Audio Database

SQ-88
Commentary

In response to the wishes of vacuum tube amplifier fans, this pre-main amplifier was developed with Luxman's long tradition in the background.

KT-88 is used for the output tube as the key device of the power amplifier.
The Williamson circuit, which has a clear reference point for amplification and does not have characteristics peculiar to low frequencies, forms an inverted signal by PK division with little degradation of sound quality, and uses the output tube KT-88 by push-pull.
In addition, by minimizing the total NFB, we have achieved music playback without losing the dynamic feeling of music.

As an output transformer, we have adopted the OY type which has determined the reputation of Lux as a transformer manufacturer.
This transformer uses an Orient Core material and is finished by hand by skilled engineers based on the OY type's unique split winding, resulting in straight sound quality with very little phase rotation.
Transformers are carefully shielded and filled with fixing fixing material, and placed in an iron case to completely eliminate leakage flux.

The preamp section incorporates design know-how focused on sound quality that has been refined through the manufacture of many vacuum tube amplifiers, and the tone control circuit, which is an attached circuit, also uses a circuit configuration using vacuum tubes.

In addition to four line inputs, a high-quality phono equalizer circuit with an excellent S/N ratio is built in for analog playback.

Many custom parts are used to fully draw out the original characteristics of the circuit and to carry out the design philosophy.
Low-distortion type high-quality volume is used for the volume, and low-noise, high-information-content custom parts are used for electrolytic capacitors and mold resistors as well.

The exterior design is unified with champagne gold, and aluminum is used for the side panel and bonnet.

Model Rating
Type Tube type integrated amplifier
Rated output 50W + 50W (6 Ω)
Input Sensitivity / Impedance Phono MM : 2.5mV/47k Ω
Line1, 2, 3 : 150mV/47k Ω
CD : 150mV/47k Ω
Tape monitor : 150mV/47k Ω
Total harmonic distortion factor 0.5% (6 Ω, 1 kH)
Frequency characteristic 20 Hz ~ 20 kHz + 0 -0.5 dB
Tone control ± 15 dB (maximum variation)
Attachment Line straight switch
Monitor switch
REC OUT switch
Bass/Treble Tone Controls
AC inlet
Phono equalizer (MM)
Large vise speaker terminal
Vacuum tube used Output Tube : KT-88x4 (2 Push-Pull per ch)
First Stage : 5814A (12AU7) x4
Driver Stage : 12BH7Ax2
Power supply voltage 100 VAC, 50Hz/60Hz
Power consumption 230W (according to the Electrical Appliance and Material Control Law)
External dimensions Width 424x Height 194x Depth 384 mm
Weight 24.5kg