Hafler DH-120 power amplifier

The DH-120 may shatter the illusions of some audiophiles in their search for perfection with ever larger, heavier and more costly amplifiers. It demonstrates once again that quality, not quantity, is the deciding sonic factor. Engineered for adequate power, proper headroom and excellent overload characteristics, together with conservative ratings, the DH-120 surpasses in sound quality many amplifiers of substantially higher advertised output.

To the technically knowledgeable observer, the DH-120 is quite elegant. Its novel drive circuit is extraordinarily linear. Its very low distortion is achieved with relatively little negative feedback. The oversized heat sinks and power supply, the careful selection of critical components for their sonic attributes, and the evident product quality demonstrates our commitment to excellence.

The most important design element is the utilization of power MOSFET output devices MOSFET advantages include self-stabilization  robustness linearity, high speed, vaccum tibe-like characteristics and they require no thermal compensation. Because MOSFETs can handle heavy currents current limiting circuits are not required.

The audio enthusiast will appreciate the extra features which make the DH-120 more versatile than conventional amplifiers. Independent level controls on each channel are valuable for such applications as bi-amplification. For those needing higher power in a small package a back panel switch converts to a bridged mono mode which uses both channels to deliver in excess of 125 watts. If separate speakers are to be used in another area, a second set of speaker terminals is provided. Alternatively, these terminals can be switched to power rear speakers to add ambience recovery to the main system.

Hafler ingenuity has developed a uniquely simple and effective means of recovering heretofore inaccessible sonic details which have been hidden in many recordings and broadcasts. These elusive signals consist of reflected and reverberant sounds which contribute the sense of space and depth in the recording location. When these sounds are reintroduced through loudspeakers placed behind the listener using the Hafler Ambience Recovery System you will find a new sense of immediacy and involvement emerging from many of your familiar recordings.

 

Specifications

Power rating:  less than 0,009% Total Harmonic Distortion at any power level up to 62 watts continuous average power per channel into 8 Ω  at any frequency between 20 Hz and 20 kHz with both channels driven.

Intermodulation DIstortion (SMPTE): less than 0,005% from 1 watt in 62 watts each channel into 8 Ω

Total Harmonic Distortion : 0,002% (8 Ω , 1 kHz)

Frequency Response (at 8 Ω )

At 1 watt :  4 Hz - 200 kHz -3db

At 62 watts :  10 Hz -40 kHz +0 -1/2 dB

Typical Channel Separation: 

20 Hz :  better than 75 dB

1 kHz :  better than 85 dB

20 kHz :  better than 65 dB

Signal-to-Noise Ratio (Unweighted):  exceeded 103 dB referred to 62 watts into 8 Ω

Input Impedance:  22,000 Ω

Input Sensitivity:  11 volts rms for 62 watts into 8 Ω

Damping Factor:  100 to 1 kHz into 8 Ω ; 50 to 10 kHz into 8 Ω

Rise Time:  10 kHz, 45 volts peak to peak square wave, 10% to 90%, 2 µs

Slew Rate:  10 kHz, 45 volts peak to peak square wave, 30 V µs

Semiconductors:  22 Transistors; 4 Power MOSFETs; 23 Diodes; 8 Zener Diodes; 1 Diode Bridge

Power Consumption:  62 watts both channels into 8 Ω , 300 VA

Dimensions (W x H x D):  15-3/8" x 3-1/2" x 9"

Weight:  18 lbs Net

 

Hafler DH-220 power amplifier

A State of The Art. Power Amplifier

The DH-220 follows in the path of the widely acclaimed DH-200 amplifier which has had highly laudatory reviews and widespread consumer acceptance. Like the DH-200 amplifier, this 115 watt per channel amplifier is available either in easy-to-assemble kit form or factory assembled. Either way it is a highly reliable piece of equipment which can satisfy the most hyper-critical listener, including the audiophile with the most difficult loudspeaker load. And, in kit form the DH-220 provides a significant cost saving for a pleasant few hours of assembly time, using factory pre-assembled and tested audio modules.

The DH-220 utilizes all polypropylene capacitors in the circuit path. All electrolytic are bypassed by polypropylene capacitors. This results in a clarity of sound unusual in an amplifier of this size.

Two completely assembled and fully tested amplifier modules comprise all of the kit's active circuitry, leaving just a handful of parts for the builder to complete the mechanical assembly and power supply wiring. This makes your job simpler and faster, and assures that your finished kit will easily meet all of its specs, and provide the ultimate in listening pleasure.

 

The DH-220 employs a unique circuit configuration using all discrete transistors, operating the very latest output devices, power MOSFETs, in a conservative array. The result is that the benefits of Class A output stages are obtained - such as high speed, minimal crossover distortion, and decreasing distortion at lower signal levels - without the disaddvantages of high cost, high heat, low efficiency and thermal instability that are a part of conventional Class A operation. Like other Hafler products, this new power amplifier has a completely symmetrical, mirror-image complementary push-pull circuit from input to output.

 

Exceptionally low distortion is apparent on reading the specifications, but such figures cannot detail the unit's true capabilities. The significance of achieving orders of magnitude reduction in total harmonic distortion and intermodulation distortion lies in the correlative elimination of other distortion products. Presently recognized test standards are seemingly unable to quantify to many listeners. The DH-220's characteristics of vanishing distortion at lower signal levels, and minimal indication of any forms of transient distortion, such as slew induced distortion, as observed at all power levels of square waves, tone bursts and pulse tests, will, we are confident, maintain its superiority as new standards and tests become applicable.

 

Specifications

Power Rating:  less than 0,02% T.H.D. at any power level up to 115 watts continuous average power per channel into 8 Ω  at any frequency between 20 Hz and 20 kHz with both channels driven.

Intermodulation DIstortion (SMPTE): less than 0,005% from 1 watt to 115 watt into 8 Ω

Typical Total Harmonic Distortion at 115 wats into 8 Ω :

1 kHz :  0,0015%

10 kHz :  0,005%

20 kh :  0,012%

Frequency Response (into 8 Ω ):

2 Hz to 160 kHz at 1 watt (-3 dB)

6 Hz to 60 kHz at 115 watts (-0,5 dB)

Typical Channel Separation:

20 Hz :  75 dB

1 kHz :  85 dB

20 kHz :  65 dB

Signal-to-Noise Ratio (Unweighted): better than 100 dB at 115 watts into 8 Ω

Input Impedance:  47,000 Ω

Input Sensitivity:  1,55 volts rms for 115 watts into 8 Ω

Damping Factor:

300 to 1 kHz into 8 Ω

60 to 10 kHz into 8 Ω

Rise Time:  10 kHz, 60 volts peak to peak square wave, 10% to 90% :  2,5 µs

Slew rate:  10 kHz, 60 volts peak to peak square wave :  30 V/µs

Semiconductors:  26 Transistors; 8 Power MOSFETs; 29 Diodes; 4 Zener Diodes; 1 Diode Bridge

Power Consumption:  Quiescent 125 VA, 115 watts into 8 Ω  ; 580 VA

Dimensions (W x H x D): 16" x 5-1/8" x 10-1/2"

Weight: 26 lbs net

SAE 2200 power amplifier

 

Stereo Power Amplifier

The new SAE2200 Power Amplifier achieves the ultimate. It combines performance and value with aesthetic balance and beauty. Delivering 100 watts rms/channel from 20 Hz to 20 kHz at less than 0,05% Total Harmonic Distortion, the 2200 shares the SAE engineering heritage which includes fully complementary circuitry, high slew rate and low transient distortion. The 2200 package also includes a 15 LED/channel power display which instantly indicates the amount of power being delivered to your speakers, and because of the quality of material and components that go into every SAE, the 200 offers a Free transferable 5 year Service Contract.

 

Fully Complementary Circuitry

The 2200 is completely balenced from input to output utilizing full complementary dual-differential inputs, full complementary drivers and full complementary output stages. This design approach offers inherently low steady-state or transient distortion while assuring accurate reproduction of complex musical waveforms.

 

LED Power Display

This display can instantly inform you of the power output to your speakers, channel imbalance and other information pertinent to the proper performance of your system. Utilizing 15 light Emitting Diodes per channel the amplifier's average power (peak responding) is constantly displayed from 20 mW to full rated power. Amplifier overload is also indicated. The circuit is analog in nature and displays power output in 3 dB increments over its full range, making it the most accurate indicator of its type available in the industry today.

 

Amplifier Protection

Three means of circuit protection are included in the 2200;

-A VI limiter which senses load impedance below 2 Ω  without being affected by reactive loads (i.e. electrostatic speakers) which are rated at 4 Ω  or greater

-A thermal cutout device shuts down the amplifier should the heatsink reach an abnormal high temperature

-An AC line fuse for overall protection

 

Loudspeaker Protection

Should subsonic pulses or ±DC Voltages, which could damage your speakers, appear at the amplifiers outputs, a relay circuit will automatically disconnect the speakers from the amplifier. The circuit is also used during turn-on/off to prevent annoying transients. This relay circuit incorporates many features unique to SAE products, the most important of which alleviates high frequency distortion developed by the relay due to "contact diode effect"

 

Plug-in Board Design

Easily accessible input-drive, relay-power, and meter boards make the 2200 consistent in performance from one amplifier to another in production, and simple to service.

 

Monocoque Construction

Utilizing technology developed in our other amplifier designs, the 2200 mechanical package is constructed in the form of a box, offering structural rigidity and integrity, plus high strength to weight coefficient,

 

Premium materials

Only the finest materials have been used in the construction of the 2200. among the components used you will 5% carbon deposit resistors throughout, military grade glass-epoxy circuit boards and high-grain iron-ore laminations in the transformer. These efforts to use quality materials throughout insures that the 2200 will deliver superior performance and reliability in any application.

 

Precision Construction

No effort has been spared in taking these raw materials to manufacture the highest grade audio components available. It was because of this goal that our 36,000 sq,ft, primary production facility was built. This plant was designed exclusively for the manufacture and assembly of audio components. Further, critical parts unique to SAE products, such as metal work, toroid inductors and circuit boards are produced at our facilities. As a testimonial to SAE thoroughness, our metal shop fabricates all parts with a tolerance of 0,005 in (,013 cm) for proper fit. All front panels are hand brushed for proper aesthetic appearance, and all aluminum parts are mil-spec anodized for long life and easy upkeep. This attention to detail is the hallmark of SAE Components.

 

Specifications

RMS Continuous Power Output per Channel (20 Hz - 20 kHz, both channels driven into 4 or 8 Ω ):  100 Watts at 0,05% T.H.D.

Total Harmonic Distortion (from 20 Hz to 20 kHz at 250 mW to rated power into 4 or 8 Ω ):  0,05% max

Intermodulation Distortion:  0,05% max.

Frequency Response at Rated Power:  20 Hz - 20 kHz ±0,25 dB

Noise:  Greater Than 100 dB below rated power

Transient Response of Any Square Wave:  2,5 microseconds rise and fall time

Slew Rate:  40 Volts/microsecond

Stability:  Unconditionally stable with any type of load or no load including full range electrostatic loudspeakers

Damping Factor:  150 Min (100 Hz)

Input Sensitivity:  1,5 Volts RMS

Input Impedance:  50 k Ω

Overload Protection:

Low impedance electronic-sensing circuit limits with output current below 2 Ω  without limiting with 4 Ω  or higher (or reactive Loads)

Thermal sensing of inadequate ventilation.

Loudspeaker Protection:

Relay circuit protects loudspeakers from low frequency oscillations and plus or minus DC output.

Five second turn on disturbances

Power Requirements:  110 - 120 V, 50 /60 Hz. 75 Watts at idling to 600 Watts at rated poer

Dimensions (W x H x D):  483 x 133 x 21,6 mm (19" x 5,25" x 8,5")

Weight:  11,4 kg (25 pounds) shipping

Denon POA-800 power amplifier

Stereo-Monaural Power Amplifier

 

 

Specifications

Rated Power Output

Stereo

50 W per channel, min. RMS, at 8 Ω  from 20 Hz to 20 kHz with no more than 0,05% T.H.D.

90 W + 90 W (4 Ω , 1khz, T.H.D. 1%)

Monaural

120 W channel, min. RMS, at 8 Ω  from 20 Hz to 20 kHz with no more than 0,08% T.H.D.

150W (4 Ω , 1khz, T.H.D. 1%)

Dynamic Power

Stereo

130 W + 130 W at 4 Ω

150 W +150 W at 2 Ω

Monaural

180 W at 4 Ω

190 W at 2 Ω

Total Harmonic Distortion (-3 dB at rated output , 8 Ω ) 

Stereo :  less than 0,008%

Mono :  less than 0,007%

Intermodulation Distortion (60 Hz/7 kHz : 4/1 at rated output , 8 Ω )

Stereo/Mono :  less than 0,03%

Power Bandwidth:  10 Hz - 50 kHz (8 Ω , T.H.D. 0,1%)

Frequency Response:  1 Hz - 100 kHz +0 -3 dB at 1 W

Input Sensitivity/Impedance: 

Stereo :  1 V/ 25 k Ω

Mono :  0,85 V/ 25 k Ω

Output Impedance:  0,1 Ω  (1 kHz)

Signal-to-Noise Ratio (A weighting)

Stereo :  120 dB

Mono :  114 dB

Output Terminals

Speakers :  4 Ω  Min.

Power Requirements:  AC 110, 120, 220, 240 V 50/60 Hz

Power Consumption: 150 - 160 W (3 A in USA, Canada)

Dimensions (W x H x D):  434 x 120 x 300 mm

Weight:  6,8 kg

 

Hafler DH-200 power amplifier

Both ears and instruments attest to the excellent quality of the DH-200 power amplifier. It has both superior test specifications and the listening quality to satisfy the most critical listeners, including those for whom price is not a limitation.

The DH-200 follows in the path of the widely acclaimed DH-101 preamplifier which has had highly laudatory reviews and wide spread consumer acceptance. Like the preamplifier this 100 watt per channel amplifier is available either in easy-to-assemble kit form or factory assembled. Either way it is a highly reliable piece of equipment which can satisfy the most hyper-critical listener, including the audiophile with the most difficult loudspeaker load. And, in kit form the DH-200 provides a significant cost saving for a pleasant few hours of assembly time, using factory pre-assembled and tested audio modules.

Two completely assembled and fully tested amplifier modules comprise all of the kit's active circuitry, leaving just a handful of parts for the builder to complete the mechanical assembly and power supply wiring. This makes your job simpler and faster, and assures that your finished kit will easily meet all of its specs, and provide the ultimate in listening pleasure.

The DH-200 employs a unique circuit configuration using all discrete transistors, operating the very latest output devices, power MOSFET's in a conservative array. The result is that the benefits of Class A output stages are obtained - such as high speed, minimal crossover distortion, and decreasing distortion at lower signal levels - without the disadvantages of high cost, high heat, low efficiency and thermal instability that are a part of conventional Class A operation. Like the Hafler preamplifier, this power amplifier has a completely symmetrical, mirror-image complementary push-pull circuit from input to output.

Exceptionally low distortion is apparent on reading the specifications, but such figures cannot detail the unit's true capabilities. The significance of achieving orders of magnitude reduction in Total Harmonic Distortion and Intermodulation DIstortion lies in the correlative elimination of other distortion products. The footnote at the end discusses this in detail.

 

The DH-200's characteristics of vanishing distortion at lower signal levels, and minimal indication of any forms of transient distortion, such as slew induced distortion, as observed at all power levels of square waves, tone bursts and pulse tests, will , we are confident, maintain its superiority as new standards and tests become applicable.

T.H.D. and Intermodulation Distortion (both SMPTE and CCIR measurements) are below the threshold of the finest test equipment - from one-tenth of a watt to beyond 70 watts. Measured with the Sound Technology Model 1701A analyzer, typical mid-band distortion at full power into 8 ohms averages 0,0015%

Another limiting factor in correlating sound quality to measured performance is that conventional amplifiers may measure well on the standard resistive test loads, but exhibit distortion when confronted by the complex reactive loads of the loudspeaker and its crossover network. The Hafler DH-200 has the power reserves to handle mismatched loads (it can deliver 150 watts into 4 ohms, and 100 watts into 2 ohms), but more important, it can handle the back - EMF from the loudspeaker cone without generating interfacing distortion components.

With no need for special protective circuits which may compromise sonic performance, the self-protective design of the DH-200 output stage prevents the thermal runaway which is a threat to other designs.

For applications requiring extraordinary power, the DH-200 may also be bridged to convert it to 300 watt (at 8 ohms) monophonic amplifier, with similar distortion specifications. As a modestly priced, versatile "no frills" design, operating premium quality components conservatively for extended life, this new Hafler amplifier is the audio perfectionist's answer to state of the art. Performance at affordable prices.

 

Specifications

Power Rating:  less than 0,02% T.H.D. at any power level up to 100 watts continuous average power per channel into 8 Ω  at any frequency between 20 Hz and 20 kHz with both channels driven.

Intermodulation DIstortion (SMPTE): less than 0,005% from 1 watt to 100 watt into 8 Ω

Typical Total Harmonic Distortion at 100 wats into 8 Ω :

1 kHz :  0,0015%

10 kHz :  0,005%

20 kh :  0,012%

Frequency Response (into 8 Ω ):

-3db, 1 Hz to 100 kHz at 1 watt

±0,5 dB, 10 Hz to 40 kHz at 100 watts

Typical Channel Separation:

20 Hz :  66 dB

1 kHz :  66 dB

20 kHz :  60 dB

Signal-to-Noise Ratio (Unweighted): better than 100 dB at 100 watts into 8 Ω

Input Impedance:  22,000 Ω

Input Sensitivity:  1,5 volts rms for 100 watts into 8 Ω

Damping Factor:

150 to 1 kHz into 8 Ω

50 to 10 kHz into 8 Ω

Rise Time:  10 kHz, 60 volts peak to peak square wave, 10% to 90% :  2,5 µs

Slew rate:  10 kHz, 60 volts peak to peak square wave :  25 V/µs

Semiconductors:  26 Transistors; 8 Power MOSFETs; 24 Diodes; 4 Zener Diodes; 1 Diode Bridge

Power Consumption:  Quiescent 100 VA, 100 watts into 8 Ω  ; 370 VA

Dimensions (W x H x D): 16" x 5-1/8" x 10-1/2"

Weight: 26 lbs net

 

Musical Fidelity X-AS100 power amp

Musical Fidelity X-AS100 Power Amplifier.

Used properly and carefully, it should give you many years of outstanding musical reproduction.

Aesthetically and electronically the X-AS100 matches perfectly with the X-P100 Preamplifier, X-RAY CD player and X-PLORA tuner. Together, they form one of the finest hi-fi systems available.

The X-AS100 has been designed to be switched on continuously. The PSU should be positioned as far away from the X-AS100 as possible. We suggest that the PSU is placed on the floor near the mains outlet.

Dust regularly with a soft duster or soft brush but be careful when using cleaning or polishing agents - they may harm the surface finish

 

Connections

The X-AS100 is a stereo amplifier which can if required be mono for use in passive bi-amping systems.

The X-AS100 can be used with a preamplifier or any line level source which has a volume control. We highly recommend the matching X-P100 or Nu-Vista Preamps available from Musical Fidelity as an excellent choice.

 

Specifications:

Power Output: 100 watts per channel, 8 Ω

Total Harmonic Distortion:

less than 0.005% (at 1 kHz)

Less than  0.04% (20 Hz - 20 kHz unweighted)

Less than  0.003% (20 Hz - 20 kHz 'A' weighted)

Frequency Response:  10 Hz - 70 kHz ±1 dB

Input Sensitivity:  900 mV

Signal-to-Noise Ratio

Better than  106 dB unweighted (ref 100W)

Better than  117 dB ‘A’ weighted (ref 100W)

Better than  86 dB unweighted (ref 1W)

Better than  97 dB 'A' weighted (ref 1W)

Channel Separation: better than 90 dB( 20 Hz-20 kHz)

Power Consumption: 450 watts (maximum)

Dimensions (W x H x D): 230 x 110 x 330mm (Width and height include feet, depth include terminals)

Standard accessories

 X-AS100 power supply unit

IEC type mains lead

Technics SE-A1000 power amp

Stereo Power Amplifier

 

Specifications

Continuous Power Output (both channels driven)

From 20 Hz to 20 kHz :  2 x 70 W at 8 Ω 

At 1 kHz (T.H.D. 1%) :  2 x 85 W at 8 Ω ; 2 x 120 W at 4 Ω 

From 63 Hz to 12,5 kHz (T.H.D. 0,7%) :  2 x 80 W at 8 Ω  ; 2 x 105 W at 4 Ω

Total Harmonic Distortion (rated power at 20 Hz - 20 kHz):  0,01 at 8 Ω

Intermodulation Distortion (50 Hz : 7 kHz = 4 : 1 SMPTE):  0,007% at 8 Ω

Residual Hum and Noise:  0,3 mV

Damping Factor:  70 at 8 Ω ; 35 at 4 Ω 

Headphone Output Level/Impedance:  540 mV/330 Ω

Load Impedance

A or B, Bi Wiring :  4 - 16 Ω

A and B :  8 - 16 Ω

Input Sensitivity/Impedance:  1 V/33 k Ω

Signal-to-Noise Ratio (rated power at 4 Ω ):  95 dB (110 dB, IHF '66)

Frequency Response

Power Amp Direct :  5 Hz - 70 kHz (+0 -3 dB); 20 Hz - 20 kHz (+0 -0,5 dB)

Power Consumption:  280 W

Power Requirements:  AC 120 V, 220 - 240V 50/60 Hz

Dimensions (W x H x D):  430 x 136 x 344 mm (16-59/64" x 5-23/64" x 13-35/64")

Weight:  9,8 kg (21,6 lbs)

Conrad-Johnson MV125 power amp

Vaccum Tube Power Amplifier

The Conrad-Johnson MV125 offers an unparalleled level of sophistication and refinement in music reproduction, but it cannot transform an inferior stereo system. Only the very best loudspeaker systems will be capable of fully revealing the capabilities of this precision instrument. Proper set-up is important in any high-fidelity system, but with state-of-the-art components it is essential. Given a system of high quality components, there remain a number of important details which must be attended to.

 

Absolute Phase

Musical notes are heard through the ear’s response to waves of alternating rise and fall of air pressure. Musical transients are exclusively positive: that is, the initial effect is a rise in pressure. The ear is capable of distinguishing these positive transients from the musically unnatural alternative of a negative transient (an initial fall in air pressure). In your stereo system, these transients are created by your loudspeakers. If the speakers respond to musical transients by first moving out, they are creating a rise in pressure, and the system is said to be "phase correct". If they respond by moving in, they create a fall in pressure and the system is said to be "phase inverting". Each component in the stereo system is either phase correct or phase inverting (including the cartridge and speakers-these are normally phase correct). Your MV125 is phase correct. It is of no consequence if an individual component is phase inverting, as long as the system as a whole is phase correct. This will be the case as long as the number of phase inversions is even (or zero). If your system has an odd number of inversions, then you must add one phase inversion. This is conveniently done by reversing the positive and negative connections on either your cartridge or your speakers (be sure to reverse both channels).

 

Circuit Design

It has been our experience that simple designs with few active stages when executed with care and great attention to detail will be both more musical and more reliable than overcomplicated alternatives. Accordingly, the audio circuit of the MV125 is remarkably straightforward. A triode input amplifier comprised of paralleled sections of a 5751 is direct coupled to a cathode coupled differential phase inverter using high

current triodes to provide balanced, low impedance drive to the push-pull output stage. The output stage features ultralinear operation of two pairs of 6550s for high power levels with reduced source impedance. As a result, the amplifier is capable of supplying the large current demands of high amplitude musical transients driven into reactive speaker loads.

A substantial main power supply of massive polypropylene capacitors enables the MV125 to easily meet these extraordinary current demands. Voltage regulators for the voltage amplifiers and phase inverters provide nearly absolute isolation of these sensitive stages from the output stages.

 

The MV125 uses twelve vacuum tubes of three different types: two 5751 (V1 and V2), two 6FQ7 (V3 and V4) and eight 6550s (V5 through V12).

 

Specifications

Power:  125 watts per channel RMS both channels driven into 8 ohms from 30Hz to 15KHz at no more than 1% total harmonic distortion or intermodulation distortion.

Sensitivity:  880 mV to full power.

Small Siganal Distortion:  Less than .1% at midband

Phase:  Phase correct (non-inverting)

Frequency Response:  20 Hz to 20 kHz +0, -.5 dB

Hum and Noise:  96 dB below full power output.

Input Impedance:  100 K Ω 

Dimensions (W x H x D) : 19" x 20.5" x 8.75"

Weight: 80 lbs

 

Aiwa SA-P50 power amp

DC Stereo Power Amplifier

A high-efficiency power amplifier capable of unmistakably "full-sized" performance, the SA-P50 puts out a muscular 50 Watts per channel into 8 ohms, form 20 to 20,000 Hz, both channels driven, with no more than 0,03% Total Harmonic Distortion .

Coupling capacitors, a cause of phase distortion in the amplifier's negative feedback loop, have been eliminated. An FET in the first output stage and dual transistors in the second stage combine to form a 2-stage differential configuration having low distortion and superb temperature stability characteristics. Super linear transistors (SLPT) with an ultra high-speed frequency cut-off and ring emitter transistors in the final stage make up a pure complementary SEPP OCL circuit with exciting, low distortion reproduction at any output level. For stable power regulation essential for reproduction of dynamic musical passages, power supply is composed of a high-efficiency toroidal power transformer and two large capacity 15,00 µF electrolytic capacitors. A newly developed IC and relay function to suppress "pop" noises during On/Off switching; the self-resetting protection circuit also protects the power transistors from shorts in the output and speakers are isolated if potentially damaging DC is detected at speaker output terminals.

 

Features:

LED Power On indicator

9-point logarithmic peak power LED indicator (0,1 - 100 Watts)

A/B speaker system selector

Stereo headphone jack

One-touch speaker connection terminals

 

Specifications

Power Output:  50 watts per channel, Min. RMS at 8 Ω , from 20 Hz - 20 kHz, with no more than 0,03% T.H.D.

Total Harmonic Distortion :  0,01% ( 50 W, 8 Ω , 1 kHz)

Intermodulation Distortion:  0,01% (50 W, * Ω , 1 kHz)

Power Bandwidth:  10 Hz - 50 kHz (T.H.D. 0,05%)

Damping Factor:  40 at 1 kHz

Frequency Response:  10 Hz - 100 kHz (-3 dB)

Signal-to-Noise Ratio:  112 dB

Input Sensitivity/Impedance:  800 mV/ 47 k Ω

Output Terminals:

Speaker :  A/B (8 - 16 Ω ); A + B (16 Ω )

Headphone :  1 mW/1W, 8 Ω

Dimensions (W x H x D):  250 x 71 x 247,5 mm (9-7/8" x 2-13/16" x 9-3/4")

Weight:  5,4 kg (11,9 lbs)

 

McIntosh MC 2002 power amplifier

Power Amplifier. 

 The MC 2002 amplifier is designed for the Real world of 10 decibel overloads from compact disc players. It combines: 200 watts of extremely low distortion power at 8 ohms; 300 watts of the same power at 4 ohms. The greatest reliability in modern amplifiers to protect your investment. And most important today, design for 10 decibels of overload stress with the greatest Spectral Fidelity.

Spectral Fidelity is one of the most meaningful characteristics of an amplifier. The harmonic distortion and the two tone intermodulation measurements are important criteria in predicting the sonic performance. However to obtain better correlation with human hearing response, we need to know not only the energy in the distortion spectrum, but also the number of discords and their frequency spacing from the desired tones. This is what the Spectral Fidelity testing can do, enlarging the scope of the data and showing its meaning more fully.

Spectral Fidelity Protection

The threshold for human hearing shows a pronounced sensitivity in the region of 1500 Hz. At low levels of music, during pianissimo passages for example, is where we hear most intermodulation discords. But during the periods of sonic overload, this sensitivity characteristic changes. Under this condition, the sensitivity of the human ear becomes more uniform over most of the range of hearing. Thus all of the discords from sonic overload combine to reduce the musicality of instruments and voices, their clarity and definition. This loss of the order, the structure, and harmony, remebered from live musical experience, is frustrating and disappointing to the human psycho=physical hearing phenomenon. This frustration is the major cause of unacceptable  Listening Fatique.

Of all the amplifiers tested for Spectral Fidelity under stress, the McIntosh alone could accept the compact disc overload without exceeding 3/10 of 1% distortion. The others produced high levels of distortion, distortion from 20% to 30%. Some designs blew fuses. Others suffered output stage device failures.

 

Specifications

Power Output: 

Stereo :  200 watts into 8 Ω  loads or 300 watts into 4 Ω  loads is the minimum sine wave continuous average power output per channel for 20 Hz to 20,000 Hz with both channels operating, which is:

40,0 volts RMS across 8 oh or 34,6 volts RMS across 4 Ω

Mono :  600 watts into an 8 Ω  load, is the minimum sine wave continuous average power output from 20 Hz to 20,000 Hz, which is 69,3 volts RMS across 8 Ω

Output Load Impedance

Stereo :  4 Ω  to 8 Ω

Mono :  8 Ω  obtained by connecting across the output terminals of both channels

Rated Power Band:  20 Hz to 20,000 Hz

Total Harmonic Distortion

Stereo :  0,01% maximum harmonic distortion at any power level from 250 milliwatts to rated power per channel from 20 Hz to 20,000 Hz, both channels operating

Mono :  0,01% maximum harmonic distortion at any power level from 250 milliwatts to rated power from 20 Hz to 20,000 Hz

Intermodulation Distortion

Stereo :  0,01% maximum at any power level from 250 milliwatts to rated power with both channels operating, for any combination of frequencies from 20 Hz to 20,000 Hz

Mono :  0,01% maximum at any power level from 250 milliwatts to rated power for any combination of frequencies, 20 Hz to 20,000 Hz

Frequency Response (at 1 watt output):

20 Hz to 20,000 Hz  +0 -0,25 dB

10 Hz to 100,000 Hz +0 -3,0 dB

Hum and Noise:  100 dB below rated output 90 dB IHF

Ratings IHF Dynamic Headroom:

2,1 dB at 4 Ω  load

1,7 dB at 8 Ω  load

Damping Factor:  greater than 100

Input Impedance:  20,000 Ω

Input Sensitivity:  Switchable for either 1,4 Volt or 2,5 Volt

Power Requirements:  120 Volts, 50/60 Hz 0,6 to 15 ampers

Dimensions

Front Panel (W x H) :  411 mm x 181 mm (16-3/16" x 7-1/8")

Chassis :  375 x 165 x 368 mm (14-3/4" x 6-1/2" x 14-1/2")

Finish:  Front panel is anodized gold and black with special gold/teal nomenclature illumination. Chassis is black

Weight (net):  22,7 hg (50 pounds)