แอมป์หลอด Luxman รุ่น SQ65 เสียงดี ทรงพลัง รุ่นหายากน่าสะสม Made in Japan
แอมป์หลอด Luxman รุ่น SQ65 เสียงดี ทรงพลัง รุ่นหายากน่าสะสม Made in Japan
อ่าน เสปค และ รีวิวร์จากต่างประเทศก่อนนะครับ....
LUXMAN SQ65
52,000 yen (released in August, 1965)
explanation
A high-output pre-main amplifier developed based on the technology obtained from
medium-power amplifiers.
It is designed with high output and low distortion in mind, rather than simply pursuing high output,
and achieves an output of 28W.
The output circuit uses a cathode NF circuit.
In addition to the commonly used NF circuit, the cathode NF circuit is a kind of multiplexed
NF circuit that provides local feedback to the output tube, which greatly reduces the internal
resistance of the output tube and stabilizes the NFB over a wide bandwidth.
In addition, the output transformer adopts a special winding type designed for cathode NF circuits.
The output tube is a 7591 Nova tube 7868.
The Nova tube is a large 9-pin MT tube with the capacity of the GT tube in the shape of an MT
tube, eliminating problems caused by tearing of the stem base and poor soldering, which were
considered to be shortcomings of GT tubes.
The 7581 (7868) is a Hi-Fi output tube that has established a reputation for being used in the
McIntosh-225 type, and is a sphere such as a 6L6GC high-sensitivity type with 40W or more
(AB class P.P.) Large output can be extracted.
The paired output tubes are fully AC balanced by independent regulators, and the output tubes
are operated in a fixed-bias fashion.
The driver circuit adopts the so-called LEAK type used in the point one amplifier of the British
company LEAK.
In addition, DC ignition is used for the first stage tube of this main part, which has succeeded
in improving the overall SN.
The preamplifier section uses the all-NF type used in the SQ5B and SQ38 as a lux type, and
a pentade is arranged to prevent increased distortion and increase input sensitivity.
The equalizer circuit is equipped with two types of tapes: one for NAB standard 5 cm and one
for low speed 19.9 cm.
The tone control is lux-shaped.
It is equipped with an Extra Bass circuit.
This circuit is a kind of MFB circuit for low-frequency compensation, and can automatically shift
fo to the low frequency according to the characteristics of the speaker.
For example, in a system with a fo of 5 Hz, the frequency can be reduced to 2 Hz, which is half
of that, effectively extending the playback capability by one octave to the lower frequencies.
However, this circuit can only be used with enclosed speaker systems.
It is equipped with functions such as two types of filters (Low and High), a tape monitor with
a three-head tape recorder, and a blend control to adjust the spread of the stereo sound source.
Model rating
Model Tube pre-main amplifier
Output (50Hz) 28W+28W
Distortion Within 0.5% (28W)
Frequency response Within 20Hz~20kHz -1.5dB
Input sensitivity (20W, 1kHz) Tape(9.5cm):1.7mV
Tape(19cm):2mV
Phono:4mV
AUX1:250mV
AUX2:500mV
SNR ratio Tape:54dB
Phono:63dB
Tone Control ±16dB, LUX NF
equalizer Tape:NARTB(9.5cm、19cm)
Phono:RIAA
filter Low cut:100Hz、6dB/oct
High cut:5kHz、6dB/oct
Main NFB Cathode NF: 6dB
Major NF: 15dB Total 21dB
Vacuum tubes, etc.
Vacuum tubes (11 pcs) 7868: 4 pcs
6DT8: 3 pcs
12AX7(T): 2 pcs 6AU6 For Hi-Fi: 2 pcs
Diodes (6 pcs) SE0.5a: 2 pcs
SE0.5b: 4 pcs
Power consumption No signal: 125W Maximum output: 156W
External dimensions W363×H127×D320mm
weight 14.2 kg.