Audio Database
U-22
Commentary

This tube type preamplifier was completed after approximately one and a half years of planning and one year of development.

There are two versions, black and white. Only black uses a P-type custom attenuator and coupling capacitor.

The use of a simple circuit structure eliminates factors that cause sound quality degradation.
The power supply unit and amplifier unit can be removed from each block by plug-in for easy inspection during rack-mounting.

The CR type tone control reduces the deterioration of sound quality.

All parts, such as vacuum tubes, capacitors, resistors, switches, etc., are made of quality controlled superior parts.
All vacuum tubes are made by Telefunken, and rotary switches use Siemens type, metal film resistor made by Philips, etc.

Equipped with a large VU meter.

Model Rating
Type Control amplifier
Frequency characteristic 32 Hz to 32 kHz ± 0.5 dB
RIAA deviation 30 Hz to 15 kHz ± 0.5 dB
Input Sensitivity / Impedance Phono : 1.8mV/47k Ω
Aux, Tuner, Tape : 88mV/120k Ω
Signal-to-noise ratio Phono : 60 dB (open), 75 dB (shunt)
Aux : 75 dB (open, shunt)
Phono allowed input 400mV
Distortion factor (at rated input) Phono:0.4%(to Pre out)
Aux:0.3%(to Pre out)
Output 22 v (non-clip)
Tone control CR Type
Input / output terminal Phono : Route 3
Aux : 2 routes
Tuner : one line
Tape : 1 system
Pre-out : 2 routes
Gain Phono:55dB
Aux, Tuner : 21 dB
Vacuum tube used ECC83 : 4 Pieces
ECC82 : 2 pieces
Pwer AC100V
Power consumption 45W
External dimensions Width 440x Height 150x Depth 265 mm
Weight 7.2kg