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





Pioneer PL-516X (1978/79)



Features:
Auto-run mechanism,
Anti-skating control.
40 mm thick particle board cabinet,
Cueing device,
Strobe light
Fine speed adjuster.
Insulator feet
Plug-in type headshell


Specifications
Turntable Section
Drive System:  Belt-Drive
Motor:  FG-servo  DC motor
Speeds:  33 and 45 rpm
Speeds Control Range:  ±2%
Turntable Platter:  320 mm  diameter, aluminum alloy die-cast
Platter Weight:  2,1 kg
Wow and Flutter:  less than 0,045%
S/N Ratio (DIN-B):  More than 65 dB (with cartridge PC-135)

Tonearm Section
Type:  Static- balance yupe, S-shaped pipe arm
Effective Length:  221 mm
Overhang:  15,5 mm
Maximum tracking error:  0,21 deg/cm  (0,525 deg/in)
Usable cartridge weight:  4 - 10 g
General
Power Requirements:  AC  120 V,  220 - 240 V, 50/60 Hz
Power Consumption:  2,3 W
Dimensions (W x H x D):  440 x 140 x 365 mm (17⁵⁄₁₆  x 5½ x 14 inch)
Weight:  7,2 kg (15 lb, 14 oz)

Cartridge Pioneer PC-135
Type:  Induced magnet type
Stylus:  0,5 mil diamond (PN-135)
Output voltage:   3 mV (1 kHz, 50 mm/s Peak velocity, LAT)
Tracking Force:  1,5 g to 2,3 g (proper 2 g)
Frequency Response:  10 - 25,000 Hz

Pioneer TX-606 (1978)



Specifications
Audio Section
Output Level: 650 mV/ 3,3 kΩ (FM 100% MOD:)
FM Section (87,5 -108 MHz)
Sensitivity:
Mono IHF: 10,7 dBf (1,9 μV)
Mono DIN:  1,0 μV (26 dB S/R , 75 ohms)
Stereo DIN:  25 μV (46 dB S/R , 75 ohms)
Signal-to-Noise Ratio (IHF stereo):  74 dB
Total Harmonic Distortion (1 kHz stereo):  0,25%
Capture Ratio:  1.0 dB
Alternate Channel Selectivity:  60 dB
Stereo Separetion (1 kHz):  40 dB;
Frequency Response  (+0.2 dB, -1 dB):  20 Hz to 15 kHz
Image Response Ratio: 60 dB
Subcarrier Product Ratio:  53 dB
Antenna Input: 300 ohms balanced; 75 ohms unbalanced
AM Section ( 525 - 1605 kHz)
Sensitivity (IHF, external antenna): 15μV
Selectivity: 30 dB
Signal-to-Noise Ratio: 50 dB
Image Response Ratio: 40 dB
Antenna: Built in Ferrite Antenna
General
Power Requirements: 110 - 220 V, 50/60 Hz
Power Consumption: 14 W
Dimensions (W x H xD): 420 x 147 x 264 mm
Weight (Without Package): 4,63 kg,

Pioneer SA-606 (1978)



Specifications
Amplifier section
Circuitry:  1-st stage current mirror loaded differential amplifier, constant current loaded all-stage direct-coupled OCL.
Continuous Power Output:  40 watts per channel (8 ohm from 20 Hz to 20 kHz, 0,05% THD)
Total Harmonic Distortion 20 Hz to 20 kHz from AUX):
Continuous rated output: No more than 0,05%
20 watts per channel power output, 8 ohms: No more than 0,3%
1 watt er channel power output, 8 ohms: No more than 0,03%
Intermodulation Distortion (50 Hz:7,000 Hz = 4 : 1):
Continuous rated output: No more than 0,05%
20 watts per channel power output, 8 ohms: No more than 0,2%
1 watt er channel power output, 8 ohms: No more than 0,02%
Output Speaker:  A, B, A+B
Damping Factor (8 ohm from 20 Hz to 20 kHz):  30
Input Sensitvity/Impedance:
Phono : 2,5 mV/50 kΩ
Tuner : 150 mV/50 kΩ
AUX : 150 mV/50 kΩ
Tape Play : 150 mV/50 kΩ
Phono Overload Level ( THD 0,05%, 1 kHz):  180 mV
Output Level/Impedance:
Tape Rec (DIN) : 30 mV/80 kΩ
Frequency Response:
Phono (RIAA Equalization): 20 Hz - 20 kHz ±0,3 dB
Tuner, AUX, Tape Play:  20 Hz - 40 kHz ±2 dB
Tone Control:
Bass : +12 dB, -10 dB (100 Hz)
Treble : +10 dB, -10 dB (10 kHz)
Loudness Contour (Volume control set at -40 dB):  +6 dB (100 Hz), +3 dB (10 kHz)
Hum and Noise (DIN, continuous power/50 W):
Phono : 58/66 dB
 AUX,  : 60/95 dB
Semiconductors:  2 x ICs, 25 x Transistors, 27 x Diodes
General
Power Requirements:  120 V - 240 V 50/60 Hz
Power Consumption:  420 W, Dimensions ( W x H x D):  420 x 147 x 261 mm (16-9/16 x 5-13/16 x 12-7/8 in)
Weight:  7,5 kg (16 lb 9 oz) net

Pioneer CT-606

 The CT-606 is designed to playback recordings of records played on your turntable or FM broadcasts heard on your tuner, prerecorded music tapes, live recordings using microphones, and tapes which have been pre-recorded. If you use the optional timer in combination with this deck, you will be able to practice unattended recordings and allow yourself to be woken up to the sweet sound of music rather than the harsh sound of an alarm clock.


Highly Reliable Tape Transport Mechanism
the model employs a DC servo-controlled motor featuring superior ability in transporting the tape at the rated speed stably. The capsran, belt, large-sized flywheel, which are all precision tape winding mechanism combine to yield top-notch wow and flutter characteristics and stability. Furthermore, the loading mechanism for the cassette is simply designed for surefire and easy operation.
Permalloy Solid Head
The recording/playback head adopts a hard permalloy core which allows the special characteristics of chrome tapes and ferrichrome tapes to be displayed to the full. With this top reliability head which provides excellence resistance to wear and a superb signal-to-noise ratio, high-quality recording and playback are quaranteed.
Dolby System for Reduced Tape Hiss
The model employs the Dolby Noise Reduction System and this markedly lowers the level of tape hiss which is annoying to the listener when a tape is played back without impairing the sound quality of the orginal program source. (Hiss reduced by 10 dB in high frequencies.) This in turn expands the dynamic range and makes for recording and playback with a high signal-to-noise ratio.
Tape Selector Switch AUtomatic Chrome Tape Selection Mechanism
The bias and equalization circuits are selected by the tape switches which allow the characteristics of all types of tapes, ranging from chrome tape and ferrichrome tapes to low-noise and standard tapes, to be displayed to the full. In addition, the built-in chrome tape selection mechanism serves to detect the special detecting holes on chrome tapes and automatically selects the chrome tape positions. The signal circuitry employs an electronic switch so that there is no noise during actual selection.
Full Auto-stop Mechanism
The full auto-stop mechanism is designed to stop the tape automatically once the tape is wound up on matter what the model of operation: recording, playback, fast forward or rewind. This means that the tape is not damaged when it comes to the end.


Specifications
Systems:  Compact cassette, 2-channel stereo
Motor:  Electronically-controlled DC motor (built-in generator) x1; (4,8 cm/s speed drive)
Heads:  One Permalloy Solid recording/playback head
Fast Winding Time:  Approx. 85 seconds (C-60 tape)
Wow and Flutter:  No more than 0,06% WRMS; no more than ±0,18% DIN
Frequency Response:
Standard, LH tapes : 30 - 14,000 Hz (40 - 13,000 Hz ±3 dB)
Ferrichrome tape:  30 - 17,000 Hz (40 - 15,000 Hz ±3 dB)
Cromium dioxide tape:  30 - 17,000 Hz (40 - 15,000 Hz ±3 dB)
Signal-to-Noise Ratio: 
Dolby OFF : More than 54 dB
Dolby ON : More than 64 dB (over 5 kHz, standard, LH tape)
(When chromium dioxide tape is used, S/N ratio is further improved by 4,5 dB over 5 kHz)
Harmonic Distortion:  No more than 1,3% (0 dB)
Inputs (Sensitivity/Max. allowable input/Impedance):
MIC (L, R) : 0,2 mV/45 mV/10 kΩ, 6 mm jack (reference Mic impedance: 250 Ω to 10 kΩ)
Line  (2-channel stereo) : 50 mV/25 V/100 kΩ
Rec/Play x 1 : Input & output : 9 mV/2 V/2,2 kΩ; 5 p jack (DIN standard)
Outputs (Reference level/Max. level/Load impedance):
Line  : 450 mV/700 mV/50 kΩ (2-channel stereo)
Headphone x 1 : 65 mV/100 mV/ 8 Ω
With output level controls
Semiconductors:
Amplifier Section:  50  Transistors (including 2 x FETs ); 35 Diodes
Motor control Section : 3 x Transistors; 1 x Diodes
Subfunctions:
Dolby system (On-Off) with indicator lamp
Tape Selector (STD/FeCr/ CrO₂)
Automatic tape selector for Chromium tape
Cassette compartment illumination
Power requirements:  AC 220 V or AC 110, 120, 130, 220, 240 V (switchable) 50/60 Hz
Power Consumption:  15 watts
Dimensions (W x H x D):  420 x 151 x 323,5 mm (16-9/16 x 5-15/16 x 12-3/4 inch)
Weight:  7,5 kg (16 lbs 8 oz) net

Pioneer CT-F 9191


The recording tape in a cassette is only an eight of an inch may be as many as 64 original tracks mixed down to two. A hundred musicians. Countless overdubbings. Not to menttion the entire audible frequency range.
Any cassette deck can reproduce part of what's been put down on that eighth of an inch.
The Pioneer 9191 was designed to reproduce all of it. Superlatively. Without dropouts, unacceptable tape hiss, or noticeable wow and flutter. 

Take our tape transport system.
Since the tape in a cassette moves at only 1-7/8 inches per second, even the most minuscule variation in tape speed will make a major variation in sound. To quard against this, where most cassette decks give you one motor, the 9191 comes with two. The first is used only for fast forward and rewind, so the second can be designed exclusively for maintaining a constant speed for paly and record.
All of our tape drive components - the capstan, belt, and flywheel - are finished to incredible tolerances. Which give the 9191 the kind of wow and flutter figures that no deck in our price range can match.
of course, having a great tape transport system means nothing if you don't have great electronics to back it up. We do.

The 9191 comes with an advanced three stage direct coupled amplifier that extends high frequency response and minimizes distortion. The built-in Dolby system can reduce tape hiss by as much as 10 decibels in high frequencies. Our multiplex filter lets you record FM broadcasts without picking up a lot of unwanted noise, or the multiplex signal every FM stereo station sends out.
Even our ferrite solid tape head offers the best combination of accuracy and long life you can get in a cassette head.

There's also a peak limiter that lets you cram as much pnto a cassette as possible without distortion. large VU meters ans a peak indicator light taht let you know if you do begin to oversaturate bias and equalization switches that let you get the most out of different brands of tape.
 And an automatic CrO2 selector. if all this isn't enough, you'll find that the 9191 comes with memory that lets you go back to a favorite spot on the tape automatically. And electronic solenoid controls for going from play to rewind, or from rewind to fast forward, without hitting the stop button. And without jamming the tape.
There's also the convenience of front loading. A door over the cassette compartment to help keep the tape heads clean. And a light behind the cassette that lets you see where you are on the tape.

Specifications
Systems:  Compact cassette, 2-channel stereo
Motor:  Electronically-controlled DC motor (built-in generator) x1; (4,8 cm/s speed drive)
DC torque motor x1 (Fast forward and rewind drive)
heads:  One Ferrite Solid recording/playback head; One Ferrite erasing head
Operation:  Solenoid drive, direct switchable and timer play presettable
Fast Winding Time:  Approx. 65 seconds (C-60 tape)
Wow and Flutter:  No more than 0,07% WRMS
Frequency Response:
Standard, LH tapes : 20 - 16,000 Hz (30 - 13,000 Hz ±3 dB)
CrO₂ dioxide tape:  20 - 17,000 Hz (30 - 15,000 Hz ±3 dB)
Signal-to-Noise Ratio: 
Dolby OFF : More than 53 dB
Dolby ON : More than 63 dB (over 5 kHz, standard, LH tape)
(When chromium dioxide tape is used, S/N ratio is further improved by 4,5 dB over 5 kHz)
Harmonic Distortion:  No more than 1,5% (0 dB)
Inputs (Sensitivity/Max. allowable input/Impedance):
Mic x 2 : 0,22 mV/100mV/30 kΩ, 6 mm jack (reference Mic impedance: 600Ω to 30 kΩ)
Line x 4 (2-channel stereo, Parallel connection system) : 65 mV.25 V/100 kΩ
Rec/Pb x 1 : Input & output, 5 p jack (DIN standard)
Outputs (Reference level/Max. level/Load impedance):
Line x 4 : 315 mV/530 mV/50 kΩ (2-channel stereo, parellel connection system)
Headphone x 1 : 40 mV/65 mV/ 8 Ω
With output level controls
Semiconductors:
Amplifier Section:  75 Transistors (including 6 x FETs ); 86 Diodes (including 5 x Zener Diodes and 2 x LED)
Motor control Section : 3 x Transistors; 2 x Diodes
Subfunctions:
Dolby system (On-Off) with indicator lamp;
MPX Filter (On-Off)
Tape Selector (STD/CrO₂) with indicator lamps
Automatic tape selector for CrO₂ tape, and Manual tape selector of independently BIAS/EQ (Ferri-chrome tape available)
Cassette compartment illumination
Mixing control used for Mic and Line input
Tape counter with rewind memory switch (On/Off) for starting point [Rew-Stop/Play (REC)]
Recording limiter (-40 dB to +5 dB)
Recording peak level indicator (Lightable level; +5 dB)
Level Memory Marker for inputs and output
Power requirements:  AC 220 V or AC 110, 120, 130, 220, 240 V (switchable) 50/60 Hz
Power Consumption:  53 watts
Dimensions (W x H x D):  457 x 197 x 315 mm (17 x 7 x 12 inch)
Weight:  13,2 kg (29 lbs) net


Trio KX-920 (1977)


Trio cassette decks are manufactured to the highhest standards of quality, to ensure stable performance over a long working life.
The following important design considerations always apply:
Sensible positioning of control functions for ease of operation.
The use of large clearly defined VU meters to ensure the accurate setting of recording levels.
Purpose-designed tape transport controls for quick smooth operation Trio cassette decks offer facilities that are purely functional, and unnecessary styling features are always avoided.

Each model incorporates the Dolby Noise Reduction system and caters for ferric, ferric-chrome and chrome dioxide tape.
The tape transport systems used are high precision devices, which have undergone rigorous test procedures, including continous operation tests of 800 hours.
All in all, it's easy tosee why Trio cassette decks have quickly gained an enviable reputation for quality, reliability and professional performance.
KX-920 Dolby cassette decks
Having truly professional features and a performance to match, the KX-920 is designed to satisfy even the most discriminating tape enthusiast.
Features:
DC servo motor driving an extra large 90mm flywheel system.
New Super-Ferrite recording/playback head.
Full mixing facilitles for microphone and line inputs.
Separate tape bias and equalization switches catering for normal, ferrochrome and chrome-dioxide tapes.
Pitch control to provide 3% speed adjustment.
Quick reaction peak recording level indicator.
Cue and Review system for precise programme selection.
Three digit tape counter.
Connections:  two microphones, stereo line input/output, stereo DIN input.output, headphones.





Specifications
Tape system:  4-track, 2 channel stereo
Tape speed:  1 i.p.s.
Usable tape: C-30, C-60, C-90 Compact Cassette
Heads:  Super ferrite
Motor: DC servo
Wow and Flutter:  0,08%
Frequency response:
Normal tape:  30 Hz - 14 kHz
Cr0₂ tape: 30 Hz -16 kHz
S/N ratio (Dolby IN):  62 dB (Cr0₂ tape)
Recording system: AC bias 85 kHz
Erasing system:  AC bias
Inputs Line:  77,5 mV/340 kΩ
DIN:  0,45 mV/1,3 kΩ
Microphone:  0,24 mV/10 kΩ
Output:  490 mV/100 kΩ
Fast forward/rewind time:  80 sec  (C-60 Compact Cassette)
Power consumption: 23 watts
power requirements:  240 V AC
Dimwnsions:  404 x 124 x 252 mm
Weight: 5,3 kg

Trio KX-720 (1977)


KX-720 Dolby cassette deck
Similar in design to the KX-920, the KX-720 retains many of its fine features at a realistic price level.

DC servo motor driving an extra large 90mm flywheel system.
New Super-Ferrite recording/playback head.
Slider control memory markers
Separate tape bias and equalization switches catering for normal, ferrochrome and chrome-dioxide tapes.
Quick reaction peak recording level indicator.
Cue and Review system for precise programme selection.
Three digit tape counter.
Connections:  two microphones, stereo line input/output, stereo DIN input.output, headphones.

Specifications
Tape system:  4-track, 2 channel stereo
Tape speed:  1 i.p.s.
Usable tape: C-30, C-60, C-90 Compact Cassette
Heads:  Super ferrite
Motor: DC servo
Wow and Flutter:  0,08%
Frequency response:
Normal tape:  30 Hz - 14 kHz
Cr0₂ tape: 30 Hz -16 kHz
S/N ratio (Dolby IN):  62 dB (Cr0₂ tape)
Recording system: AC bias 85 kHz
Erasing system:  AC bias
Inputs Line:  77,5 mV/340 kΩ
DIN:  0,45 mV/1,3 kΩ
Microphone:  0,24 mV/10 kΩ
Output:  490 mV/100 kΩ
Fast forward/rewind time:  80 sec  (C-60 Compact Cassette)
Power consumption: 23 watts
power requirements:  240 V AC
Dimwnsions:  404 x 124 x 252 mm
Weight: 5,3 kg

Aiwa AD-R470

 Nearly imperceptible quick reverse recording and playback is featured in AIWA's advanced AD-R470 cassette deck, which is certain to impress budget-minded audio enthusiasts everywhere. Amazingly quick 0,3 second auto reverse during both recording and playback is assured by AIWA's accurate radial-pivot mechanism, which turns the tape head 180 degrees in the blink of an eye.
Feather-touch full logic IC controls respond to a light touch, with Cue & Review for speedy location of desired pasages.
Sound quality features include Dolby HX Professional circuitry, which improves high frequency response regardless of the tape type, and an amorphous tape head for superb sound linearity. (The C, H, and U versions feature AIWA's super hard DX head for a corresponding level of performance.) Plus, Dolby B and C noise reduction reduce tape hiss for clear recordings that capture the dynamic  performance of today's digital and high-level analog sound sources. And, the fine bias control allows +/-20% adjustment to obtain the best response from Normal and CrO2 tapes.
 Dolby HX Professional
Not a form of noise reduction, Dolby HX professional is an advanced method for varying bias according to the characteristics of audio signals for an audible improvement in high frequency response. HX stands for "headroom extension'" and it operates during recording to dynamically adjust bias levels in response to the unput signals. This contributes to significant improvements in dynamic  range, while at the same time making possible "flatter" response in the upper frequencies. Under ordinary conditions, normal-position tapes recorded with Dolby HX professional actually outperform CrO2 tapes recorded without it in terms of high frequency response. You'll be amazed at the sound clarity and absence of distortion. Better yet, since Dolby HX professional is applied during recording only, the benefits can be heard when playing back these tapes on any playback equipment.


Plus Features:
Bi-directional auto rewind playback
Auto rec-mute
Auto tape selector: Metal/CrO₂/Normal
Rec/Play timer standby
Tape counter with reset
Headphone jack

Specifications
Track:  4-track, 2-channel
Tape Speed:  1 lps (4,8 cm/sec)
Frequency Response
Normal Tape, at -20 VU:  20 - 16,000 Hz, 30 - 13,000 Hz (±3 dB)
CrO₂ Tape, at -20 VU:  20 - 17,000 Hz, 30 - 14,000 Hz (±3 dB)
Metal Tape, at -20 VU:  20 - 18,000 Hz, 30 - 15,000 Hz (±3 dB)
S/N Ratio:  65 dB (Dolby B, Metal); 78 dB (Dolby C, Metal, above 5 kHz)
Wow and Flutter (WRMS):  0,065%
Forward and Rewind Time for C-60 Tape:  90 sec.
Head:  REC/PB: Amorphous Alloy Head (H, U and C types; DX Head)
Erase Head:  Double-gap Ferrite Head
Motors:  DC servo motor x 1
Input Sensitivity Impedance  Line-In:  50 mV/50 kΩ
Output Level Impedance
Line Out:  0,36 V/50 kΩ
Headphone:  0,14 mW/8Ω
 Power Source:  AC  110-120/220-240 V, 50/60 Hz
Dimensions (W x H x D):  430 x 127,5 x 233,5 mm
Weight:  3,3 kg

Aiwa AD-F370

 Superior AIWA performance with Remarkable Value
The AD-F370 is a superb 2-head deck with the accent on easy operation and great music fidelity. A host of advanced features make the AD-F 370 a remarkable sound value.
Operation is easy thanks to the feather-touch full logic IC controls, which also enable Cue and Review operations for the speedy location by sound of desired musical passages.
Dolby HX professional is incorporated for improved high frequency esponse regardless of tape type, while Dolby B and C noise reduction are also included to reduce tape hiss. Superb sound linearity is assured by the amorphous head. (the C, H and U versions feature AIWA's super hard DX head for a corresponding level of performance).
Plus, the fine bias control assures the best performance from Normal and CrO2 tapes, with a +/-20% range of adjustment that makes it easy to "fine Tune" bias for response that sounds best to you.
 Extra Features:
Auto repeat playback
Auto rewind playback
Auto Rec-Mute
Auto tape selector: Metal/CrO₂/Normal
Rec/Play timer standby
Tape counter with reset
Headphone jack

Specifications
Track:  4-track, 2-channel
Tape Speed:  1 lps (4,8 cm/sec)
Frequency Response
Normal Tape, at -20 VU:  20 - 16,000 Hz, 30 - 13,000 Hz (±3 dB)
CrO₂ Tape, at -20 VU:  20 - 17,000 Hz, 30 - 14,000 Hz (±3 dB)
Metal Tape, at -20 VU:  20 - 18,000 Hz, 30 - 15,000 Hz (±3 dB)
S/N Ratio:  65 dB (Dolby B, Metal); 78 dB (Dolby C, Metal, above 5 kHz)
Wow and Flutter (WRMS):  0,065%
Forward and Rewind Time for C-60 Tape:  90 sec.
Head:  REC/PB: Amorphous Alloy Head (H, U and C types; DX Head)
Erase Head:  Double-gap Ferrite Head
Motors:  DC servo motor x 1
Input Sensitivity Impedance  Line-In:  50 mV/50 kΩ
Output Level Impedance
Line Out:  0,35 V/50 kΩ
Headphone:  0,14 mW/8Ω
 Power Source:  AC  110-120/220-240 V, 50/60 Hz
Dimensions (W x H x D):  430 x 127,5 x 233,5 mm
Weight:  3,3 kg

Aiwa AD-F270 (1988)

 Advanced Features for Extra Value
The AD-F270 combines superb features with rellable AIWA quality for an excellent audio value in a quality 2-head deck. The AD-F270 boasts many features commonly found on more expansive decks, like Dolby B and C, high performance DX head, and fine bias control. A perfect blend of features, fidelity and quality, the AD-F270 is an unsurpassed value in sound enjoyment.
  Dolby B and C noise reduction out tape hiss for clear, dynamic recordings. And for the best performance from Normal and CrO2 tapes, the fine bias control on the AD-F270 gives you a +/-20% range of adjustment that makes it easy to "fine tune" bias for optimum response.
Finally, the Ad-F270 is equipped with an array of convenience features including Rec-mute functioning and timer Rec/play for unattended recording and playback with an optional audio timer. That,s your assurance of extra value.

Specifications
Track:  4-track, 2-channel
Tape Speed:  1 lps (4,8 cm/sec)
Frequency Response
Normal Tape, at -20 VU:  20 - 15,000 Hz, 30 - 12,000 Hz (±3 dB)
CrO₂ Tape, at -20 VU:  20 - 16,000 Hz, 30 - 13,000 Hz (±3 dB)
Metal Tape, at -20 VU:  20 - 17,000 Hz, 30 - 14,000 Hz (±3 dB)
S/N Ratio:  65 dB (Dolby B, Metal); 78 dB (Dolby C, Metal, above 5 kHz)
Wow and Flutter (WRMS):  0,09%
Forward and Rewind Time for C-60 Tape:  125 sec.
Head:  REC/PB: Super Hard Permalloy Head
Erase Head:  Ferrite Head
Motors:  DC servo motor x 1
Input Sensitivity Impedance  Line-In:  50 mV/50 kΩ
Output Level Impedance
Line Out:  0,4 V/50 kΩ
Headphone:  0,14 mW/8Ω
 Power Source:  AC  110-120/220-240 V, 50/60 Hz
Dimensions (W x H x D):  430 x 127,5 x 234,5 mm
Weight:  2,9 kg

Marantz Model 510 M

 The Model 510 is one of marantz's newest amplifiers in the medium to high power range, continuing their 500 series, and its styling is typical of recent products from this company. The front panel of the basic model contains two level controls, a power switch, and peak indicators; included in the "M" version we tested are two large, illuminated meters and a meter range switch.
The unit is well made and very compact, with a large encapsulated power transformer, two filter capacitors, and the cooling tunnel occupying the majority of the chassis interior. Inside the tunnel are 16 output transistors, each having a small staggered-fin radiator, across which cooling air is drawn from a temperature-controlled two-speed fan. Mounted on either side of the tunnel are the amplifier boards, which allows the transistor pins to solder directly to the printed conductors, thereby saving both space and considerable chassis wiring. The top cover is perforated and has a foam air filter mounted to its underside to keep dust and other debris from being drawn into the box. Marantz recommends periodic cleaning; this is easily accomplished by vacuuming the top surface of the amplifier. Mounting and installation of the unit is straightforward, widh details in the owner's manual.
Several inches should be allowed atop the amplifier installation for it to draw cool air, and an opening is similarly required behind the fan for warm air exhaust. All connections are made to the rear panel. Speaker jacks are the five-way binding post type, and inputs are 1/4-inch phone plugs. provided with the amplifier are adaptors to convert the inputs to the more common RCA jacks.
 Marantz tells us their design intent on the peak load indication system was to indicate the approach of clipping on peak transients, rather than an actual clipping situation. Thus, the system should not be considered as indicating an overdrive situation, as the LEDs will light up before actual clipping. the system tracks the power supply voltage so it will always give the same warning margin that clipping is approaching, regardless of the AC power line variations. While the circuit turns on in microseconds, the "hold" portion of the circuit keeps the LEDs lit long enough so they can be seen by the eye. The system indicates an actual overload condition by staying on more or less continually. Thus, 510  users should consider occasional flashing of the LEDs as full use of the normal operating range.
 Circuit Description
 Suitably attenuated input signals are a.c. coupled to the unity gain buffer amplifier, which uses Q301 and Q302 in a circuit often called an amplifier emitter follower. This stage exhibits a high input impedance which minimizes the the loading on the gain control and the preamplifier. Minimum input impedance for the 501 is approximately 31 kilohms, so preamp manufactures' specifications should be checked to ensure compatibility, especially if vacuum tube preamp models are used.
Capacitor C307 couples the buffer amplifier to the noninverting input of the differential amplifier Q304 and Q306, and feedback is applied as usual to the inverting input. Marantz has used an uncommon but simple circuit to combine both phases of output signal from the input stage, while also getting the ability to pull the driver stage hard in either the positive or negative direction. Transistor Q307 is the key to this circuit; it is connected as a common emitter amplifier to get the necessary signal inversion and voltage translocation, but degenerated to a gain slightly less than 1, in order to match its characteristics to its mate, Q308, conected as an emitter follower. It can be shown that the driving signal at the collectors of Q309 and Q310 will be relatively free of even harmonics by nature, if the transistors are chosen carefully and the resistors involved are properly balanced.
The output stage and its drivers are straightforward, being similar in design to those of other high quality amplifiers currently in production. Eight output transistors are used per channel in a complimentary, series-parallel arrangement. Such a design allows the use of low voltage expitaxial base devices, giving the composite  stage a very good safe operating area (especially important with reactive loads such as electrostatic speakers) and good current linearity as well.
V-1 limiting is employed for protection, but its action is not instantaneous, so short duration transient will not trigger unnecessary limiting. Capacitors C315 and C316 are used to accomplish this effect

Specifications
Power Output:
256 continuous average watts per channel, into 8 ohms from 20 Hz to 20 kHz with 0,05% THD.
350 average watts per channel, with similar conditions except 4 ohm loads with 0,10% THD
140 average watts per channel with similar conditions except 16 ohm loads with 0,10% THD
Intermodulation Distortion:  less than 0,1% at or below rated power using SMPTE method
One-Watt Frequency Response:  -3 dB at 2 Hz and 120 kHz
Input Sensitivity:  2,26V RMS for 256 W into 8 ohms
Input Impedance:  25 kohms, not afected by gain control setting
Slew Rate:  ±15 V/μS.
Hum and Noise:  -110 dB below rated output, 8 ohms
Damping Factor:  Greater than 100 at 1 kHz, 8 ohm load.
Phase Shift:  leading 9 degrees at 20 Hz, lagging 10 degrees at 20 kHz
Dimensions (W x H x D):  390,4 x 155,5 x 355,6 mm (15 x 6 x 14 inch)
Weight:  20,7 kg (46 lbs)

ADCOM ACE-515 (1987)

You've probably invested a lot of time and money putting together your stereo system.  So obtaining the best performance, electrical protection, and reliability from all this valuable gear is more than an option, it's a necessity. But, regardless of how sophisticated the design of your electronic equipment is, it may not be performing to full potential if it's plugged directly into an ordinary AC outlet.  Standard AC outlets often supply raw and unprocessed power that not only can diminish the clarity of audio signals, but it can also cause damage to the sensitive Integrated Circuits (ICs) inside your valuable equipment. ADCOM's ACE-515 AC Enhancer continuously avoids many of the problems caused by unreliable AC power supplies by filtering and conditioning the AC power, and eliminating "spikes" injected into the line by refrigerators, air conditioners, heating systems, atmospheric disturbances, etc.  A little-publicized fact is that many industrial centers, because of the machinery they use, inject a large number of "spikes" and other interference into the power lines. Similarly, radio transmitters can "pollute" power lines with  interference. These disturbances can be carried by power lines over very long distances and can affect AC outlets miles away. ADCOM's ACE-515 will provide, even if these disruptive signals are present at your AC outlet, both superior performance and additional protection for all the sensitive electronic equipment connected to it (up to 1800 watts total).

 Performance
The ACE-515 can not only protect but actually improve the performance capabilities of your audio or video systems. As it filters the line voltage from your AC receptacle, eliminating noise and interference, such as radio frequency interference (RFI) and electromagnetic interference (EMI), it will reduce the residual noise in the system, enhancing both audio and video clarity. Simply stated, the ACE-515 provides your electronics with the purest input power so it can deliver its purest performance.
 Protection
ADCOM has also designed the ACE-515 to protect your electronic equipment from potentially damaging high-voltage spikes and surges. The spike and surge protection built into its circuits is fast acting (less than 10 billionths of a second), and thorough (works on both sides of the AC line, and to Ground as well). For use with your audio system, the AC Enhancer is supplied with a special sequential turn-on/turn-off circuit designed to protect your speakers from turn-on/turn-off "thumps" which originate in one or more accessories and could otherwise be amplified to disturbing levels. The sequence was designed so that when you initiate the turn-on cycle, the CE-515 will energize the accessories immediately and delay power to your amplifier for 10 seconds - until the circuits in your accessories have stabilized. Only then will the amplifiers be turned on; so the thump often heard through the speakers while circuits are stabilizing will not be amplified. Similarly, when you initiate the turn-off sequence, the ACE-515 will remove AC power from the amplifier at once and hold the accessory power on for 30 seconds - until the power amplifier has completely discharged. This on/off process automatically provides your system components with power in the safest possible sequence and eliminates the need to do all this manually. And this sequencing can be advantageous when you're powering a video theater or computer system as well.

Only the ADCOM ACE-515 AC power enhancer has all of these important features:
High power-handling capability (up to 1800 W total).
Surge, spike, RFI and EMI filtering.
Correct, sequential turn-on and turn-off of your equipment.
All heavy duty electrical and structural components, outlets, power cord, etc.
Massive anodized aluminum front panel, heavy gauge steel chassis.
Safety Certification: ETL listed, and approved under UL Standard Number 498.

Specifications
Electrical:
Input Power:  120VAC, ±20%, 50/60Hz
Protection:  15A Circuit breaker
Internal Power Consumption:  Less than 10W
Control Input:  120VAC, ±20%, 50/60Hz, fused at 1 Amp
Output:  Amplifiers, 10 Amps maximum per pole continuous.
Accessories, 2.5 Amps maximum continuous
Time Delays:  Delay-on-make 10 seconds ±20%.
Delay-on-break 30 seconds ±20%
Environmental:  Operating temperature, 0 degrees C to +50 degrees C.
Storage temperature, 40 degrees C to +80 degrees C

Filter:
Filter provides reduction of both Transverse and Common Mode noise, interference and spikes (voltage transients).
Noise:  Begins attenuation above 10kHz, down 40dB at 150kHz
Maximum ContinuousAC RMS Voltage:  130
Maximum Continuous DC Voltage:  175
Transient Energy Dissipation:  11 Joules(10/1000uS)
Peak Current:  1200A
Response Time:  Less than 10 nanoseconds
Maximum Clamping Voltage:  390 at 10A (8/20uS)

Generic:
Mechanical Dimensions (W x H x D):  432 x 76 x 150 mm, (17" x  3" x 5-15/16")
Maximum Dimensions (W x H x D):  432 x 81 x 171 mm, (17" x 3-3/16" x  6-3/4")
Weight:  2,7 kg (6 lbs.)
Main AC Cord:  1,8 m (6 ft)
Control AC Cord:  1,8 m (6 ft)
Outlets.....Three, 3 prong, grounded, polarized; Four, 2-prong. polarized; Seven, total
Also available with optional white front panel. 

McIntosh MR 75

 The Mclntosh MR 75 AM-FM Stereo Tuner is a superb tuner using the latest high technology circuits. This fine tuner will discover more FM stations with good quality than ever before.

 FM AUTOMATIC FREQUENCY LOCK
The Automatic Frequency Lock (AFL) is a patented Mclntosh circuit that activates when you tune to the center frequency of an FM station. When the center ON-STATION vertical LED indicator lights, there will be no drift from accurate tuning, insuring minimum distortion and best performance.

AUTOMATIC STEREO NOISE SUPPRESSION
When listening to weak or distant FM stations, optimum stereo separation and signal to noise ratio is automatically provided by a third generation phase locked loop stereo decoder.

UNIQUE AM TUNER SECTION
The AM tuner's design is unique for a superheterodyne receiver. It has constant selectivity, constant sensitivity and high image rejection across the band. There is no loss of frequency response at the low end of the band, the only AM circuit with all these performance features.



PERFORMANCE LIMITS AND RATINGS FM SECTION
TUNING:  88 to 108 MHz
ANTENNA INPUTS:  One 300W balanced and one 75W unbalanced.
INTERMEDIATE FREQUENCY:  10.7 MHz
USABLE SENSITIVITY:  2mV (11.2 dBf) IHF
QUIETING SENSITIVITY:
5mV (19.1 dBf) IHF -50 dB (Mono)
50mV (39.5 dBf) IHF -50 dB (Stereo)
SIGNAL TO NOISE RATIO:  70 dB IHF minimum both Mono and Stereo
HARMONIC DISTORTION:
0.18% (Mono) IHF maximum
0.38% (Stereo) IHF maximum
ALTERNATE CHANNEL SELECTIVITY:  75 dB IHF minimum
IMAGE REJECTION:  100 dB IHF minimum
STEREO SEPARATION:  45 dB minimum at 1 kHz
AUDIO FREQUENCY RESPONSE:  20 Hz to 15 kHz +0, -1 dB
CAPTURE RATIO:  1.8 dB
SELECTIVITY:  75 dB IHF minimum
SPURIOUS REJECTION:  100 dB IHF minimum
SCA REJECTION:  60 dB minimum
AM SECTION
SENSITIVITY:  75mV IHF with external antenna
SIGNAL TO NOISE RATIO:  45 dB minimum IHF or 55 dB at 100% modulation
FREQUENCY RESPONSE:  + 0 -6 dB from 20 Hz to 3500 Hz
HARMONIC DISTORTION:  0.8% maximum at 30% modulation
ADJACENT CHANNEL SELECTIVITY:  30 dB minimum IHF
IMAGE REJECTION:  65 dB minimum from 550 kHz to 1600 kHz
GENERAL INFORMATION
AUDIO OUTPUT:
Variable:  2.5V into 47kW
Fixed:  1V into 47kW
AUDIO HUM:  75 dB down from 100% modulation
POWER REQUIREMENT:  120 Volts 50/60 Hz, 20 Watts
SEMI CONDUCTOR COMPLEMENT:
22 Bipolar Transistors
4 Field Effect Transistors
23 Silicon Diodes
15 Integrated Circuits
19 LED's
2 Bridge Rectifiers
MECHANICAL INFORMATION
SIZE:
Front panel measures 16 inches wide (40.6 cm) by 5 7/16 inches high (13.8 cm). Chassis measures 14
3/4 inches wide (37.5 cm) by 4 13/16 inches high (12.2 cm) by 13 inches deep (33 cm), including connectors.
Knob clearance required is 1 1/4 inches (3.2 cm) in front of 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 (net):  10,43 kg (23 pounds)