• Please review our updated Terms and Rules here

Sound issues with an Amiga 500?

L

linuxlove

Veteran Member
Joined
Jan 11, 2009
Messages
1,018
Location
Auburn, AL
So I finally got a working null modem cable together and I decided to play some games on my new Amiga. The games play fine but the sound? Not so much. Everything sounds overdriven and distorted.

Here's a recording of one of Skid Row's cracktros as heard on my Amiga: http://goput.it/9pz.mp3
By comparison, how it's supposed to sound: http://www.youtube.com/watch?v=cMYz8Aigi6c

I'm going to take a guess here and say it's bad caps in the audio department? I have a Marantz amplifier in need of a recap that sometimes distorts the audio in a similar fashion. I'm not sure if it's relevant to the sound problem, but this is a Revision 6 motherboard and I did do a small mod that switched it from NTSC to PAL ( http://www.lemonamiga.com/forum/viewtopic.php?p=44574#44574 ).
 
linuxlove said:
So I finally got a working null modem cable together and I decided to play some games on my new Amiga. The games play fine but the sound? Not so much. Everything sounds overdriven and distorted.

Here's a recording of one of Skid Row's cracktros as heard on my Amiga: http://goput.it/9pz.mp3
By comparison, how it's supposed to sound: http://www.youtube.com/watch?v=cMYz8Aigi6c

I'm going to take a guess here and say it's bad caps in the audio department? I have a Marantz amplifier in need of a recap that sometimes distorts the audio in a similar fashion. I'm not sure if it's relevant to the sound problem, but this is a Revision 6 motherboard and I did do a small mod that switched it from NTSC to PAL ( http://www.lemonamiga.com/forum/viewtopic.php?p=44574#44574 ).
Click to expand...

It sounds to me as though the LPF is disabled while playing your sample. Is the Power LED normal brightness or dim? If dim this is normal.
 
Oh yeah... if you can find a MOD file of the cracktro music, play it in a mod file player. Usually there's a button in the tracker program to enable/disable the low pass filter manually. That would be an easy way to test. Could use any mod file I guess to test.
 
I tried ProTracker and that didn't seem to do anything. The power LED goes dim when I hold in the reset key combo and brightens when I release it.
 
Is one channel better or worse than the other, or are they both the same? If the power LED is going dim and bright when you do the reset combo then the CIA output to enable/disable the filter should be working (it's shared with the LED brightness itself), so that's probably not it. It could be with the cutoff circuitry in the filter or as you indicated before, any electrolytic caps in the filter section. If you have access to a multimeter you should be able to check the output of the cutoff circuit to the audio filters.
 
It could be bad capacitors in the audio circuit. Check the Commodore forum here for more details.
 
geoffm3 said:
Is one channel better or worse than the other, or are they both the same?
Click to expand...
They both sound the same as far as I can tell.

geoffm3 said:
If you have access to a multimeter you should be able to check the output of the cutoff circuit to the audio filters.
Click to expand...
I guess that means I need to figure out where to stick the probes. Finding documentation shouldn't be too difficult online, right?


I was actually going to go buy some new capacitors today, but I left without taking the list of caps I need. Oops.
 
You must log in or register to reply here.
Back
Top