MOTM Madness

[Paul Schreiber]

OK OK you win!

The re-issue will be a MOTU! This takes the pressure off me (with a new day job started this week!!) and also
releives the worry of explaining to my non-synth-hip wife unit why the garage is full of metal plates.

For the synth-hip MOTU suggesting wife: a genuine Moog sticker I've had for 12 years in the closet. Still
has adhesive. Send snail address.

RACKS

Well, the majority like 19" rack. Here are the problems I see

1) do you really want the electronics exposed in the open (dust, beer, whatever)
2) current Digisound users cannot "plug and play" with their racks

Now, I have no objection to selling without front panels, but these are EXPENSIVE to tool up, and I'm worried
that only 5% will want them. I don't care if it's rack or cabinet, but we need to pick ONE size. Send in the votes.

Also, in a rack, exactly how would the power distribution work? The Condor supply I am specing is somewhat
heavy. Mounting it to a vertical surface would not exactly be PORTABLE. The nice thing about a cabinet
is the supply bolts to the base, and the wiring harness can be pre-wired (I contract this out to a local
assembler). I plan to use the 4 pin MOLEX connector used on floppy and hard drives. Maplin, Radio Shack, etc 
sell these with 8" of wire already crimped if you want to wire it yourself. These are cheap and keyed.

SPLIT BOARDS

Several people want 2 pc boards per kit: a front panel board and a "electronics board". Well, it's $$$$. I estimate
I would have to charge $12 more per kit, so if you buy 15 kits that's alot of $$$. Vote, please.

PRICES

Most kits (remember YOU buy the resistors, caps, etc) will be around $100. The VCO and 14-stage ARP Phaser
are the most expensive. Yes, I'm using 3340s (2) in the VCOs. I have about 70 chips set aside for this. I will
offer a 3374 VCO, but the engineering is about 80 hours, and right now I don't have 80 hours!

Now, I could use a SEM or Electronotes VCO, or even a DCO. But those are advanced kits, and if you don't
have a scope, painful!

MODULES

The first module will be (drum roll) a noise gen, S&H, lag processor, and ring mod. Why?

1) Easy to build, cheap, few parts.
2) If you can't get this to work, we need to talk.
3) immediately useful to terrorize friends and neighbors.
4) uses only 1 CEM3330 and a couple of op amps

FILTER

Well, there are about 4 different ones. Current Digisound owners: your vote? I was going to offer the 3320-based
filter first, then the Xpander 15-mode filter. The Xpander filter has LOTS of passive parts, and the pcb layout
is tedious. I want to do a Moog ladder filter as well. And the dual 3350 state-variable filter.

PARTS

Since I have a zillion CEM chips, and I don't want a zillion "it don't work" emails/phone calls, CEM will be
in the initial modules. In fact, the chips come PRE_SOLDERED to the pc board. AND, I giving you ample
FREE SOLDER (it uses water-soluable flux, rinse under the faucet and scrub with an old toothbrush). The
pc boards are silkscreened with BOTH reference designator AND values.

I will have parts listed with Digikey, Mouser, and Maplin parts numbers.

POTS

The pots are Panasonic vertical pcb mount. They have an integral mounting support which is soldered as well.
These are used in Mackie mixers. Now the "downside" is the pot is NOT secured to the front panel. Rather, the
shaft sticks out of the hole, and the knob is pushed on. The front panel attaches with standoffs.

Is this the "best way"? No. There will always be "play" (wiggle) in the knobs, based on shaft length (he says,
wiggling knobs on his mixer). BUT: the advantage is no hand wiring of all those pots, AND swapping the wires
to get reverse envelopes, backwards filter cutoff knobs, etc.

Again, NOTHING prevents you from hand wiring to the 3 pads where the pots solder to, and mounting my pcb
2 feet from the front panel with good old Allen Bradley Type J pots (a la Minimoog).

OFFERINGS (as of now)

Kits will be as:

Full kit - pcb, CEM chips, solder, panel, pots, knobs, 3.5mm jacks
PCB only (NO CEM)
Blank panels
Power supply (standard, off the shelf UL/CSA/CE approved Condor linear supply)
Cabinet with wiring harness and rails (10 units wide)

Because, (correct me if I'm wrong), if you do your own panels, then you don't want the pots, and probably don't want (or can buy seperate) the 3.5mm jacks or drill out the holes to banana.

SUPPORT

I will accept calls from 9PM to 11PM Central US time (heck, call me now!) 817-498-3782. This is also a fax # for
orders, for those of you who don't (or can't) use the on-line form. And if it really won't work at all, you can mail it
back and I'll repair it and charge you a fee.

SUBSCRIPTIONS?

No, you have to buy each MOTM. I'm not Columbia House.

IN CONCLUSION

Here is what needs to be decided:

1) If you want rack mount (and a cabinet to match height wise), this negates current Digisount owner's CURRENT
cabinets. If DAC, and Steve and David P (the 3 big users of current sizes) all say "No big deal, I'll just buy
a new cabinet!" then there is no issue.

2) If you want rack mount, how is the power distributed? Do you expect enclosed little boxes do kep the dust out?

3) 2 pc boards or 1.

Send votes to me in PRIVATE email, please.

Paul Schreiber
Synthesis Technology