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Garrard GT-20 turntable


 The fact that the belt-driven manual turntable GT20 is the most affordable in our series may have led you to believe that we have cut corners on traditional Garrard quality.
They couldn't have been further from the truth. Consider, first of all, that it has the exact same ultra-low-mass S-shaped tonearm as our most expensive direct-drive model, and the same precisely calibrated anti-skating device to eliminate unwanted centrifugal forces.
And the same jewel-encrusted, ultra-fine pivot bearings that virtually eliminate friction, allowing you to use the highest quality cartridge systems. Consider also the heavy, die-cast aluminum platter, which is dynamically balanced for exceptionally smooth operation. And finally, consider the exquisite design, which is on par with the other models in this series.



Specifications
Operation Mode:  Manual
Turntable Platter:  Die-cast aluminium
Platter Diameter:  311 mm
Turntable Inertia:  160 kg/cm
Drive System:  Flexible belt
Motor:  4-pole synchronous
Speeds:  33-1/3 and 45 rpm
Tonearm Type:  “S” shaped aluminium
Effective Length:  230 mm
Effective Mass less Cartridge:  12 grams
Pivots:  Jewel/Ball
Stylus Force Adjustment:  Isolated calibrated counterbalanced weight
Cue Control:  Viscous damped
Usable Cartridge Weight:  4 – 9 grams
Minimum Tracking Force:  0,75 grams
Optional Cartridge:  Shure M75 ED II
Performance
Wow and Flutter (DIN):  0,06% slow weighted
Rumble:  -50 dB (DIN-A); -70 dB  (DIN-B)
Dimensions (W x H x D):  450 x 150 x 365 mm (with cover closed)


Luxman PX-101 turntable


 Luxman PX-101
Fully Automatic Tangential Tracking Turntable
The PX-101 plays back records exactly as they were cut; in a straight line. Essentially providing zero-deviation from the cutting process, as well as zero tracking error and zero tracking distortion during playback.
The advantages of tangential tracking are immediately evident. The music sounds “cleaner”, with better separation between channels, better separation of instruments within the orchestra, and a far more vivid recreation of the “soundstage”.
With the PX-101, wow and flutter is inaudible. Rumble, non-existent. Speed of 33-1/3 and 45 RPM, with a ±3% deviation available at will. Both the tonearm and headshell are constructed of improved aluminum alloy for resonance-control and damping. Fully automatic, direct-drive, it requires but a touch to operate. A built-in circuit of the PX-101 will automatically place your accompanying Luxman KX-101 or KX-102 cassette deck in the pause mode when the record you’re recording has reached the end of play. And the PX-101 is also responsive to the Infrared Wireles Remote Control system of the new Luxman RX-103 Receiver.


Features:
Tangential Tracking System – The straight tone arm of the PX-101 tracks in a straight line from the outer grooves to the inner grooves of a disc, exactly as the disc was cut. This virtually eliminates tracking errors and inside force problems; giving better stereo separation, and a more vivid recreation of the recording “soundstage”. The high performance tonearm is driven by a separate tonearm control motor, which is superior in its construction of computerized control circuits and improved stainless steel wire.
Optical Sensing Fully Automatic Function – Fully automatic, smooth, accurate response is ensured thanks to the exclusive integrated Circuit TIP and Optical Sensing Circuit. (Detection of the auto return point occurs without side-force.) Press the Start/Cut button after selecting the speed. Automatic lead in and lead out of the tonearm is activated by Feather-Touch Control. Interruption of operation during play is made easy by pressing the Start/Cut button. The tonearm automatically returns to the armrest and shuts off the motor. In the “Repeat” position, playback of the same record is endlessly repeated.
Auto Disc Pause – When activated, a built-in circuit of the PX-101 automatically places your accompanying KX-101 or KX-102 cassette deck  in the pause mode from the record mode, when the record being taped reaches the end of play. Allows you to leave the system unattended while taping.
Remote Control Capability – In combination with the RX-103 Receiver, the PX-101 Turntable may be controlled through the RX-103’s infrared wireless Remote Control. The Remote Control activates the turnable’s play, cut, cue up, and cue down functions.
Electrical Cueing and Arm Speed Switches – A touch of the Cueing Switch controls the tonearm, up and down. The Arm Speed Switch allows you to move the tonearm into position over the exact cur desired on the disc. A slight touch and the arm moves slowly; a further touch and the arm moves faster, either toward the inside or outside of the disc.
External Control Board – The controls are located outside of the dust cover, to protect discs while in play.
Detachable Head Shell – Cartridges are easy to install. The PX-101 accepts a variety of cartridges and other standard universal head shells.
Mirror Reflex Stroboscope – The unique Stroboscope system of mirror-reflection makes adjustments on accurate feed rotation easy.
Pitch Control – The speed can be adjusted by tuning pitch control up to ±3%


Specifications
Drive System:  Direct drive system
Speeds:  33-1/3 and 45 rpm
Pitch Control: ±3%
Speed Indication:  Stroboscope
Platter:  Aluminum diecast
Platter Diameter:  300 mm (12 “)
s/n (DIN-B):  70 dB 
Wow and Flutter (WRMS):  0,045%
Tonearm:  Improved Aluminum
Effective Length:  165 mm
Tracking:  Tangential
Cartridge Weight:  4 – 8 g
Stylus Pressure:  0 – 3 g
Headshell:  Detachable, improved aluminum
Arm Lifter:  Touch switch control
Auto Function:  Fully automatic, Start/Cut, Auto Repeat Switch
Dimensions (W x H x D):  440 x 115 x 405 mm (17,6” x 4,6” x 16,2”)
Weight (Net):  7,4 kg (16,3 lbs)

Sony STR-VX250 receiver


 Sony Direct Access Receiver

Key Selling Feature: Direct Access
Within the past years, the accuracy of quartz frequency synthesis tuning has become increasingly available in popular priced receivers. It’s available in this Sony. However, this receivers offers another feature which is not available on other receivers – the convenience of Direct Access tuning. With this system, your customers can directly “key-in” their station frequencies then memorize them by entering the station into the presets.

Key Demonstration
Ask your customer for the frequency of his favourite station. If it’s FM, have him press the FM button first, then, have him enter the numbers on the receiver keypad. If, for instance, the station is 102,70 FM, he should press FM, then one-zero-two-seven-zero. A final zero needs to be added to complete the access. Then perform an additional demo, show the customer how the receiver can find stations without complete information. Press one-zero-two- and then press the “+” button. The receiver will scan up and find the station. To complete the demo, enter this station as a memory preset. After the station is tuned, press memory, then key marked1. This will preset the station.

Convenience Features
Direct Access – design for easy convenience tuning
8 station random access – presets for fast recall favourite stations
Station card – insert to mark preset stations
Auto Tuning – between FM stations
Fluorescent display – indicates station frequency and function
Tape Monitor
Memory backup system – retains memory settings – even it the recover is unplugged
Speaker Switch: A, B, A&B, Off

Technology Features
Quartz Frequency Synthesis – provides the most accurate, most convenient tuning available


Specifications
Amplifier Section
Continuous Power Output (RMS)
25 watts per channel, both channels driven into 8 Ω  from 40 Hz to 20 kHz, at no more than 0,8% Total Harmonic Distortion.
20 watts per channel, both channels driven into 4 Ω  from 20 Hz to 20 kHz, at no more than 0,08% Total Harmonic Distortion.
Total Harmonic Distortion
0,08% from 20 Hz to 20 kHz , 20 watts , 8 Ω
Intermodulation Distortion
0,08% (60 Hz : 7 kHz = 4:1) , 20 watts , 8 Ω
Damping Factor:  30
Frequency Response
Phono : RIAA standard curve +0,5 dB -0,5 dB
Tape, Aux :  10 Hz - 50,000 Hz -3 dB
Input Sensitivity/Impedance
Phono:  2,5 mV/ 50 k Ω
Tape, Aux :  150 mV/50 k Ω
Signal-to-Noise Ratio
Phono :  72 dB (IHF-A); 76 dB (new IHF) at 2,5 mV
Tape, Aux :  94 dB (IHF-A); 74 dB (new IHF) at 150 mV
Speaker Impedance
8 - 16 Ω  A or B
8 - 16 Ω  A and B
Tuner Section
Usable Sensitivity
Mono :  11,2 dBf (2,0 µV)
50 dB Quieting Sensitivity:
Mono :  17,3 dBf (4,0 µV)
Stereo :  38,3 dBf (45 µV)
Signal-to-Noise Ratio
Mono :  75 dB
Stereo :  70 dB
Total Harmonic Distortion at 1 kHz
Mono :  0,2%
Stereo :  0,3%
Alternate Channel Selectivity, 400 kHz :  60 dB
Frequency Response:  30 Hz - 15,000 Hz +0,5 dB -2 dB
Stereo Separation:  45 dB at 1 kHz
AM Suppression:  54 dB
AM Sensitivity:  300 µV/m (built-in antenna)
AM Signal-to-Noise Ratio:  54 dB at 50 µV/m
AM Selectivity:  40 dB
General
Power Supply:  AC 120 V, 220 - 240 V, 50/60 Hz
Power Consumption:  65 watts (UL)
Power Outlets:  100 Watts switched; 100 Watts unswitched
Dimensions (W x H x D):  430 x 105 x 305 mm (17" x 4-1/4" x 12-1/8")
Weight:  5,6 kg (12 lbs 5 oz)
Supplied Accessories:  FM ribbon antenna; Memory system batteries “AA” x 2

Dual 1229Q turntable

Motor and Pulley
Power for the turntable platter and the changing mechanism is supplied by a four—pole Dual continuous pole synchronous motor suspended by radially located elastic mounts and having a very small stray magnetic field and little vibration. The speed of the motor is independent of line voltage, temperature or load variations. Speed is dependent on, and proportional to power—line frequency. The motor is adapted to 50 or 60 cycle (Hz) power—line frequencies by the correct choice of motor pulley.

The motor pulley is fastened to the motor shaft by a setscrew. When you change pulleys, be sure that the new pulley is set at the correct height The turntable platter is driven by the idler wheel, which, to prevent damage to its friction surfaces, is automatically disengaged when the unit is shut off. Setting the turntable speed to 33 1/3, 45 or 78 rpm is done by raising or lowering the idler to bear against the proper step of the motor pulley. Upon actuation of the switch, the switch segment rotates. This causes the lever fitted into a slot on the segment to move vertically. The drive wheel carried on the swinging arm is then lifted off the motor pulley, moved and replaced on the motor pulley step corresponding to the selected speed.



Tonearm and Tonearm Bearing
Tubular tonearm, extra lightweight, torsionally rigid tonearm of the Dual 1229 Q pivots both horizontally and vertically on needle bearings and precision ball bearings in hardened and polished races. lt is suspended in a gimbal arrangement. This keeps friction to a minimum.
Vertical pivot friction = 0.007 gram
Horizontal pivot friction = 0.015 gram
referred to stylus tip
The arm is thus able to track extremely well. The tonearm head is removable. Before setting the tracking force for the cartridge being used, set the tracking—force scale to zero and balance the tonearm. Initial balance is by sliding the counterweight .Final adjustment is by turning the weight. You can balance cartridges with a weight of 1 to 10 grams.
To reduce the effects of small shock impulses on the arm, the counterbalance weight is resiliently mounted on a threaded spindle, and friction—braked to prevent accidental rotation. The cartridge holder will accept all cartridges with international standard mounting centers of 1/2 inch. Stylus force is set by turning a calibrated housing which stresses or releases a spiral spring contained inside. The scale adjustment is calibrated from 0 — 3 p, from 0 — 1.5 p at 1/10 p and from 1.5 — 3 p at 1/4 p intervals. Tracking forces of mors than 3 p can be adjusted with the help of the counter—weight on the tonearm; turning left (counter—clock—wise) increases the tracking force by 1/2 p per complete turn.



Specifications
Drive : Dual synchronous/continuous-pole motor, with radial elastic suspension
Platter:  Non-magnetic,  dynamically balanced
platter Weight:  3,1 kg
Platter Diameter:  305 mm
Platter Speeds:  33-1/2 ; 45 and 78 rpm
Pitch Control:  Range of variation, one semitone (6%), on all three speeds
Stroboscope:  For 33 1/3 and 45 rpm speeds. I Iluminated by special neon glow lamp
Speed Variation:  less than  ± 0.06% according to DIN 45 507
Noise (Measured according to DIN 45 500): 
Rumble 42 dB below standard signal 
Weighted audible rumble 63 dB below standard signal
Tonearm:  Torsionally rigid, extra-long tubular tonearm in four-point gimbal type bearing
Maximum Tracking Error:  0.16°/cm
Tonearm Bearing Friction (referred to stylus tip) 
Vertical : less than  0.007 gram
Horizontal : less than  0.015 gram
Tonearm Head (cartridge holder) :  Removable, accepts all cartridges weighing 2 to 10 grams and having standard 1/2" mounting centers
Current Type:  AC 50 or 60 cycle, with appropriate motor pulleys
Line Voltage:  110/130 V and 220/240 V selector
Power Consumption:  < 10 watt
Current Requirements
approx. 62 mA at 220 V 50 cycle
approx. 115 mA at 110 V 60 cycle
Dimensions (W x H x D): 14-3/4" x 3" x 12"
Weight:  7.2 kg unpacked
 

Dual 1228 turntable


 Motor and Drive
Power for the turntable platter and the changing mechanism is supplied by a four-pole, split-pole synchronous motor suspended by radially located elastic mounts and having a very small stray magnetic field as well as little vibration.
The speed of the motor is independent of line voltage, temperature or load variations. Speed is dependent on, and proportional to, power line frequency. The motor is adapted to 50 or 60 cycle (Hz) power line frequencies by the correct choice of the motor pulley.
The platter is driven by the idler wheel which is automatically disengaged from the motor pulley when the unit is shut off in order to protect its driving surface.
Platter speeds of 33-1/3 and 45 rpm are selected by raising or lowering the idler wheel to the appropriate step on the motor pulley.


Tonearm
The Dual 1228 has a light, torsionally rigid metal tonearm in a gimbal type suspension. The actual support is provided by four hardened and precision-polished steel points resting in precision ball bearings. Tonearm pivot friction is thus reduced to a minimum.
It therefore guarantees exceptionally good tracking characteristics. The tonearm head is removable. Before setting the correct stylus force for the particular cartridge installed in the tonearm head, the tonearm should be balanced with the stylus force setting dial at the zero position. Coarse balancing is accomplished by sliding the counterweight and using setcrew, after which a fine adjustment is made by turning the weight. The counterweight is proportioned so that cartridges with a weight of from 1 to 12 grams can be balanced. For the absorption of vibration and rapid small shocks, the counterweight is coupled to its threaded shaft through an elastic medium, and braked to prevent unintended rotation. The tonearm head accommodates all cartridges that conform to the internationally standard ½ inch mounting centers, and whose weight does not exceed 10 grams. Stylus force is set by turning apring housing, which is equipped with calibrations and which stresses or relaxes a spiral spring inside it. The scale is calibrated for a range of zero to 5 grams, and permits exact settings every 0,5 gram within that range.



Specifications
Drive:  4-pole synchronous motor
Platter:  Non-magnetic
platter Weight:  1,4 kg
Platter Diameter:  270 cm (10,5 inch)
Platter Speeds:  33-1/2 and 45 rpm, automatic tonearm setdown coupled to speed selector
Pitch Control:  Adjustment of approx. 1 semi-tone (6%) at both platter speeds
Speed Check:  with light stroboscope for platter speed of 33-1/3 and 45 rpm adjustable for 50 or 60 Hz
Wow and Flutter:  less than  ±0,00 % rated in accordance with DIN 45 507
Signal-to-Noise-Ratio:  (in accordance with DIN 45 500)
Better than  58 dB at rumble s/n
Better than 39 dB at rumble unweight ted s/n
Tonearm :  Torsion resistant, aluminum tonearm in universal four-point gimbal suspension
Tonearm Bearing Friction
Vertical :  <  0,008 p
Horizontal :  less than 0,18 p
Pick-up Head (Cartridge Holder):  Removable, suitable for acceptance of all cartridges having ½” mounting and a deadweight of 2 – 8 gram (including mounting fixtures)
Stylus Pressure:  Continuously-adjustable from 0 – 10 p, reliable as from 0,5 p stylus pressure
Current Type:  AC 50 or 60 cycle, with appropriate motor pulleys
Line Voltage:  110/130 V and 220/240 V selector
Power Consumption:  less than  10 watt
Current Requirements
approx. 64 mA at 220 V 50 cycle
approx. 115 mA at 110 V 60 cycle
Dimensions (W x H x D):  13" x 5" x 10-3/4"
Weight:  4,3 kg

Dual 1226 turntable


AUTO/Standard Turntable
The 1226 is likely to become known as Dual's "best buy" automatic. It shares all of Dual's standard features with the higher priced Duals, plus such refinements as the rotating single=play spindle. The platter of the 1226 is a one-piece die-casting that weighs a full four pounds. It is driven by a high torque motor which brings the platter to full speed in less than a half revolution and maintains speed within 0,1% despite wide variations in line voltage. Tonearm pivots with special low-friction bearings assure flawless tracking at as low as 0,75 gram



Specifications
Drive:  4-pole Dual synchronous motor with vertically adjustable drive pulley
Platter:  Non-magnetic
Platter Weight/Diameter:  1,45 kg or 1,8 kg/270 mm
Platter Speed:  33-1/3 and 45 rpm
Automatic tonearm set-down coupled to speed selection
Pitch Control Variation:  Adjustment range of approx. 1 semitone (6%) at all both platter speeds
Wow and Flutter (according to DiN 45 500):  
Less than ±0,12% with 1,8 kg platter
Less than ±0.15% with 1,45 kg platter
Rumble:(according to DIN 45 500)
Unweighted:  less than 38 dB
Weighted :  ,57 dB
Tonearm :  Torsion-resistant tubular aluminium tonearm in self-adjusting pivot bearing
Tonearm bearing Friction (related to stylus tip):
Vertical :  less than 0,01 gram
Horizontal :  less than 0,04 gram
Stylus Pressure:  from 0 to 5 grams infinitely variable, operable from 0,5 gram stylus pressure up
Cartridge Holder:  removable, accepting any cartridges with 1/2" ,mounting and a weight from 2 to 10 grams (including mounting hardware)
Power Supply:  110 - 130 V and 220 - 240 V, AC 50/60 Hz
Power Consumption:  less than 10 watts
Current Drain
64 mA approx. At 220 V , 50 cycle
115 mA approx. At 110 V, 60 cycle
Dimensions (W x H x D):  13" x 5" x 10-3/4"
Weight:  13 lbs

Technics RS-M250 cassette deck


 Technics RS-M250

A new cassette deck from Technics, the RS-M250 , is packed with a tremendous variety of convenience and handling features. And, as with all technics cassette decks, its performance represents excellent value – the RS-M250 is capable of making recordings which are virtually indistinguishable from the original program source. In fact, on a price/performance basis, Technics products traditionally have compared quite favourably with those of our competitors. The new Technics cassette deck line is no exception – it offers outstanding value at all price levels.

Versatile Microprocessor
Simply turning on the power will show you that the RS-M250 is different from other cassette decks . notice, for example, the digital tape counter. The readout is large and bright, and can be seen from across the room. One count of the counter corresponds to 2 rotations of the reels. Yet it is more accurate than many similar devices because it includes 4 fractional divisions which break down the readout more precisely – half-turns of the take-up hub can be accurately measured. But the readout is only part of the story.
Suppose you want to repeat a track on the tape, or refer back to any point on the recording. It’s easy with the RS-M250 and its microprocessor. The memory has four settings; “stop”, “off”, “play”, and “repeat”/ in the “repeat” mode , you simply press the reset button at the point on the tape you want to recall. Then, a touch of the rewind button will return the transport to this spot, where it will automatically switch into play. If allowed to continue and play the remainder of the side, the microprocessor will then instruct the transport to return to “000” where, once again, playback begins. “Play” works the same way, except that it doesn’t repeat, and “stop” simply returns the tape to the “000” point without beginning playback. For checking recordings, or finding an exact point on the tape for future reference, the RS-M250 is a very convenient deck at a reasonable price.

Effortless, Error-Free Mode Changing
The transport controls are logic-controlled switches. There’s no need to use the stop button when changing modes – just go directly into any mode (except record), including rewind, fast forward, and play. And when recording, a touch of the record button also engages both the play and the pause mechanisms automatically – then just touch the play button to begin recording. Thus, you avoid the difficulties and inconvenience of having to engage all these controls separately and manually.
If you want even more convenient operation, use the optional RP-9645 remote control module. You can control all transport functions, plus record muting, from the comfort of your listening position. There is even a convenient front panel input jack for connecting the remote control unit; when not in use, a special cover protects the jack from dust and impurities.

Simple-to-Use Features
We believe that convenience features are worthwhile only if they are easy to use – all the RS-M250’s features can be engaged and used with a minimum of effort. For example, we provide a switch which allows the use of an external timer, and the hook-up is extremely simple – the entire operation can be controlled from the front panel. The same point of view explains the door on the cassette well.  It is removable for easy access to the heads for examination or cleaning. No bolts or screws – the door simply slides into place. As you can see, the RS-M250 is designed for simple operation of all functions.



Performance
Of course all the features in the world aren’t worth much if the deck lacks good basic performance characteristics. Fortunately, the RS-M250’s performance is superb, particularly in light of its modest price tag. A glance at the spec table will demonstrate our devotion to quality. And the tapes which you make with the RS-M250 will sound consistently clean, crisp, realistic, and natural. We have also included the necessary extras to ensure this excellent performance undervirtually any circumstances.

Meters
For example, our FL peak reading meters employ a peak hold readout – this means that peaks are retained on the meter for 2 seconds. Then the meters automatically reset until the next peak comes along. The 2 color readout clearly indicates the 0 dB point, so you can be sure that the recording level will always be accurate. Result? Tape recordings with low noise, low distortion, and superb fidelity.

Tape Selector Switch
Naturally, we have included a selector switch to set bias and equalization for metal tape , the latest technological advance in the cassette medium. This formulation also necessitated an improvement in the saturation flux density of the recording head itself – our improved SX record/playback head yields exemplary performance with any type of tape. The Sendust formulation also assures a long life for the head with only normal routine maintenance.

FM Recording
Recording a program from an FM signal source will also yield a very high quality recording. The front panel MPX filter switch removes the carrier pilot signal from the tape input, thereby avoiding the distortion associated with this signal.
The Technics RS-M250 – an excellent combination of fine basic performance and the features to make the deck flexible enough for a wide variety of applications. Plus, it includes something which has become a Technics tradition – outstanding value for the money.

Other Features:
2 motor drive system – one for driving the capstan and another powers the reels and the head block during transport mode switching. This system contributes to low wow and flutter and good reliability.
Input selector switch – allows you to choose between “line” and “mic” inputs. If “mic” is selected, you can utilize the 2 front panel microphone jacks.
Dual concentric input level controls – friction coupled knobs, for adjusting one channel at a time, or both together.
Output level control – useful for matching the volume output of the deck to that of your tuner and turntable, so there’s no need for repeated adjustments in volume



Specifications
Track System:  4-track, 2-channel stereo recording and playback
Tape Speed:  4,8 cm/s (1-7/8 ips)
Wow and Flutter: 0,04% (WRMS)
Frequency Response
Metal Tape :  20 – 20,000 Hz  [30 – 17,000 Hz  ± 3 dB ]
CrO₂/FeCr Tape :  20 – 18,000 Hz  {30 – 16,000 Hz  ±3 dB ]
Normal Tape :  20 – 17,000 Hz  [30 – 15,000 Hz  ±3 dB ]
Signal-to-Noise-Ratio: 
Dolby NR In :  67 dB  (above 5 kHz)
Dolby NR Out :  57 dB  (signal level =max recording level, CrO₂/FECr type tape)
Fast Forward and Rewind Time:  Approx. 80 sec. with C-60 cassette tape
Inputs Sensitivity/Impedance
Mic :  0,25 mV/50 k Ω  (applicable microphone impedance 400 Ω  – 10 k Ω )
Line :  60 mV/ 47 k Ω 
Outputs Level/Impedance
Line :  700 mV/3 k Ω  or less (load impedance 22 k Ω  over)
Headphone :  85 mV/8 – 125 Ω 
Bias Frequency:  85 kHz
Motors 
1 electronically controlled DC motor for capstan drive
1 DC motor for reel table drive
Heads 
1 SX (Sendust  Extra) head for record/playback
1 double gap ferrite head for erasure
Power Requirements:  AC 120 V, 50/60 Hz
Power Consumption:  20 W
Dimensions (W x H x D): :  430 x 119 x 293 mm (16-7/8” x 4-3/4” x 11-1/2”)
Weight:  5,1 kg (11 lbs 3 oz)

Technics RS-B665 cassette deck

Technics RS-B665

Quartz Direct Drive Stereo Cassette Deck
the RS-B665 direct drive cassette deck clarifies the Technics technological lead in this realm. The motor uses an improved planar opposed design for its amazingly high torque while individual balancing of each flywheel prevents torque ripple. For precise servo control, the RS-B665 digitally compares the motor’s FG pulse to a quartz reference frequency. This direct comparison greatly improves rotational precision. So musical details come through in their original pure state.

2-Motor Tape Transport
A division of labor results in greater reliability of the tape transport mechanism. The high-torque DD motor drives the critical capstan, while a second motor drives the supply and take-up reels. Microprocessor full-logic control coordinates motor activity for smoothly integrated task performance.

Linear Magne-Field Class AA Circuit
Located after the recording amp. The Linear Magne-Field Class AA circuit overcomes the typical non-linearity occurring during electromagnetic transduction in the tape heads. The key is a refinement of the Technics Class AA circuit technique which prevents phase shift and avoids loss of mid-to-high frequency gain caused by head-coil inductance.

Dolby HX pro
HX Pro extends the headroom of virtually any tape, allowing it to record more high frequency information without overloading and causing distortion.

PXS Capacitors
Developed specially for improved sound quality. PXS capacitors are employed in various locations in the deck circuitry, including the power supply. This new technology helps preserve the fidelity of the original audio signal

Bias Fine Adjustment
You can “fine tune” the recording bias to maximize performance of your favorite tape formulations (Normal, cro2)

APRS (Advanced Precise Rec Level System)
Now APRS simplifies location of the ideal recording level. Since the meters hold the highest peak reached in your source program, you simply adjust the rec-level knob until the meters indicate the optimum setting. Great for use with the peak level search function in Technics CD players.

Dual-Range Peak-Hold Meters
For fine adjustments of recording level you can switch the meter range so that it indicates a range from -7 dB to +8 dB in 1 dB steps (instead of the usual -30 dB to +16 dB )

Linear Electronic Counter with memory Stop/Repeat
This 4-digit display shows elapsed tape time in minutes and seconds. Or you can switch it to work as a 3-digit counter. In whichever counter mode, you can have the tape stop automatically at the “00:00” or “000” position. Repeated play is also possible

More Valuable Features
microprocessor-controlled feather-touch operation
Phase Compensation Circuitry (PCC) in playback amp.
Dolby B-C NR systems
MPX filter on/off switch
Non-resonant TNRC base
Large insulating feet


Specifications 
Deck System:  Stereo cassette deck
Track System:  4-track, 2-channel
Heads
Rec/Play :  Permalloy head
Erasure :  Double-gap ferrite head
Motors
Capstan Drive :  Quartz direct drive DC motor
Reel Table Drive :  DC motor
Recording System:  AC Bias
Bias Frequency:  80 kHz 
Erasing System:  AC erase
Tape Speed:  4,8 cm/sec (1-7/8 ips)
Frequency Response: 
Normal :  30 Hz  – 16 kHz (± 3 dB ) [20 Hz  – 16 kHz  (DIN)]
CrO₂  :  30 Hz  – 16 kHz (± 3 dB ) [20 Hz  – 17 kHz  (DIN)]
Metal  : 30 Hz  – 18 kHz (± 3 db) [20 Hz  – 18 kHz  (DIN)]
Signal-to-Noise-Ratio:  (signal level=max recording level, CrO₂ type tape)
Dolby C NR On :  74 dB  (CCIR)
Dolby B NR On :  66 dB  (CCIR)
Dolby NR Off :  56 dB  (A weighted)
Wow and Flutter:  0,05% (WRMS) ± 01,15% (DIN)
Fast Forward and Rewind Time:  appox. 90 sec C-60 tape
Input Sensitivity/Impedance:
MIC :  0,25 mV/400 Ω  -10 k Ω 
Line-IN :  60 mV/47 k Ω 
Output Voltage/Impedance
Line Out :  400 mV/800 Ω 
Headphones :  125 mV/8 Ω 
General
Power Consumption:  21 W
Power Supply:  AC 50/60 Hz , 240 V
Dimensions (W x H x D):  430 x 135 x 290 mm
Weight:  4,9 kg (10,8 lb)

 

Toshiba SS-47 loudspeakers


3-way concave speaker system
3-step tweeter/mid-range tone control
Terminals for electronic cross-over multi-channel system
Natural walnut cabinet with removable grill panel

Specifications
Enclosure:  Infinite Baffle type
Mounted Speakers:
Woofer :  300 mm (12") concave
Mid-range :  120 mm (5") concave
Tweeter :  25 mm (1") dome
Frequency Range:  35 - 20,000 Hz
Crossover Frequency:  700 Hz (Low/Mid-range);  7,000 Hz (Mid/High)
Power Handling Capacity:  50 W Max.
Impedance:  8 Ω
Sensitivity:  93 dB /IEC
Fundamental resonance Frequency:  60 Hz
Timber Control:  Tweeter/Mid-range 3-step ±3 dB
Multi-amp. Connection:  2 & 3 way
Front Panel:  removable 
Dimensions (W x H x D):  400 x 680 x 330 mm (15-3/4" x 26-3/4" x 13")
Weight: 15 kg (33 lbs)

Toshiba SS-37 loudspeakers


3-way speaker system
3-step tweeter/midrange tone control
Terminals for electronic cross-over multi-channel system
Natural walnut cabinet with removable grill panel

Specifications
Enclosure:  Infinite Baffle type
Mounted Speakers:
Woofer :  200 mm (8") concave
Mid-range :  120 mm (5") concave
Tweeter :  25 mm (1") dome
Frequency Range:  40 - 20,000 Hz
Crossover Frequency:  700 Hz (Low/Mid-range);  7,000 Hz (Mid/High)
Power Handling Capacity:  40 W Max.
Impedance:  8 Ω
Sensitivity:  92 dB /IEC
Fundamental Resonance Frequency:  65 Hz
Timber Control:  tweeter/Mid-range 3-step ±3 dB
Dimensions (W x H x D):  342 x 590 x 295 mm (13-7/16" x 23-1/4" x 11-5/8")
Weight: 10 kg (22 lbs)

Toshiba SS-27 speakers


2-way speaker system
3-way high frequency level control
Mellow walnut cabinet with removable grill panel

Specifications
Enclosure:  Infinite Baffle type
Mounted Speakers:
Woofer :  200 mm (8") concave
Tweeter :  25 mm (1"0 dome
Frequency Range:  45 - 20,000 Hz
Crossover Frequency:  7,000 Hz
Power Handling Capacity:  30 W Max.
Impedance:  8 Ω
Sensitivity:  93 dB /IEC
Fundamental resonance Frequency:  85 Hz
Timber Control:  High 3-step ±3 dB
Dimensions (W x H x D):  300 x 500 x 252 mm (11-13/16" x 19-11/16" x 10")
Weight: 6 kg (13- 1/4 lbs)

Toshiba PT-490 cassette tape deck


 Toshiba – Now you can record on a Dolby cassette deck for 2 straight hours without flipping the tape.
Recording Beethoven’s  4th, 5th and 6th on one continuous taping. Or playing a two hour tape of The Beatles without even being in the same room. Or catching yourself in duet with Brubeck and not having to stop flip the tape. Well, if your cassette deck is a Toshiba PT-490 with the automatic reverse feature it’s easy.
Just set the Mode dial and the machine knows exactly what you want it to do. Whether you want it to record one side of the tape and then stop. Or play and turn itself off. Or record both sides of the tape for two uninterrupted hours. Or play back the same tape indefinitely. The machine does it all for you. And it does it automatically.
In addition to reversing its own tape, the PT-490 also gives you outstanding performance and sound. That’s because it comes with Dolby noise reduction. Mechanical auto shut-off. Separate record and playback volume controls. Two large, illuminated VU-meter. And a bias selector switch for normal, hi-fi and CrO₂ tape. And it’s one more example of the fine craftsmanship that goes into all Toshiba products.

Stereo Cassette deck
Features
Dolby noise reduction for improving Signal-to-Noise-Ratio as much as 10 dB
Mechanical automatic shut off prevents tape and mechanism damage
Tape counter for easy and simple tape indexing
3-step tape selector permits suitable bias level and appropriate frequency compensation for any kind of tape
Push-to-start/push-to-release type pause-control for recording level preset, preventing waste of tape when recording
Playback volume control gives suitable output level to any amplifier
Large and illuminated level-meter for easy monitoring of level
Automatic reverse system


Specifications
Usable Tape:  Compact cassette
Tape Speed:  4,8 cm/s (1-7/8 ips)
Track/Channel :  4-track / 2-channel stereo
Bias and Erasure:  AC 85 kHz
Input Jack:  Microphone, Line-input, DIN
Output Jack:  Line-output, Stereo headphone, DIN
Motor:  4-pole synchronous motor
Controls:  Slide volume (REC, playback), tape selector (Normal, HiFi, Special), mode selector (Non-reverse, reverse, repeat), power switch, Dolby system switch
Operations:  Piano type push button (reverse, REC, REW, Play, F.F., Stop, Cassette-up, pause)
Auxiliary Device:  Auto-reverse, auto-shut off, Dolby noise reduction, lighted 2-VU meters, 3-digit tape counter
Performance
Output Level/Impedance:  0 - 1 V/ 2 k Ω
Frequency Response:  30 - 15,000 Hz
Tape Speed Tolerance:  ±1%
Wow and Flutter:  0,1% WRMS
CrossTalk:  60 dB
Channel Separation::  35 dB
Signal-to-Noise-Ratio:  50 dB or 60 dB (with Dolby noise reduction) at 10 kHz, 50 dB or 55 dB at full spectrum
Erasure:  65 dB
Input Level/Impedance
Line-in :  80 mV/680 k Ω
DIN IN :  0m,56 mV/5 k Ω
Mic:  0,56 mV/ 10 kΩ
FF Time:  105 sec. (C-60 cassette)
Rewind Time:  105 sec. (C-60 cassette) 
General
Power Source:  AC 100/120/220/240 V, 50 or 60 Hz
Dimensions (W x H x D)::  425 x 140 x 290 mm (16-7/8" x 5-1/2" x 11-1/2")
Weight:  8 kg (18 lbs)
Accessory:  Patch cord, C-30C pre-recorded cassette, 

Toshiba PT-470 cassette deck


 Stereo Cassette deck PT-470
Features
Dolby noise reduction for improving Signal-to-Noise-Ratio as much as 10 dB
Mechanical automatic shut off prevents tape and mechanism damage
Tape counter for easy and simple tape indexing
3-step tape selector permits suitable bias level and appropriate frequency compensation for any kind of tape
Push-to-start/push-to-release type pause-control for recording level preset, preventing waste of tape when recording
Playback volume control gives suitable output level to any amplifier
Large and illuminated level-meter for easy monitoring of level


Specifications
Usable Tape:  Compact cassette
Tape Speed:  4,8 cm/s (1-7/8 ips)
Track/Channel :  4-track / 2-channel stereo
Bias and Erasure:  AC 85 kHz
Input Jack:  Microphone, Line-input, DIN
Output Jack:  Line-output, Stereo headphone, DIN
Motor:  4-pole synchronous motor
Controls:  Slide volume (REC, playback), tape selector (Normal, HiFi, Special), power switch, Dolby system switch, Dolby system switch
Operations:  Piano type push button (REC, REW, Play, F.F., Stop, Cassette-up, pause)
Auxiliary Device:  Auto-shut-off, Dolby noise reduction, lighted 2-VU meters, 3-digit tape counter
Performance
Output Level/Impedance:  0 - 1 V/ 2 k Ω
Frequency Response:  30 - 15,000 Hz
Tape Speed Tolerance:  ±1%
Wow and Flutter:  0,1% WRMS
CrossTalk:  60 dB
Channel Separation::  35 dB
Signal-to-Noise-Ratio:  50 dB or 60 dB (with Dolby noise reduction) at 10 kHz, 50 dB or 55 dB at full spectrum
Erasure:  65 dB
Input Level/Impedance
Line-in :  80 mV/680 k Ω
DIN IN :  0m,56 mV/5 k Ω
Mic:  0,56 mV/ 10 kΩ
FF Time:  105 sec. (C-60 cassette)
Rewind Time:  105 sec. (C-60 cassette) 
General
Power Source:  AC 100/120/220/240 V, 50 or 60 Hz
Dimensions (W x H x D):  425 x 140 x 290 mm (16-7/8" x 5-1/2" x 11-1/2")
Weight:  8 kg (18 lbs)
Accessory:  Patch cord, C-30C pre-recorded cassette, 

Yamaha P-2250 dual-mono power amp


 Yamaha P-series Professional Power Amplifiers P2250

The dual-channel amplifier shall include a rear-panel switch that converts the amplifier to monaural operation, in which case the bridged outputs shall deliver maximum continuous sine wave power output over a 20 Hz to 20 kHz bandwidth of (300 watts, 500 watts) into a minimum 8 ohm load impedance, or (220 watts, 340 watts) into a 16 ohm load with no more than 0,05% thd s/n in bridge mono mode, as established by comparing the maximum output with signal to the minimum output noise with a shorted input, shall be no less than 106 dB measured with a _6 dB/octave low pass filter at 12,47 kHz (equal to a “brick wall” filter at 20 kHz), and no less than 115 dB measured with an IHF “A” weighting network. Channel separation shall be at least 90 db at 1 khz, and shall be at least 70 db at any frequency from 20 Hz to 20 kHz. Slew rate in bridged mono mode shall be at least 90 volts per microsecond, full swing.


Single and Dual –Channel Models in Two Power Ranges
the P1150 is a single channel amplifier rated at 100 watts into 8 ohm or 150 watts into 4 ohm; the dual-channel P2150 delivers the same power output per channel, the P1250 is a single channel  amplifier rated at 170 watts into 8 ohm or 250 watts into 4 ohm, the dual-channel P2250 delivers the same power output per channel.

A rear panel switch on both dual-channel models rewires them internally for use in a bridged , MONO (single-channel) configuration; in this mode the P1250 delivers 200 watts into 16 ohm or 300 watts into 8 ohm, and the P2250 delivers 340 watts into 16 ohm or 500 watts into 4 ohm.
by using both channels of a dual-channel model to drive a single speaker load in the bridged (mono) configuration, it is possible to achieve the wide headroom and dynamic range needed for accurate reproduction of peaks and transient sounds. The P2250 in bridged Mono mode, will deliver 63 volts to the speaker line and therefore may be used to drive a slightly de-rated 70 volt line (for use with a distributed speaker system)

Multiple Protection Techniques Avoid Damaged Speakers
theoretically , a power amplifier is capable of damaging speakers in many ways. The new Yamaha professional amps are designed to eliminate as many potential damage modes as is practical without causing unwanted shut-down or impairment of the sound.

A turn-on transient (a low frequency “thump”) may occur as the power supplies in mixers, console or auxiliary signal processing equipment activate their internal circuits. One does not want these “thumps” to be amplified by the power amp. Or speaker damage might occur. The safest approach here is to disconnect the speakers from the amplifier until all equipment in the sound system has stabilized. That’s why we designed these amplifiers with a relay that disconnects the output until after power has been on a few seconds. This protection is only effective, however, with good operating practice – i.e., if you turn on the amplifier Last – after first turning on the console, electronic crossover, and any signal processing equipment.

If DC were to appear at an amplifier’s output, it would cause speaker voice coils to move to one position and stay there, which can quickly lead to voice coil overheating and premature failure of the speaker. Even relatively low levels of DC can cause this problem, DC can appear at a direct coupled amplifier’s output when the input signal has just a few millivolts of DC offset. That’s the advantage of AC coupled amplifiers such as these. Still, it is conceivable that some DC might appear at the output of an AC-coupled amplifier in the presence of asymmetrical, very low frequency input signals. In any event, high DC levels, as might be caused by a short between the power supply “ralls” and the output , can instantly destroy a speaker or compression driver. To prevent any such catastrophe circuitry in these amplifiers senses the presence of any significant DC component at the output(more than 2 volts), and opens the speaker relay immediately, when this occurs, the front-panel Protection LED turns on. Given that the average 8 ohm speaker has a DC resistance of about 5 ohms, this means that the relay would shut down the output before so much as 1 watt of DC power reached the speaker load.
If a short circuit in the speaker or cable or a very low impedance speaker load overloads the amplifier, current limiting circuitry in the amplifier prevents excessive power from being delivered to the load.

Features
Every effort has been made to provide the features that musicians, soundmen and engineers feel they need in a professional power amplifier. Rather than experiment with exotic designs, we have applied field-proven principles to design amplifiers which are highly stable, and will deliver the kind of reliability enjoyed for over a decade by Yamaha professional and commercial sound products.
Recessed input attenuators with 32 calibrated, detented positions are easily operated. To discourage casual tampering, rubber security covers are included.
Electronically balanced, differential input circuits allow the use of long, shielded 3-wire input cables to reduce susceptibility to hum.
Two methods to connect each input: XLRs combine the advantages of electrostatic and electromagnetic noise rejection, with locking terminals that won’t pull out accidentally should the cable be tugged. Phone jacks provide for fast, compatible connection to equipment that utilizes phone jacks instead of one per channel, we have made it easier to “daisy chain” connect more than one amplifier to a given signal source – on “Y” adapter cable is required.
The output circuitry is fully protected from overloads and short circuits, and the speaker outputs are relay-protected against turn-on transients and DC offset.
five-way binding post output connections provide more secure wiring, better current handling capability, and less tendency to built up contact resistance than typical phone jack outputs. Phone jack outputs are provided for convenience in fast setup situations.
Rated for 4-ohm or higher impedance loads
P2250, in bridged mono mode , can drive 70-volt lins without an output transformer.
Two-stage, temperature-operated cooling fan pulls air through a front panel filter to keep the power transformer and heat sinks cool, further protection afforded by a thermal breaker.
Convenient power cord holders on rear panel enable amp to be set “on end” without damage to connectors; sturdy front panel handles for easy removal from rack and more comfortable carrying.
Well suited to a variety of sound reinforcement, recording and musical instrument applications.


Specifications P2250

Power Output Level (THD =0,05%)
Stereo
20 Hz – 20 kHz :  170 W + 170 W (at 8 Ω ); 250 W + 250 W (at 4 Ω )
1 kHz:  185 W + 185 W (at 8 Ω ); 265 W +265 W (at 4 Ω )
BTL-Mono
20 Hz – 20 kHz :  3400 W (at 16 Ω ); 500 W (at 8 Ω )
1 kHz:  370 W (at 16 Ω ); 530 W (at 8 Ω )
Frequency Response:   10 Hz – 50,000 Hz (8 Ω ) +0 -1 dB
Power Bandwidth (THD =0,1%)
Stereo
10 Hz to 50,000 Hz (85 W) at 8 Ω 
10 Hz to 50,000 Hz (125 W) at 4 Ω 
BTL-Mono
10 Hz to 50,000 Hz (170 W) at 16 Ω 
10 Hz to 50,000 Hz (250 W) at 8 Ω 
Total harmonic Distortion: 
Stereo
Less than 0,007% ( 85 W, 20 Hz – 20 kHz, 8 Ω )
Less than 0,003% ( 85 W, 1 kHz, 8 Ω )
Less than 0,005% ( 75 W, 1 kHz, 4 Ω )
Less than 0,01% ( 125 W, 20 Hz – 20 kHz, 4 Ω )
BTL-Mono
Less than 0,007% ( 85 W, 20 Hz – 20 kHz, 16 Ω )
Less than 0,003% ( 85 W, 1 kHz, 16 Ω )
Less than 0,005% ( 125 W, 1 kHz, 8 Ω )
Less than 0,01% ( 125 W, 20 Hz – 20 kHz, 8 Ω )
Intermodulation  Distortion (60 Hz : 7 kHz = 4:1)
Stereo
less than 0,005% (85 W, 8 Ω )
less than 0,01% (12 W, 4 Ω )
BTL-Mono
less than 0,01% (250 W, 8 Ω )
less than 0,01% (170 W, 16 Ω )
Damping Factor
Better than 110 (1 kHz , 8 Ω); better than 55 (1 kHz  , 4 Ω )
Signal-to-Noise-Ratio: 
Stereo
Better than 110 dB (Input Short; at 12,47 kHz, -6 dB/octave LPF)
Better than 115 dB (Input Short, IHF A Network)
BTL-Mono
Better than 106 dB (Input Short; at 12,47 kHz, -6 dB/octave LPF)
Better than 110 dB (Input Short, IHF A Network)
Slew Rate
Stereo :  ±50 V/µsec (8 ohm, Full Swing)
BTL-Mono :  ±90 V/µsec (16 ohm, Full Swing)
Sensitivity :  +4 dB (1,23 V rms) for nominal output (4 Ω load)
Voltage Gain:  28,3 dB
Input Impedance:  better than 15 k Ω, Balanced or Unbalanced (Att. Max)
Residual Noise (Input Att. Minimum)
Less than -80 dBm, -6 dB/oct. LPF at 12,47 kHz 
Less than -90 dBm, IHF A network
Indicators
Signal:  Green LED (-20 Hz to 20 kHz, Vo better than 2 V
Clipping:  Red LED Total harmonic Distortion: better than 1%
Protection: Red LED (during the protection or muting is on)
Pilot:  Red LED Power ON
Protection Circuits
Muting:  6 ±2sec After Power ON
DC Sense:  DC ±2  sec. Ouptut Voltage
Thermal:  better than 85°C Heat sink temperature
PC Limiter:  ON RL less than 2 Ω 
FAN Circuit
Better than 60°C High speed run, Heat sink temperature
Less than 45°C Restoration of a low speed run, Heat sink temperature
Front Controls:  2 x 32 step Input Attenuator (0 to -20 dB in 1 dB steps, -20 to -30 dB in 2 dB steps, then -33, -37, -42, -50, -60 dB, and infinite attenuation
Push ON/Push Off Power Switch
Rear Control:  Mono/Stereo Mode Switch
Power Requirements
220/240 V AC 50/60 Hz (General model) 120 V AC, 60 Hz (US and Canada models)
Power Consumption
1300 W (General mode); 850 W, 950 VA (US and Canada model)
dimensions (W x H x D):  480 x 132 x 423 MM (18-7/8” x 5-1/4” x 16-5/8”)
Weight:  19 kg (41,8 lbs)

Yamaha P-2150 dual-mono power amp

Yamaha P-series Professional Power Amplifiers P2150

The dual-channel amplifier shall include a rear-panel switch that converts the amplifier to monaural operation, in which case the bridged outputs shall deliver maximum continuous sine wave power output over a 20 Hz to 20 kHz bandwidth of (300 watts, 500 watts) into a minimum 8 ohm load impedance, or (220 watts, 340 watts) into a 16 ohm load with no more than 0,05% thd s/n in bridge mono mode, as established by comparing the maximum output with signal to the minimum output noise with a shorted input, shall be no less than 106 dB measured with a _6 dB/octave low pass filter at 12,47 kHz (equal to a “brick wall” filter at 20 kHz), and no less than 115 dB measured with an IHF “A” weighting network. Channel separation shall be at least 90 db at 1 khz, and shall be at least 70 db at any frequency from 20 Hz to 20 kHz. Slew rate in bridged mono mode shall be at least 90 volts per microsecond, full swing.


Single and Dual –Channel Models in Two Power Ranges
the P1150 is a single channel amplifier rated at 100 watts into 8 ohm or 150 watts into 4 ohm; the dual-channel P2150 delivers the same power output per channel, the P1250 is a single channel  amplifier rated at 170 watts into 8 ohm or 250 watts into 4 ohm, the dual-channel P2250 delivers the same power output per channel.

A rear panel switch on both dual-channel models rewires them internally for use in a bridged , MONO (single-channel) configuration; in this mode the P1250 delivers 200 watts into 16 ohm or 300 watts into 8 ohm, and the P2250 delivers 340 watts into 16 ohm or 500 watts into 4 ohm.
by using both channels of a dual-channel model to drive a single speaker load in the bridged (mono) configuration, it is possible to achieve the wide headroom and dynamic range needed for accurate reproduction of peaks and transient sounds. The P2250 in bridged Mono mode, will deliver 63 volts to the speaker line and therefore may be used to drive a slightly de-rated 70 volt line (for use with a distributed speaker system)

Multiple Protection Techniques Avoid Damaged Speakers
theoretically , a power amplifier is capable of damaging speakers in many ways. The new Yamaha professional amps are designed to eliminate as many potential damage modes as is practical without causing unwanted shut-down or impairment of the sound.

A turn-on transient (a low frequency “thump”) may occur as the power supplies in mixers, console or auxiliary signal processing equipment activate their internal circuits. One does not want these “thumps” to be amplified by the power amp. Or speaker damage might occur. The safest approach here is to disconnect the speakers from the amplifier until all equipment in the sound system has stabilized. That’s why we designed these amplifiers with a relay that disconnects the output until after power has been on a few seconds. This protection is only effective, however, with good operating practice – i.e., if you turn on the amplifier Last – after first turning on the console, electronic crossover, and any signal processing equipment.

If DC were to appear at an amplifier’s output, it would cause speaker voice coils to move to one position and stay there, which can quickly lead to voice coil overheating and premature failure of the speaker. Even relatively low levels of DC can cause this problem, DC can appear at a direct coupled amplifier’s output when the input signal has just a few millivolts of DC offset. That’s the advantage of AC coupled amplifiers such as these. Still, it is conceivable that some DC might appear at the output of an AC-coupled amplifier in the presence of asymmetrical, very low frequency input signals. In any event, high DC levels, as might be caused by a short between the power supply “ralls” and the output , can instantly destroy a speaker or compression driver. To prevent any such catastrophe circuitry in these amplifiers senses the presence of any significant DC component at the output(more than 2 volts), and opens the speaker relay immediately, when this occurs, the front-panel Protection LED turns on. Given that the average 8 ohm speaker has a DC resistance of about 5 ohms, this means that the relay would shut down the output before so much as 1 watt of DC power reached the speaker load.
If a short circuit in the speaker or cable or a very low impedance speaker load overloads the amplifier, current limiting circuitry in the amplifier prevents excessive power from being delivered to the load.

Features
Every effort has been made to provide the features that musicians, soundmen and engineers feel they need in a professional power amplifier. Rather than experiment with exotic designs, we have applied field-proven principles to design amplifiers which are highly stable, and will deliver the kind of reliability enjoyed for over a decade by Yamaha professional and commercial sound products.
Recessed input attenuators with 32 calibrated, detented positions are easily operated. To discourage casual tampering, rubber security covers are included.
Electronically balanced, differential input circuits allow the use of long, shielded 3-wire input cables to reduce susceptibility to hum.
Two methods to connect each input: XLRs combine the advantages of electrostatic and electromagnetic noise rejection, with locking terminals that won’t pull out accidentally should the cable be tugged. Phone jacks provide for fast, compatible connection to equipment that utilizes phone jacks instead of one per channel, we have made it easier to “daisy chain” connect more than one amplifier to a given signal source – on “Y” adapter cable is required.
The output circuitry is fully protected from overloads and short circuits, and the speaker outputs are relay-protected against turn-on transients and DC offset.
five-way binding post output connections provide more secure wiring, better current handling capability, and less tendency to built up contact resistance than typical phone jack outputs. Phone jack outputs are provided for convenience in fast setup situations.
Rated for 4-ohm or higher impedance loads
P2250, in bridged mono mode , can drive 70-volt lins without an output transformer.
Two-stage, temperature-operated cooling fan pulls air through a front panel filter to keep the power transformer and heat sinks cool, further protection afforded by a thermal breaker.
Convenient power cord holders on rear panel enable amp to be set “on end” without damage to connectors; sturdy front panel handles for easy removal from rack and more comfortable carrying.
Well suited to a variety of sound reinforcement, recording and musical instrument applications.


Specifications P2150

Power Output Level (THD =0,05%)
Stereo
20 Hz – 20 kHz :  100 W + 100 W (at 8 Ω ); 150 W + 150 W (at 4 Ω )
1 kHz:  105 W + 105 W (at 8 Ω ); 165 W +165 W (at 4 Ω )
BTL-Mono
20 Hz – 20 kHz :  220 W (at 16 Ω ); 300 W (at 8 Ω )
1 kHz:  250 W (at 16 ohm); 330 W (at 8 ohm
Frequency Response:   10 Hz – 50,000 Hz (8 Ω ) +0 -1 dB
Power Bandwidth (THD =0,1%)
Stereo
10 Hz to 50,000 Hz (55 W) at 8 Ω 
10 Hz to 50,000 Hz (75 W) at 4 Ω 
BTL-Mono
10 Hz to 50,000 Hz (110 W) at 16 Ω 
10 Hz to 50,000 Hz (150 W) at 8 Ω 
Total harmonic Distortion: 
Stereo
Less than 0,007% ( 55 W, 20 Hz – 20 kHz, 8 Ω )
Less than 0,003% ( 55 W, 1 kHz, 8 Ω )
Less than 0,005% ( 75 W, 1 kHz, 4 Ω )
Less than 0,01% ( 75 W, 20 Hz – 20 kHz, 4 Ω )
BTL-Mono
Less than 0,007% ( 110 W, 20 Hz – 20 kHz, 16 Ω )
Less than 0,003% ( 110 W, 1 kHz, 16 Ω )
Less than 0,005% ( 150 W, 1 kHz, 8 Ω )
Less than 0,01% ( 150 W, 20 Hz – 20 kHz, 8 Ω )
Intermodulation  Distortion (60 Hz : 7 kHz = 4:1)
Stereo
less than 0,005% (55 W, 8 Ω )
less than 0,01% (75 W, 4 Ω )
BTL-Mono
less than 0,01% (150 W, 8 Ω )
less than 0,01% (110 W, 16 Ω )
Damping Factor
Better than 110 (1 kHz , 8 Ω ); >55 (1 kHz , 4 Ω )
Signal-to-Noise-Ratio: 
Stereo
Better than 110 dB (Input Short; at 12,47 kHz, -6 dB/octave LPF)
Better than 115 dB (Input Short, IHF A Network)
BTL-Mono
Better than 106 dB (Input Short; at 12,47 kHz, -6 dB/octave LPF)
Better than 110 dB (Input Short, IHF A Network)
Slew Rate
Stereo :  ± 50 V/µsec (8 ohm, Full Swing)
BTL-Mono :  ±90 V/µsec (16 Ω , Full Swing)
Sensitivity :  +4 dB (1,23 V rms) for nominal output (4 Ω  load)
Voltage Gain:  26,0 dB
Input Impedance:  better than  15 k Ω , Balanced or Unbalanced (Att. Max)
Residual Noise (Input Att. Minimum)
Less than -80 dBm, -6 dB/oct. LPF at 12,47 kHz 
Less than -90 dBm, IHF A network
Indicators
Signal:  Green LED(-20 Hz to 20 kHz, Vo better than  2 V
Clipping:  Red LED Total harmonic Distortion: better than 1%
Protection: Red LED (during the protection or muting is on)
Pilot:  Red LED Power ON
Protection Circuits
Muting:  6 ± 2sec After Power ON
DC Sense:  DC ±2 sec. Ouptut Voltage
Thermal:  better than 85°C Heat sink temperature
PC Limiter:  ON RL less than 2 Ω 
FAN Circuit
Better than 60°C High speed run, Heat sink temperature
Less than 45°C Restoration of a low speed run, Heat sink temperature
Front Controls:  2 x 32 step Input Attenuator (0 to -20 dB in 1 dB steps, -20 to -30 dB in 2 dB steps, then -33, -37, -42, -50, -60 dB, and infinite attenuation
Push ON/Push Off Power Switch
Rear Control:  Mono/Stereo Mode Switch
Power Requirements
220/240 V AC 50/60 Hz (General model) 120 V AC, 60 Hz (US and Canada models)
Power Consumption
800 W (General mode); 500 W, 600 VA (US and Canada model)
dimensions (W x H x D):  480 x 132 x 423 MM (18-7/8” x 5-1/4” x 16-5/8”)
Weight:  17 kg (37,4 lbs)