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MVS 4 Slot MV4 Capacitor List/Audio Issue? (Scratchy Noise)

channelmaniac said:
Post a short video
Click to expand...
I know the older videos I uploaded weren't very clear of the issue, so I got one of those cheap analog to digital audio converters for $16.

Hopefully It's more obvious what the distortion is.

Samurai Shodown Attract/Intro:

Blazing Star Intro:

It seems like the highs and lows are distorted. Both the connector edge and headphone output audio have the same distortion.

When I hook up directly to the YM3016, the distortion is not there.
 
Hansuke said:
I know the older videos I uploaded weren't very clear of the issue, so I got one of those cheap analog to digital audio converters for $16.

Hopefully It's more obvious what the distortion is.

Samurai Shodown Attract/Intro:

Blazing Star Intro:

It seems like the highs and lows are distorted. Both the connector edge and headphone output audio have the same distortion.

When I hook up directly to the YM3016, the distortion is not there.
Click to expand...
Sounds normal to me. Turn down the volume a bit when recording from the headphone jack. Get better speakers.

Directly from the YM3016 probably sounds good by comparison because it's line level.
 
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channelmaniac said:
Sounds like every other 4 slot with the volume cranked way up... They aren't hi-fi.
Click to expand...

Neo-Alec said:
Sounds normal to me. Turn down the volume a bit when recording from the headphone jack. Get better speakers.

Directly from the YM3016 probably sounds good by comparison because it's line level.
Click to expand...
It sounds like that no matter what the volume slider is at though. Both the edge connector and headphone volume slider.

Why does a 1 slot and 2 slot system not have this issue on the same setup?

Does the 4 slot MVS just have inherently worse audio than other models?
 
djsheep said:
What cab / supergun are you running?
Click to expand...
I'm running it through a PARSEC supergun to get those audio recordings I posted earlier, but the distortion is also present when the 4-slot is hooked up to my Goldie cab 2-slot cabinet.

So I don't think it's the supergun's or the goldie cab's fault. The cab has a 2-slot in there originally and it sounds flawless in the cabinet and on the supergun.
 
The cab and supergun are wired for stereo?

Does the supergun have a switch to set it to Neo Stereo?
 
Were you going to replace the amp next?

My 4-slot sounds fine, but doesn't go nearly as loud as my big 1-slot. These old boards do seem to vary a bit.
 
Neo-Alec said:
Were you going to replace the amp next?

My 4-slot sounds fine, but doesn't go nearly as loud as my big 1-slot. These old boards do seem to vary a bit.
Click to expand...
Since both the edge and headphone amps have the exact same distortion, I'm assuming that the distortion happens earlier in the audio chain in the preamps.

So I was planning on hooking up a 3.5mm stereo headphone cable to those preamp outputs and see which chip creates the distortion. However, since the chips are so cheap, I'll probably just replace each one at a time and test to see if anything's changed.

There seems to be only 3 preamps on the MV4 if I'm not mistaken. Two LM324 and one B4558.

I hope it's not the B4588. The only places I see to get replacements from are China or Taiwan and I heard fake ICs are kind of ubiquitous coming from there.
 
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So I went ahead and replaced all the preamp chips including the B4588 and there's no change.

Does anyone know what pins to hookup a 3.5mm stereo breakout cable to the HA13001 amp to get the L and R inputs before they're amplified?
I want to see if the distortion is present before it's amplified, if not, then I'll replace the amp.
 
Take it from the headphone outputs...


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