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





Harman/Kardon HK460i receiver

 

Like all Harman/Kardon receivers, the hk460i will develop much more power under peak loads than its rated 30 watts per channel

And when it comes to features, the hk460i gives you a lot more than just the basics. Like tape monitor circuitry, subsonic filter and an auto FM switch that automatically shifts the receiver into mono mode when the signal is too weak for stereo reception.

You also get a 5-level signal strength meter for accurate tuning and a station look beacon that lets you know when you're precisely tuned to the channel center.

The hk460i features a tone defeat switch that lets you bypass the tone control circuitry altogether. That means less distortion for crystal-clear, accurate reproduction when listening is critical.

The hk460i, it gigves you a full 30 watts per channel, and performs like a whole lot more.



Harman/Kardon HK350i receiver

Although conservatively rated at 20 watts per channel into 8 ohms, the new Hk350i has the ability to develop great amounts of instantaneous power to handle peak loads. The result is an economical receiver that will outperform conventional receivers of the same power rating.

To ensure optimum separation and minimum distortion under all operating conditionas, the HK350i uses phase-locked loop circuitry in the tuner section. This system senses any phase error in the broadcast system and automatically makes the necessary corrections, providing better stereo separation and Total Harmonic Distortion levels than in conventionals tuners. The Hk350i also features our new stereo blend control that allows your speakers to sound their best even when they cannot be positioned perfectly.

The HK350i lso offers more convenience features than you'd expect from an economy receiver. Like LED signal strength meter, tpe monitor function, FM muting loudness contour, and accommodations for two pairs of speakers.

The Hk350i, although it's our lowest priced receiver, it gives you the ame advanced technology found only on the most expensive esoteric equipment.

 


Specifications

Amplifier Section

RMS Power Output (into 8  , 20-20,000 Hz):  20 watts (at less than 0,09% T.H.D.

Frequency Response (at rated output):  below 3 Hz - 120 kHz (-3 dB)

Intermodulation Distortion (at rated output):  ,09%

TIM Distortion (at rated output):  ,06%

Slew Rate/Power Amplifier:  40 volts/µsec

Overall Negative Feedback:  30 dB

Hum and Noise (A-weighted):

Phono :  -85 dB

Aux :  -95 dB

Residual :  -95 dB

Phono Overall:  >100 mV

Tuner Section

FM Sensitivity MONO:  2,5 µV

50 dB Quieting Sensitivity

Mono :  3,5 µV

Stereo :  45 µV

FM Noise:  -65 dB

Capture Ratio:  2,0 dB

Alternate Channel Selectivity:  -60 dB

Stereo Separation (1 kHz):  40 dB

FM Frequency Response at Detector Output:  DC -60 kHz (-3 dB)

AM Sensitivity:  300 µV/m

Dimensions (W x H x D):  440 x 122 x 368 mm

Weight:  8,13 kg

Genesis M60 power amp

The Genesis Monoblock 60-Watt Valve (or vacuum tube) Amplifier is a limited-edition product that was created as proof of concept that a well-designed, well-executed, value-priced amplifier will be able to drive any Genesis loudspeaker with ease and authority. The transparency, detail retrieval, dynamics, and wide frequency extension of Genesis loudspeakers place great demands on the quality of amplification. Because of our emphasis on absolute fidelity™ above all else, the speakers do represent a difficult, but not impossible load for an amplifier to drive.
The M60 was created as a partner to a pair of Genesis loudspeakers, and as a result, it has the quality of amplifiers costing much more. The M60, together with a pair of Genesis loudspeakers, will give your entire music collection a whole new life. In a well set-up system, it is capable of transporting the musical performance into your room. The hiss and hum normally associated with vacuum tubes are completely absent, while retaining the richness and rightness of the best of this genre of amplifiers.

While developing a value-priced product, quality has not been scaled down. Hand-selected, precisely matched components are used throughout: custom-made military-spec paper-in-oil capacitors with aluminum cans are selectively used; the output transformers and power transformer are laboriously hand wound to precise specifications tailored to the circuit and valves used. Point-to-point wiring using solid-core silver wire is used in the entire signal path. This reduces the resistance, capacitance and inductance normally associated with ordinary printed circuit boards. Each and every unit is first burned-in on the test bench, and then run in for over 100 hours before final test and packaging.

Very little feedback is used – just enough to make the amplifier unconditionally stable. Not the excessive amount usually employed to make amplifiers measure better at the expense of musicality. The result of all this obsessive attention to detail is a fabulously musical power amplifier capable of driving almost any loudspeaker in the world.

Before using this unit, please take the time to carefully review the safety instructions and operating information contained in this Owner’s Manual and Set-up Guide. Becoming familiar with your new amplifier and the correct operating procedures will help assure you of safe usage, reliable operation, and maximum musical enjoyment.

 

About M60 Amplifier

The Genesis Monoblock 60-Watt Valve Amplifier uses proprietary circuits, high quality components, and state-of-the-art vacuum tube topology to deliver sonic performance rivaling other amplifiers costing much more. The design objectives of this product are to: 1.  Deliver musically accurate amplification, 2.  Provide a vacuum tube amplifier that would approach the reliability and ease of use of solid state amplifiers, and 3.  Provide an affordable vacuum tube amplifier that would be able to drive the Genesis family of loudspeakers. A valve amplifier matched with an appropriate loudspeaker can produce a sound that we can only call magic. The hard, brittle, and edgy presentation of many transistor amplifiers is contrasted with the rich, lush and silky sound of the tube amplifier. Often, valve amplifiers offer much better imaging and sound stage presentation compared to an equivalently priced solid-state amplifier. It is more musical, and the performance seems almost alive.

A properly designed and built valve amplifier, such as the Genesis M60, is capable of reproducing midrange and treble with crystal clear definition – the sound can only be described as smooth and silky, and musically accurate with the right timbre and harmonics.  As for the bass, the M60 is designed to maintain tight control over the bass, and deliver the powerful punch and dynamics at the low end with the solidity and weight of transistor amplifiers. 

Design and Construction

The Genesis M60 uses a single 6SL7 as an input stage in the standard mu-follower configuration with 6SN7’s in the driver stage. No ordinary 6SN7’s for the M60 though – military spec 6N8P are selected for their reliability and durability, and then hand-picked for linearity and low noise. A matched-pair of KT88 power output valves are used to deliver a very conservative 60 watts. While the M60 is developed as a value-priced product, quality has not been scaled down. Extensive listening tests were done throughout the design process, and expensive components were used where they were appropriate. Custom-made military-spec paper-in-oil capacitors with aluminum cans are selectively used and low-noise gold plated military-spec ceramic tube sockets are used throughout.

Very little feedback is used – just enough to make the amplifier unconditionally stable. Not the excessive amount usually employed to make amplifiers measure better at the expense of musicality.

During construction, all components are hand-selected and precisely matched. The output transformers and power transformer are laboriously hand wound to precise specifications tailored to the circuit and valves used.  Point-to-point wiring using solid-core silver wire is used in the entire signal path. This reduces the resistance, capacitance and inductance normally associated with ordinary printed circuit boards.

The only PCBs you see in the “guts” of the amplifier are the boards associated with biasing of the power tubes, and the soft-start electronics. The output transformers are custom designed and hand-wound with a core of grain-oriented silicon steel specifically for the output tubes used. Two output taps are provided on the secondary – 4ohm and 8ohm – with the 4 Ohm tap specifically tuned using Genesis loudspeakers. Each amplifier is extensively inspected and tested at every stage of manufacturing. It is also allowed to burn-in before the valves are biased and calibrated, and then run-in for 100 hours before finally being electronically tested prior to packing for shipment. Hence, it should come to you ready to use straight out of the box


Specifications

Rated Power Output:   60 W RMS

Frequency Response:  20 Hz - 30 kHz,   (<1% T.H.D)

Input Impedance:  250 k

Output Impedance:  4   or 8   

Signal to Noise Ratio:  >90 dB

Vacuum Tubes:  KT88 x 2;  6N8P x 2 (or 6SN7 may be used); 6SL7 x 1 (or 5691 may be used)

Dimensions (W x H x D):  480 x 185 x 380 mm (17" x 7 ¼” x 15”)

Weight:  17 kg (38 lbs)

Denon DP-2500 turntable

Direct Drive Quartz Control Turntable

Denon knows what recording and reproducing system are. The fact that Japanese radio, TV and recording studios are using Denon audio equipments and system proves it.

Model DP-2500 was developed with this technology, i.e. experience and innovation; Servo system is phase-locked to a quartz crystal oscillation ; materials and parts subject to vibration were analized with the aid of laser optics. Model DP-2500 direct-drive record player consists of this Model DP-2000 mounted on a vinyl veneered playwood cabinet; feddback insulator legs; a dynamically damped tonearm with convenient facilities.

 

Direct drive turntable assisted by quartz-lock

Quartz crystal oscillation is so stable that it is applied in a system where a very high stability and accuracy are essential against temperature change or in a long period of time. In a quartz-lock record player, rotation accuracy is brought up very high (99,998% for the DP-2000/DP-2500). Stylus pressure of cartridges or ordinary fluctuation of supply voltage or frequency can hardly disturb the speed.

The function of servo circuit forces the phase of speed data pulses to synchronize to that of quartz controlled oscillator pulses. Accordingly, speed variation in the range of low frequency (Wow) down to DC can be kept much smaller than that of conventional servo system. However, the Wow could increase if the speed detecter alignment were inaccurate (a wow per rotation could arise) or if the speed data pulse generator were poor. That is, a higher accuracy of speed data pulses is also inevitable.

Denon has established a unique method to keep the accuracy of speed data pulse generator at a professional atandard. 1000 pulses with the accuracy of 99,99% are magnetically recorded on the inside circumference of the turntable platter by a Denon exclusive method. This allows a quick response and a high gain of servomechanism and, assisted by the quartz-lock system, has driven away the wow and flutter into less than 0,015% WRMS.

 

AC motor gives quiet and smooth rotation

Signal-to-Noise Ratio or mechanical vibration (rumble) are unfortunately not under control of quartz-lock system. Instead, motor and its driving method are the keystone. The AC motor on Model DP-2000 is driven by a smooth rotation of magnetic field with an optimum condition. The result is the signal to noise ratio of 75 dB (DIN-B)

 

A unique DC brake controlls deceleration

The stop time and duration after speed change over from 45 rpm to 33-⅓ rpm are short and smooth. This has been achieved by an excellent servo system free from overshoot and by a special DC brake (Pated pending). This new type brake neither produces mechanical friction noise not causes reverse movement of platter as is the case of stopping a DC motor. So, the cartridge stylus will not be affected by an irregular motion of the turntable platter.

The electrical brake is applied at stop (or decelation) mode only and disengaged automatically after the platter is completely motionless. The turntable will be set free for easier cueing or selection of bands on the record.

 

Stroboscope lighted synchronously to the quartz oscillation

The neonlamp for speed monitoring is lighted by pulse voltage whose frequency is divided down suitable for each speed from the quartz oscillation time base. Only one strobo pattern is needed and it is completely immune to the supply source frequency which commolny lights the neon lamp in a record player without quartz-lock. Accordingly, the strobo pattern is clear and stable.

 

Turntable mat developed through vibration analysis.

New material of turntable mat for Model DP-2500 has been developed through a vibration analysis with laser beams. The new turntable mat effectively damps the vibration of record disk. The sound quality a step higher has been realized here also.

 

Dynamically damped tonearm for DP-2500

Denon has developed a dynamic damping system to effectively damp the partial resonance of tonearm pipe (patent pending). This damping system also prevents acoustic feedback to the cartridge. Through the careful study and craftsmanship, the tonearm of Model DP-2500 draws the performance of your cartridge in every detail without any modification or colouring. Anti-skating device and cueing device provide stable and convenient operation.

 

Acoustic feedback prevention

Feedback insulator legs shut off external vibrations while supporting the cabinet. Paying good attention even to small parts or components, Denon has made this cabinet most suited for deriving every benefit of combination of Model DP-2000 and the tonearm

 

Specifications

Drive System:  Direct drive by AC Servo motor

Speed Control:  frequency detection dervo system phase-locked to a quartz crystal oscillation

Speed:  33-⅓ and 45 rpm

Speed Selection:  Slide switched

Wow and Flutter:  less Than 0,015% WRMS

Signal-to-Noise Ratio:  over 75 dB (DIN-B)

Starting Time:  less than 1,5 sec (33-⅓ rpm)

Absolute Speed Accuracy:  over 99,998%

Turntable Platter:  Aluminium alloy diecast

Diameter Platter:  300 mm

Moment of Inertia of 200 kg / cm² (including turntable mat)

Tonearm

Type :  Dynamically damped, static balance type

Effective Length:  244 mm overhang:  14 mm

Tracking Error:  less than 2,5°

Cartridge Weight:  5 - 11 grams

Head Shell:  Aluminium alloy (PLC-3)

Other Facilities:  Oil damped cueing; Anti-skating

General

Cabinet:  Vinyl veneered plywood

Power Requirements:  AC 120/200/220/240 V; 50/60 Hz

Power Consumption:  15 W

Dimensions (W x H x D):  485 x 175 x 405

Weight:  12 kg

Pioneer SA-9100 amplifier

The SA-9100 is Pioneer's finest two-channel stereo integrated amplifier. Featuring a wealth of improvements in design, this distinguished amplifier offers more than just great power output, but the professional reliability that is so necessary for undistorted sound in today's advanced systems. Employed throughout all the circuit stages is a plus-minus split-power supply. In all amplifier first-stages is a differential amplifier design used in the equalizer, control amplifier and power amplifier section. The result is extraordinary stable and reliable performance exceeding the characteristics of some of the most expensive amplfiers now available. The equalizer section, for example, has a large input handling capability of 250 mV (RMS) and precise RIAA equalization within ±0,2 dB for true hi-fi sound reproduction. Signal-to-Noise ratio, distortion, and dynamic margin are also greatly improved, and the power amplifier section uses the complementary direct-coupled OCL design to provide a wide frequency response and power bandwith - with automatic electronic protection circuit. Tone control function is also unique, featuring Pioneer's new Twin Tone Control system that uses special sub tone controls plus ordinary main controls for bass and treble adjustment. With this complex arrangement, extremely high and low sound spectrum adjustment is possible - and by combining the main and sub controls, even more precise tone control characteristics may be obtained that reflect the performance of your speaker system or phono cartridge, or even the acoustical properties of your musical listening room. In terms of power, 

 


Pioneer guarantees a solid 60 watts plus 60 watts (both channels driven at 8 ohms) as the minimum standard output, and stands behind this guarantee with a factory tested data sheet which is included with each SA-9100. this power output is indicated by the continuous power output measurement, with both channels driven at 8 ohms within the all-important 20 - 20,000 Hz sound range. Versatility is top-notch, as one would expect from an amplifier of this price and quality; the SA-9100 handles up to three pairs of speaker systems, two turntables, two tape decks, two microphones,, and two additional auxiliary sound sources. There is also a level set switch that widens the optimum control range for the volume level, with stops at 0 dB, -15 dB and -30 dB. Subsonic filters are provided for both individual pre- and power-amp sections with, 12 dB/oct at 8 Hz. As ana investment in professional quality sound reproduction, the SA-9100 is totally uncompromising. It deliveres more for your money, in keeping with Pioneer's high standards. If is one of the finest high-power amplifiers now being made.

 


Specifications

Semiconductors

Transistors ;  63

Diodes ;  30

Power Amplifier Section

Circuitry :  2-stage differential amplifiers, direct coupled complementary, OCL

Continuous Power Output

20 Hz - 20 kHz (Both Channel Driven): 

60 + 60 watts at 8 Ω

75 +75 watts at 4 Ω

1 kHz (Both Channel Driven):

65 + 65 watts at 8 Ω

85 + 85 watts at 4 Ω

1 kHz (Each Channel Driven): 

75 / 75 watts at 8 Ω

 100 / 100 watts at 4 Ω

Total Harmonic Distortion: 

less than 01% (Continuous power output)

less than 0,04% (1 watt + 1 watt power output)

Power Bandwidth:  5 Hz to 40 kHz (T.H.D. 0,1%; IHF, both channels driven)

Frequency Response:  7 Hz to 80 kHz +0 -1 dB

Input Sensitivity/Impedance:  500 mV/50 k Ω (power Amp In)

Outputs

Speaker :  A, B, C A+B, A+C (4 to 16 Ω)

Headphone :  4 to 16 ohms

Damping Factor:  more than 70 (1 kHz, 8 Ω)

Hum and Noise:  more than 95 dB (IHF, short-circuited A network)

Residual Hum and Noise (8 Ω, pre- power-amp):  less than 1 mV (0,13 µ watt) 

Subsonic Filter :  8 Hz 912 dB/oct)

Preamplifier Sectin

Circuitry:

Equalizer Amplifier:  1st. Stage differential amplifier; 3-stage direct coupled SEPP NF type

Controll Amplifier:  1st. Stage differential amplifier , 3-stage direct coupled NF type

Input Sensitivity/Impedance

Phono  1 :  2,5 mV/50 k Ω

Phono  2 ;  2,5 mV to 10 mV/ 25, 50 100 k Ω

Phono Overal Level (RMS/p-p):  250 mV / 700 mV (at 1 kHz)

Mic :  2,0 mV/50 k Ω

Tuner :  150 mV/100 k Ω

Aux 1 :  150 mV/100 k Ω

Aux 2 :  150 mV to 1,5 V / 50 k Ω to 100 k Ω

Tape Monitor 1, 2 :  150 mV/100 k Ω

Tape Monitor 2 (DIN) :  150 mV/100 k Ω

Output level/Impedance

Tape rec 1, 2 :  150 mV

Tape rec 2 (DIN) :  30 mV/80 k Ω

Pre Out :  2 V/8 Ω

Total Harmonic Distortion:  less than 0,03% (20 Hz - 20 kHz)

Frequency Response:

Phono RIAA Equalization:  30 Hz - 15,000 Hz ±0,2 dB

Mic ;  10 Hz - 10,000 Hz  +0 -1 dB

Tuner, Aux, tape Mon :  10 Hz - 70,000 Hz  +0 -1 dB

Tone Controls

Bass : 

Main Control :  ±10 dB at 100 Hz

Sub Control :  ±6 dB at 50 Hz

Treble:

Main Control :  ±10 dB at 10 kHz

Sub Control :  ±6 dB at 20 kHz

Filters

Subsonic:  8 Hz (12 dB/oct)

Low :  30 Hz 912 dB/oct)

High :  8 kHz; 12 kHz 912 dB/oct0

Loudness Contour (Volume control set at -40 dB position) :  +10 dB (100 Hz)

Hum and Noise (IHF, short-circuited A network)

Phono :  more than 80 dB

Mic :  more than 70 dB

Tuner, Aux, Tape Mon :  more than 90 dB

Muting:  - 20 dB

Level Set:  0, -15, -30 dB

Miscellaneous

Power Requirements:  110, 120, 130, 220, 240 V (switchanle) 50/60 Hz

Power Consumption: 430 watts max

AC Outlets:  1 Switched ; 2 Unswitched

Dimensions (W x H x D):  430 x 138 x 341 mm (16-15/16" x 5-7/16" x 13-7/16")

Weight:  13,6 kg (30 lbs)