Vintage Simmons Drums (UK) Users Group

Hello:
I recently got hold of an SDS 1, with a "bright tom" eprom. The problem
is that it puts out a distorted sound. I've swapped cables, played it
through differnt amplifiers, and still, the sound is distorted. I
haven't swapped eproms, because I only have the one at the moment. The
controls all seem to operate properly. Could it be that the eprom is
corrupted? Any insights anyone can provide would be great.
Thanks,
Jim Stewart

jimstew37 skrev:

>
>
> Hello:
> I recently got hold of an SDS 1, with a "bright tom" eprom. The problem
> is that it puts out a distorted sound. I've swapped cables, played it
> through differnt amplifiers, and still, the sound is distorted. I
> haven't swapped eproms, because I only have the one at the moment. The
> controls all seem to operate properly. Could it be that the eprom is
> corrupted? Any insights anyone can provide would be great.
> Thanks,
> Jim Stewart

Yes, it might very well be corrupted. In my world this is cool, but try
finding another e-prom to test...
Even a salvaged e-prom from an old scrap computer etc might work just to
test the unit. Sure, it'll sound awful (to you) but most probably
without the distortion and then you know the SDS-1 is healthy...

--
electronically yours, jesper - with 2 x SDS-1 and a lot of proms from
printers, computers and other old machines. Program code sounds so
crunchy! :D
- -- --- ---- ----- ---- --- -- -
www.electronic-obsession.se
www.myspace.com/machinepop
- -- --- ---- ----- ---- --- -- -

Thanks. I have a few EPROMs coming, via eBay, but won't be able to
compare until I receive them, because I don't have any others of any
sort on hand. To give an idea of the sound I'm hearing, it's a little
like when you bump a guitar amp that has a spring reverb; sort of a
crashing sound. It actually sounds kind of cool through an effects
processor. I'm not quite set up for sampling and posting the sound just
yet. Anyway, I'll have to see if I can find some other non-Simmons
eproms to play around with!

Jim Stewart

--- In Simmons_Drums@yahoogroups.com, jesper <jesper@...> wrote:
> Yes, it might very well be corrupted. In my world this is cool, but
try
> finding another e-prom to test...
> Even a salvaged e-prom from an old scrap computer etc might work just
to
> test the unit. Sure, it'll sound awful (to you) but most probably
> without the distortion and then you know the SDS-1 is healthy...
>
> --
> electronically yours, jesper - with 2 x SDS-1 and a lot of proms from
> printers, computers and other old machines. Program code sounds so
> crunchy! :D
> - -- --- ---- ----- ---- --- -- -
> www.electronic-obsession.se
> www.myspace.com/machinepop
> - -- --- ---- ----- ---- --- -- -
>

jimstew37 skrev:

> Thanks. I have a few EPROMs coming, via eBay, but won't be able to
> compare until I receive them, because I don't have any others of any
> sort on hand. To give an idea of the sound I'm hearing, it's a little
> like when you bump a guitar amp that has a spring reverb; sort of a
> crashing sound. It actually sounds kind of cool through an effects
> processor. I'm not quite set up for sampling and posting the sound just
> yet. Anyway, I'll have to see if I can find some other non-Simmons
> eproms to play around with!

OK, so either the eprom is corrupted or it's a bad contact as someone
else said. We keep our fingers crossed, but I sure recognise the
description of the sound.

My bet is still the eprom. Bad contacts more often result in dropouts IMHO.

--
electronically yours, jesper
- -- --- ---- ----- ---- --- -- -
www.electronic-obsession.se
www.myspace.com/machinepop
- -- --- ---- ----- ---- --- -- -

A few years ago I had a distortion problem with an SDS1000, and
I came up with a useful trick for checking the system out.

I bought a 28 pin IC socket - same size as a Simmons EPROM
and connected 8 wires from address line A0 to data line O0,
from A1 to O1 throught to A7 to O7. Eg, pin 10 to pin 11,
pin 9 to pin 12 etc. The wires just push into the socket.

You can get a 2764 EPROM pinout here.

http://pdf1.alldatasheet.com/datasheet-pdf/view/117107/NSC/NMC2764-2.html

As the SDS1 counts through the EPROM, it counts up the data
and you get a staircase sawtooth wave sound out. Look at the
SDS1 output on some sort of wave editor or audio oscilloscope
software on your PC and look for a smooth regular sawtooth
wave with 256 steps. If you get big or uneven steps, you've
got a faulty SDS1. (My SDS1000 turned out to have a faulty
DAC.)


Steve

Steve Ridley skrev:

>
>
>
> A few years ago I had a distortion problem with an SDS1000, and
> I came up with a useful trick for checking the system out.
>
> I bought a 28 pin IC socket - same size as a Simmons EPROM
> and connected 8 wires from address line A0 to data line O0,
> from A1 to O1 throught to A7 to O7. Eg, pin 10 to pin 11,
> pin 9 to pin 12 etc. The wires just push into the socket.
>
> You can get a 2764 EPROM pinout here.
>
> http://pdf1.alldatasheet.com/datasheet-pdf/view/117107/NSC/NMC2764-2.html
> <http://pdf1.alldatasheet.com/datasheet-pdf/view/117107/NSC/NMC2764-2.html>
>
> As the SDS1 counts through the EPROM, it counts up the data
> and you get a staircase sawtooth wave sound out. Look at the
> SDS1 output on some sort of wave editor or audio oscilloscope
> software on your PC and look for a smooth regular sawtooth
> wave with 256 steps. If you get big or uneven steps, you've
> got a faulty SDS1. (My SDS1000 turned out to have a faulty
> DAC.)

Splendid tip - that goes into the "good advice-folder".
Thanks!

--
electronically yours, jesper
- -- --- ---- ----- ---- --- -- -
www.electronic-obsession.se
www.myspace.com/machinepop
- -- --- ---- ----- ---- --- -- -

Thanks, I'll see about trying this out. Are there any wave editors
that are freeware that you'd suggest (a guy can hope, anyway)? And,
please excuse my ignorance, but what would you use as an input probe
and how would this be connected to a computer - the mic jack? I've
used a "standard" oscilloscope before, but nothing like you suggested.

Thanks,

Jim Stewart

--- In Simmons_Drums@yahoogroups.com, Steve Ridley <spr@...> wrote:
>
>
> A few years ago I had a distortion problem with an SDS1000, and
> I came up with a useful trick for checking the system out.
>
> I bought a 28 pin IC socket - same size as a Simmons EPROM
> and connected 8 wires from address line A0 to data line O0,
> from A1 to O1 throught to A7 to O7. Eg, pin 10 to pin 11,
> pin 9 to pin 12 etc. The wires just push into the socket.
>
> You can get a 2764 EPROM pinout here.
>
> http://pdf1.alldatasheet.com/datasheet-pdf/view/117107/NSC/NMC2764-
2.html
>
> As the SDS1 counts through the EPROM, it counts up the data
> and you get a staircase sawtooth wave sound out. Look at the
> SDS1 output on some sort of wave editor or audio oscilloscope
> software on your PC and look for a smooth regular sawtooth
> wave with 256 steps. If you get big or uneven steps, you've
> got a faulty SDS1. (My SDS1000 turned out to have a faulty
> DAC.)
>
>
> Steve
>

> Thanks, I'll see about trying this out. Are there any wave editors
> that are freeware that you'd suggest (a guy can hope, anyway)?

There's a free (audio range) oscilloscope in this package:

http://www.sonicspot.com/wavetools/wavetools.html

It says it's for Windows 3.1, but it seems happy on
XP, as long as vbrun300.dll etc are in the same folder.
The whole suite is just over 1 meg!

> And, please excuse my ignorance, but what would you use as an input
> probe and how would this be connected to a computer - the mic jack?

Just plug the SDS1 into the line in of your PC soundcard
and select the soundcard as input in the file menu.

Or you could borrow a real scope...


Steve

So, I finally got some hardware together to run the test mentioned
below. Using the "dummy" EPROM, and that Wave Tool program, the output
looks like a decent sawtooth wave. I was able to copy the data and put
it into a spreadsheet to better analyze. I also made a .wav file of
the sound that I get using the "bright tom" EPROM. Is there some way I
can post my sound file to this board? If anyone is interested in
looking at my spreadsheet, I'd be happy to post that as well.

Also, I got hold of several more Simmons EPROMs, and they all sound
distorted, so, unless they're all messed up, it seems like something
is indeed amiss with my SDS1.

Thanks,
Jim Stewart

>
> As the SDS1 counts through the EPROM, it counts up the data
> and you get a staircase sawtooth wave sound out. Look at the
> SDS1 output on some sort of wave editor or audio oscilloscope
> software on your PC and look for a smooth regular sawtooth
> wave with 256 steps. If you get big or uneven steps, you've
> got a faulty SDS1. (My SDS1000 turned out to have a faulty
> DAC.)
>
>
> Steve
>

jimstew37 skrev:

>
>
> So, I finally got some hardware together to run the test mentioned
> below. Using the "dummy" EPROM, and that Wave Tool program, the output
> looks like a decent sawtooth wave. I was able to copy the data and put
> it into a spreadsheet to better analyze. I also made a .wav file of
> the sound that I get using the "bright tom" EPROM. Is there some way I
> can post my sound file to this board? If anyone is interested in
> looking at my spreadsheet, I'd be happy to post that as well.
>
> Also, I got hold of several more Simmons EPROMs, and they all sound
> distorted, so, unless they're all messed up, it seems like something
> is indeed amiss with my SDS1.

If you have no space yourself and the archive at yahoogroups is too
small - mail them to me and I can put them on my site temporarily...

--
electronically yours, jesper
- -- --- ---- ----- ---- --- -- -
www.electronic-obsession.se
www.myspace.com/machinepop
- -- --- ---- ----- ---- --- -- -

I uploaded both files to the file archive. Unfortunately, folks here
will receive a message indicating a file that I mistakenly uploaded
(i.e., bright_tom.wav), and that I deleted.
Anyway, I hope someone here can have a look/listen to them, and maybe
provide some insight.
Thanks,
Jim Stewart

>
> If you have no space yourself and the archive at yahoogroups is too
> small - mail them to me and I can put them on my site temporarily...
>
> --
> electronically yours, jesper