The Nakamichi 1000ZXL is the best cassette deck for recording, based on specs.
For playback the CR7A is regarded as the most accurate one.
Here's the playback and recording chains isolated from the messy schematic.
The deck isn't very new so there's no Dolby C, S, SR. No HX Pro or DBX.
It could've likely been upgraded with HX Pro capability since the recording bias level is already set by the CPU. There's an A/D converter. So all the circuitry is there that would allow HX Pro to be implemented in software.
Today you probably could drive the recording heads directly from a DAC and avoid all the analog complexity
The RAMM code is an audio signal encoded on the cassette that stores the calibration data when recorded on this deck so you dont need to run the auto-cal procedure.
For the CR7A/Dragon schematic; The schematic is from the CR7A, the text in red is the differences in the Dragon.
as you can see it's nearly the exact same circuit. Biggest differences probably are the 4066 switch which are problematic and add noise. And the change in the feedback circuit resistor on the first opamp from 280k to 316k.
For playback the CR7A is regarded as the most accurate one.
Here's the playback and recording chains isolated from the messy schematic.
The deck isn't very new so there's no Dolby C, S, SR. No HX Pro or DBX.
It could've likely been upgraded with HX Pro capability since the recording bias level is already set by the CPU. There's an A/D converter. So all the circuitry is there that would allow HX Pro to be implemented in software.
Today you probably could drive the recording heads directly from a DAC and avoid all the analog complexity
The RAMM code is an audio signal encoded on the cassette that stores the calibration data when recorded on this deck so you dont need to run the auto-cal procedure.
For the CR7A/Dragon schematic; The schematic is from the CR7A, the text in red is the differences in the Dragon.
as you can see it's nearly the exact same circuit. Biggest differences probably are the 4066 switch which are problematic and add noise. And the change in the feedback circuit resistor on the first opamp from 280k to 316k.
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