Apple IIGS Noise

[bluethunder]

I recently aquired a couple IIgs, and have a baffling problem in both. They are plain ROM 1 machines with a CFFA3000, and a Briel 4MEG GS ram card.

The machines are quiet as long as I don't run GS/OS 6.01. As soon as I start that, I can here disk access noises, mouse movement noise, and a low rrrrrrr...rrrrrrr...rrrrrr coming from the machines.

I thought maybe the PS needed a recap, so I replaced all the eletrolytics in one supply, but it still does it.

I thought maybe it was my cffa3000, so I created a 3.5" boot disk, still does it.

Maybe the GS 4Meg memory card.. That was a little tougher, but I managed to get an older GS/OS (4 or 5 I think) to boot with just the 256k expansion card (512k total). Still get the rrrrr..rrrrrr.rrrrr... noise.

I'm going to throw the scope onto the power pins, and see what they look like while GS/OS is running. If i can find a high power graphics/sound demo (non GS/OS), I'm going to try that too.

Has anyone run into this before?

Cheers, Joe

 

[david__schmidt]

Yes. That's a common characteristic of the ROM01. The ROM03 is better at keeping the electrical noise down.

 

[njroadfan]

I always thought it was my power supply. It certainly sounds like its coming from that area. I guess replacing it won't quiet down the machine.

 

[david__schmidt]

I always thought it was my power supply. It certainly sounds like its coming from that area. I guess replacing it won't quiet down the machine.

Nope. You will notice that the speaker is in that area too, though... unplug it and relish the (relative) silence.

 

[bluethunder]

Wow. I'd be pretty pissed if my brand new computer made that kind of racket with the gee-wiz GS/OS that sold me on it in the first place..

Is there anyway to silence it?

 

[david__schmidt]

Wow. I'd be pretty pissed if my brand new computer made that kind of racket with the gee-wiz GS/OS that sold me on it in the first place..

Is there anyway to silence it?

1. Get a ROM03 machine
2. Don't run GSOS
3. Unplug the speaker

http://mirrors.apple2.org.za/ground.icaen.uiowa.edu/MiscInfo/Empson/soundnoise

 

[olePigeon]

Would a Mockingboard alleviate the sound?

 

[magnusfalkirk]

This is interesting to me because I have ROM 01 GS and don't notice any kind of noise like the OP is talking about, other than the disk access, which is pretty normal.

 

[njroadfan]

My own machine has the amusing "menu item piano" effect. The noise comes over every soundcard I have had in the machine. I hoped that it was the power supply causing the noise and that swapping it with a unit with cleaner power rails would reduce/eliminate the problem. I guess that isn't the case.

 

[a2fan]

I always thought it was my power supply. It certainly sounds like its coming from that area. I guess replacing it won't quiet down the machine.

The noise is on the bus.

 

[RWallmow]

Yeah, super common on ROM1 (and probably ROM0) IIgs's

Not real audible when a noisy power supply fan is installed though, so I live with it on mine, but I do hope to come across a ROM3 board some day for mine, for multiple other reasons than just sound, like of 1MB onboard RAM, and newer ROMs, cleaner sound is a REALLY nice side effect ;-)