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Sony RX77ES calibration fun!

DJDDay

DJDDay

Active Member
Spent some time with my 1991-ish era Sony RX77ES cassette deck getting it calibrated over the weekend. The playback speed was coming in around 2930 hz with a 3000 Hz test tape, which was irritating. Cracked her open, added a few drops of oil in what mechanical spots I could access easily, and grabbed my potentiometer tool. Laid a thick polyester cloth over the transformer since the power supply terminals are exposed - didn't feel like moving it nor getting zapped. Lol!

Looks like I'm back in business - was able to get it adjusted almost perfectly to 3000 Hz, give or take +/- 3 to 6 Hz. Not too shabby! Also, wow and flutter is thankfully within spec (slightly better actually), so that's a relief. Getting those pinch rollers off are a bear, so I'm glad they're still OK.

Highly recommend the fantastic NAK T-100 software by Anax Waves. Chen is awesome and is always fast to respond to feature requests and technical advice. Check it out:

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Sadly you are comparing a Weighted RMS reading of 0.13% with a Weighted DIN Peak spec of 0.16%.

0.13% is a lot, likely audible, but no wonder given the deplorable quality of most belts these days.
 
WernerO said:
Sadly you are comparing a Weighted RMS reading of 0.13% with a Weighted DIN Peak spec of 0.16%.
Click to expand...

Oof! I just realized that - yes - you are correct. I made a major blunder. Looks like I should be at or less than .06%, not +/-.16%!

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WernerO said:
0.13% is a lot, likely audible, but no wonder given the deplorable quality of most belts these days.
Click to expand...

While I do agree the belts are deplorable quality these days (and my pinch rollers likely do need to be replaced), the .13% that I'm measuring isn't audible in my test recordings at all. Even playing test tape sine waves at 340 Hz and 3000 Hz seem pretty consistent (audibly) now that I've got my speed back to normal. Does it show on a scope?

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Absolutely. But this isn't translating to my ears in a negative way. Then again, I also grew up on a lot of early 90's shoegaze, so maybe I'm just used to wobbly guitars. LOL!
 
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