Luxman MQ-88

 MQ-88 VACUUM TUBE POWER AMPLIFIER

We, Luxman could be said a maker who has been pursuing the possibility of adopting the vacuum tube in amplifier for a long term in Japan. Although it happens that the replacing into the semiconductor has become the main stream in audio amplification, the high reality and wide range owned by vacuum tube enables it be actively used in the design as well as in the constitution of amplification circuit. Here comes the CL-88/MQ-88, a separate type vacuum tube amplifier poured with the latest (development) results and everlasting enthusiasm and republished after 11 years’ dormancy.

 Driving KT88 with Mulardo type circuit

The vacuum tube was adopted in power amplifier MQ-88 after overall careful consideration. In the primary stage of ECC83S, JI-made vacuum tube of Slovakia, and in the drive stage of 12BH7A and output tube of KT88, the Sobulikku–made vacuum tube of Russia are respectively adopted. The products with a good fame in quality, sound quality and in long term stable delivery are used. In circuit type, the cathode directly connecting type aiming at gaining flexibility and forcefulness, namely the Mulardo type was adopted. It features that the second distortion occurred at the drive section of differential construction in the primary stage could be eliminated and the balances of push-pull actions of output tube KT88 is stabilized. In addition, the product that has same size with OY36 which boasts wide range features and dynamic sound was specially designed into the output transistor. Lastly, the transistor using oriented core material was built in the sealed box for protecting it from noise.

 The bias adjusting function equipped with monitoring meter The meter using for adjusting the bias current aiming at guaranteeing the visibility by the combination of blue LEDs was equipped on the top panel. For keeping 4 KT88 (vacuum tubes) at usually best conditions, and for highlighting the stability and reliability in semi-fixed volume, the wirewound sealed construction type was adopted

 The high grade/high sound quality parts made with carefulness

This is the MQ-88 aiming at increasing the high fidelity of the amplification of signal by decreasing the attached functions. So the parts used in this must be in good quality. First of all, the single wire of the gold plating 4N non-copper oxide coated with the ideal insulating material—fluorine resin insulating coating was adopted in the signal wire. So the sound with core and long term stable feature could be reached. In CR parts type, many best-known parts such as tubular type condenser immersed in vitamin Q oil, the Ligen Dengu-made carbon film resistor used in audio are adopted. In addition, many high-grade custom-made parts such as gold-plating tight socket, super-high insulation lug terminal plate, etc. are adequately used.

 Chassis construction completely pursuing rigidity

The vibration and the resonance from the outside are the formidable enemy for vacuum tube inside it the electrons collide each other in the vacuum glass tube. For MQ-88, on the basis of guaranteeing the rigid foundation by adopting the 15mm super-thick aluminum stainless plate for top panel, the constructions suitable for control amplifier and power amplifier are extensively analyzed.  On one side, the shock-proof construction integrated surface and collar of MQ-88 supports the heavy things such as transistors, etc. Because the collars are directly installed at the foot parts of case, the case body is kept upright. The existing box-type part plays a role of beam in this construction, contributing a lot for the strengthening of the horizontal intensity of the case body as a whole. The Piezon composite insulator used at the foot parts of the two models has taken the construction combining the advantages of hardware and software systems by using the stainless brass combined with damping material (piezoelectricity-type sound-proof and absorption material). It could give a solid support to the amplifier case body as well as could eliminate the vibration and resonance.

SPECIFICATIONS MQ-88

Rated Output:  

40 W + 40 W (8Ω),

50 W + 50 W (6Ω),

40 W + 40 W (4Ω)

Input Sensibility/Input Impedance:  420mV / 100kΩ

Overall Higher Harmonic Distortion Rate:  1,5%  (1 kHz rated)

Frequency Characteristic:  5 Hz - 90 kHz (+0, -3 dB)

Signal-to-Noise Ratio: less than 101 dB  (1kHz 1HF-A)

Input:  2 Coaxial  systems (one is direct input system)

Output:  Speaker Terminal 1 System

Accessory Device:  Power switch, power indicator, input level adjusting volume, bias current adjusting volume X 4, bias monitoring meter, line phase sensor, signal ground contact, AC inlet

Vacuum Tube Used: 

Output tube: KT88 X 4,

The First Stage: ECC83S X 2,

Drive Stage: 12 BH7A X 2

Circuit Format:  Murado type

Sound Quality Parts: 

Gold plating 4N non-copper oxide copper single wire,

Tubular type condenser immersed in vitamin Q oil,

Gold-plating tight socket,

Shock-proof construction used in 15mm thick aluminum top panel

Power Consumption:  190 W (Based on the Safety Law on Electrical Appliances)

Dimension (W x H x D):  400 x 186 x 397 mm

Weight:  25.1 Kg