Linear audio hum on VCR

[autoreverse]

Here's a recording of the linear audio vs. the HiFi audio track on the start of a commercial VHS-tape on my Kendo VR5442-02. A snippet of a trailer followed by 5 seconds of (tape noise) from the linear audio and HiFI audio track respectively.

test_linear_audio_vs_hifi_audio.mp3

There seems to be about 36 dB headroom on linear audio, compared to about 48 dB on Hifi, which I guess is 4 times as much perceived difference. No real surprises. Just my observations of this tape on this VCR.

My question though - as I have very limited experience with other VCRs than this one - is that it has quite a bit of hum on the linear audio. Are other VCRs better in this regard?

(From my experience with cassette tape recorders it seems excessive. I would expect the white noise from the tape itself but not the hum, which is probably coming from the signal amplifier in the VCR.)

Bonus question: Are there really tapes/VCRs with stereo linear audio?

[Cornucopia]

Optimal VHS HiFi audio should give you ~55-70dB of SNR, but YMMV quite a bit.

Hiss I would expect with linear audio. Not hum/buzz. If you are experiencing hum/buzz, it could be the playback machine, or the machine that recorded it, or it could be in the wires (incoming/outgoing).

Yes, there really are VHS tapes/VCRs that have stereo linear audio (more often on later prerecorded titles), even a few decks that support stereo linear R/P along with HiFi.


Scott

[autoreverse]

Thanks for the reply! Yeah, I also noticed on another prerecorded tape that the HiFi-signal was a fair bit louder at one point than this, so probably another 6 dB there.

Ok, so it's likely from the machine then. I don't think it's the wires or the soundcard as when the VCR is not playing, it's very silent. This might motivate me to go looking for another VCR as some of the VHS-tapes I want to digitize only has a linear audio track. I've tried dehumming using audio software and yes it works, but I'd rather get a better recording in the first place.

Yes, there really are VHS tapes/VCRs that have stereo linear audio (more often on later prerecorded titles), even a few decks that support stereo linear R/P along with HiFi.

Interesting. So there might even be stereo linear audio on this tape then, just that the sync/audio head on my VCR doesn't support stereo.

[johnmeyer]

You need to play a few more tapes which have both Hi-Fi and linear audio before you put the blame on the deck you are using.

I listened to the clip, and the silence on the linear sample sounds mostly like the hiss you get when the AGC maxes out. Nothing out of the ordinary at all.

I don't think you have a problem.

[autoreverse]

johnmeyer: I'll check more, but the reason I started questioning it was on a few other home recorded tapes with linear audio where I also heard a hum and started to wonder whether it was on the recording itself or from the machine. I was hoping that I could judge this by listening to prerecorded / commercial tapes made on professional gear.

[autoreverse]

Just for completeness sake, here's a comparison between the hum and hiss on the linear audio on the Kendo (Daewoo) vs. a newly acquired JVC HR-S7700. The noise-level is about the same but the hum character is different and I think I'll have better results filtering out the latter vs. what I've had with the former.

linear_audio_daewoo_vs_jvc_hr_s7700.mp3

(the audio clip is normalized so it's louder than the previous mp3)

[jagabo]

Of course, the audio on the HiFi track can only be as good as the source from which it was made.