A1200 making really weird noises

[Amiga1992]

OK I just discovered my A1200 is making stupid noises theough speakers whenever it does ANYTHING.

Here's a video:
[ Show youtube player ]

(you will probably have to turn the volume way up and/or use headphones).

This comes up clearly when I raise the volume quite a bit, but I could hear some of the noises when using it normally, in quiet moments, this is what brought my attention to it.

The machine has been recapped 2 years ago.
Could it be a PSU problem? This machine has a picoPSU.
My Amiga 600, also with a picoPSU, doesn't make this much noise. The constant "clicking" on the Workbench screen is most worrying.

Oh, ALSO I hear hear the disk drive noises through the speaker! When I insert it, when it's reading, it's like if the A1200 had a microphone inside amplifying all its computing sounds.

If needed, I can record this noise, amplify it and put it here (I should have done that but it was late at night and couldn't think straight :P)

[Daedalus]

Out and about so haven't watched the video, but it sounds like a bad PSU alright. The Amiga itself does very little filtering of incoming power, so if there's any noise in it, it gets fed right through to everything. Varying load seems to affect it too so I would say PSU regulation is poor. Have a look at the voltages on a 'scope, or get someone else to check them out.

[Robbie]

I've actually noticed the same thing on my 1200 with one of those old Goliath power supplies. Might have to look into changing it at some point.

[Amiga1992]

It's not random noises, it's noises the computer makes, is what I say clear in any way? Haha. For example, when it accesses IDE, when it renders stuff on screen (look at the video, when the folders are opened), when a disk is inserted, read or ejected...

I cannot try at this moment a different power supply, but I will at some point. Hopefully my picoPSU isn't dying or something.

[demolition]

It is normal that you can hear these sounds to a small degree, e.g. if you turn the volume up very loud. But they should be relatively quiet compared to the normal Amiga audio level.

[Amiga1992]

If it is normal, why does the A600 does not do it?
Also I don't really remember hearing them before, or perhaps, now that I have bad ass monitor speakers , I can hear what before i couldn't :P

[jimbob]

I would say it is normal to hear low level digital rubbish during many types of activity on the amiga, mouse movement, heavy screen updates, and particularily disk activity and it will be especially noticeable if you have changed to decent monitors and turn them up with no sound playing.

But if it is comparable in level to actual audio and much worse than your other amiga then you have an issue. It's not easy to tell whats coming from the speakers in your video so a line recording would help but near the beginning there is a low pitched whaaaaaaaaaaaaaarrrrrrrruuuuuummp(sic) which does suggest a bad PSU or knackered PSU decoupling in the audio circuits to me. Check your cabling and maybe try different mixer channels first to be sure.

[demolition]

The 600 has an extra low pass filter in the audio circuit compared to the 1200 so that will kill some of that noise. But you could have a faulty audio circuit. Is the noise the same in both channels?

[Daedalus]

You can also get that effect on cheap PC hardware and laptops. It can be down to differing design on power distribution and isolation, but I've had that effect far worse on an A1200 when using an old Dell PSU with a PicoPSU. Random whine as well as "hearing" the computer's activities. Changed it to a good quality power brick instead and it pretty much went away. Definitely worth looking at the PSU - smoothing capacitors especially as these will affect how well the PSU deals with changing power demand from the various components.

[demolition]

Originally Posted by Daedalus

You can also get that effect on cheap PC hardware and laptops.

Not just cheap PC hardware. I can hear it on all PCs if I use the on-board sound card which is why I have always used a dedicated sound card.

Since the PicoPSU is not regulating the 12V line which is supplying the audio opamps, the problem could very well be a low quality 12V PSU brick or failing decoupling caps that needs to be replaced.

[thgill]

Originally Posted by Akira

Also I don't really remember hearing them before, or perhaps, now that I have bad ass monitor speakers , I can hear what before i couldn't :P

Yamaha monitors? Good choice if so.

I use a pair of JBL LSR305 monitors on my desk and have my Amiga's regularly hooked up to them via a Scarlett 2i2 interface. I only get that sort of low level audio noise if the volume knob is cranked around to a ridiculous level.

I agree with everyone else. I would look at your power supply as a possible culprit.

[Amiga1992]

YUP I got these HS5s about a year ago and love them

Anyway, I Will do a line recording of the noise. It's not ON PAR with regular audio levels, I have to crank the fuck up on the speakers, but the most noticeable thing as jimbob described, is there's this high itched whine at powerup which doesn't seem normal at all because it doesn't sound like computer activity.

I also will remove the picoPSU and plug in a regular A1200 PSU and see what happens. Thankfully, my picoPSU was made so I don't remove the original power supply plug, for situations like this.

I will post once I have more info. Thanks for your input so far, guys!

[wazza]

I have a similar problem. I have both an A1200 and A600 which I use with a Corsair PSU:

http://www.corsair.com/en-gb/vs-seri...t-power-supply

The A1200 runs OK - there is a little bit of noise when the volume is cranked right up but no more than I would expect.

The A600 suffers from very noisy audio which makes it very annoying to use in some situations.

Both machines were re-capped last year by a very reliable engineer. Can't work out why one is fine but the other not, when using the same PSU.

[idrougge]

I think you might need a capacitor at position D215A.