Model 401

The Model 401 is identical to the Model 400 in every aspect except the head assembly. The 401 incorporates heads to erase and record over the full width of the tape. Thus tapes recorded on the 401 can be played back on the Model 300 and Model 201 without pre-erasing the unused portion of the tape and without necessitating level adjustment.

Both 400 and 401 will play back either full or half track recordings recorded on any AMPEX recorder.

Specs:

Tape Speed
15"/s and 7"/s, with motor speed change and equalization switches conveniently located

Frequency Response
At 15" +or- 2dB - 50Hz - 15kHz
At 7,5" +or- 2dB - 70Hz - 10kHz
+or- 4dB - 30Hz - 15kHz

Signal-to-Noise Ratio
Over 55db. at both 7,5 inches per second and 15 inches per second, as defined by the N. A. B. standards.
By definition, the signal-to-noise ratio is the ratio of peak recording level to- the total unweighted playback noise when erasing a signal of peak recording level and in the absence of a new signal. Thus, bias and erase noise are included, as well as playback amplifier noise. All frequencies between 30 and 15, 000 cycles are measured. The peak recording level is defined as that level at which the overall (input to output) total r. m. s. harmonic distortion does not exceed 3% when measured on a 400 cycle tone.

Starting Time
Instantaneous. (When starting the tape accelerates to full speed in less than 1/10 second because capstan motor operates when ever power is on.)

Stopping Time
When playing at 15 inches per second, the tape moves less than 2 inches after stop switch is operated.

Flutter and Wow
At 15 i.p.s. well under 2/10% r.m,s, measuring all flutter components from 0 to 300 cycles using a tone of 3, 000 cycles. At 7,5 inches per second under 1/4%.