Sequential circuits samplers

Hello peeps, I am surprised we've never as a collective figured out a way to 
make a 1 meg upgrade for these machines... when W&C ran out that seems that 
was that..  I'd love to upgrade mine fully... anyone ever thought about this?  
Nico

Nico wrote:

>Hello peeps, I am surprised we've never as a collective figured out a way 
>to make a 1 meg upgrade for these machines...

The question is, why hasn't Wine Country made more? They have the board 
layouts and schematics.
-- Pat

I have a P2K that I picked up (as some of you may recall) at a music store 
tent sale for $10. It works fine, and it has 512k memory. But it does 
something I find strange, and I want to find out if it's normal or not.
When I listen in Stereo (for example, with headphones in the headphone 
jack) and play one note over and over (either from a preset or a loaded 
disk) I hear 4 notes in one ear, 4 in the other, and then it repeats that. 
If I play a chord, some of the notes sound in one ear, and some in the 
other, and I never know which notes will be in which ear (it changes each 
time I play the chord). In mono, it sounds perfectly normal. It has OS 
version 3.0 (I have 4.3 on order).
Is what I described normal, and if not, what could be the cause?
-- Pat

I think the schematics to the memory upgrade are in the service 
manual. There could be 2 reasons why they haven't made more.
1) Not enough people want them. There are prototype PC board houses 
that do short runs however. 
2) The memory devices used are no longer available. I'll check on 
that one. 


Steve


--- In prophet2000@yahoogroups.com, Pat Swayne <me@p...> wrote:
> Nico wrote:
> 
> >Hello peeps, I am surprised we've never as a collective figured 
out a way 
> >to make a 1 meg upgrade for these machines...
> 
> The question is, why hasn't Wine Country made more? They have the 
board 
> layouts and schematics.
> -- Pat

Man, what a deal you got on that!  The stereo field jumping is 
normal.  According to the manual the first 4 voices are assigned to 
the left and the remaining 4 the right outputs if you use the stereo 
outs.  If you have dynamic allocation on, then the output to left or 
right does not necessarily happen in sequence (first 4 notes on the 
left, then the next 4 notes on the right).

I read about this before I got my p2k and the manual and thought it 
was a weird choice for stereo output.  I was hoping the manual would 
shed some light on *why* it was done that way but no luck.  This was 
the mid-'80s so I can understand the early and experimental nature of 
the technology, but I would have preferred a synthesized stereo 
output like on the old delays contemporary with the p2k (like the 
Digitech RDS delays).

toorglick wrote:

>I read about this before I got my p2k and the manual and thought it
>was a weird choice for stereo output.  I was hoping the manual would
>shed some light on *why* it was done that way but no luck.

I the people at Wine Country, and they sent this explanation for the p2k's 
strange stereo output:

Thanks for your email.. what you report is normal for the Prophet 2000. This
unit is not a STEREO output.. it is a SPLIT output.. meaning voices are
assigned to the Left and 4 voices are assigned to the right.. a cyclical voice
assignement results in 4 voices sound in the left and 4 voices sounding 
from the
right. There is logic to this design in that with Dynamic Allocation OFF, the
Prophet 2000 can assign the sound located in memory A to 4 voices out of one
output, while the sounds located in memory B assign 4 voices to the other
output.. This makes no sense if you have a piano disk with sounds in memory 
A and
memory B all being a piano.. However, if you have a Strings & Brass disk..
you can see that 4 voices of strings out the left and 4 voices of Brass out 
the
right output could be beneficial in separating these 2 different types of
sounds each with 4 voices of polyphony.

Ah, indeed. Makes sense now.  Thanks!


--- In prophet2000@yahoogroups.com, Pat Swayne <me@p...> wrote:
> toorglick wrote:
> 
> >I read about this before I got my p2k and the manual and thought it
> >was a weird choice for stereo output.  I was hoping the manual 
would
> >shed some light on *why* it was done that way but no luck.
> 
> I the people at Wine Country, and they sent this explanation for 
the p2k's 
> strange stereo output:
> 
> Thanks for your email.. what you report is normal for the Prophet 
2000. This
> unit is not a STEREO output.. it is a SPLIT output.. meaning voices 
are
> assigned to the Left and 4 voices are assigned to the right.. a 
cyclical voice
> assignement results in 4 voices sound in the left and 4 voices 
sounding 
> from the
> right. There is logic to this design in that with Dynamic 
Allocation OFF, the
> Prophet 2000 can assign the sound located in memory A to 4 voices 
out of one
> output, while the sounds located in memory B assign 4 voices to the 
other
> output.. This makes no sense if you have a piano disk with sounds 
in memory 
> A and
> memory B all being a piano.. However, if you have a Strings & Brass 
disk..
> you can see that 4 voices of strings out the left and 4 voices of 
Brass out 
> the
> right output could be beneficial in separating these 2 different 
types of
> sounds each with 4 voices of polyphony.

Like many others, I had trouble with my floppy drive on my p2k, and 
searched for a replacement. One site (www.ftg.co.uk) said a Teac FD-235HF 
would work, and I just happened to have one of those. I tried it, and it 
did not work. I emailed the guy who had suggested the drive in the first 
place, he said something must have been specially modified for his 
application. Then I got to thinking. The Teac drive in question is a 
standard PC-type drive, which (these days) means it's hard jumperd for 
"drive select 1". I figured the Prophet, being so old, must be "Apple" 
wired rather than "PC" wired, meaning it requires the drive has to be 
jumpered for "drive select 0". Well, this drive has no jumpers, but it did 
have a small surface-mount resistor on the back at a position labeled 
"DS1", and a blank place labeled "DS0". So I unsoldered the resistor from 
DS1 and re-soldered it on DS0. Presto -- the drive works! I also found that 
standard PC-type HD floppy disks will work in the p2k if you fold some tape 
over both sides of the density select hole (the small square hole on the 
opposite side from the write protect hole). So now I can read disks, save 
disks, and I don't get any errors. One strange thing though -- the light on 
the drive comes on and stays on unless I auto-load a disk (have the disk in 
the drive when I turn the p2k on) or I put in a disk for a few seconds and 
then remove it after I turn it on.
-- Pat

Hi there, well done on the floppy drive. That must be a very fine soldering
tip you have there!  There are various versions of the Teac 235 floppy
including
some with regular removable jumpers for drive select. I have one in my p2k.

Although the HD floppies work , I think that it may be a less reliable
storage medium than the correct SD types, due to the density differences.
Check on google for further info.... I believe there are potential issues
with them.

Cheers,
        Nev.

-----Original Message-----
From: Pat Swayne [mailto:me@...]
Sent: Saturday, July 19, 2003 4:08 PM
To: prophet2000@yahoogroups.com
Subject: [prophet2000] floppy drive replacement


Like many others, I had trouble with my floppy drive on my p2k, and
searched for a replacement. One site (www.ftg.co.uk) said a Teac FD-235HF
would work, and I just happened to have one of those. I tried it, and it
did not work. I emailed the guy who had suggested the drive in the first
place, he said something must have been specially modified for his
application. Then I got to thinking. The Teac drive in question is a
standard PC-type drive, which (these days) means it's hard jumperd for
"drive select 1". I figured the Prophet, being so old, must be "Apple"
wired rather than "PC" wired, meaning it requires the drive has to be
jumpered for "drive select 0". Well, this drive has no jumpers, but it did
have a small surface-mount resistor on the back at a position labeled
"DS1", and a blank place labeled "DS0". So I unsoldered the resistor from
DS1 and re-soldered it on DS0. Presto -- the drive works! I also found that
standard PC-type HD floppy disks will work in the p2k if you fold some tape
over both sides of the density select hole (the small square hole on the
opposite side from the write protect hole). So now I can read disks, save
disks, and I don't get any errors. One strange thing though -- the light on
the drive comes on and stays on unless I auto-load a disk (have the disk in
the drive when I turn the p2k on) or I put in a disk for a few seconds and
then remove it after I turn it on.
-- Pat