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Documentation about the Vampire hardware

Vampire Broken Sound

Ozzy Boshi

Posts 31
15 Sep 2018 07:39


Hi all,
I am a new vampire user and I need support here's the long story short.

Bought new v600 2.1 from amedia in june, it arrived in july.
After installation the sound was broken, very scratchy and low and distorted.
Tried to remove the vampire and boot from floppy, same issue, at this point I assumed it was not vampire's fault, just a coincidence that my audio broke the day after I installed the vampire.
The amiga went to my repairman who found some issues with some capacitors/resistors and replaced the op amp. He measured the output wave and it is perfect.
Now the strange part. The audio is really fixed, if i try to boot a game from floppy it seems perfect but the same game, launched by whdload after a coffin 52 boot presents the same old distorted audio.
In addition, almost every game under coffin -> whload crashes, this is very weird.
Tried some other software under coffin: scummvm is perfect (I only tried sam and max), mpeg, mp3 mod play works as expected, same things with rtg games like adoom.
At the end the only issue is whdload and i don't know why.
Tried to boot with another cf with workbench 3.1+whdload I usually use with an aca 500 plus on a500 plus, of course on the aca works as expected and on the vampirized a600 the sound is broken and after a while the game/demo crashes with impossibile causes like division by zero.
I am going to ask to a friend another PSU (the stock one is not enough for the vamp?) and as a a last chance, I will try installing the same vampire on another A600 and see if there are any changes.
Do you have any other suggestion?
Thanks for your time.
Alessio


Vojin Vidanovic
(Needs Verification)
Posts 1916/ 1
15 Sep 2018 07:58


Well, Amiga PSU is weak as usual, and if degrading, can cause such a Vodoo. Recaping Vamp is a good thing, IF its done properly, you might try higher clocked or safety core to eliminate its Vamp thing.

In general, GOLD3 might override it with Pamela integration in Vamp and MIGHT solve the problem, as well as you could try BETA/or older versions of WHDload to establish is it overall WHD prob or linked to some version - then you could file a bug report there.


Eric Gus

Posts 477
15 Sep 2018 09:04


Also try different speakers/amps/speaker cabling .. you never know.. I personally never assume anything .. i've seen cables just go funny for no reason.


Henryk Richter
(Apollo Team Member)
Posts 128/ 1
15 Sep 2018 09:06


The small Amigas get three voltages from the PSU: +5V, +12V, -12V. Distorted sound is often caused by +12V or -12V being sketchy. While the other parts are 5V-based, the Serial port and Audioneed stable +-12V inputs. I'd look there first.


Pat 3657

Posts 50
15 Sep 2018 10:49


Had (almost) the same issues with my vampirized A600 - distorted sound all of a sudden. Came out that my PSU was dying, only -9V on the -12V line. A new and stronger PSU fixed it.


Adam Whittaker
(Needs Verification)
Posts 270/ 1
15 Sep 2018 11:11


Pat 3657 wrote:

  Had (almost) the same issues with my vampirized A600 - distorted sound all of a sudden. Came out that my PSU was dying, only -9V on the -12V line. A new and stronger PSU fixed it.
 

  I can concur - Recapped my miggy still bad sound, built a new PSU using a MEANWELL unit and everything is great! - Also what Erik said - Check your cables too... I had my cat chew through my zx Spectrum +3 Scart cable and all sorts of crinkly, crackly sound problems!


Ozzy Boshi

Posts 31
15 Sep 2018 13:03


thanks all for your suggestions, the problem here is not the sound actually because it works perfectly with self booting disks, and the vampire is OK.
A friend lent me his a600, i placed in his amiga my vampire and my cf with my adapter using same psu, it works perfectly, there are some issues with my amiga, i really don't know why but i think it's not worth trying to repair it
thanks for your help


Ozzy Boshi

Posts 31
15 Sep 2018 13:12


actually i think that the problem is paula... i know that the upcoming core 3 will bypass that, i'd like to try


Samuel Devulder

Posts 248
15 Sep 2018 23:13


I'd say that self booting disk might use less current than when the vamp is in use. Did you try a different PSU on your vampirized amiga?


Sean Sk

Posts 488
15 Sep 2018 23:54


Ozzy boshi wrote:
there are some issues with my amiga, i really don't know why but i think it's not worth trying to repair it

With all due and sincere respect, I disagree with it not being worth fixing up the A600. For preservation purposes I think it's very worth it, but then again, that's just me. Did ALL the capacitors get replaced in your A600 or only some?

As Samuel said try a different PSU. The heavy A500 PSU's with 4.3/4.5 Amps on the 5 volt line would be a good start since they can deliver more juice to the Amiga than the A600 specific PSU which is generally only 3.0/3.5A. I use an A500 PSU with my A600/V600 and it works well (I had recapped both my A500 PSU's with superior quality caps). Maybe try modifying a Meanwell PSU or an ATX PSU. It's not hard, just requires you to do a bit of reading. :)

posts 10