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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Karlos on November 29, 2009, 07:32:33 PM

Title: A1200 dirty audio
Post by: Karlos on November 29, 2009, 07:32:33 PM
Today, for the first time in a long while, I thought I'd play with Octamed on my main A1200. I've always routed the Paula output straight into the input of my tone generator (which then applies effects and so on).

To my dismay I noticed the audio was very dirty, and not in a good way :lol: It seems I'm getting a lot of cross interference from other activity going on in the machine. There's always been a degree of "blitter music" as I used refer to it but I'm sure it never used to be this prominent.

Could this be an indicator of failing components? I've been thinking to replace the caps on the system for a long time. There's no obvious indication that they've leaked but I'm sure a few must have dried out.
Title: Re: A1200 dirty audio
Post by: koshman on November 29, 2009, 08:06:01 PM
Maybe you've just become a more demanding discerning 'audiophile' during the time you haven't used it. It happened to me :D
Title: Re: A1200 dirty audio
Post by: Tension on November 29, 2009, 08:58:48 PM
It`s definately the caps Karlos.  My A4000 been doin it for years.
Title: Re: A1200 dirty audio
Post by: tokyoracer on November 29, 2009, 09:01:40 PM
Quote from: koshman;531776
Maybe you've just become a more demanding discerning 'audiophile' during the time you haven't used it. It happened to me :D
Iv known caps to cause issues even without any visual signs.

For example, my Dad took his Hi-Fi Amp for repairs (volume control and 1 channel was distorting), dispite using what the ill minded "Doomy" would call 'Mil-spec' caps, they didn't look to be at fault.
Replacing them anyway seemes to have fixed the issue so maybe its the same case with your 1200?

Quote from: Tension;531795
It`s definately the caps Karlos.  My A4000 been doin it for years.
Speaking of which, I think my 1200T and 400D could do with a new set of higher quality non-leakable caps to be replaced to be on the safe side.
Title: Re: A1200 dirty audio
Post by: pan1k on November 29, 2009, 09:07:37 PM
Replace it.. UGH speaking of Caps... my 1 year old studio monitors blew caps.. probably some crappy ones from China
Title: Re: A1200 dirty audio
Post by: Karlos on November 29, 2009, 09:08:35 PM
To clarify, it isn't a distortion of the audio, it's just the presence of interference from other parts of the system. You can actually hear the sound change depending on what you are doing. I should sample it and make some glitch :lol:
Title: Re: A1200 dirty audio
Post by: pan1k on November 29, 2009, 09:16:04 PM
Bad power supply? Bad cap in the power supply? Could be a grounding issue..
Title: Re: A1200 dirty audio
Post by: Damion on November 29, 2009, 09:16:04 PM
If it's a C= era A1200 I would definitely start with the caps, then (if you have to) go from there. :-)
Title: Re: A1200 dirty audio
Post by: koshman on November 29, 2009, 09:25:01 PM
On second thought..... Ghost in the Shell??? :D
Title: Re: A1200 dirty audio
Post by: Zac67 on November 29, 2009, 09:34:40 PM
All active components cause power ripple, if that's not filtered out (bad caps, once again) you can hear it. The A1200's audio is not 100% clean anyway, but disconnecting Paula's outputs from the preamps and routing it directly out will take care of most of it - make sure you handle those outputs carefully though, not to blow the DACs...
Title: Re: A1200 dirty audio
Post by: Karlos on November 29, 2009, 10:27:45 PM
Quote from: pan1k;531802
Bad power supply? Bad cap in the power supply? Could be a grounding issue..


Nah, it's definitely electronic chatter. You can hear the effect of moving the mouse, disk IO and other sources of interference.
Title: Re: A1200 dirty audio
Post by: gizz72 on November 29, 2009, 11:20:30 PM
Quote from: Karlos;531817
Nah, it's definitely electronic chatter. You can hear the effect of moving the mouse, disk IO and other sources of interference.

Hi Karlos,
I've had this kind of problem before, try relocating your miggy to a different location in the room or check your cables see if it touches near an active radio source. See if that helps. ;)

Regards,

GiZz72
Title: Re: A1200 dirty audio
Post by: Karlos on November 30, 2009, 12:11:26 AM
Quote from: gizz72;531823
Hi Karlos,
I've had this kind of problem before, try relocating your miggy to a different location in the room or check your cables see if it touches near an active radio source. See if that helps. ;)

Regards,

GiZz72


Relocation is not a good option right now. It's hooked up to my old 19 inch CRT, various synths, router and other gubbins.
Title: Re: A1200 dirty audio
Post by: AmigaHeretic on November 30, 2009, 06:49:12 AM
Probably need one one of these.  

http://www.vhaudio.com/acoustic-revive-rio5.html

Make sure to read all the way down to the bottom to learn how you can increase you DVDs picture quality with this device too.
Title: Re: A1200 dirty audio
Post by: Zac67 on November 30, 2009, 07:22:35 AM
:lol:
Title: Re: A1200 dirty audio
Post by: Karlos on November 30, 2009, 07:50:54 AM
Quote from: AmigaHeretic;531857
Probably need one one of these.  

http://www.vhaudio.com/acoustic-revive-rio5.html

Make sure to read all the way down to the bottom to learn how you can increase you DVDs picture quality with this device too.


:roflmao:

There has to be a specific class of gullible to buy that.