Analogue Tape
Akai 4000 series recorders
I have owned five of these models over the years, and still have a 4000DB. They are hardy little machines, with mechanical transport controls. They have a simple and reliable way of changing the speed from 3 3/4 IPS to 7 1/2 IPS by removing a collar from the capstan. They are 1/4" 1/4 track machines.
Tape Recorder Alignment
General Procedure
Initial Maintenance
- Cleaning all heads, guides etc.
- Demagnetising
- Warm up (ie machine is at standard operating temperature).
Mechanical
A. AZIMUTH 1) Play Head Test Tape (12.5kHz or 15kHz)
2) Sync Head
Reproduce
B. PLAYBACK LEVEL Test Tape (1kHz or 400Hz)
1) Play Head
2) Sync Head
C. PLAYBACK METER LEVEL
D. PLAYBACK EQ-HI ƒ (15ips) Test Tape (10kHz or 16kHz)
1) Play Head
2) Sync Head
Do for 71/2ips if available
E. PLAYBACK EQ-LO ƒ (15ips) Test Tape (100Hz)
1) Play Head
2) Sync Head
Do for 71/2ips if available
Repeat after Record Alignments to adjust for fringing. Recorded Tone (100Hz)
Record
F. INPUT LEVEL Test Tone Osc (1kHz)
G. INPUT METER LEVEL
H. BIAS LEVEL (to suit tape type) Osc (10kHz)
I. RECORD LEVEL Osc (1kHz)
J. RECORD EQ-HI ƒ (15ips) Sweep osc (30Hz-22kHz) or 10kHz
Do for 71/2ips if available
K. RECORD EQ-LO ƒ (15ips)
Do for 71/2ips if available Sweep osc (30Hz-22kHz) or 100Hz
If J & K cannot be set recheck the bias level.
Parts in bold are the usual Assistant Engineer procedures, and assume that the tape machine meters are correctly calibrated, and the mechanical alignment is correct.
Note: a full alignment will also involve checking head wrap, tilt, and height. It will also include checking bias ƒ, the bias trap, absolute tape speed, and brake tensions.
Otari MX-5050 BII alignment
| mx5050_b2-ii_alignment_procedure.pdf |
MCI JH110 website
Spec sheets for various versions of the JH110 2 track are on the MCI website. The manual is there also, and there is information on other tape machines and mixers MCI made, including a 32 track analogue tape recorder on 3" tape. The JH110 service manual is here.