Beta hifi vcr playes mono tapes with buzzing sound.

[digicube]

Is this normal/common symptom? SL-HF750 Beta hifi vcr plays hifi tapes fine however. Did the mono audio circuitry fail due to age?

Buzzing doesn’t occur in a mono vcr. Looks like mono VCR is best for mono tapes.

[johns0]

That's a normal problem with mono head sounds,could be in the original recording plus more noise added.

[orsetto]

That's a normal problem with mono head sounds,could be in the original recording plus more noise added.

Agrreed: I've experienced the same issue with some VHS and Beta tapes in some VCRs. That specific noise isn't a "buzz" like the typical HiFi artifacts, its more of a hum akin to AC power interference (common with linear track "normal" audio playback, unusual when playing the HiFi track).

Buzzing doesn’t occur in a mono vcr. Looks like mono VCR is best for mono tapes.

That specific hum isn't inherent to HiFi capable decks: it varies with the particular recording and/or particular VCR in use. In a way, you're lucky you were able to quickly isolate the issue to your Sony SL-HF-750: if this tape plays without the hum in one of your non-HiFi decks, its highly probable you're correct that the HF750 has developed (or always had) a hum issue in its linear audio playback system. Since chances of finding a competent Betamax tech who could understand and repair the problem are practically zero today, and you do have access to a "quieter" mono deck for the mono tapes, I'd probably just route each tape to the more suitable Betamax until the transfer project is finished.

That hum can be really distracting and difficult to suppress at the source: it was common decades ago in many broadcasts, so wound up embedded in a lot of VCR recordings, where it could become magnified to truly awful scale by playing the affected tapes in a VCR that had its own audio hum issues. Lately I've noticed the hum being re-introduced in broadcasts of old TV shows and movies on "retro" ATSC sub-channels: annoying, because they have no excuse. In the bad old days it was often caused by the optical sound track of telecined film prints, but today these stations are basically broadcasting from dvd re-masters, so the loud hum shouldn't be present at all.

[dellsam34]

Clean you VCR audio head, If it is dirty and you try to raise the volume to bring the gain up you are raising the linear audio pre-amp gain as well which results in more noise.