputting triangle wave minor third higher than expected, so I cannot count that as "gone", not yet, at least. Something else could be wrong as well, but we're still doing testing and concentrating on the physical issues.
> > 
> > > The case:
> > > Buying vintage gear @ebay, you always buy "private" and because of being 
> > > "vintage" w/ no warranty and no return.
> > > You agree on this if you bid !
> > 
> > It didn't go like that.
> > 
> > I first asked a few questions very carefully, as I wasn't on the holy pony for the first time. I've owned quite a few analog synths in my past and know what they can be like. Finding a pristine - mint, whatever - thing is about as rare as waking up in Mars. Nag nag, yadda yadda, boo hoo... (cont'd)
> > 
> > > If someone is doing this, he should be prepared for issues unless it´s 
> > > made evident the item is in working condition electronically (!!!).
> > 
> > (cont'd)...which is what I was _told_, literally: "in 100% working condition". 
> > 
> > > But there´s no guarantee w/ vintage gear, (tack)-switches and pots will 
> > > be without issues or the unit won´t blow up the next time you power it 
> > > up after arrival.
> > 
> > I've got a few analog modulars that are about as moody as a difficult teenager after two beers. I have a faint feeling the behaviour you just described is remotely familiar. I just wouldn't sell any of those as "trouble-free" or "perfectly functioning". :-D
> > 
> > I'm not too keen on opening the case any more than this. What's my problem shouldn't poison the rest of you, even though I was the cat that brought the carcass in. Sorry for bad feelings, everyone, but I'll keep the lid on from now on. 
> > 
> > > Refurbishing a Xpander or a Matrix-12 means a big time investment in 
> > > search for all the available parts, investing money for the parts and 
> > > doing all the work yourself if you have the technical skills and own the 
> > > tools necessary.
> > 
> > Well, I'm relatively good at troubleshooting, the other guys do the dirty work since I'm about as handy as a paralyzed baboon could ever be. I'm pretty confident we'll sort this out with some amount of time. And money. Argh. :-/ 
> > 
> > The goal is no longer to refurbish, but reconstruct and improve, I'd say. See (x) below.
> > 
> > > Noone can expect to buy a piece of gear which cost over 10.000.- bucks 
> > > in the past for 2.000 - 3.000 $ now and it´s like new,- that´s stupid.
> > 
> > That wasn't the price I paid, not even close, I happened to pay quite a lot more. Obviously, though, you're talking "in general" and not probably referring to this case, but I'll agree with you completely.
> > 
> > > The manufacturing of dyno-synths like Matrix-12 and Prophet 10 / T-8 
> > > killed small companies like Oberheim and Sequential in the past because 
> > > of the costs and the sales.
> > 
> > I'd say we could blame DX7 and D50 at least partially for that. Them and the evolution of pop taste. 
> > 
> > > These are the CEM3374, the rotarys and the displays.
> > > Also, I´m not sure about the switches and numeric key pad.
> > > Actually, I doubt the display replacement of Steve Lenham will appear 
> > > near future.
> > 
> > (x) Newsflash! The keyboard tech replaced every rotary pot with a similar part and all he had to do was reverse the connection as the spare parts weren't identical to originals. The result: they all work now. If anyone needs further info, let me know and I'll ask dirty details. The feel is similar, but a bit quieter. No more "tr.. tr.. rrr... RRRrrr" whilst editing. The bonus: the pots have a switch built-in, so one could override the push buttons under the display as well if wanted and replace them with a nice led thingy or... never mind. :-)
> > 
> > He was also pretty confident he could replace the displays with an updated part of sorts, but it would lose the "Xpander/Matrix" style. Instead, it would be and LCD (if I remember correctly) and black/white. Again, don't blame me for not asking details before writing.
> > 
> > (Waiting for a FrankenMatrix to resurrect.)
> > 
> > > Switches and rotarys as well as displays are 2nd row IMO,- the 
> > > workaround is to use bankloader and editing software to use a 
> > > electronically working machine in the studio.
> > 
> > I agree, my approach is because of my personal preferences: I like to "feel" the synth.
> > 
> > > b.t.w.,- if someone needs processors for Xpander/Matrix-12,- you´ll find 
> > > ´em in Matrix-1000s (and eventually Matrix-6,- I´m not sure).
> > 
> > As far as I know, there are six CEM3396 IC chips inside. I don't remember Xpander using those - is there something I should know?
> >
>