Betamax VCR Problem!

I have a Betamax SL-HF 400 VCR that I bought earlier this year. All the functions on the VCR seem to work fine except the Beta Hi Fi function. Whenever I put in and play a Beta Hi Fi tape and switch the “Monitor Select” switch to “Hi Fi”, there is no audio output and the level meters show no movement. The only way I can get any audio output is to switch the “Monitor Select” switch to “Normal”, but then the audio is only in mono and is of lesser quality. I can’t figure out if I am using the VCR wrong or if there is an issue with the machine. I have tried a lot of switch combinations to see if I could get any sort of hi fi audio output. The Hi Fi switch on the back of the VCR is switched to the “on” position as well. If anyone has any suggestions on how to fix the problem, I’d truly appreciate it! Thanks!

 

Try the tape on a known working Beta Hi-Fi unit. There may be no Hi-Fi signal on the tape!
Also if you can record something, record it in Beta Hi-Fi (which I think that model defaults to) and hear if it plays with Hi-Fi.
I had that model way back when, but it is long gone..

 

Do the machines have separate audio azimuths for the hi-fi audio?
On my VHS players I sometimes have to adjust the azimuth manually to achieve the best audio quality between different cassettes.
If the hi-fi azimuth is badly aligned it may not give off a signal.
There are lots of YouTube videos showing how to adjust these heads.

 

Beta Hi-Fi does not use separate heads to record the high fidelity audio. It's dropped into a bandwdith gap between the luma and chroma video signals. The gap isn't actually wide enough to record full high fidelity audio, so Sony used a companding system to compress the audio signal and provide the necessary S/N ratio.

Beta Hi-Fi sounds pretty good, although not as good as VHS Hi-Fi, which actually does use a separate pair of heads to record a much wider bandwidth signal on a physically lower layer of the tape itself (although that can slightly increase the video noise on the video layer).

 

There is a "Betamax Is Better" group on Facebook for users to ask for advice and support on old machines. There are also a handful of repair people out there that can handle this stuff, but the good ones are not cheap (and vice versa).