The StereoKnight M-100 Monoblock Amplifiers

  

The fully balanced design M-100
These are astonishing. Fantastic power, control, detail,
transparency, openness and sheer musicality. I have
never heard a KT88 amp, or in fact any amplifier short
of the CAT that even goes close to these amps.

Specifications

* Tubes: 1 X 6H30, 2 X 6922 4 X KT88
* Power output: 2×75W (8ohms ULTRALINEAR); 2x 140W (4ohms ULTRALINEAR)
* Input: 1 x RCA, 1 x XLR
* Frequency response: 10Hz~60kHz
* THD: 1%(1kHz)
* Input sensitivity: 2 V
* Input impedance: 50 Kohms
* Output impedance: 8ohms, 4ohms
* S/N ratio: > 90 dB
* Dimensions: 500×330×240mm
* Net weight: 35Kg x 2
* Power consumption: 550W maximum

The M-100 paired monoblock amplifiers are designed for those who seek supurb performance based on high power and a fully balance design, where the reliability and easy maintenance are assured for years to come. The M-75 is mainly designed for full balance input, thus gaining the ultimate performance possible, supported by the transformer assembly, including power, input, output, and balance, newly designed and manufactured by StereoKnight. Two 6922 tubes are used for amplification when XLR input is selected. A 600 ohm input transformer was designed to split phase for balanced amplification when RCA input is used.

High power with excellent drive & control: transformer and KT88
Four matched pairs of KT88s, driven by a 600W ultra wide bandwidth, C-core type output transformer, conservatively designed for an output of 75WPC at 8 ohms, or 140W at 4 ohms, where two cimportant factors were concerned:
* Power is not the single bench mark of performance performance. The ability to drive and control the most difficult loads, in any situation is more critical;
* Achieving exceptionaly high power output, by pushing the tubes to their maximum capabilities will easily damage them in the short term, and can effect the stability and
reliability of the unit.

At 100WPC output the M-75 provides excellent drive and control, as well as plenty of power, which easily makes it a winner in any situation.
With four KT88s, we could easily achieve an output of over 125WPC, which may look impressive, but we care more about the reliability of our products, as well as our customer's long term satisfaction. Sacrificing some power does not mean we compromise the performance.
KT88s or 6550s are used for power amplifying, which are the power tubes preferred by StereoKnight. We value the KT88 based on the following considerations:
* Properly designed and engineered, and assisted by high quality transformers, KT88s can produce all typical 'tube sound' usually associated with 300Bs, 2A3s or 845s.
* KT88s are stable, reliable and have a long tube life.
* They are easily obtainable, and reasonably priced.

Two ZEROs
As for the noise, which has annoyed tube equipment for decades, it will never be a conern any more. ZERO noise concern will be the basic promise that StereoKnight brings to your musical enjoyment. Another ZERO is about negative feedback: ZERO-NEGATIVE-FEEDBACK concept and technology are fully applied in both the preamp and poweramp stages in the S-40's design and engineering. This unique feature brings single ended class A sonic characteristics to the S-40's push-pull based design.
MOSFET technology is used to stabilize voltage most precisely, which offers faster rectification, and has the ability to address a much higher capacitance than the older tube rectifiers. Tube rectifiers are designed to handle only 50 microfarads (mf) at maximum, while MOSFET rectifiers can handle capacitances greater than 4000 mf. MOSFET also offer far better reliability and don't age as quickly as tube rectifiers. Tube rectifiers age and eventually short out the power supply cap, which is an expensive repair. It can also help to reduce electro-magnetic noise (dead silent background?) and operate unit more stably and reliably.

Technology & parts
MOSFET technology is used to stabilize the voltage precisely, which offers faster rectification, and has the ability to address a much higher capacitance than the older tube rectifiers. Tube rectifiers are designed to handle only 50 microfarads (mf) at maximum, while MOSFET rectifiers can handle capacitances greater than 4000 mf. MOSFETs also offer far better reliability, and don't age as quickly as tube rectifiers. Tube rectifiers age, and eventually short out the power supply cap, which is an expensive repair. It can also help to reduce electro-magnetic noise ( dead silent background) and allow the unit to operate with more stability and reliably.
All components and each measurement which may improve sound performance or enhance the reliability of the unit have been carefully considered. StereoKnight designs and manufactures their units in a way to satisfy the most picky and ambitious audiophiles. For example, most wires connecting parts inside chassis are covered by TEFLON insulation --- (Teflon insulated wires are more suited to the higher working voltages. High voltages run on separate wires to avoid copper crystallization (whiskers, due to high voltage) --- between layers of fiberglass when high voltage is run on PC board traces. Teflon wire also has better thermic stability and can withstand higher current for a short time).
In addition, critical wires are hand made by compositing several kinds of selected enamelled wires in optimal proportions. We also use Japanese made POCC rectangular solid core copper wire as the wire in the signal path. This type of wire which is often used by the big brands to make high cost interconnect cables.

Features:
* Full balance design.
* High grade 600W EI type power transformer, extra wide band C-core output transformers (StereoKnight signature).
* High end components (Nichicon and Hovland capacitors), parts (StereoKnight designed heavy duty gold-plated binding post) and wire (TEFLON insulated wire and Japanese made POCC rectangular solid core copper wire) through the signal path.
* ZERO-NEGATIVE-FEEDBACK technology.
* ZERO noise: dead silence background.
* MOSFET voltage stabilisation.
* High control power (75WPC or 140W at 4 ohms), capable of driving a wide range of loudspeakers.
* Easily accessible individual output tube bias measurement, and adjustment points on the side of the chassis.
* Detachable IEC power cord, high quality gold-plated StereoKnight custom binding posts and RCA jacks.
* Full high quality aluminium alloy body construction, power meter in faceplate and acrylic enclosure cover design: sturdily and artistically built.

SIMPLE, BEAUTIFUL, RELIABLE was the oath taken when StereoKnight was founded. With a THREE-YEAR WARRANTY, the M-75 will give you lasting value and listening pleasure for many years to come.
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Suggested preamp: - StereoKnight signature passive preamplifier, or the magnetic Enigma-1.0R Preamplifier: use the balanced input; for the ultimate performance, CD players with XLR output are recommended.

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