Audio Database

Image of the QT-74
Commentary

An open reel deck with 4-channel recording / playback as well as 2-channel Oatley berth recording / playback.
Four channels are completely independent of each other. You can record and play four discrete channels.

The tape travel mechanism uses a center capstan mechanism with heads arranged on the left and right sides with the capstan at the center sides work under the same conditions, ensuring stable tape travel.
In addition, the pinch roller is equipped with a self-aligning device, so that the pressure applied to the tape is uniform to avoid troubles such as one end of the tape.

Equipped with a tape selector that can change the characteristics of the deck according to the characteristics of each standard tape and LH tape.

Each channel has its own independent recording and playback level adjustment for perfect balance.
When recording, the Recording Master Volume allows you to adjust the level of each channel simultaneously, allowing you to control the overall level in a centralized manner.

When it is used as a 2-channel deck, both recording and playback are possible with Oatley berth, and it can be freely changed from right to left or from left to right with one touch of push button.
By adopting a powerful motor and an auto clutch, the time required for reversing is 0.5 seconds.
In addition, if a sensing tape is attached to the end of the tape, it is automatically reversed, and if it is attached to both ends of the tape, it is possible to play Oatley Pete repeatedly.
Oatley Berth can be released.
In the case of 4 ch, it does not reverse even if you press the reverse button.

It uses an all-belt drive system in which the rotation of a large hysteresis synchronous motor is transmitted to the capstan and reel stand via a belt.
It is a simple mechanism that does not use any idler, which is a major factor of rotating machine sound and wow / flutter.

The pinch roller is a rising type, and it sinks into the body when it stops, and rises when it plays.
There is nothing on the front of the head when you put the tape, so it is easy to load the tape.

The Head cover has an opening and closing type that can be opened and closed with one touch.

Equipped with a pause lever that stops the tape running while maintaining the recording and playback state.

The metal reel (PR-80) attached in the picture was sold separately.

Model Rating
Type 4ch/2ch Stereo Tape Deck
Mode of operation 1-Motor All Belt Drive (also called capstan or reel stand)
Center capstan mechanism
Automatic and manual inversion (both for recording and playback)
Heads
For rerecording : One 4-track 4-channel head
One 4-track 2-channel head for reverse
For Erase : 2 x 4-track 2-channel heads
One 4-track 2-channel head for reverse
Motor Hysteresis synchronous motor
Tape speed 19cm/s, 9.5cm/s
Quick winding speed Approximately 110 seconds (with 370m tape)
Uneven rotation 0.10%RMS(19cm/s)
0.08%WRMS(19cm/s)
S/N LH Tape : 56 dB
General Tape : 53 dB
Distortion factor LH Tape : 1.0%
General tape : 1.2%
Frequency Response (19cm/s) 30 Hz to 20000 Hz
50 Hz to 15000 Hz ± 2 dB
Input Microphone Input : 0.3 mv ~ 240mV/50k Ω
Line Input : 30 mv ~ 24V/330k Ω
Output Line output : 0.775 V (at 0 point of level meter)
Rejack : West German DIN standard (for 2-channel stereo)
Headphone jack : Output load 8 Ω, 4-channel Front, Rear independent type
Semiconductor used Transistor : 28
Diode : 7
Attachment mechanism Tape Selector Switch (LH, General Tape)
Master-level control for 4-channel stereo recording
2-channel stereo auto-reverse ON/OFF switch
Pause lever
Playback Level Control
Four digit tape counter
Hinged Head cover
Pwer 100 VAC, 50Hz/60Hz
Power consumption 74W
External dimensions Width 434x Height 478x Depth 212 mm
Weight 17kg
Sold Separately Metal Reel PR-80 (¥ 1,200)