[comp.sys.apple2] Sonic Blaster static

platkus@en.ecn.purdue.edu (Shawn W Platkus) (02/12/91)

In article <NAGENDRA.91Feb10205942@bucsf.bu.edu> nagendra@bucsf.bu.edu (nagendra mishr) writes:
>I'm gettin a whole lot of static while digitizing sound. Is this common
>with the sonic Blaster? I tried moving the card around to different slots
>and placing strips of paper to stop intereference between different cards.
>I'm thoroughly confused. Is static common place durring recording?
>I'm pretty sure it's not my microphone because when I unplug it, i still
>see tons of static in the ossiliscope screen.


I don't have a sonic blaster, but when I digitize with a microphone on a 
FutureSound board, there is almost no static if you turn off the monitor
while digitizing.  
	This should help a Sonic Blaster too!


Platkus

taob@pnet91.cts.com (Brian Tao) (02/13/91)

From platkus@en.ecn.purdue.edu (Shawn W Platkus):

> I don't have a sonic blaster, but when I digitize with a microphone on a
> FutureSound board, there is almost no static if you turn off the monitor
> while digitizing.
>         This should help a Sonic Blaster too! 

    I've got a Sonic Blaster (plugged into slot 2) in my GS with a CD player
usually attached to it for digitizing.  I've tried turning off the monitor AND
my fluorescent desk lamp as well, but the static remains.  What is causing
this interference?  Is the ribbon cable from the card to the Molex connector
picking up noise from the motherboard?  If so, would it be possible to wrap
the ribbon cable in aluminum foil to shield it from the EM frequencies?

    How hard would it be to design some sort of sound input processor inside a
shielded box which sits OUTSIDE of the GS?  That way it won't pick up any
electrical noise.  Throw in rec level and tone controls, and you would have a
pretty decent sampling setup.  Better yet, have it take the digital output
from a CD player and transfer it directly into memory (or disk).  No hiss, no
distortion.  Doesn't sound too difficult.

Brian T. Tao  {taob@pnet91.cts.com} ||  Computer guru?  Someone who got
University of Metro Toronto         ||  their computer a couple of weeks
Scarberia, ON, MIC 3A8         *B-) ||  before you did.  (Alvin Toffler)

taob@pnet91.cts.com (Brian Tao) (02/16/91)

From swiers@plains.nodak.edu:

> Have you tried AE's Audio Animator?  I havn't done much with mine in a
> while, but I don't recall any static or anything...I'm quite impressed
> with it.

    Naw, I don't have one, just the Sonic Blaster.  Do you have a ROM 03?  The
Audio Animator uses the same Sonic Blaster card to sample sounds, so I don't
know why it would have less static.  I've tried everything other people have
suggested to me, but to no avail.  The problem must be with the card or the
ribbon cable inside the GS.  I can unplug the audio source from the card, hit
record, play back the supposedly "silent" sound file, and still the static
persists.  It's faint, but it turns into an annoying buzz when played through
external speakers.

    I think much of the problem would be solved if the A/D convertor was
placed OUTSIDE of the GS's noisy interior.  You have an insulated box about
the size of the GS mouse which houses all the circuitry to process the sound
input.  Maybe even a microprocessor to do on-the-fly ACE compression.  Then it
would feed the signal into RAM (DMA???) and the Ensoniq at the same time.  It
would be nice if the Ensoniq could play the sound as it is being digitized,
like a feedback system.

Brian T. Tao   *B-) |        taob@pnet91.cts.com         | "Though this be
U of Metro Toronto  |               - or -               |  madness, yet there
Scarberia, ON       |  t569taob@bluffs.scar.utoronto.ca  |  is method in 't."

whitewolf@gnh-starport.cts.com (Tae Song) (02/16/91)

Sonic Blaster... digitizing troubles...

OK, first off, I don't own a Sonic Blaster or AA, but I do know something about
why you might be getting static.

I don't know your setup, but here goes.  One of the most common problem is that
your getting gain is WAY TOO high... the volumn going into the Sonic Blaster is
too loud... I guess your mic is connected to a amp, try turn it down, and you
should get much better results.

If it works, please e-mail me!
 
whitewolf@gnh-starport!info-apple

taob@pnet91.cts.com (Brian Tao) (02/17/91)

From: whitewolf@gnh-starport.cts.com (Tae Song)

> I don't know your setup, but here goes.  One of the most common problem
> is that your getting gain is WAY TOO high... the volumn going into the
> Sonic Blaster is too loud... I guess your mic is connected to a amp,
> try turn it down, and you should get much better results.

    Nope, that's not it.  The "static" is the hum which is quite definitely
associated with EM and RF interference.  The clipping and popping isn't the
problem (when the gain is set too high).  I've experimented with all different
volume levels on my CD, but the level of the buzz remains the same.  I'm
convinced it is the ribbon cable inside the GS which is picking up waves from
the motherboard.  There must be a safe way to properly insulate that.

Brian T. Tao   *B-) |        taob@pnet91.cts.com         | "Though this be
U of Metro Toronto  |               - or -               |  madness, yet there
Scarberia, ON       |  t569taob@bluffs.scar.utoronto.ca  |  is method in 't."

nagendra@bucsf.bu.edu (nagendra mishr) (02/21/91)

stuff I tried to reduce static, but to no avail

1. Wrap the ribbon which goes from the sonic blaster to the motherboard
   with aluminum foil to catch any stray signals.
2. Take out my AE datalink 2400 modem.
3. Take out the Apple Scsi card and the hard drive and boot from floppy.
4. Turn the amp pots down all the way.

the only thing I couldn't or wouldn't fool with was the ZIPGSX.
I tried to take it out, bit it wouldn't "Easily" come out.

I still have a lot of static.
I have a rom 03 machine + 2 megs ram on Gs Sauce card.
Sonic Blaster in slot 4, with the slot speed set to normal from the zip
control panel.

anyone?

thanks
nagendra