boss pc-2 - percussion synth- shcmatic urgently required

[omni]

hi there. I just scored a pc-2 for free, but its has a couple of wires loose. I need a schemtic if anyone has one... cheers. omni

[Dan N]

I don't have a schematic, but I have a working unit I could open up.

[Paul Perry (Frostwave)]

I'm suprised nothing has shown up, seeing as (I believe) it was the same as the Amdek PCK-100 kit sold in the UK.

[Coriolis]

...annabumpiddiybump! 

[omni]

hi dan n. could you perhaps get a photo for me?  i would appreciate getting this thing working again.

[Mark Hammer]

I am pretty positive I have a schem for one at home, though I will need to sift through some things.  It came in a Japanese collection of schems.

[Dan N]

Omni, it might be easier if you post which wires are loose.

Mark, good luck finding the schematic. It's probably really close to a Coron DS-7. Uses a BA662 for the ota.

Lots of crazy sounds out of this little guy.

[Mark Hammer]

It wouldn't be the first time I've remembered things wrong, but in this case I am pretty confident it is the Amdek kit, which is the same as the PC-2.  It may well have a BA662, given that an OTA is called for and it's a Roland/Boss product.

A page from the manual (or maybe the whole manual) can be found here: http://machines.hyperreal.org/manufacturers/Boss/PC-2/images/pc2_man.jpg

DiscoFreq's website has Amdek info here: http://filters.muziq.be/model/amdek/pck100
and PC-2 info here: http://filters.muziq.be/model/boss/pc2

[Mark Hammer]

Found it!.  Yes it (PCK100) does use a BA662.  And no, it is not identical to the Coron DS7 or DS8, though a number of similarities in conception are certainly present.  Because of the source, I'd rather not post it, out of respect.  Send me a PM with your e-mail address, though, and I'll pop you the file.

[DiscoFreq]

DiscoFreq's website has Amdek info here: http://filters.muziq.be/model/amdek/pck100
and PC-2 info here: http://filters.muziq.be/model/boss/pc2

Thanks

I have some of those Amdek kits (still need to build them...) with the original papers, they have a schematic and some mod info. I also have some mod info to add a CV input (from Marc Bareille). I still have to put it on the site, but I can do that a bit faster if you still need it after receiving Mark Hammer's info.

[omni]

DiscoFreq's website has Amdek info here: http://filters.muziq.be/model/amdek/pck100
and PC-2 info here: http://filters.muziq.be/model/boss/pc2

Thanks

I have some of those Amdek kits (still need to build them...) with the original papers, they have a schematic and some mod info. I also have some mod info to add a CV input (from Marc Bareille). I still have to put it on the site, but I can do that a bit faster if you still need it after receiving Mark Hammer's info.

thanks again to mark hammer- i got this baby working sweet!!!. I wouldn't mind trying some of those mods. I noticed it has about 3 or 4 mod points on the solder side which can be changed by soldering or desoldering certain traces. pretty cool little unit.seeing how my unit doesnt have the touch pad, ill have to tyrigger it externally.....thanks for the help guys!

[Mark Hammer]

My guess is that the touch pad is simply a piezo disc wedged in some suitably soft foam that will let you strike it without risk of breaking.  I'm not sure if it is absolutely true, but I find that I get bigger output voltages from hitting piezo discs of greater diameter.  In that spirit, cut up a mouse pad or buy some bulletin board cork sheet, and wedge any piezo disc bigger than an inch or so in diameter between two pieces (I have some that are 2", courtesy of Peter Snow).  That should serve as a suitable touch pad with a nice big striking zone.  You can easily make a bigger disc give you a 1.5v peak output.  Given that the detector/rectifier stage (note D4 and the decay pot) has a gain of 1001, I think you'll be in pretty good shape.  Of course if mounting the controls separate from the strike pad is appealing, you can do that too.

[DiscoFreq]

thanks again to mark hammer- i got this baby working sweet!!!. I wouldn't mind trying some of those mods. I noticed it has about 3 or 4 mod points on the solder side which can be changed by soldering or desoldering certain traces. pretty cool little unit.seeing how my unit doesnt have the touch pad, ill have to tyrigger it externally.....thanks for the help guys!

What is missing: the rubber pad or the sensor inside?

I'll try to put those files (mods etc.) online ASAP.

[DiscoFreq]

I added some files to my Amdek page: http://filters.muziq.be/model/amdek/pck100

There's a schematic, the mods suggested by Amdek (your "mod points") and a mod for a CV input.
I didn't test the CV input on the Amdeks yet, but they work great on my Coron DS-7's and DS-8's

I also uploaded the kit instructions (how to solder the wires etc.) and sound settings, but those are not that interesting

[Dan N]

Thanks DiscoFreq! I've been looking forward to your update. Unfortunately, the links to the schematic and mods are not working.

Edit: the links don't have the directory /files/ in them. Thanks for the schematic and CV mod!

[DiscoFreq]

Oops

It's ok now

Bart

[StephenGiles]

If I'm not much mistaken, this makes similar noises to the EH Spacedrum, and again I speculate that it probably contains the basis of an envelope generator which, if driven by a suitably amplified guitar, would follow the peak level of the input and provide (or could be made to provide) a decay function for the sweep voltage independant of the decay attributable to the input signal. In other words a ripple free sweep ......going up......or going down! The Spacedrum is more flash of course because it uses the CA3094.
Stephen