Audio Database

Image of A-UK3
Commentary

This pre-main amplifier of the UK series was developed and designed by Mr. John Bamford of the UK aiming at simplicity and straightness.

Based on the concept of "Simple is best", it intentionally excludes tone control, balance control and headphone port.
By reducing the number of auxiliary circuits, the contact points of the switch are reduced and wasteful routing of the signal path is greatly reduced.

Newly developed wide range linear circuit is adopted.
This circuit has a simple structure in which the required gain is obtained by a single-stage amplifier circuit. It has a feature that the output impedance is flat from the low band to the high band, enabling stable driving over a wide band.
In addition, the low-load drive design improves the drive performance of the speaker at low load.

The A-UK3, which was developed by further improving the amplifier released in the UK, uses a large volume with sound quality tuning in order to realize the expansion of low and high frequencies so that the sound spreads around the wide speaker.

In order to eliminate resonance in the casing, a honeycomb structure with excellent rigidity is used for the heat sink that reduces vibration of the internal transformer. The same honeycomb structure is also used for the chassis and five insulators that support the casing to reduce the adverse effect of vibration on sound quality.
In addition, the position of the screw stopper is determined based on computer simulation, and copper-plated screw with high vibration absorption rate is used for the position which is least affected by vibration.

A simple circuit configuration is achieved by using only one speaker output system.
On top of that, two terminals are provided for bi-wiring connection.

A replaceable inlet system is used for the power cord.

Model Rating
Type Pre-main amplifier
Rated output
(Both channel drive, 20 Hz to 20 kHz)
60W + 60W (4 Ω, 0.05%)
30W + 30W (8 Ω, 0.03%)
Damping factor 130 (20 Hz ~ 20 kHz, 8 Ω)
Input Sensitivity / Impedance Phono MM : 2.8mV/50k Ω
CD, Tuner, Line, DAT/Tape1, Tape2 : 200mV/40k Ω
Phono maximum allowable input MM : 150 mV (1 kHz, 0.1%)
Output Level / Impedance DAT/Tape1, Tape2, Line, Rec, Adapter Out : 200mV/1k Ω
Frequency characteristic Phono MM : 20 Hz to 20 kHz ± 0.3 dB
CD, Tuner, Line, DAT/Tape1, Tape2 : 1 Hz to 300 kHz + 0 -3dB
S/N (IHF, A-network
Short circuit)
Phono MM:86dB(2.8mV)
CD, Tuner, Line, DAT/Tape1, Tape2 : 110 dB
Speaker load impedance 1 pair : 4 Ω ~ 16 Ω
2 sets : 8 Ω ~ 32 Ω
Power supply voltage 100 VAC, 50Hz/60Hz
Power consumption (Electrical Appliance and Material Control Law) 130W
External dimensions Width 420x Height 126x Depth 352 mm
Weight 7.3kg