HITACHI HMA-8500MKII / HCA-8500MKII (JAPAN 1981)
The HITACHI HMA-8500 MkII was introduced in 1981 and was the last model in a long series of MOSFET power amplifiers by HITACHI (Lo-D in Japan) It is a high quality MOSFET class AB stereo power amplifier that work on principals similar to vacuum tubes rather than bipolar transistors. It's a real dual-mono design with two power transformers and two sets of rectifiers and capacitors. This amplifier runs hot and sounds great. Technical data: 100 W/ch (continuous 8 ohm 20-20,000 Hz with no more than 0.005 THD) Dimensions: 435x165x320 mm.
TRIO KENWOOD 700 Line (JAPAN 1973)
Formed in 1946, the Trio Corporation has gained an enviable reputation for its development and manufacture of high-class equipment. For those sophisticated audiophiles who can appreciate the 0.0024% tuning accuracy of the 700T Frequency Synthesizing Tuner ... the exceptional control flexibility of the 700C Preamplifier-Control ... the masterful power of the 700M Main Amplifier with its incredible 170 watts per channel Min. RMS (at 8 ohms, 20 to 20,000 Hz with no more than 0.1% total harmonic distortion) ... Trio-Kenwood proudly presents the 700 Series. Each boasts technical specifications well beyond any previous efforts. Each incorporates the most advanced electronics, the most imaginative design concepts. Together they go beyond state-of-the-art performance and come closer to realizing total fidelity by producing a range of realistically priced high-grade equipment that is among the best on the world market. During its 6 years of manufacturing the 700 Series was sold under TRIO, TRIO Supreme and KENWOOD badges. Priced approximately 2150 USD (1975)
LUXMAN C-05 / M-05 (JAPAN 1982)
Over the years, Luxman's strength in engineering excellence has always been most evident in amplifier design. The M-05 represented the latest in electronic technology in 1982 from Luxman and it contains the most current circuit designs, including Duo-Beta with single-stage amplification and L.E.D. bias circuitry. The M-05 utilize discrete output transistors and maintain high dynamic power even into low impedance loads.
The top-of-the-line M-05 is a pure class "A" configuration and sonically ranks with the finest amplifiers in the world. A slim but effective power transformer with outstanding regulation is newly designed for this high-quality separate, which ensure long-lasting, stabilized performance in combination with the select capacitors specially developed for audio use. Especially, the power transformer employed this time offers far better efficiency than those with the conventional EI core, which makes it possible to reproduce solid bass sound.
Unprecedented speedy attack and decay are given in the actual auditory feelings thanks to our unique bias current circuit employing LED's in lieu of normal diodes. In fact, the LED provides very sharp rise and decay in the statics when compared with silicon diode, and therefore ensures stable bias power supply. In addition, it is possible to cope with even an unexpected, sudden fluctuation due to its inherent high-speed response. Furthermore, the inter-terminal voltage per LED is higher than that of diode in general, and to share the same voltage the smaller number of LED's will do in comparison with that of diode. Thus, the response speed as well as the decay and rise characteristics show multiple effect, providing conspicuous improvement in the auditory feelings. Unexperienced pure sound is now unveiled.
The top-of-the-line M-05 is a pure class "A" configuration and sonically ranks with the finest amplifiers in the world. A slim but effective power transformer with outstanding regulation is newly designed for this high-quality separate, which ensure long-lasting, stabilized performance in combination with the select capacitors specially developed for audio use. Especially, the power transformer employed this time offers far better efficiency than those with the conventional EI core, which makes it possible to reproduce solid bass sound.
Unprecedented speedy attack and decay are given in the actual auditory feelings thanks to our unique bias current circuit employing LED's in lieu of normal diodes. In fact, the LED provides very sharp rise and decay in the statics when compared with silicon diode, and therefore ensures stable bias power supply. In addition, it is possible to cope with even an unexpected, sudden fluctuation due to its inherent high-speed response. Furthermore, the inter-terminal voltage per LED is higher than that of diode in general, and to share the same voltage the smaller number of LED's will do in comparison with that of diode. Thus, the response speed as well as the decay and rise characteristics show multiple effect, providing conspicuous improvement in the auditory feelings. Unexperienced pure sound is now unveiled.
Specifications:
Power Output (from 20 Hz to 20 kHz) - 105 W per Channel at 8 Ohms - 210 W per Channel at 4 Ohms Dynamic Power (1 kHz, IHF Signal): - 400 W BTL at 8 Ohms Total Harmonic Distortion: less than 0,025% Frequency Response: 10 Hz to 100 kHz (-0,5 dB) Signal-to-Noise Ratio: greater than 120 dB Dimensions (W x Hx D): 461 x 210 x 440 mm Weight: 39,8 kg |
Sansui BA-3000 (JAPAN 1975)
Uncompromising. When a musical performance must be reproduced to the most critical standards, The Definition Series from Sansui can deliver flawlessly the entire audio spectrum. The Sansui BA-3000 has all the design features of the Definition Series, with a power output of 170 watts per channel, minimum RMS, both channels driven into 8 ohms over a 20 to 20,000Hz bandwidth, with no more than 0,05 % total harmonic distortion; 340 watts, minimum RMS in mono. Features include: Four jumbo heat sinks coupled directly to the power transistors eliminate the need for a cooling fan. LED Power/Protector indicator on front panel glows red when power is switched on, turns green to indicate safe operation; turns red to warn of potentially harmful conditions. BA-3000 has all the safety features, subsonic filters and distortion-free toroidal coil winding power transformer. The Sansui CA-3000 is a stereo control preamplifier featuring advanced space-age design in every link of the circuit chain, for unprecedented accuracy. It has RIAA ± 0.2dB Equalization which is capable of meeting all the strenuous demands of contemporary disc recordings which feature extremely wide dynamic range. The CA-3000 handles an extremely wide frequency response covering all musical signals with low distortion, no clipping or noise. Features include: High input impedance and low output impedance, through newly-developed unit amplifier circuits: a differential amplifier at input, and an emitter-follower or SEPP buffer amplifier at output. Phono equalizer features a packed differential dual FET amplifier (with a matched pair of low-noise FET's) at the initial stage, and Class-A complementary SEPP amp at output. Full controls and connections for any combination you're likely to need.
Specifications
Power output: 170 watts per channel into 8Ω (stereo), 340 watts into 8Ω (mono)
Frequency response: 5Hz to 100kHz
Total harmonic distortion: 0.05%
Damping factor: 100
Input sensitivity: 0.7V
Signal to noise ratio: 100dB
Speaker load impedance: 4Ω to 16Ω
Dimensions: 460 x 178 x 400mm
Weight: 22.6kg
Original sale price: 3600 DM Germany
Specifications
Power output: 170 watts per channel into 8Ω (stereo), 340 watts into 8Ω (mono)
Frequency response: 5Hz to 100kHz
Total harmonic distortion: 0.05%
Damping factor: 100
Input sensitivity: 0.7V
Signal to noise ratio: 100dB
Speaker load impedance: 4Ω to 16Ω
Dimensions: 460 x 178 x 400mm
Weight: 22.6kg
Original sale price: 3600 DM Germany
Technics SE-A3 / SU-A4 (JAPAN 1980)
The Technics SE-A3 power amplifier introduced in 1980 employs a New Class A circuitry that makes it something special. New Class A is a unique Technics design that provides the distortion-free fidelity of class A amplifiers and the high-power efficiency of class B (or AB) amplifiers. The SE-A3 delivers a rated output of 200 watts per channel, both channels driven into 8 ohms, with no more than 0.002% total harmonic distortion from 20 to 20,000 Hz. Signal-to-noise ratio is 123 dB (IHF '66) and TIM is so low that it is unmeasurable. Although these specifications speak for themselves, the New Class A circuitry eliminates the switching distortion and crossover distortion that are characteristic of conventional amplifiers with the use of the original "synchro bias" circuit. To eliminate chances of cross-channel interference the SE-A3 is equipped with separate transformers for the left and right stereo channels.
To complement the overall aesthetics this power amplifier uses large Peak Power Meters that have an attack time of only 50us and give direct readings from 0.0001W to full power. We can almost consider this, a Technics trademark. Unfortunately, rumor is that there are two types of Technics SE-A3, one that is broken while the other one will be soon broken. The good news however is that the special DLPT symmetrical configuration dual transistors can be replaced with two independent Toshiba power transistors.
To complement the overall aesthetics this power amplifier uses large Peak Power Meters that have an attack time of only 50us and give direct readings from 0.0001W to full power. We can almost consider this, a Technics trademark. Unfortunately, rumor is that there are two types of Technics SE-A3, one that is broken while the other one will be soon broken. The good news however is that the special DLPT symmetrical configuration dual transistors can be replaced with two independent Toshiba power transistors.
Technics SE-A100 / SU-A200 (JAPAN 1985)
The Class AA circuitry drove the voltage control amp and current drive amp separately. This isolated the voltage control amp from the current supply source, resulting in faithful voltage control according to the input signal as well as reduced distortion. The current drive amp stably supplied the electric current necessary for driving the speakers, thus maximizing its superb speaker drive capability. Two control amps and two current drive amps were provided for each channel. These four amps configured the VC-4 amplifier system. In addition, the completely symmetrical construction eliminated the mutual interference of the left and right channels. Other features included a power supply transformer with oxygen-free copper wires, a three-layer magnetic shielding case and large power meter for direct reading of 0.0001 W to 300 W. Technical data: 170 W/ch 8 ohm 20Hz-20kHz, THD 0.0007%, 430x209x475 mm (SE-A100) 31.2 kg.
YAMAHA B-6 (JAPAN 1980)
Rare (truncated) pyramid shaped stereo power amplifier from Yamaha. At the heart of the Yamaha B-6 from 1980 is the so called "X-Amp" scheme. Initially known as "X-Power", this power scheme was first used in the Benytone X-Calibre lineup and the Carver lineup they were building at this time. It seems that Yamaha, as a later adopter, for some reason didn't implemented fully the Benytone/Carver technology so it was renamed "X-Amp". Basically, this system is using a TRIAC which switches between high or low power supplies according to the input signal and output needs. This results in increased output power capacity, but some say that it is not necessarily a good sound too. (200 W/ch 8Ohm, THD: 0,003%, 10-100.000 Hz, 29 x 17,65 x 29 cm, 9,2 kg) As a long time Yamaha collaborator the design is signed by the GK Design Group.
PIONEER C-90 / M-90 (JAPAN 1986)
The PIONEER M-90 power amplifier was introduced in 1986. It features two outsize transformers (one for each channel), large electrolytic capacitors (for a total capacitance of 48000 microfarad), four bridged rectifier circuits using fast-recovering diodes and 16 power transistors (8 per channel) in a "four-in-parallel" configuration. The amplifier can deliver a dynamic power of 800 watts at 2 ohms (with EIA dynamic test signal) The aluminium front panel with a deep lacquer-like finish incorporates the switchable fluorescent power output indicators. Continuous Power Output: 200 W/ch (20-20000 Hz T.H.D. 0.003%, 8 ohms)
Dimensions: 457x154x430 mm Weight 20.4 kg
Dimensions: 457x154x430 mm Weight 20.4 kg
SANSUI C-2301 / B-2301 (JAPAN 1983)
The Sansui C-2301 pre-amplifier and Sansui B-2301 power amplifier were introduced in 1983 and manufactured until 1991. Sansui introduced the X-Balanced Amp technology, a new design which prevents ground-related problems such as IHM distortion. In it, all circuits are balanced - from input through power supply and negative feedback to output - thus providing extraordinarily pure and clean sound. Technical data: 300 W/ch min. RMS 8 ohms from 20 to 20,000 Hz with no more than 0.003% total harmonic distortion. Dimensions 474x215x500 mm Weight 37 kg
YAMAHA M-85 / C-85 (JAPAN 1986)
The M-85 is Yamaha's finest Natural Sound power amplifier, offering massive output power and extreme reproduction purity for the discriminating audiophile. It delivers an astounding 250 watts of power per channel into an 8 ohm load with a mere 0.003% THD. In short, the M-85 offers power to suit any listening requirement. Further, Auto Class A Power and Zero Distortion Rule circuitry make this one of the cleanest sounding amplifiers available. Regardless of the type of music you enjoy - rock, jazz, classical, or anything in between - the M-85 responds with dynamic power on demand, making the most of today's dynamic audio sources. It is capable of driving up to three speaker pairs independently, simultaneously, or in any combination of two. You'll appreciate its heavy-duty speaker connection terminals, wide-range LED peak power level meters, meter display load selector, meter Peak Hold and Range selectors, and full overload protection circuitry. The M-85 is an outstanding achievement in power amplifier design.
DENON POA-3000RG / PRA-2000RG (JAPAN 1991)
The first model of the PRA-2000 / POA-3000 series from DENON was introduced in may 1979. Production has continued for 14 years and the 4th generation, the PRA-2000RG / POA-3000RG, were manufactured until 1993. This power amplifier used a DENON proprietary technology called "MOS Super Optical Class A Circuit" This new inverted-Darlington connection in the driver stage allows a flow of bias current 10 times higher than the previous DENON Optical Class A circuit. Supporting this optical power amplifier is "optical coupling" which transmits the control signal from the bias control circuit to the bias circuit. By using the optical element, the interference between the main signal system and the bias control circuit is completely eliminated, and the bias control is realized at high speed. The amplifier delivers 250 W/ch in Stereo mode while the power increases to 500W when switched to mono operation. For the power section a large toroidal transformer is used with large power source capacitors. Current is independently supplied to the power stage and the pre-driver stage, all this through a complete dual mono construction.
Rated output
STEREO: 250 W + 250 W (8 Ohm, THD: 0.05%), 400 W + 400 W (4 Ohm, THD: 0.1%)
MONAURAL: 500 W (8 Ohm, THD: 0.05%), 800 W (4 Ohm, THD: 0.1%)
Total harmonic distortion rate: STEREO: 0.005% (20 Hz to 20 kHz, 8 Ohm, -3 dB)
Intermodulation distortion: 0.003% or less (7 kHz / 60 Hz = 1/4, 8 ohms)
Output bandwidth: STEREO / MONO: 5 Hz to 50 kHz (THD: 0.05%, 8 Ohm, -3 dB)
Frequency characteristic: STEREO / MONO: 1 Hz to 100 kHz (8 ohm, 1 W output)
Dimensions: 495 (W) x 200 (H) x 490 (D) mm (including knobs, leg height)
Weight: 35.5 kg
Rated output
STEREO: 250 W + 250 W (8 Ohm, THD: 0.05%), 400 W + 400 W (4 Ohm, THD: 0.1%)
MONAURAL: 500 W (8 Ohm, THD: 0.05%), 800 W (4 Ohm, THD: 0.1%)
Total harmonic distortion rate: STEREO: 0.005% (20 Hz to 20 kHz, 8 Ohm, -3 dB)
Intermodulation distortion: 0.003% or less (7 kHz / 60 Hz = 1/4, 8 ohms)
Output bandwidth: STEREO / MONO: 5 Hz to 50 kHz (THD: 0.05%, 8 Ohm, -3 dB)
Frequency characteristic: STEREO / MONO: 1 Hz to 100 kHz (8 ohm, 1 W output)
Dimensions: 495 (W) x 200 (H) x 490 (D) mm (including knobs, leg height)
Weight: 35.5 kg
EXCLUSIVE by PIONEER M3 / C3 (JAPAN 1973)
The "soul of audio" combined with the advanced art of high-fidelity electronics is behind the unique concept of the EXCLUSIVE M3 stereo power amplifier by Pioneer. Analyses of both the "dynamic" and the "pulsive" characteristics of audio were studied carefully in the creation of the M3. These include transient response, crossover distortion and many other critical aspects of performance. Such static characteristics as power bandwidth and frequency response were also closely examined. The results are as brilliant as they are daring.
To illustrate, consider the problem of providing stability versus the question of assuring wide frequency response and minimum distortion. Pioneer designed an entirely new type of circuit for the M3 to achieve both: it features the reliable circuit design and high-quality parts for stability, yet allows a small amount of negative feedback to be applied to improve frequency response and assure low-distortion performance. Sophisticated features like peak-power level meters, a front sub-panel providing access to speaker selector and function of the M3. Individual technical-data sheets giving the exact test information for each unit is packed with every M3 as it leaves the Pioneer factory. The EXLUSIVE M3 is the perfect blend of technology and musicality, the stereo amplifier you can depend on to deliver the "soul of audio" without compromise. As a quality power amplifier for musical reproduction, the M3 has no peer. It offers you RMS 150 watts+150 watts of continuous power (both channels driven at 8 ohms) within critical 20-20,000 Hz frequency range, with both harmonic and intermodulation distortion held to less than 0.1%. There are two large, very precise peak power level meters on the front panel of the M3. The peak transient levels as high as 20dB contained in any audio signal are indicated instantly and accurately. Compared with ordinary VU meters, the power indication range of this peak meter is exceedingly wide: 0.01W to 200W on a logarithmic compression scale, operating from built-in circuits, thus, you can read the power level without changing meter sensitivity.
To illustrate, consider the problem of providing stability versus the question of assuring wide frequency response and minimum distortion. Pioneer designed an entirely new type of circuit for the M3 to achieve both: it features the reliable circuit design and high-quality parts for stability, yet allows a small amount of negative feedback to be applied to improve frequency response and assure low-distortion performance. Sophisticated features like peak-power level meters, a front sub-panel providing access to speaker selector and function of the M3. Individual technical-data sheets giving the exact test information for each unit is packed with every M3 as it leaves the Pioneer factory. The EXLUSIVE M3 is the perfect blend of technology and musicality, the stereo amplifier you can depend on to deliver the "soul of audio" without compromise. As a quality power amplifier for musical reproduction, the M3 has no peer. It offers you RMS 150 watts+150 watts of continuous power (both channels driven at 8 ohms) within critical 20-20,000 Hz frequency range, with both harmonic and intermodulation distortion held to less than 0.1%. There are two large, very precise peak power level meters on the front panel of the M3. The peak transient levels as high as 20dB contained in any audio signal are indicated instantly and accurately. Compared with ordinary VU meters, the power indication range of this peak meter is exceedingly wide: 0.01W to 200W on a logarithmic compression scale, operating from built-in circuits, thus, you can read the power level without changing meter sensitivity.
SONY TA-N77ES / TA-E77ESD (JAPAN 1988)
Introduced in 1988 the SONY TA-N77ES was the only power amplifier ever from SONY to support large VU meters as a visual element.
Power amplifiers are usually tested when hooked up to 8-ohm laboratory resistors. While results may look fine on a spec sheet, they simply ignore an undeniable fact. Real loudspeakers - even those nominally rated at 8 ohms - simply refuse to behave like laboratory resistors. While the resistor presents a simple impedance that's constant at all audio frequencies, the speaker presents a complex impedance that varies dramatically. A typical "8-ohm" loudspeaker can have impedance peaks higher than 30 ohms and impedance dips lower than 3 ohms! And here's the catch: as impedance drops, more and more current is demanded from the amplifier. Thanks to large power transformers, generous power supplies, big output transistors and massive heat sinks, the SONY TA-N77ES produce this current in casual disregard of loads. In preference to inexpensive integrated circuit "power packs" SONY ES insists on individual (discrete) output transistors. Sony's carefully-selected discrete transistors cost more, but their enhanced cooling, proven reliability and superior frequency response make them more than worth the cost. To reduce resonance and vibration Sony used a G-Base made of calcium carbonate reinforced with glass fibers, a unique compound similar in composition to marble. To accompany the SONY TA-N77ES power amplifier there were two remote controlled preamplifiers, the SONY TA-E77ES and the TA-E77ESD with added Digital inputs. Technical data: 200 W/ch 20-20,000 Hz 8 ohm THD 0.004% Dimensions: 470 W x 185 H x 440 D mm, Weight: 25 kg.
Power amplifiers are usually tested when hooked up to 8-ohm laboratory resistors. While results may look fine on a spec sheet, they simply ignore an undeniable fact. Real loudspeakers - even those nominally rated at 8 ohms - simply refuse to behave like laboratory resistors. While the resistor presents a simple impedance that's constant at all audio frequencies, the speaker presents a complex impedance that varies dramatically. A typical "8-ohm" loudspeaker can have impedance peaks higher than 30 ohms and impedance dips lower than 3 ohms! And here's the catch: as impedance drops, more and more current is demanded from the amplifier. Thanks to large power transformers, generous power supplies, big output transistors and massive heat sinks, the SONY TA-N77ES produce this current in casual disregard of loads. In preference to inexpensive integrated circuit "power packs" SONY ES insists on individual (discrete) output transistors. Sony's carefully-selected discrete transistors cost more, but their enhanced cooling, proven reliability and superior frequency response make them more than worth the cost. To reduce resonance and vibration Sony used a G-Base made of calcium carbonate reinforced with glass fibers, a unique compound similar in composition to marble. To accompany the SONY TA-N77ES power amplifier there were two remote controlled preamplifiers, the SONY TA-E77ES and the TA-E77ESD with added Digital inputs. Technical data: 200 W/ch 20-20,000 Hz 8 ohm THD 0.004% Dimensions: 470 W x 185 H x 440 D mm, Weight: 25 kg.
Technics SU-C3000 / SE-A3000 (JAPAN 1998)
The Technics SU-C3000 pre-amplifier and SE-A3000 power amplifier were introduced in 1999. The preamplifier uses a so called "Variable Gain Control" volume control for minimum noise and 124 dB signal to noise ratio while the unit is battery operated. The preamplifier features two Pre-Output for two power amplifiers. The power amplifier uses a dual-mono construction and can be used in Bi-Amp mode. Technical data: 100 W/ch RMS, 8 ohm, 20-20,000 Hz. THD 0.01% Dimensions: 453x186x441 mm (SE-A3000)
Victor (JVC) M-L10 / P-L10 (JAPAN 1981)
The Victor (JVC) M-L10 power amplifier was introduced in 1981 and was based on the earlier Laboratory Series M-7050 from 1979. The power amplifier is based on the high efficiency class A operation method called "Super A" with zero switching noise. The output stage transistors operate at a constant voltage, only the current is changed, and the whole stage adopts a cascade circuit construction. A distinctive (21 step lacquering) mirror finish real wood cabinet is used for both the pre-amplifier and power amplifier. This beautiful Laboratory Series amplifier combo was sold under the Victor brand name in Japan while worldwide it was sold as JVC. Technical data: 160 W/ch (RMS, 8 Ohm, 20Hz-20Khz, 0.002%THD), Dimensions: 46*20.35*41.75, Weight: 28 kg