SANYO VWM-900 VCR Audio Fault

[JR North]

When playing tapes recorded in monaural from another VCR, the audio is
muddled, highs are clipped, and there is a slow,low level flucuating
hiss from the stereo TV speakers. Tapes recorded on *this* VCR in stereo
play back OK.
I tried turning off stereo in the VCR menu. I tweaked the AC head with
slight improvement, but still not satisfactory. These tapes play back OK
on another Sanyo Hi-Fi VCR VWM-668. Ideas, besides pitch this $40. VCR?
Thanks
JR

 

[Jim Adney]

When playing tapes recorded in monaural from another VCR, the audio is
muddled, highs are clipped, and there is a slow,low level flucuating
hiss from the stereo TV speakers. Tapes recorded on *this* VCR in stereo
play back OK.
I tried turning off stereo in the VCR menu. I tweaked the AC head with
slight improvement, but still not satisfactory. These tapes play back OK
on another Sanyo Hi-Fi VCR VWM-668. Ideas, besides pitch this $40. VCR?

I'm not sure about this, but I think there's a possibility that the
stereo audio is RF modulated and recorded on the helical scan, along
with the video signal. Such tapes would have a separate linear audio
track on the edge of the tape for backwards compatability.

If I'm right about this, then it would point to a problem with the
mono ACE head, or the circuitry that follows it up to the point where
the VCR chooses which signal to use.

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