Specifications:

Technical Specifications:

1. Serial Number: A124/07388
2. Power Supply

• Fully overhauled and upgraded power supply and logic PCB
• All operating voltages are meticulously rectified, filtered and stabilized
• Precise voltage reference points:
  • Stop: 0 V (-2.0 V)
  • Fast Forward & Rewind: -2.0 V (-2.0V)
  • Pause: -6.5 V (2.6 V)
  • Play: -9.1 V (2.6 V)

3. Mechanical Adjustments

• Control Motor Driver precisely offset-adjusted
• Fine offset control motor driver adjustment
• Reel motor speed calibrated in play mode
• Record and playback head tilt aligned
• Head base stroke meticulously adjusted
• Tape guide heights precisely set for:
  • Supply tape guide
  • Take-up tape guide
  • Erase head
• Comprehensive tape tension adjustment
• The Flywheel holder precisely positioned

4. Head System

• Demagnetized:
  • Playback head
  • Recording head
  • Erase head
• Azimuth alignment performed for both playback and record heads
• Height adjustments completed for all heads

5. Lubrication Points

• Capstan shaft
• Pinch roller shaft
• Thrust cap
• Reel hub shaft
• Capstan shaft thrust portion

6. Electrical Calibrations

• Tone level calibration at 400 Hz and 15 kHz
• Meter level calibration
• MPX filter adjustment
• Playback and record level calibration
• Frequency response adjustment across multiple frequencies
• Bias oscillation frequency and erase current calibration
• Record amplifier equalizer adjustment
• Bias trap adjustment for both record and playback amplifiers

7. Performance Measurements

• Crosstalk measurements
• Channel separation measurements
• Signal-to-noise ratio measurement
• Total harmonic distortion measurements
• Wow & flutter speed adjustment

8. Frequency Response

• Comprehensive adjustment from 20 Hz to 20 kHz
• Precise level calibration at various input levels

This Nakamichi ZX-7 is a super audio engineering that pays great detail in improving this unit in all aspects and getting an extremely close sound to the sound in the original recording. It serves as a remembrance of something the absolute best that analog audio can supply and provides an experience that is still entrancing and pleasing to audiophiles after having been rolled out numerous years ago.