Sounds very good. I could also see healthy 14kHz content in Foobar's spectrum analyzer. Not bad at all. You kept the loading on the BASF moderate for that, up to 0dB peak it seems (?)The old Sony TCK-5 (see post #2) turns in a surprisingly decent performance even today.
I recorded this 3 or 4 weeks back when I last fired it up. Sadly it sits wrapped up for months/years with just an occasional spin to keep it all in order and the caps formed. All original electrically. No recapping (yet).
This was recorded and played back with Dolby B engaged and the circuitry is all discrete on this oldie, no IC's apart from the motor servo, not even an opamp anywhere. BASF chrome tape. The file is 320kbps MP3
It might very well be that the original caps are better than today's best caps...just finished recapping an old telefunken...all the 40 years old nippon chemicon caps measure as new...and this deck was not used for at least 15 years ...Sadly it sits wrapped up for months/years with just an occasional spin to keep it all in order and the caps formed. All original electrically. No recapping (yet).
Yes, it's a lost technology since Atlantis got under watter...some of the old rubycon, sanyo, siemens or nippon chemicon were simply better than the new ones advertized for industrial heavy use.Shelf life wasn't mentioned 40 years ago...why would they tell you're guaranteed up to 30 years shelf life?!
Its also the 21V rail and higher bias few transistors than in op-amps contributing to the sense of dynamics I would think.Thanks I didn't push the tape to hard at all. That discrete Dolby stage works really well I think, its simple but carefully designed. The variable headphone output uses a small coupling transformer.
I measured 0.573Ω 100kHz ESR in 4.7uF/50V Nichicon VX pulled from a 35 years old deck when Panasonic FC spec is 1.3Ω for their 4.7/50 same 5X11mm size type!
I have helped to restore and tune a Sony seven gang ST-A6B belonging to a friend. Very nice sound.