Yamaha CA-800 amplifier

Yamaha CA-800 stereo integrated amplifier offers, at a surprisingly agreeable features. Like the more expensive Yamaha CA-1000, the CA-800 has been created with emphasis on its primary function, that is to amplify the stereo signals from different program source components with the least possible distortion and without any other form of undesirable coloration. It accomplishes this objective by the use of a direct-coupled OCL complementary power amplifier, a plus/minus dual power supply system, a 3-stage direct-coupled tone control amplifier, and many other advanced features. You will note immediately that the CA-800 is designed with typical Yamaha attention to fine detail.

 

Direct-Coupled OCL Pure Complementary Stereo Power Amplifier for High Power and Low Distortion

The power amplifier of the CA-800 is the most advanced made today. This is the all-stage direct0coupled OCL pure complementary design which provides flat, linear amplification over an extremely wide bandwidth. Power for its operation is derived from an advanced plus/minus dual power supply system that combines an over-sized transformer and a pair of large 6,800 µF capacitors. Moreover, the power supply system drives all amplification stages, with the exception of the power amplifier, at a constant voltage. Such advanced design characteristics contribute greatly to the CA-800's low-range frequency response and stability, as well as to excellent performance specifications. These include RMS continuous power output of 45 watts per channel into 8 ohms, 20 - 20,000 Hz, both channels driven at 0,1 T.H.D., or 55 watts into 8 Ω , 1 kHz each channel driven, also at 0,1% T.H.D..pure, clean sound reproduction - quite enough to fill a large listening room - is only one solid reason to choose the CA-800.

 

Class-A Stereo Power Amplifier for Even Lower Distortion.

While the CA-800 is complete with a large stereo power amplifier of the Class-B operation like any other stereo amplifier available today, it also haas an exclusive feature; a switch to alter the circuit configuration of the power amplifier and convert it to a quality Class-A power amplifier. The difference is significant. A Class-B amplifier is a very effective design for transitor-type amplifiers, and delivers a high power output. A Class-A amplifier, in comparison, is less efficient, yet compensates for its inefficiency by virtually eliminating crossover distortion, which is the major source of distortion, which is the major source of distortion in the high frequency range for a transistor amplifier.

These figures underscore the importance of a Class-A amplifier; the RMS continuous power output is reduced to 10 watts per channel into 8 Ω , both channels driven at a T.H.D. of 0,1% over 20-20,000 Hz. That same distortion figure is reduced to 0,02% or less over 20 - 20,000 Hz at an output of one watt, or even to 0,015% - the very limit of the measuring instruments themselves - at 20 kHz at an output of 8 watts. Obviously, there is simply no better amplifier type to reproduce the transparent, delicate sounds of string instruments at a low volume level. Another conclusion is equally apt; the CA-800 is a most versatile stereo amplifier.

 

Four-Stage Direct-Coupled Phono Equalizer Amplifier for Transparent Tonal Quality

Since the phono equalizer enables the reproduction of the most popular source of music, the disc record, it is the key component of any hi-fi preamplifier, in the CA-800, this component is of the very highest quality, an advanced 4-stage direct-coupled amplifier employing selected low noise transistors. The virtures of this amplifier are three-fold; One; it is capable of handling a phono input signal of up to 310 mV, or approx. 100 times greater that what is required to drive it to the full output (input sensitivity is 3 mV). This capability is significant insomuch as that it practically exceeds the wide dynamic range offered these days by the latest and most advanced disc cutting techniques, as well as the new and improved pickup cartridges. Thus, you can be assured that every subtle shade of sound and every powerful burst of sound cut into your records will be reproduced without distortion. Secondly, the phono equalizer has an excellent Signal-to-Noise Ratio of 80 dB or better. This also contributes to the transparency of reproduced sound. Thirdly, absolute accuracy in the reproduction of stereo records is assured, since the phono equalizer provides an almost identical facsimile of the RIAA disc playback characteristics, keeping deviation from it to within a tolerance of ±0,2 dB.

 

Specifications

Power Output

Dynamic Power IHF

Class-B :  150 watts (4 Ω ); 130 watts (8 Ω )

Class-A :  20 watts (8 Ω )

Continuous RMS Power

Each Channel Driven at 1,000 Hz

Class-B :  70/70 watts (4 Ω ); 55/55 watts (8 Ω )

Class-A :  10/10 watts (8 Ω )

Both Channel Driven :   at 1,000 Hz

Class-B :  60 +60 watts (4 Ω ); 50 + 50 watts (8 Ω )

Class-A :  10 + 10 watts (8 Ω )

Both Channel Driven at 20 to 20,000 Hz

Class-B :  50 + 50 watts (4 Ω ); 45 + 45 watts (8 Ω )

Class-A : 10  + 10 watts (8 Ω )

Total Harmonic Distortion

Power Amplifier Only

Class -B :  less than 0,1% (at rated power): 0,04% (at 1 watt)

Class-A :  less than 0,1% (at rated power): 0,02% (at 1 watt)

Preamp Only Phono to Pre Out

Class-B :  less than 0,1% at rated power

Class-A :  less than 0,1% at rated power

Pream Only Aux to Pre Out :

Class-B :  less than 0,02% at rated power

Class-A :  less than 0,02% at rated power

Overall Aux to Power Output

Class-B :  less than 0,1% at rated power

Class-A :  less than 0,05% at rated power

Intermodulation Distortion (70 Hz : 7 kHz = 4 : 1 SMPTE method)

Power Amplifier Only

Class-B :  less than 0,1% (8 Ω ) at rated power

Class-A :  less than 0,1% (8 Ω ) at rated power

Power Amplifier Only

Class-B :  less than 0,05% (8 Ω ) at 1 watt

Class-A :  less than 0,05% (8 Ω ) at 1 watt

Overall (Aux to Power Output)

Class-B :  less than 0,1% (* Ω ) at rated output

Class-A :  less than 0,1% (8 Ω ) at rated output

Power bandwidth (IHF distortion 0,5% const)

Class-B :  5 to 70,000 Hz

Class-A ;  5 to 100,000 Hz

Load Impedance

Class-B :  4 to 160

Class-A :  (4 ) to 8 to 160

Damping Factor (8 Ω )

Class-B :  70 at 1,000 Hz

Class-A :  70 at 1,000 Hz

Frequency Response (at 1 watt)

Overal Tuner, Aux, Tape Power Bandwidth to Power Output:  10 to 50,000 Hz +0,5 dB -1 dB

Overall Mic to Power Output :  20 to 20,000 Hz +0,5 dB -2 dB

Power Amplifier Only :  10 to 100,000 Hz +0 dB -1 dB

Deviation from RIAA :  30 to 15,000 Hz +0,2 dB -0,2 dB

Channel Separation ( at rated power, 1,000 Hz)

Power Amplifier Only :  better than 60 dB

Overall from Phono 1, 2 :  better than 50 dB

Overall from Tuner, Aux, Tape Pb :  better than 50 dB

Overall from Mic :  better than 50 dB

Hum and Noise (IHF, Closed circuit A Network)

Overall from Phono 1, 2 :  better than 80 dB

Overall from Mic :  better than 70 dB

Overall from Tuner, Aux, Tape Pb :  better than 90 dB

Power Amplifier Only :  better than 100 dB

Volume at Minimum :  better than 90 dB

Input Sensitivity/Impedance (at rated power, 1,000 Hz)

Phono 1 :  3 mV/30 k Ω , 50 k Ω , 100 k Ω

Phono 2 :  3 mV/50 k Ω

Phono 1, 2 Max. Input Capability :  310 mV (T.H.D. 0,1%)

Mic :  2,5 mV/ 50 k Ω

Mic Max. Input Capability :  245 mV (T.H.D. 0,1%)

Tuner , Aux 1,2 :  120 mV/40 k Ω

Tape Pb A, B :  120 mV/40 k Ω

Power Amplifier Input  :  775 mV/ 40 k Ω , 345 k Ω (Class-A)

Output Level / Impedance (at rated power, 1,000 Hz)

Tape Rec Out A, B ;  120 mV/ 2 k Ω

Pre Out :  775 mV/ 2 k Ω ; 3,000 mV (Max. Output T.H.D. 0,1%)

Tone Controls

Bass :  ±15 dB at 50 Hz

Treble :  ±10 dB at 10 kHz

Filters

Low :  -3 dB at 20 Hz, 70 Hz (12 dB/oct)

High :  -3 dB at 6 kHz ; 12 kHz (6 dB/oct)

Loudness Control (Continuous Loudness Vol. At Minimum):  +10 dB at 100 Hz; +5 dB at 10 kHz

General

Semiconductors:  2 FETs; 49 Transistors; 12 Diodes; 4 Zener Diodes

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

Pc :  300 watts Max; 190 watts Rated

AC Outlets :  2 x Switched; 2 x Unswitched

Dimensions (W x H x D):  436 x 144 x 323 mm (17-1/4" x 5-3/4" x 12-3/4")

Weight:  13,5 kg (29,7 lbs)