Originally Posted by packsnap85
Thanks for the reply. I tried to tweak the head alignment and that didn’t seem to be the issue. The baseline was a JVC vp59u, which I’m pretty happy with (fed through a Panasonic ES10 for capture). I have just been trying to find an improved setup to get the best capture I can. The weird thing to me is that the noise still exists when the audio head ribbon is unplugged. On a different JVC VCR here, I did notice an improvement in audio noise by putting aluminum foil behind the video head ribbon and its connection. Are there any known issues with audio interference and JVC machines of that time period, or have the machines with issues just seen better days?
Unplugging the audio head ribbon or cable often makes the noise worse although not from the head but interference within the VCR. It's not really a valid test though. Better to test with everything connected.
Yes sometimes extra shielding on the A/C head ribbon reduces interference as the ribbon is unshielded. Of course whatever extra shielding used needs to be grounded itself to the VCR metal chassis. But JVC is not the only VCR manufacturer which started to use unshielded ribbons from the A/C head. All of my later model VHS VCR's use the unshielded ribbon regardless of brand.
Later VCR's also changed to "Switchmode Power Supplies" which unless well shielded in a metal box themselves can radiate a lot of high frequency noise such as those horizontal lines displayed.
Hard to generalise but I get the impression the more pro rack mountable VCR's maintained quality engineering on linear audio into the later models even though they also carried HiFi stereo sound. Unfortunately being an S-VHS model is no guarantee the linear audio playback will be good quality.
Be careful adjusting the head azimuth. Only one of the usual three or sometimes four screws is the correct one! With a felt pen I write a mark or an arrow on the chassis indicating which is the azimuth screw. Adjusting a height/tilt screw accidentally can introduce new problems. It can be tricky to re establish the verticality of the head in the tape path.