Category:Super High Fidelity
Country of Manufacture:Japan
Release dates:1979 - 1982
Speeds: 3 3/4, 7 1/2
Max Reel Size("): 10.5"
Number of heads: 6
Dimension: 19 x 17.3 x 10" (483 x 440 x 256mm)
Head Composition: Ferrite/Glass
Head Configuration: Stereo
# Motors: 3
Voltage(s): 110-120v, 220-240v
Frequency Response:( 3dB): 7½ ips: 30Hz to 27kHz
Wow and Flutter:less than 0.03% at 7½ ips
Signal-to-Noise Ratio:better than 65 dB
Sound quality rating:7 / 10
Long-term reliability rating: 8/ 10
Weight: 46.2 lbs (21.0 kg)
The GX-636/DB was almost identical to the 635D/DB. It had a symmetrical 6-head design (Glass Crystal) which permitted both playback AND recording in both directions.
The GX-636 had no additional functions to the GX-635D: the main improvements were mostly internal.
The recorder was also available with Dolby N.R. (GX-636DB).
To service the GX-636, one requires a GX-635D service manual plus some additional 636 sheets. The printed circuit board layouts are also a little different. The 636 has no servo tape tension, so tension changes constantly and in proportion to tape diameter,
TheGX-636 was superceded by the GX 646 in 1982.
Price when new (UK) £399
Erase: E4-241 (x2)
Record: R4-241 GX head (x2)
Playback: P4-251 GX head (x2)
1 x SCM200 capstan drive
2 x eddy current outer rotor motors (XO24-TD)
Frequency response ( 3dB)
7½ ips: 30Hz to 27kHz
3¾ ips: 30Hz to 20kHz
Wow & flutter
less than 0.03% at 7½ ips
Signal to noise ratio
better than 65 dB
Mic: 0.25 mV; Line: 70 mV impedance 100 Kohm; DIN: 2mV/10Kohm
Line: .775 / 20 Kohm; Headphones: 100 mV at 8 ohms; DIN 0.3V
75 seconds for a 1200 ft tape
-The 2SC458 transistors should be replaced
-Low playback volume on one or both channels when using the reverse button. One of four relays which are in the service manual having part number my4-02-US-L