McIntosh C-28

 McIntosh engineers could not be content with just another preamplifier. New concepts and new technology have produced a preamplifier that gives you the greatest flexibility ever. Look at the great number of ways you can enjoy the C 28 .......

Use 3 tape machines 2 with their own electronics and 1 tape playback deck with complete easy front panel switching Built-in Headphone Amplifier listen to your favorite music - - - privately.

Main and Remote Loudspeaker Switching turn the main speakers on or off without affecting the remote speakers and vice versa (operates with accessory relay).

New Low Noise Phono Input listen to your records with a new quietness.

Individual Channel Phono Level Controls match levels from different phono cartridges without degrading signal to noise ratio.

Individual Channel Output Level Controls perfect balance from your stereo always.

Individual Channel Tone Control Switches complete, repeatable flexibility.

NEW Compensation Control one position for loudness compensation, one position is flat and (NEW) a third position that adds presence compensation!

 NEW LOW NOISE PHONO CIRCUITS

New records and tapes with greatly increased dynamic range demanded new low noise circuits. McIntosh scientists developed a new DIFFERENTIAL INPUT CIRCUIT that reduced phono input noise levels from approximately 2.4 microvolts in an excellent preamplifier to a new level of only 1.2 microvolts! The differential input circuit has only been used in very sensitive professional test equipment and in medico-electronics. The preamplifier will not overload or change distortion for any phono input signal from 2 millivolts up to 500 millivolts. This represents a dynamic range of approximately 3000 to 1 on a voltage basis. This fantastic improvement necessitated extreme care in layout and manufacturing. The signal circuits need careful shielding and wiring with coaxial cable to prevent noise and crosstalk in the preamplifier from destroying the low noise of the input circuit.

 NEW TAPE FLEXIBILITY

With the C 28 you can copy from one tape recorder to another while listening to a completely different program! In addition, you can monitor the recording by simply pushing a button and an input circuit has been provided to accept the signal from a tape playback deck. You can use three tape machines with the C 28. There are front panel jacks that permit the use of the third tape recorder. When plugged into the front panel jacks the tape recorder connected to Tape Recorder 2 is automatically disconnected and the controls provided are used with the third tape recorder.

 NEW HEADPHONE AMPLIFIER

Use your headphones for private listening. Ample power has been provided to power todays high quality low impedance dynamic headphones, plus a separate power switch in the preamplifier turns the power amplifiers on or off. It is not necessary to operate the power amplifiers while listening to headphones.

FACILITIES AND FEATURES

BASS CONTROLS:

11 position rotary switch in each channel, ± 20 dB at 20 Hz.

TREBLE CONTROLS:

11 position rotary switch in each channel, ± 18 dB at 20,000 Hz.

COMPENSATION SWITCH:

Three position switch for Flat, Loudness, or Presence.

Loudness position boosts low frequencies for low level

listening. Presence position boosts mid frequencies 4 dB to increase "presence" effect.

VOLUME CONTROL:

AC power ON/OFF switch is coupled with this control.

MODE SELECTOR (Seven positions): Left channel only to both speakers, Right channel only to both speakers. Stereo Reverse, Stereo,

Mono, L + R to left speaker only, and L + R to right speaker only.

TAPE MONITOR SWITCHES:

Either of two tape recorders can be monitored by use of either the TAPE 1 or TAPE 2 pushbutton.

TAPE COPY SWITCH:

Provides switching to copy from tape machine 1 to tape machine 2 or vice versa without affecting the program being heard.

LF FILTER SWITCH (Rumble Filter):

Flat or roll-off at 12 dB per octave below 50 Hz, down

18 dB at 20 Hz.

HF FILTER SWITCH (Scratch Filter):

Flat or roll-off at 12 dB per octave above 7,000 Hz, down 18 dB at 20,000 Hz.

SPEAKER SWITCHES (Operates with accessory relay):

Turn the main speakers on or off without affecting the remote speakers and vice versa.

HEADPHONE JACK:

Power to this jack is supplied by an amplifier provided in the C 28.

LOW FREQUENCY TRIM CONTROLS:

Use to compensate for unequal speaker response or the unequal influence of room acoustics.

PHONO 1 AND PHONO 2 LEVEL CONTROLS:

Provides for optimum signal to noise ratio and proper balance of the channels of the phono cartridge.

OUTPUT LEVEL CONTROLS:

Permits presetting the balance of the entire system.

HEADPHONE LEVEL CONTROLS:

Adjusts the output of the headphone/line amplifier output.

TRANSISTOR COMPLEMENT:

26 silicon-planar transistors, 4 silicon diodes, 2 silicon bridge rectifiers.

Specifications

FREQUENCY RESPONSE:  +0-0.5 dB 20 Hz to 20,000 Hz

DISTORTION:  Will not exceed 0.1% at rated output level, 20 Hz to 20,000 Hz.

INPUT SENSITIVITY AND IMPEDANCE: 

Aux, Tuner, Tape 1, Tape 2 : 0.25 volts / 250,000 ohms.

Phono 1 and Phono 2 : 2 millivolts / 47,000 ohms (1,000 Hz).

Microphone : 2.5 millivolts / 500,000 ohms.

Tape Head : 2 millivolts / 500,000 ohms (500 Hz).

HUM AND NOISE:

Aux, Tuner, Tape 1, Tape 2 : 90 dB below rated output.

Phono 1, Phono 2 and Tape Head : 78 dB below 10 millivolts input, equivalent to less than 1.2 microvolts at the input terminals. Microphone : equivalent to less than 1.5 microvolts at the input terminals.

OUTPUT LEVEL AND IMPEDANCE:

Main Output : 2.5 volts with rated input, 100 ohms source impedance, to operate into 47,000 ohms or more.

Tape Output : 0.25 volts, 150 ohms source impedance, from low level inputs, to operate into 47,000 ohms or more.

Headphone/Line Output : 0.75 volts into 8 ohm load or 2.5 volts into 600 ohm line, 0.2 ohm source impedance,

Center Channel Output : 1.25 volts with rated input to both channels, to operate into 47,000 ohms or greater.

AMPLIFICATION IN DECIBELS:

Aux, Tuner, Tape 1 and 2:

to Main Output : 20 dB;

to Tape Output : 0 dB;

to Headphone/Line Output : 17.5 dB.

Phono 1 and Phono 2 at 1,000 Hz:

to Main Output : 62 dB;

to Tape Output : 42 dB;

to Headphone/Line Output : 59.5 dB.

Microphone:

to Main Output : 60dB;

to Tape Output : 40 dB;

to Headphone/Line Output : 57.5 dB.

Tape Head at 500 Hz:

to Main Output : 64 dB;

to Tape Output : 44 dB:

to Headphone/Line Output : 61.5 dB.

POWER REQUIREMENT:  120 volts, 50/60 Hz, 45 watts.

DIMENSIONS:  Front panel measures 16 inches wide (40.64 cm) by 5-7/16 inches high (13.81 cm). Chassis measures 15 inches wide (38.1 cm] by 5 inches high (12.7 cm) by 13 inches deep (33.02 cm) including PANLOC mounting brackets and back panel connectors. Knob clearance required is 1-1/2 inches (3.81 cm) in front of the mounting panel.

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

MOUNTING:  Exclusive Mclntosh developed professional PANLOC.

WEIGHT:  25 pounds (11.34 kg) net, 37 pounds (16.78 kg) in shipping carton.

Marantz 2325

Tuner Section

Steep Quieting Slope

The quieting slope specification measures a tuner's ability to provide good signal-to-noise performance under actual operating conditions. it's a far more reliable indication of performance quality than the IHF (Institute of High Fidelity) sensitivity figure often quoted as the prime specification to consider when evaluating an FM tuner.

The IHF figure gives only the number of microvolts necessary for minimum quality reception. A signal with 3% distortion and noise (30 dB quieting) hardly qualities as high fidelity. A signal-to-noise ratio in excess of 50 dB (the revised 1975 IHF specification) is generally recognized  to be necessary for high quality listening. It is most important then, to examine a receiver's ability to quiet quickly beyond the 30 dB quieting point.

Quieting slope sensitivity figures measure the signal-to-noise ratio in the crucial five to 500 microvolt range, where the majority of usable broadcast signals fall. The steeper the slope, the quieter, and therefore the more listenable the station.

 Highly Sensitive and Selective RF Front End

Superior selectivity is assured by a five-gang tuning capacitor in the Marantz 2325 and 2275 and four-gang in the 2250B. A triple-tuned RF interstage on Models 2325 and 2275 and a dual-tuned RF interstage on Model 2250B provide excellent image and spurious response rejection.

Marantz FET RF amplifiers and mixer stages provide excellent spurious signal rejection and extremely low noise operation that results in excellent quieting sensitivity.

 Phase Loced Loop FM Stereo Demodulator

The Phase Locked Loop (PLL) design was developed originally to provide  a state-of-the-art communication system for the space industry. Today  the same technology is used in all Marantz tuners and receivers to assure you of low distortion,excellent stereo separation and superior noise rejection.

PLL circuitry positively locks to the stereo pilot signal broadcast by a FM station. This precise "phase lock" is absolutely necessary for high performance in the stereo demodulation process. It enables the multiplex demodulator to separate the stereo channel information from the FM multiplex signal with more accuracy and less distortion than multiplex demodulators using other designs.

In addition, PLL is dependent on pilot phase and not on pilot amplitude, making it less susceptible to false triggering from various types of noise interference.

Ceramic IF Filters

The performance of an FM tuner is determined to a great extent by the performance of its Intermediate Frequency (IF) amplifier. The ideal IF amplifier should accept the desired band of frequencies with minimum phase distortion, while rejecting all adjacent frequency signals.

Marantz stereo receivers feature IF amplifiers consisting of ceramic filters, whose characteristics produce a 200 kHz passband that's linear in phase. This eliminates a major source of high frequency distortion and of loss of stereo separation. Sharp cut-off slopes improve the tuner's rejection and selectivity characteristics, permitting clear reception even when stations are closely spaced.

 Positive FM Muting

FM tuning is made completely noise-free by a special parametric-type muting circuit. The circuit responds to three characteristics of the FM signal: RF noise level, RF signal strength and DC offset at the ratio detector, thus assuring positive muting of the audio signal even under the most adverse conditions.

 FM Dolby De-Emphasis Network

Today there are more than 100 FM stations throughout the U.S. broadcasting with a Dolby Noise Reduction System, and others are sure to follow. To help you recieve the clean, quiet FM reception promised by these Dolbyized broadcasts, Marantz Models 2325, 2275, and 2250B incorporate a built-in 25 microsecond Dolby FM equalization circuit that provides complete de-emphasis compatibility when used with a Dolby Noise Reduction system. 

(NOTE: Model 2325 also has a complete Dolby Noise Reduction system built-in)

Noise from a Dolbyized FM broadcast can be reduced approximately 12 dB by changing the de-emphasis curve from 75 to 25 microseconds and utilizing the Dolby system. This is the equivalent of reducing the noise power of a received FM broadcast sixteen times below normal.

Dolby encoding allows an FM station the choice of operating with significantly reduces distortion, while still improving signal-to-noise ny approximately 9 dB - or of broadcasting a signal that's effectively double in strength with a signal-to-noise improvement of approximately 12 dB.

PREAMPLIFIER SECTION

Flexible Tone Controls

The more flexible the tone controls, the more accurately you can adjust for non-linearities in frequency response caused by speakers, speaker placement, room acoustics of the program source itself. The tone control system in Marantz Models 2325, 2275 and 2250B features a sophisticated five-position tone turner/mode switch for versatile bass, midrange and treble control. This eliminates a major shortcoming of conventional tone controls - their tendency to affect too wide a band of frequencies. Optional frequency turnover points limit the effect of the bass and treble controls to just the desired range.

The advantages can be illustrated by a practical example: Boosting the low bass (under 100 Hz) to compensate for a deficiency in room acoustics. Most conventional tone control, even if capable of supplying the boost,  will also increase the output in the 300 Hz to 1000 Hz region. With the turnover point set at 250 Hz on a Marantz receiver, the bass control can provide the desired bass boost (or cut) up to the frequency point of 250 Hz, and leave the frequency range above the point essentially flat and unaffected.

This flexible, easy-to-set system permits over seven million combinations of repeatable tone control settings, enabling you to adjust for the desired tonal balance in any listening environment.

 High performance Phono Preamp

Low noise and a wide dynamic range are of paramount importance in the circuit design of a phono section.

The three-stage, 40 dB gain amplifier built into Marantz receivers utilizes feedback-equalized circuitry to maintain extremely low distortion.

the use of close tolerance, stable components, such as tantalum input coupling capacitors, low noise carbon film resistors, Mylar output coupling and polystyrene-type equalization capacitors assures superior performance.

RIAA equalization is precise - within +/-0,5 dB, from 20 Hz to 20 kHz -  and under test in the 2325, the equivalent noise input to the phono section measures a low 0,8 microvolts. The phono overload point occurs at over 100 millivolts in the 2250B, and at over 125 millivolts in the 2325 and 2275. These figures result in a dynamic range capability of greater than 96 dB.

 A full Complement of Inputs and Outputs

In addition to the standard phono and auxiliary inputs, two sets of tape inputs and outputs are provided to facilitate copying from one tape deck to another. Front panel dubbing jacks allow you to add a third tape deck without disrupting any rear panel connections.

The preamp-out/main-in jacks on the rear panel enable you to use the preamplifier and amplifier sections independently. You get simplified connection of external components such as noise reduction systems, equalizers and electronic crossovers - and the ability to use the receiver's preamp section to drive a separate power amplifier.

here's another benefit: Connecting the preamp section directly to a tape deck enables you to make specially equalized recordings by using the preamp's flexible tone controls.

Power Amplifier Section

 Full Complementary Symmetry Output

Assures higher stability, better linearity and lower distortion than the quasi-complementary outputs used in the amplifier sections of most receivers.

Quasi-complementary circuitry tends to generage high order harmonic distortion and is particularly susceptible to crossover distortion. To reduce theses types of distortion, manufactures increase the amount of feedback within the amplifier. Under actual dynamic conditions, however, the amplifier with exessive feedback is prone to higher transient distortion and also lower stability.

In contrast, full complementary symmetry output circuitry requires less feedback by incorporating positive and negative amplifiers which are balanced to mirror-image each other's characteristics. This design produces exceptional linearity, lower total harmonic distortion and lower intermodulation distortion.

For these excellent reasons, Marantz receivers feature full complementary symmetry design, as used extensively in Marantz professional products.

 Direct Coupled Power Output

Provides wide power bandwidth, excellent low frequency transient response and improved damping fators.

Early transistorized power amplifiers featured one of two types of output design. A transformer or a capacitor was incorporated between the power output stage and the speaker system. However necessary this was for proper output-to-speaker coupling, it tended to limit low frequency power response or to cause degrading phase shift, and thus impair sound accuracy.

Today's more advanced technology has eliminated the need for coupling transformers and capacitors and the sound inaccuracies they can cause.

The sophisticated direct coupled output stages used in Marantz amplifiers assure you of extremely high damping factors at low frequencies and the best possible low frequency response.

 Heavy-Duty Power Supply

High reserve power supply sections and power output circuitry ensure that Marantz receivers will continue to meet specifications through years of steady performance.

A massive power transformer forms the heart of a dual-balanced positive and negative power supply that symmetrically powers the amplifier stages. large capacity electrolitic capacitors assure high energy power reserves, while massive heat sink promote highly reliable, long-term operation even under full power output conditions.

Specifications

Rated Power Output:  125 Watts (Minimum Continuous Watts per Channel, Both Channels Driven)

Power Band:  20 Hz to 20 kHz

Total Harmonic Distortion:  0,1%

Load Impedance:  8 ohms

I M Distortion (IHF Method, 60 Hz and 7 kHz mixed 4:1 at Rated Power Output):  0,1%

Damping Factor (at 1 kHz):  70

Main Inputs Sensitivity/Impedance:  1,0 V/55 kΩ

Frequency Response (at 1W Output, 20 Hz to 20 kHz): ±20 dB

Pre-Amplifier Section

Phono

Dynamic Range (Ratio of Input Overload to Equivalent Input Noise):  96 dB

Equivalent Input Noise (RMS, 20 Hz to 20 kHz):  1,5 μV

Input Sensitivity and Impedance:  1,8 mV/47 kΩ

Frequency Response (re. RIAA, 20 Hz to 20 kHz):  ±0.5 dB

High Level Inputs (Aux and Tape)

Input Sensitivity and Impedance:  180 mV/100 kΩ

Output Impedance

Tape record:  200

Pre-Out:  900

Tone Controls

Bass:  ±12 dB (50 Hz)

Mid:  ±6 dB (700 Hz)

Treble:  ±12 dB (15 kHz)

AM/FM SPECIFICATIONS

Quieting Slope (Mono) 30 dB Quieting:  1,8 μV (10,3 dBf)

5 μV (19,2 dBf) : 55 dB

10 μV (25,2 dBf) : 60 dB

50 μV (39,2 dBf) : 70 dB

1000 μV (65,2 dBf) : 75 dB

Distortion at 1000 μV (65 ,2 dBf, Mono)

100 Hz : 0,25%

1000 Hz : 0,15%

6000 Hz : 0,3%

Distortion at 1000 μV 965,2 dBF, Stereo)

100 Hz : 0,35%

1000 Hz : 0,3%

6000 Hz : 0,5%

Distortion at 50 dB Quieting (Mono and Stereo)

1000 hz : 0,6%

Hum and Ni=oise at 1000 μV (65,2 dBf)

Mono : 70 dB

Stereo : 60 dB

Frequency Response 30 Hz to 15 kHz

Mono : ±1,0 dB

Stereo : ±1,5 dB

Capture Ratio

at 100 μV (45,2 dBf) : 1,8 dB

at 1000 μV (65,2 dBf) :  1,25 dB

Alternate Channel  Selectivity:  80 dB

Spurious Response Rejection:  100 dB

Image Response Rejection:  100 dB

IF Rejection (Balanced):  100 dB

AM Suppression at 100 μV (45,2 dBf):  62 dB

Stereo Separation

100 Hz : 38 dB

1000 hz : 42 dB

10 kHz : 30 dB

Pilot (19 kHz) Rejection:  65 dB

AM usable Sensitivity:  20 μV

Pioneer SX-850

Pioneer SX-850 Features:

Refined Design and Operation Features

Power Supply and Protection Of Power Amplifier

Hign Class Equalizer And Control Preamplifier

AM (Long and Medium Wave) Reception

FM Muting

Multiplex (MPX) Circuit

FM Front End and FM IF Section

Because it enables you to enjoy both the joys of records and of the numerous musical programmes broadcast on the air in mono and stereo, the receiver is by far the most convenient piece of hi-fi equipment. It is no coincidence that Pioneer is particulary reputed for this type of equipment, the refinement, performance and sturdiness of Pioneer receivers is almost legendary.  Ask one of the thousands of audiophiles already equipped with even an old Pioneer receiver and you'll be convincend. The range of Pioneer receivers is particulary wide.  As many 12 models, including the two stereophonics, from 2 x 65 watts for the SX-850 up to the  SX-950 with a 2 x 85 watts.

Specifications  SX-850

Audio Section

Continuous power:

2 x 85 W  (both channel driven at 20 Hz - 20 kHz, 4Ω)

2 x 65 W  (both channel driven at 20 Hz - 20 KHz, 8Ω)

THD at rated output power  (DIN), 8Ω:  0,1%

Power bandwidth (DIN) both channel driven 8Ω:  5 Hz - 45 kHz

Frequency response at AUX input (DIN):  10 Hz - 50 kHz (+0 dB, -1 dB)

Input sensitivity impedance:

Phono:  2,5 mV/50 kΩ

Microphone:  6,5 mV/50 kΩ

Tape monitor, Tuner, Aux:  150 mV/100 kΩ

Bass control (100 Hz):  ±10 dB

Treble control (10 kHz):  ±10 dB

FM Section (87,5 to 108 Hz)

Sensitivity (DIN):

Mono  (26 dB S/N ratio):  1,6 μV

Stereo (46 dB/S/N ratio):  44μV

Capture ratio: 1 dB

Selectivity (±400 kHz):  80 dB

S/N ratio (IHF):  72 dB

THD (stereo) 1kHz (DIN):  <0,3%

Frequency response (DIN):  30 Hz - 15 kHz (+0,2 dB, -2 dB)

Stereo separation 1 kHz (DIN):  40 dB

Subcarrier suppression:  62 dB

AM Section (525 - 1605 kHz)

Sensitivity (IHF):  15 μV/m

Selectivity:  35 dB

Dimensions (W x H x D):  526 x 173 x 412 mm

Weight:  19,1 kg

Pioneer SX-950

Because it enables you to enjoy both the joys of records and of the numerous musical programmes broadcast on the air in mono and stereo, the receiver is by far the most convenient piece of hi-fi equipment. It is no coincidence that Pioneer is particulary reputed for this type of equipment, the refinement, performance and sturdiness of Pioneer receivers is almost legendary.  Ask one of the thousands of audiophiles already equipped with even an old Pioneer receiver and you'll be convincend. The range of Pioneer receivers is particulary wide.  As many 12 models, including the two stereophonics, from 2 x 65 watts for the SX-850 up to the  SX-950 with a 2 x 85 watts.

Features:

Refined Design and Operation Features

Power Supply and Protection Of Power Amplifier

Hign Class Equalizer And Control Preamplifier

AM (Long and Medium Wave) Reception

FM Muting

Multiplex (MPX) Circuit

FM Front End and FM IF Section

Specifications  SX-950

Audio Section

Continuous power:

2 x 110 W  (both channel driven at 20 Hz - 20 kHz, 4Ω)

2 x 85 W  (both channel driven at 20 Hz - 20 KHz, 8Ω)

THD at rated output power  (DIN), 8Ω:  0,1%

Power bandwidth (DIN) both channel driven 8Ω:  5 Hz - 35 kHz

Frequency response at AUX input (DIN):  15 Hz - 40 kHz (+0 dB, -1 dB)

Input sensitivity impedance:

Phono:  2,5 mV/50 kΩ

Microphone:  6,5 mV/50 kΩ

Tape monitor, Tuner, Aux:  150 mV/100 kΩ

Bass control (100 Hz):  ±10 dB

Treble control (10 kHz):  ±10 dB

FM Section (87,5 to 108 Hz)

Sensitivity (DIN):

Mono  (26 dB S/N ratio):  1,6 μV

Stereo (46 dB/S/N ratio):  44μV

Capture ratio: 1 dB

Selectivity (±400 kHz):  80 dB

S/N ratio (IHF):  72 dB

THD (stereo) 1kHz (DIN):  <0,3%

Frequency response (DIN):  30 Hz - 15 kHz (+0,2 dB, -2 dB)

Stereo separation 1 kHz (DIN):  40 dB

Subcarrier suppression:  62 dB

AM Section (525 - 1605 kHz)

Sensitivity (IHF):  15 μV/m

Selectivity:  40 dB

Dimensions (W x H x D):  526 x 173 x 412 mm

Weight:  19,1 kg

Pioneer SX-1050

FM Front End And FM IF Section

The quality of these two sections is decisive for sensitivity, enabling you to get stations whose signals are weak or weakended by distance or obstacles and for selectivity which rejects undesirable stations. This is why Pioneer uses field-effect transistors (FET and MOS-FET) for the first section and variable capacitors with a minimum of 3 gangs and up to 5 gangs. Multipath switch ensures accurate antenna mouting for optimum reception.

 Multiplex (MPX) Circuit

Its function is to separate the right and left channels from the stereo FM signal. This is a very complex operation and often influenced by temperature and air humidity. The phase lock loop integrated circuits (PLL) automatically control the stability of this separation.

Refined Design and Operation Features

The presentation of the Pioneer receivers SX-1050 is of a remarkable quality. Pioneer styling is also legendary, touch the button of a Pioneer and compare to others. Such production precision is almost incredible. Finally, it's the power and the variety of possibilities which will enable you to choose.

   

FM Muting

A built-in muting circuit effetively eliminates irritating pop and interstation noises during tuning and detuning on all Pioneer receivers.

 AM (Long and Medium Wave) Reception

AM reception is often a neglected point on many receivers, and the poor quality of the sound drivers you back to FM eben when you want to listen to an interesting program on AM. Not on a Pioneer, thanks to the use of LSI (Large Scale Integrated Circuits), ceramic filters,  and two or three gang capacitors.

Hign Class Equalizer And Control Preamplifier

The quality signal produced by the FM section must be as carefully treated as the signals from the turntable, the tape recorder, or the cassette deck.

For records the direct coupled 3 or 4 stage preamplifier equalizers give an RIAA correction always within ±0.3 dB, and input tolerances of 150 mV  to 500 mV assuring good rstitution of the high and low frequencies and a god dynamics range.

The control preamp using field effect transistors and integrated circuits (CR type) allows very delicate control. The SX-1050 have double effect and twin tone control system.

Power Supply and Protection Of Power Amplifier

The power of the Pioneer receivers is a real power, always indicated from 20 to 20,000 Hz with the corresponding maximum distortion. Direct coupled PNP, NPN circuits  and Darlington transistorized circuits, assure this succes. So that this power can be supplied, Pioneer chose oversize transformers and electrolytic capacitors to provide all the energy necessary for the lowest frequencies.

Specifications  SX-1050

Audio Section

Continuous power:

2 x 170 W  (both channel driven at 20 Hz - 20 kHz, 4Ω)

2 x 120 W  (both channel driven at 20 Hz - 20 KHz, 8Ω)

THD at rated output power  (DIN), 8Ω:  <0,1%

Power bandwidth (DIN) both channel driven 8Ω:  5 Hz - 40 kHz

Frequency response at AUX input (DIN):  10 Hz - 50 kHz (+0 dB, -1 dB)

Input sensitivity impedance:

Phono:  2,5 mV/50 kΩ

Microphone:  6,5 mV/50 kΩ

Tape monitor, Tuner, Aux:  150 mV/100 kΩ

Bass control (100 Hz):  ±10 dB

Treble control (10 kHz):  ±10 dB

FM Section (87,5 to 108 Hz)

Sensitivity (DIN):

Mono  (26 dB S/N ratio):  1,6 μV

Stereo (46 dB/S/N ratio):  35μV

Capture ratio: 1 dB

Selectivity (±400 kHz):  80 dB

S/N ratio (IHF):  78 dB

THD (stereo) 1kHz (DIN):  <0,25%

Frequency response (DIN):  30 Hz - 15 kHz (+0,2 dB, -2 dB)

Stereo separation 1 kHz (DIN):  45 dB

Subcarrier suppression:  73 dB

AM Section (525 - 1605 kHz)

Sensitivity (IHF):  15 μV/m

Selectivity:  40 dB

Dimensions (W x H x D):  526 x 173 x 454 mm

Weight:  23,4 kg

Yamaha R-100 Receiver

Introducing command performance music. Introducing the R-100, the most astounding, musical-sounding receiver ever to come from Yamaha. or anyone.

There's 100 watts RMS per channel (both channels driven into 8 ohms, 20 Hz to 20 kHz, with no more then 0,015 THD) combined with our unique Zero Distortion Rule circuitry to virtually eliminate power amplifier and thermal distortion. But such wonders have been heard from yamaha before.

The unheard-of part is the phenomenal control the R-100 gives you over your music. For the first time, a five-band graphic equalizer is combined with a microcomputer. This unique Computer-Controlled Sound System (CCSS) allows you to select from five different preset frequency response curves (loudness, Bass, Presence, Treble or High Filter), and then further adjust each of the five curves in four different preset variations. You can then store any three of the preset variations in memory for instant recall.

And if you really want to be creative with your music listening, you can adjust the five bands independently to form any frequency response curve you choose, then store it in memory.

The CCSS offers you unparalleled flexibility to tailor the music to your personal taste and listening enviroment.

And you cancontrol all this (and a lot more) by just pressing the right button on the remote control unit that is a standar accessory.

There's more that comes standard with the R-100. Like Yamaha's spatial expander, dynamic noise canceller, the ability to handle low impedance loads, and the headroom to handle "hot" source inputs.

And there are four more models to choose from, each with the same natural sound Yamaha is famous for. Whichever one you choose , you'll hear your music like you've always wanted to hear it. 

Specifications

Audio Sections

Minimum RMS Output Power per Channel:

100 W at 8Ω, 20Hz-20kHz, 0,01% THD;

130 W at 4Ω, 1 kHz, IHF Signal (Dynamic Power);

130 W at 2Ω, 1 kHz, IHF Signal (Dynamic Power)

Dynamic Haedroom (IHF, 8Ω):  1,5 dB

Power Bandwidth (8Ω, 0,012% THD, 50 W):  10 Hz to 30 kHz

Damping Factor (8Ω, 1 kHz):  45

Input Sensitivity/Impedance:

Phono MM : 2,5 mV/47 kΩ

Phono MC : 160 μV/100 Ω

Aux, Tape, Tuner : 120 mV/47 kΩ

Input Sensitivity (New IHF):

Phono MM : 0,25 mV

Phono MC : 16 μV

Aux, Tape, Tuner : 12 mV

Maximum Input Level (1 kHz, 0,02% THD):

Phono MM : 110 mV

Phono MC : 7 mV

Output Level/Impedance:

Rec Out : 120 mV/4,7 kΩ

headphone Output/Impedance (0,25% THD):  0,81 V/ 270 Ω

Frequency Response:

Aux, Tape, Tuner : 20 Hz - 20 kHz,  +0, -1 dB

RIAA Deviation:

Phono MM (20 Hz to 20 kHz):  ±0,5 dB

Phono MC (50 Hz to 20 kHz):  ±0,5 dB

Total harmonic Distortion (20 Hz to 20 kHz):

Phono MM to Rec Out (1 V): 0,008%

Phono MC to Rec Out (1 V): 0,008%

Aux/Tape/Tuner to Sp Out (1W/8Ω): 0,008%

Intermodulation Distortion(Rated Power, 8Ω):

Aux, Tape, Tuner : 0,01%

Signal-to-Noise Ratio (IHF A Network):

Phono MM (5 mV, Input Shorted): 88 dB

Phono MC (500 μV, Input Shorted): 75 dB

Aux, Tape, Tuner (AM position, Input Shorted): 100 dB

Signal-to-Noise Ratio (IHF A Network):

Phono MM : 72 dB

Phono MC : 74 dB

Aux, Tape, Tuner (AM position): 81 dB

Residual Noise (IHF A Network):  140 μV

Channel Separation (1 kHz):

Phono MM (Input Shorted) : 60 dB

Aux, Tape (5,1 kΩ Shorted) : 60 dB

Low Filter Characteristics (Subsonic, Built-in):  15 Hz -12 dB/oct

FM Section

Tuning Range:  87,5 to 108 MHz

50 dB Quieting Sensitivity (IHF, 75 Ω):

Mono : 1,5 μV 914,8 dBf)

Stereo : 20 μV (37,3 dB)

Usable Sensitivity (30 dB Quieting, 75 Ω, Mono):  0,75 μV (8,8 dBf)

Image Response Ratio:  75 dB

IF Response Ratio:  95 dB

Spurious Ratio:  95 dB

Am Suppression Ratio:  66 dB

Capture Ratio:  1,2 dV (local); 2,5 dB (DX)

Alternate Channel Selectivity (IHF):  35 dB (local); 85 dB (DX)

Signal-to-Noise Ratio (IHF): 

Mono : 88 dB

Stereo : 83 dB

Harmonic Distortion(Local)

Mono (100 Hz / 1 kHz / 6 kHz):  0,05% / 0,05% / 0,1%

Stereo (100 Hz / 1 kHz / 6 kHz):  0,07% / 0,07% / 0,15%

Stereo Separation (IHF, Local):

50 Hz / 1 kHz / 10 kHz : 50 db / 50 dB / 45 dB

Frequency Response:

50 Hz to 10 kHz : ±0,3 dB

30 Hz to 15 kHz : =0,3 dB, -0,5 dB

Subcarrier Product Ratio (IHF):  55 dB

AM Section

Tuning Range:  510 kHz to 1,620 kHz

Usable Sensitivity:  250 μV/m

Selectivity:  25 dB

Signal-to-Noise Ratio:  52 dB

Image Response Ratio:  40 dB

Spurious Response Ratio;  50 dB

Harmonic Distortion (400 Hz):  0,3%

Output level/Impedance (fixed):

FM 100% mod. 1 kHz:  500 mv/5 kΩ

AM 30% mod. 400 Hz:  150 mV/5 kΩ

General

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

Power Consumption:  410 W / 170 W / 680 W (U.C. / R / A)

AC Outlet

Switched x1 : 200 W max.

Unswitched x 2 : 200 W max. Total

Dimensions (W x H x D):  435 x 122 x 386 mm (17-1/8" x 4-13/16" x 15-3/16")

Weight:  11 kg (24 lbs 3 oz)

Fostex RM 765

The typical placement of speakers in the typical room results in a confusion of sound. You end up hearing a lot of the room colorations and reflections mixed in with the direct source. Sure, you can spend even more money and equalize the room. Even then you may have to invest in an outboard crossover in order to compensate for the loudspeakers design.

Avoid all these problems with Fostex Near-Field Monitors. They are Point Source, coaxial speakers. A,, the sound emanates from a point reference, just like in nature, so all the sound reaches your ears at the same time. Stereo imaging is rock solid.

This design produces a "sweet spot" so you know that what you're hearing from the RM Series will sound proportionally the same in a car, on a hi-fi system or through a custom-tuned playback system in the studio.

An unusually low crossover point gives you another imoprtant benefit not found in conventional designs: vital midband information like vocals will not be modulated by high impact low frequency sounds like kick drums.

The same RP patented driver gives you uniformly flat high frequency response in all three models; the woofers increase from 6,5 inches to 8 inches to 10 inches. The two drivers in the RM 765 are the identical elements in the RM 865 3-way system, which simply adds a 10-inch woofwr.

This larger system is also ready for biamplification. In our listening tests with 800W -1000W per side, these beauties have generated 116 dB SPL at the console with no audible distortion. The Near-Field Monitors from Fostex give you clarity and punch and definition - as loud as you need it.

The Initail Reference

RP stands for Regulated Phase. It's new a new trasducer technology which has been under development at Fostex for the last ten years. So far, more than 20 international patents have been awarded. The first products with the RP Technology were Headphones. The idea worked so well, the inventors immediately began applying it to the reciprocal trasducer, the microphone.

A whole series of microphones now exists' with the same basic principles embodied in the new RM 765 and RM 780 tweeters. The essential idea of this RP Trasducer is a flat, thin film diaphragm onto which the voice coil is printed; this assembly is then suspended between magnetic circuits arranged on both side of the diaphragm, with the same polarities facing each other and the opposite polarities adjacent to one another.

The end result of this arrangement permits the diaphragm to be driven with absolute uniformity. Which means it doesn't sound differently at different levels. It provides the same uniform frequency response across an extremely wide dynamic range.

It won't break up, either. Which means three won't be the usual high frequency distortion to mask the over-use of 12 kHz boost, for example.

Because the printed film diaphragm moves identically in both directions, and the entire diaphragm surface is with in the magnetic field, it by-passes all of the response variations caused by conventional mounting designs. There simply is no mechanically induced distortion in the RP tweeter. It functions as an edgeless device.

In this sense, the double spider design of the RM-Series woofers is the perfect complement to the RP tweeter. In a conventional single spider design, the compliance from one direction differs from the other. This difference produces unacceptable distortion, particularly in the second harmonic region. Fostex engineers added a second spider in a push/pull complementary configuration to cancel the compliance effects of a single spider design. The result is a 10 dB improvement in second harmonic distortion. A 2" voice coil/magnet assembly and a computer modeled bass reflex design complete the profile of what is definitive low and response in the Reference Monitor Series.

Specifications

RM 765

Enclosure Type:  Vented reflex

Power Capacity: 

150 watts continuous program power;

75 watts continuous pink noise.

Frequency response (2 TT or 4 TT):  58 Hz to 20 kHz  ±3 dB

Sensitivity (1W, 1m):

2 TT : 93 dB

4 TT : 90 dB

Reference efficiency

2 TT : 1,25 %

4 TT : 0,63 %

Distortion (10 W):

less than 2%  2nd harmonic;

less than 1% 3rd harmonic (from 58 Hz to 20 kHz)

Nominal impedance:  8 ohms

Miniumu Impedance:  6,5 ohms

Controls:  Field controls; High frequency level

Cabinet finish:  Mar resistant matle

Dimensions (W x H x D):  264 x 430 x 270 mm (10⅜ x 17 x 10⅝ inches)

Weight net:  8,5 kg (18,7 lbs)