Unveiling the Bare Bones: Part 2 of the JVC DD-9 Revival
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- Опубликовано: 6 сен 2024
- Watch as we strip down the JVC DD-9 to its essential parts, a necessary step in our exciting restoration journey.
Experience the fascinating world of vintage audio tech and see firsthand what it takes to revive a classic like the JVC DD-9. Whether you're an audio enthusiast or a curious spectator, this continuation of our restoration project is not to be missed. Tune in now!
Great work!
I don't know much about audio equipment, but from an EE perspective if the unit is old tech and the chip isn't amplifying properly, since it's perhaps unlikely the chip is bad, check for cold solders or cracks on all the pins on that chip, and probe the actual chip's pins (not the solder side) to verify things like power to the chip is OK during the 15kHz test, and check that reference voltage (pin 4?) as that seems important to the amplification. And since it seems there's a duplicate chip for playback and record, compare each pin between the chips with the scope to look for differences between them. At worst, you could maybe swap the chips (if they're the same) to see if the problem follows the chip.
The B.E.S.T. system is out of whack. The only way to fix it is with the JVC Technician B.E.S.T. calibration unit that is unobtanium.
No, you are wrong here. Even without Best system sound should go from the source to output without loss. And record well considering that the BIAS is set correctly. BEST can just improve results a little bit when it is active. Same with other decks having automated system. You may or may not use it. It still should record just fine and play source without loss.
Also, Dont be so naive. calibration unit in nothing more than set of switches to select necessary mode. Same as with Nakamichi's units. Not a rocket science.
What mod did you do for the playback frequency response improvement?
I compensated for a head loss in the playback amplifier, but will review again if this was a Dolby chip fault. Then I may go a different route. I am very unhappy how this Dolby IC processes the sound.
@@hifirulezzz Is that by adjusting the EQ value switching or adding extra capacitance to the input side?
@@johnnyg1700 As it was just 2 dB capacitors did help, in worse than that cases I would use both.
I ended up with installing pots to fully compensate non-linearity. Now it plays perfectly fine.