I have purchased a Sony EV-S7000. I am having a problem with playback audio on old tapes regardless of where they originally came from/were recorded on or which output source I choose (even the headphone jack). I have also verified that interference from some sort of SAP on the tapes wasn't fouling it either.
I have attached a sample of the "chatter" you can hear.
I haven't encountered anything exactly like that that wouldn't be burned in, but, I would begin by eliminating mechanical problems. Check if the linear audio part of the tape is damaged, check if the mechanism of the player works. Then try to adjust tracking.
That clip sure sounds like a motor of sorts running near the mic, but per your post it isn't.
You might be able to filter it somewhat with a program like Audition. Make the noise profile from a section without any desired audio.
Have you tried the tapes in a different 8mm/Hi8 player to isolate the problem to the EV-S7000.
FWIW, 8mm/Hi8 does not use a linear audio track. Normal audio is AFM, and some units, like the EV-S7000 also support PCM audio. I take it your reference to SAP indicates that you set the audio monitor switch to STD to eliminate any possible PCM track source.
I cleaned the heads to no avail. I did discover that audio is good on the coax output, so something is wacky on the component output. Good enough for now. Play with it later.
Do i understand that the audio on the RF output (CH3/4) is OK?
If so, check the head phone output - it might be OK also, and usable for capture.
There is not much in the way of circuitry beyond where the RF unit picks up audio, so if it is OK I suspect a connector issue, or possibly a weird ground loop.
Also, if you have other tapes, could you post a sample recorded at a less noise-prone venue, perhaps someone speaking in an other wise quiet location without track-like sound sources near by.
If you don't have a handy tape, try a record/playback cycle with the EV-S7000 with feed from a source such as the SD analog output of a STB or camcorder..