What is stereo?

There are now two system of high fidelity, monophonic (monaural) and stereophonic. Monophonic is a system that starts from one microphone and is fed through a single high fidelity set. Stereophonic is a double system. Two separate microphones are placed at different sides of the orchestra and two different systems are used to keep the two signals or channels separated. Two separate speakers are used, placed on different sides of you room. Stereo is much like 3-D photography, two slightly different sound reach your ears giving you a new dimension in sound.

H.H. Scott '59

SAE 5000 noise reduction system

Impulse Noise Reduction System
Ever since the invention of the recorded disc, annoying "clicks" and "pops" caused by scratches, static, and other imperfections, have consistently disturbed the listening pleasure of mysic lovers. Now, SAE introduces the unique model 5000, an Impulse Noise Reduction System which eliminates those unwanted sounds with no adverse effect on the quality of the recorded material.
This break-through in electronic circuitry is so demonstrably effective, that the SAE 5000 is destined to beacome an essential part of any sound system.
The SAE 5000 is compact and sleek, built to SAE's exacting standards, and ready to enhance the performance of any system, from the standard receiver/turntable combination to the most sophisticated audiophile components.
Before the technological break trough achieved by the 5000, there were many records that offered less than ultimate performance and some which were rendered virtually unlistenable due to the presence of impulse noise. Impulse noise is generated by static discharge, record blemishes or accumilation of dirt, and is often referred to as "clicks"  and "pops". Now, with the 5000, most of these problems can be overcome. Many virtually lost recordings can be played again with their fidelity unnamed by impulse noise. Ofcourse, unblemished recordings can be played without being adversely affected by the 5000. only sounds which are detected as impulse noise are eradicated. All else remains. Old recordings, even 78 rpm's may be rejuvenated by our new system.
The circuitry in the SAE 5000 is the result of extensive research and evaluation by its inventor, Jack Sacks, into the field of impulse noise.
At the start of research a careful statistical analysis was made of impulse noise and those properties which are unique to it. From this information a logic circuit was developed for the 5000 which constantly monitors the music, searching for those unique parameters which  indicate the presence of impulse noise. Upon detection of the presence and duration of the offending impulse, which is accomplished by examining the shape of the "spike", and other parameters, the noise removal circuit comes into play which deletes pnly the damaged segment from the sound sequence. Because the duration of this impulse noise is usually so minute, (less than one thousandth of a second), it is possible to extrapolate forward a tiny segment from the music information immediately preceding the gap and thus maintain total continuity and integrity at the same time. This technique is undetectable to the ear and does not adversely affect the frequency response, dynamic range, or spectral balance of the music. The system remains passive and "transparent" at all times, doing its job only when called upon by the detection of unwanted noise.

The SAE 5000 has simple and effective controls. The principal control is a threshold adjustment which varies the sensitvity of the detection circuit. Different record characteristics may require some sensitivity adjustment.
There is a system defeat button which allows the Impulse Noise Reduction (INR) circuit to be bypassed electrically. A tape monitor switch and rear mounted jacks reconnect the tape monitor circuitry used to hook up the 5000.
Finally, the incredible effectiveness of the INR system can be demonstrated by activating the Invert switch. This action reverses the active circuitry and you  are now able to hear Only the noise your system eliminates while in the operating model.

Total Harmonic Distortion (at any level to rated output from  20 Hz to 20 kHz):  less than 0.1%  Intermodulation Distortion (at any level or rated output with  any 2 mixed frequencies between  20 Hz to 20 kHz at 4/1 Voltage Ratio):  less than 0.1%
Signal-to-Noise Ratio:  greater than 90 dB (below rated output)
Rated Output:  2.50 Volts RMS
Frequency Response:  ±1 dB (20 Hz to 20kHz)
Output at Clipping:  greater than 9 Volts into 10 K  
Input Impedance:  75 K
Output Source Impedance:  500  
Output Lead Impedance:  600  (minimum)
Insertion Loss:  less than 1 dB
Power Supply / Consumption:  110-125 VAC, 50 Hz to 60 Hz / 7 watts
Dimensions (W x H x D):  10.75" x 3"  x  9.25"
Shipping Weight:  8 Ibs.
Rack Mount Kit available

JVC SEA-66 equalizer

SEA-66 Stereo Graphic Equalizer
10 LED-lit frequency equalizer controls per channel
10-band real-time spectrum analyzer for frequency analysis
Buil-in pink noise generator for room acoustics compensation
3 deck connections with dubbing from 1 to 2/3 , 3 to 1, and 3 to 1
Selectable ±12 dB/  ±6 dB control range
S.E.A. defeat switch

If your living room doesn't have the fine acoustics of music hall, don't despair, the capable SEA-66 is at your command . It is equipped with a spectrum analyzer, a pink noise generator and a mic input, making it a simple procedure to compensate for the individual acoustics of your room. For this purpose, JVC recommends the precisely calibrated MU-S80 microphone.
 a total of 10 equalizer controls per channel are spaced at one octave intervals, giving you tremendous equalizing versatility. Individual controls are tipped with LEDs to graphically display the selected response. The SEA-66 can connect and monitor up to three tape decks and offers complete dubbing capabilities.

Input Impedance
S.E.A. Input :  47 k
Tape Monitor Input :  47 k
Output Impedance
S.E.A. Output :  680
Tape Rec Output :  680
Rated Output (Freq. EQ Controls at Flat):  2 V RMS
Maximum Output(Freq. EQ Controls at Flat):  6 V RMS
Total Harmonic Distortion:  0,005% (20 Hz - 20 kHz rated output)
Intermodulation Distortion (Freq. EQ Controls at Flat):  0,005%
Gain:  0 dB
Frequency Response:  10 Hz - 100 kHz +0 -2 dB
Signal-to-Noise Ratio :  115 dB
Center Frequencies:  31,5; 63; 125; 250; 50; 1 k; 2 k; 4 k; 8 k; 16 kHz
Control Range:  ±12 dB/±6 dB
Pink Noise Oscilator Output:  35 mv RMS
Optimum Microphone Sensitivity:  over 72 dB
Optimum Microphone Output/Impedance:  less than  1 k
Dimensions (W x H x D):  435 x 77 x 275 mm
Weight:  3,5 kg

JVC SEA-33 equalizer

S.E.A. Stereo Graphic Equalizer, features:
10 frequency equalizer controls per channel
S.E.A. recording and defeat switches
-6db input atenuator to prevent overload distortion
Transistor inductors for expanded dynamic range
Slim, low-profile styling

While every hi-fi system benefits from the addition of a graphic equalizer, not every system can accommodate a large or costly model. That's why we've developed the SEA-33, the slim equalizer that's perfect for popular packaged component systems and compacts.
Yet it has the same advanced features and performance of our larger models - like transistor inductors for lowest possible noise and distortion, ten equalizer controls per channel, and S.E.A. recording and defeat switches.
The ten equalizer controls cover a range from 31,5 Hz to 16 kHz in one-octave steps, giving you the ability to personalize your sound, and compensate for listening room and equipment deficiencies. One popular use of a graphic equalizer is to make equalized tapes for use in prtables and car stereo. The S.E.A. Rec switch gives you this capability.

Input Impedance
S.E.A. Input :  47 k
Tape Monitor Input :  47 k
Output Impedance
S.E.A. Output :  100
Tape Rec Output :  100
Rated Output (Freq. EQ Controls at Flat):  2 V RMS
Maximum Output(Freq. EQ Controls at Flat):  7 V RMS
Total Harmonic Distortion:  0,005% (20 Hz - 20 kHz rated output)
Intermodulation Distortion (Freq. EQ Controls at Flat):  0,005%
Gain:  0 dB
Frequency Response:  10 Hz - 50 kHz +0 -2 dB
Signal-to-Noise Ratio :  115 dB
Center Frequencies:  31,5; 63; 125; 250; 50; 1 k; 2 k; 4 k; 8 k; 16 kHz
Control Range:  ±12 dB
Input Attenuator Level:  -6 dB
Dimensions (W x H x D):  435 x 61 x 265 mm
Weight:  3 kg

Philips AF 829 turntable

Philips model AF829 turntable is front operated, direct control, and fully automated. Direct control is a new system combining the advantages of measuring the actual speed at the turntable and the well-known advantages of belt drive, in combination with the subchassis  principle used in earlier Philips turntables. The major achievement, according tp Philips, is that it brings the specifications to the level of direct drive, but without the inherent problems of direct drive which requires extremely fine construction to avoid rumble, suppress microphony, and decrease sensitivity to shocks. Direct control begins rotating the motor at 33 or 45 RPM, as selected. The belt transfers the rotation to the turntable. The speed of the turntable is continuously sensed by the tacho-generator and converted into a voltage, the output of which is fed into the control unit where this voltage is compared to a reference voltage. The resulting difference voltage is used as a control signal to adjust motor speed. Thus in this system all extrnal influences are compensated, including changes in tracking force, different record weights, use of a dust bug, changes in environmental temperatures and relative humidity, mains voltage, and frequency fluctuations. 
free-floating sub-chassis
low torsion tone-arms
speed regulation
CMOS memories
System:  Direct Control
Operations:  Full-automatc
Speeds:  3-1/3 and 45 rpm
Turntable Diameter:  310 mm
Wow and Flutter : less than 0,025 (WRMS)
Rumble:  less than 73 dB (DIN B)
Tonearm Type:  Linear
Tonearm length:  215 mm
Tracking Error:  less than 0°9' /cm
Dimensions (W x H x D):  450 x 141 x 365 mm

KLH 354 loudspeakers

KLH has always made fine loudspeakers. It's a tradition. But with the introduction of our new Model 354,, we believe we are adding a new dimension to that tradition. For the 354 is the best of KLH, made even better. Like all of our classic loudsppeakers, it is of acoustic suspension design. It also uses our famous 273 mm extended low-frequency woofer. But the tweeter, midrange and crossover network are all vastly improved devices of completely new manufacture that represent the industry's most advanced technology. Indeed, the 4-1/2" midrange used in the 354 is considered by most experts too be the finest cone-type ever made. The 354 is considerably more efficient than previous models - with an extended top end, more open sound and greater overall musically. It flawlessly recreates the subtleties and innervoices of the orchestra. Stated simply. It is easily one of the best loudspeakers we, or anybody else, have ever made. It is unquestionably the most beautiful - finished both inside and out in a deeply handsome walnut veneer on high-density particle board. Whether you put a pair of 354s on pedestals (optional) or display them with their grille cloths on or off, they are striking and important additions to any home. But for all their richness, they are surorisingly modest in price.

Type:  tree-way acoustic suspension loudspeaker system
Impedance:  8 ohms
Frequency Response:  25 Hz - 22,000 Hz
1 x 12-inch low resonance KLH woofer
1 x 4-1/2-inch midrange
1 x 2-1/4-inch cone tweeter
Minimum Recommended Power (per channel):  25 watts RMS
Maximum Power Handling:  can be safely used with amplifiers rated up to 175 watts RMS per channel
Two Rotary Switches - one 3-position midrange control and one3-position tweeter control
Walnut veneer on high density particle board (including baffle)
Removable front grille panel (Hedlok)
Dimensions (W x H x D):  360 x 660 x 320 mm (14" x 25" x 12-6/8")
Weight:  50 lbs (per carton)

Soundcraftsmen AE2420-R analyzer/equalizer

Soundcraftsmen's  AE2420-R  Analyzer/Equalizer is claimed to be a "revolutionary breakthrough" in enabling accurate analusis of a room's "imperfections", as ell as compensating for system imperfections. A new concept is used to apply differential/comparator circuitry  to equalization analysis. By sampling the complex waveshapes of a pink noise input signal on the one hand, and the speaker output signal on the other hand, the circuitry of the device converts the complex wave shapes to DC levels; these are then compared through the differential/comparator circuit to provide readout of the exact differential between these two complex waves shapes with an accuracy of 1/1oth dB. Even if the pink noise input amplitude is variable across the spectrum, there is no effect on the analyzer's dB readings because the analyzer is actually looking at both the selected frequency spectrum signals simultaneously, without regard to amplitude. Any good quality low- or high-impedance microphone may be used, regardless of the mike's response curve. The calibrated curve supplied by the microphone manufacturer can be programmed into the obtained flat response curve through use of the "computer charts" the maker of this device provides.

Analyzer Section
Differential Comparator: 
Minimum Input :  75 mV
Differential Measurement accuracy :  ±0,1 dB
Hi Level Input:
Input Impedance :  47 k Ω
Gain :  30 dB max (adjustbetter than)
Frequency Response :  ±0,1 dB 20 to 20,000 Hz
Mic Preamp: 
Input Impedance :  200 Ω or 20 k Ω (switchable Lo or Hi Z)
Gain :  80 dB max.
Frequency Response :  ±0,1 dB 20 Hz to 20,000 Hz
Pink Noise Source: 
Internal Generator Level :  approx. 300 mV
Bandpass Filter:
Center Frequencies :  30,60, 120, 240, 480, 960 Hz; 1,92; 3,84; 7,68; 15,36 kHz
11-position switch for selecting each of the 10 individual Bandpass Fiters, or All pass, for initial LED balancing.
Equalizer Section
Harmonic Distortion:  less than ,01% at 2 V
IM Distortion:  less than ,01% at 2 V
Signal-to-Noise Ratio: 
105 dB at 10 V output
100 dB at 2 V output
Octave Controls:
±16 dB boost or cut-each octave (all octaves set at max)
±12 dB boost or cut-each octave 9all octaves set at zero)
Gain Cut Capability:  +22 dB / -23 dB (all controls at maximum)
Zero gain Controls:  18 dB range
Filter Type:  Op-Amp synthesized inductors
Dimensions (W x H x D):  19" x 5-3/4" x 11-3/4"
Weight:  21 lbs

Micro-Acoustics QDC-1 phono cartridge

Stereo Phono Cartridge. It will make any well recorded L.P. sound exactly like its master tape.
People in the record business have known for a long time that a well recorded stereo disc is potentially every bit as good as its master tape. Our founder and president. Arnold Schwartz, created the Series 300 Micro-Point Recording Stylus - an ultra precision cutting tool used to master the world's finest recordingd. (Over two-hundred million records a year are manufactured from masters cut with our Series 300 Micro Point Styli.) And it has been our experience that there's no problem in getting the music onto the record the problem has been in retrieving it.

The cartridge is the culprit.
Until the advent of the QDC-1, there really wasn't a cartridge on the market that could make a stereo record sound as good as its master tape. So cartridge manufactures didn't have to deal with an absolute standard of measurement for their product. They sold their cartridges very much like loudspeakers , using subjective criteria. In the end, the customer had to choose between the "sound" of one cartridge or another. The fact is that a cartridge shouldn't have any sound of its own. Ideally it should just be a direct link between the record groove and the preamp input. That's precisely what the new QDC-1 is - an ultra precision component that neither adds  nor detracts from the music you hear. And because it does what it does so well, it will change the way all cartridges are judged. Now a cartridge's performance can be measured against a completely reliable abjective standard.

Stated simply; "Does a cartridge make a well recorded disc sound identical to its master tape? Or doesn't it?" our does. Here's why.
[1] The  QDC-1 Series 300 playback styli (QDC-1e, 1s, 1q) are shaped and polished with the same ultra precision as our world famous Micro-Point recording styli. These styli follow the complexities of the record groove with greater tracing accuracy than heretofore obtainable.
[2] The QDC-1 stylus bar is directly attached to its transducer, eliminating the losses inherent in standard flux field coupling. This unique method of lossless coupling provides a faster response time than any other known system.
[3] The QDC-1 stylus is balanced by two elastic bearings positioned to provide precise 45°-45° signal resolution. This symmetrical configuration precisely controls stylus excursion from minimum to maximum groove amplitude, without the floppy overshoot of conventional single bearing designs.
[4] The QDC-1 electret transducer puts out a perfectly linear signal from 5 Hz to 50 kHz, without the phase shift normally associated with inductive transducers. Its reproduction of complex wave forms is equal to the best direct coupled amplifiers.

Stylus Configuration (User Replaceable):
QDC-1e :  .0002 x .0007 elliptical solid nude diamond
QDC-1s  :  .0005 spherical soild nude diamond
QDC-1q  :  Quadra-Point/CD-4 solid nude diamond
Frequency Response: 
QDC-1e  :  5 Hz to 20 kHz ±2 dB
QDC-1s  :  5 Hz to 20 kHz ±2 dB
QDC-1q  :  5 Hz - 50 kHz ±3 dB
Tracking Force Range:
QDC-1e :  0,75 to 1,5 grams
QDC-1s  :  0,9 to 1,5 grams
QDC-1q  :  0,9 to 2,0 grams
Channel Separation: 
QDC-1e :  Nominally 30 dB at 1 kHz (nominally 20 dB at 10 kHz)
QDC-1s  :  Nominally 30 dB at 1 kHz (nominally 20 dB at 10 kHz)
QDC-1q  :  Nominally 30 dB at 1 kHz (nominally 15 dB at 20 kHz)
Output Voltage:  3,5 mV each channel at 5 cm/sec peak recorded velocity
Load Impedance:  47 k Ω

Heathkit AA-1800 power amplifier

New Higher-Power pro-Series Amplifier - the most powerful Heathkit amp ever.
Heath Company helped pioneer the field of high-power amplifeiers. Now, advances in high-power output devices, new design technology and extensive listening tests make the Heathkit AA-1800  Pro-Series Audio Amplifier one of the best high-power amps available. The wider dynamic range achieved by new recording techniques require power and headroom to reproduce the full sound spectrum, without clipping peaks. People who listen to the AA-1800 find accurate, clearly defined music - at a wallet-pleasing price.
From the power cords to the speaker outputs, more value is built into the AA-1800. a wire-frame chassis, similar to those used in computers, makes the AA-1800 a more durable unit in a smaller package, with excellent ventilation. This new chassis simplifies the easy 24-hour kitbuilding experience, too. Two line cords with remote AC switching relieve your preamp from the need to switch high currents. Convection cooling means no fans and quieter operation. Individually fused power supply lines, along with rugged output devices, eliminate electronic dissipation limiters - which can cause tweeter-damaging clicks and pops. LEDs for each channel indicate full easy access.
Complete speaker  protection includes a speaker turn-on delay - which keeps power-up and power-down transients away from the speakers. In fact, the AA-1800's speaker protection system is so efective, we've applied for a patent.
Thermal circuit breakers protect the system from excessive heat.
Designed in the striking pro-Series style, the AA-1800 can be mounted in any EIA Standard 19-inch rack, such as the AE-1705 Pro-Series Rack. Large side handles are provided for easy rack mount installation.

Frequency Response:  20 Hz - 20 kHz ±0,1 dB;  3 Hz - 100 kHz ±1 dB (at 1 watt)
Total Harmonic Distortion Plus Noise:  0,025% (from 250 mW to 250 Watts)
TIM (DIM 100):  less than 0,03% (3,18 kHz square wave and 15 kHz sine wave mixed 4 to 1, f[c]=100 kHz, measured at rated output.
Hum and Noise (unweighted):  -85 dB (1 watt ref.)
Full Power Trip  Frequencies of Speaker Protection Circuit:  less than 16 Hz, more than 30 kHz.
Low Frequency Damping Factor:  greater than 100
Input Sensitivity:  110 mV ( for 1 W at 8 Ω)
Input Impedance:  20 k Ω, shunted by less 50 pF
Channel Separation:  60 dB min. 20 Hz to 20 kHz
Power Requirements:  120 V AC, 60 Hz
Power Consumption:  1200 Watts
Dimensions (W x H x D):   472,6 x 177,5 x 415,5 mm (19" x 7" x 16,75")
Weight:  22,68 kg ( 50 lbs)

Heathkit AA-1600 power amplifier

High-Performance Rack-Mount Stereo Power Amplifier
The AA-1600 is the first amplifier in our new series of professional-style rack-mount stereo components. Other products in the series include the AD-1701 Graphic Indicator, the AJ-1600 AM/FM Digital Tuner, and the AP-a800 Deluxe Stereo Preamplifier. In performance, specifications and sound reproduction, these products are designed to rank with the finest stereo components available anywhere.
The AA-1600 reproduces the entire musical spectrum with a clarity and definition that make it an excellent choice for use with the most demanding speaker systems. Hhum and noise are a full 100 dB down, so music springs forth from a background of total silence. Transient Intermodulation Distortion, a recently discovered form of amplifier distortion which tends to "muddy" the sound, is so low (less than 0,05%) we're one of the few manufacturers to specify it. This low T.I.M. contributes to clean, well-defined sound especially at the high end of the frequency spectrum. Fused B+ and B- power supply lines for each channel, along with especially rugged output devices, eliminate the need for dissipation limiters which can cause tweeter-damaging clicks and pops from faalse triggering.
Of course, there's complete speaker and circuit protection, including speaker turn-on delay and a thermal circuit breaker.
To assure performance to our superior specifications, the amplifier and power supply circuit boards are supplied fully assembled, tested and adjusted. Minimal point-to-point wiring and a clean, opem chassis layout contribute to easy building. The AA-1600 is designed for mounting in a standard EIA equipment rack, or for installation in the AEA-1800-1 accessory cabinet. The AA-1600 is one of the finest amplifiers Heath has ever designed, and an easy and enjoyable kitbuilding experience too. Make it a part of your music system now.

Frequency Response:  7 Hz to 50 kHz ±1 dB
Intermodulation Distortion (SMPTE):  less than 0,05% (from 250 mW to 125 watts)
Transient Intermodulation Distortion (T.I.M.) after, Leinonen, Otala and Curl:  0,05%
Damping Factor:  greater than 50
Hum and Noise:  100 dB below 125 watts
Channel Separation:  70 dB minimum
Input Impedance:  20 k Ω at 1 khz
Input Sensitivity:  1,5 Volts
Power Requirements:   108 to 132 volts, 60 Hz, (60 watts at zero output and 560 watts at full output)
Dimensions (W x H x D):  482,6 x 180,1 x 330,2 mm ( 19" x 7,125" x 13")
Weight:  17,4 kg (38-1/4 lbs)

Rotel RC-1000 pre amplifier

Rotel RC-1000
A stereo preamplifier/control center featuring a ten-octaave graphic equalizer with center frequencies of 32, 63, 125, 250, 500, 1 k, 2k, 4k, 8k, and 16 kHz. Other features include; a magnetic phono input with selectable loads of 35 k, 50 k and 70 k ohms; a moving coil (MC) phono pickup input; automatic dubbing from/to either of two recorders; and a subsonic filter for the phono input.
There are inputs for magnetic phono, MC phono, tuner, aux, and two tape. One set of stereo line level outputs is provided.
There are controls for volume, balance, ten equalizers, tape monitor/tape dubbing selector, and phono input load selection. Switches for power, octave equalizer on-off, subsonic filter, stereo/mono mode, loudness compensation, 20 dB audio muting, and input selection. Two switched AC outlets are provided.
Performance. The rated output is 1 volt, and all tests were conducted at thic value. With the equalizers in the center,, or Off, position, the frequency response measured ±1 dB from 20 to 20,000 Hz frequency. The output clipping level measured 4,2 volts, with a worse-case distortion of 0,8%.
The equalization range for each equalizer control was nominally ±12 dB at the center frequency. The worse-case distortion with full equalization applied and no more than 1 volt output measured 0,05% T.H.D. the equalizers are relatively broad band and can function either as graphic equalizers or standard tone controls if two or more controls are used to contour the frequency response. Because of their broad characteristic, the equalizers avoid the usual "peaky" midband equalization generally associated with octave equalizers.
The subsonic filter, which is in the phono channel, provides 6 dB attenuation at 10 Hz with absolutely no effect from 20 Hz up. The magneti input hum and noise measured 70 dB, stereo separation was into the noise level.
 Overall dimensions are 16-15/16-inch (wide); 3-27/32-inch (high); 11-13/32-inch (deep). Weight is 10,8 lbs.

Specificationspre Amplifier Section
Output Voltage/Impedance
Rated output :  1 V/1 k Ω
Max. Output (0,1% T.H.D.0 :  3 V/1 k Ω
Total Harmonic Distortion 9rated output, 20 - 20,000 Hz):
Output :  0,03%
Frequency Response:
Output :  5 - 70,000 Hz ±1 dB
Huma nd Noise (IHF A network):
Tuner, Aux :  95 dB
Tape Monitor 1, 2 :  95 dB
Residual :  0,05 mV ( Volume set at min.)
Input Sensitivity/Impedance:
Tuner, Aux :  150 mV/30 k Ω
Tape Monitor 1,2 :  150 mV/30 k Ω
Overload (1 kHz, 0,1% T.H.D.):
Tuner, Aux :  6 V
Tape Monitor 1, 2 :  6 V
Phono Equalizer Section:phono Equalization:  ±0,5 dB (20 to 20,000 Hz)
Huma and Noise (IHF A network):
Phono ! :  75 dB
Phono 2 (MC) :  65 dB
Input Sensitvity/Impedance:
Phono 1 :  2,5 mV/35, 50, 70 k Ω
Phono 2 (MC) :  0,12 mV/30 k Ω
Overload (1 kHz, 0,5% T.H.D.)
Phono 1 :  180 mV
Phono 2 (MC) :  10 mV
Headphones Amplifer Section (Ref. Pre Amplifier Rated Input)
Total Harmonic Distortion (1 kHz) :  0,6%
Frequency Response:  30 - 10,000 Hz +0 dB -3 dB
Huma and Noise (IHF A network):  85 dB
Residual Noise:  35 µV
Output Impedance :  4 - 16 ohms
Crosstalk (at 10 kHz):  40 dB
Control Characteristics:
Octave Equalizer (±12 dB) :  32, 63, 125, 250, 500, 1000, 2000, 4000, 8000, 16000
Loudness Contour:  100 Hz (+10 dB), 10 kHz (+4 dB)
Subsonic Filter:  15 Hz /12 dB/oct
Audio Muting:  -15 dB
Power Requirements:  120 V/60 Hz or 220 V/50 Hz or 240 V/50 Hz or 100, 120, 220, 240 V \; 50/60 Hz
Power Consumption:   16 watt max
Dimensions (W x H x D):  430 x 98 x 290 mm
Weight:  4,9 kg (10,78 lbs)

Rotel BR-1000 power amplifier

RB-1000 Power Amplifier
A stereo power amplifier FTC rated for 8 ohms at 65 watts RMS per channel, 20 to 20,000 Hz , at a distortion no higher than 0,003% T.H.D.
There is one set of line level stereo inputs. Putputs for two speaker systems. An output hold-off prevents power supply turn-on transients from being fed to the speakers. The front panel has controls for left input level and right input level. Switches for power, speaker system A, and speaker system B. two switched AC outlets are provided.
Performance. The power output per channel at the clipping level with both channels driven 20 to 20,000 Hz measured 66 watts RMS. The Frequency Response at 66 watts/8 ohms was "ruler flat" from 20 to 20,000 Hz at a distortion no higher than 0,022% T.H.D. at any frequency.
Overall dimensions are 16-15/16-inch (wide), 3-27/32-inch (high), 11-11/32-inch (deep). Weight is 15,6 lbs.

Continuous Power Output:  65 watts per channel min. RMS both channels driven into 8 Ω or 75 watts per channel both channels driven into 4 Ω from 20 Hz to 20 kHz with no more than 0,03% T.H.D.
Total Harmonic Distortion (20 Hz to 20,000 Hz): 
No more than 0,03% (continuous rated power output)
No more than 0,01% (32,5 watts per channel power output,, 8 Ω)
No more than 0,01% (1 watt per channel power output, 8 Ω)
Intermodulation Distortion (60 Hz : 7 kHz = 4 : 1):
No more than 0,03% (continuous rated power output)
No more than 0,01% (32,5 watts per channel power output,, 8 Ω)
No more than 0,01% (1 watt per channel power output, 8 Ω)
Frequency Response:  5 - 100,000 Hz +0 dB -1 dB (1 watt per channel power output, 8 Ω)
Input Sensitivity/Impedance:  1 V/20 k Ω
Damping Factor:  50 (20 - 20,000 Hz , 8 Ω)
Hun and Noise:  110 dB )IHF, A network)
Residual Noise:  150 µV
Crosstalk (10 kHz):  55 dB
Power Requirements:   120 V/60 Hz or 220 V/50 Hz or 240 V/50 Hz or 100, 120, 220, 240 V \; 50/60 Hz
Power Consumption:   500 watt max
Dimensions (W x H x D):  430 x 98 x 290 mm
Weight:  7,1 kg (15,62 lbs)

Pioneer CT-3131 cassette deck

A stereo cassette tape deck with wide frequency response range, chrome tape selector and a range of new,versatile professional features.

New tape technology has led to outstanding improvements in the sound of cassette tape, and Pioneer's new CT-3131 stereo cassette tape deck is designed to make the very most of these improvements. With its extra wide frequency response range of 30 to 15,000 Hz with the new chromium dioxide tape, the CT-3131 compares more than favorably with many reel-to-reel decks now available on the market. With its new permalloy solid head and 1,5 µ narrow gap, it deliveres sound that will start you thinking all over again about the reality of cassette tape for professional sound quality. As one of Pioneer's most advanced cassette decks, the CT-3131 is equipped with a variety of important features. It has, an automatic-stop mechanism that functions in all modes, a running pilot light, a stereo/mono changing switch and level memory marker, along with an improved electronically controlled type DC motor. And its performance specifications are nothing but first-rate. If you've ever had doubts about the use of cassette tape  in your own stereo system, today's the day you can stop doubling. And start listening to Pioneer
The CT-3131 is designed for use with the new high performance chromium dioxide tapes, which are especially made for high frequency response and dynamic stereo sound. The unit is equiped with a chrome tape selector switch that ensures you'll get the very most from these new and different kinds of tapes.

The tape head in the CT-3131 is made of permalloy and exhibits 10 times the durability of the conventional tape head. Along with the extra long-life you can expect from this head, it also delivers extended frequency response, especially in the high ranges, from its 1,5 µ narrow gap. With these tape head improvements, you can expect sound reproduction from the CT-3131 which is the equal of many expensive reel-to-reel tape decks, and even surpasses some.
Modes:  Compact cassette, 2-channel stereo, stere/mono
Tapes:  C-30, C-60, C-90, C-120 (standard, L. H., chrome)
Recording System: AC bias system (bias frequency 85 kHz)
Erasing System:  AC system
Recording/Playback Head:  Permalloy Solid Head with 1,5 µ gap
Motor:  Electronically controlled type DC motor
Wow and Flutter:  less than 0,13%
Signal-to-Noise Ratio:
Standard Tape :  48 dB
Chrome Tape :  50 dB
Frequency Response:
Standard Tape :  30 to 12,500 Hz
Chrome Tape :  30 to 15,000 Hz
Fast Winding Time:  within 80 sec (C-60 tape)
Line Input (recording line input):  50 mV/300 k Ω
Mic (microphone jack) :  0,5 mV/50 k Ω
Line Output (playback line output) :  0,775 V/50 k Ω
Phones (headphone jack) :  0,2 mW/8 Ω
Rec/P.B. (recording/playback jack) :  DIN type connector
Amplifier Section :  15 transistors; 1 thyristor; 9 diodes
Motor Section :  2 transitors; 1 diode
Power Requirements:  110-130 V/ 200-240V,  50/60 Hz
Power Consumption: 11 watts (max)
Dimensions (W x H x D):  396 x 96 x 242 mm (15-9/32" x 3-25/32" x 9-17/32")
Weight:  4,4 kg (9 lb 11 oz)