Arcam Delta 90 amplifier

Good hi-fi equipment is much more than just a set of highly impressive technical specifications; the listening quality is more important than any set of figures. A&R's Delta Series of audiophile components has been designed to combine modern aesthetics with A&R's proven ability in electronics, to produce a matched range of equipment that will satisfy even the most critical music lover. The first product in this stylish new generation is the Arcam Delta 90 intergated stereo amplifier. This combines great functional flexibility with good looks and a tremendous dynamic range seldom found in equipment at this price level. The use of the highest quality components, such as 1% metal film resistors and polypropylene capacitors, ensures a notably clean and beautifully natural sound quality up to and beyond the amplifier's rated 70 watts per channel.

 

The Delta 90 can accept inputs from both moving magnet and moving coil cartridges, selected using a switch on the back panel. Moving magnet cartridges can be optimally matched by the addition of a switchable internal loading module, type ULM/M. additionally the Delta 90 can accept inputs from CD, tuner and two tape recorders - all four inputs having high overload margins to enable any source to be accepted without distortion. There are independent controls for both "listen" and "record" functions, allowing the user to listen to one programme at the same time as recording another from an entirely separate source. The bass and treble controls have been designed so that deficiencies in samll loudspaekers and cartridges may be corrected without affecting the critical midrange. For the ultimate in audiophile sound these controls may be bypassed with the "direct" switch on the front panel' nevertheless, used sensibily they can help correct for many imperfections that may be present elsewhere in the audio system. All input sockets are via high quality phono sockets. The loudspeakers are connected using heavy duty posts which will accept any type of connector;4 mm plugs, spade, pin connectors. Although the main speaker sockets are wired directly to the amplifier outputs (to obtain the best possible sound quality), a second pair of switched outputs is also provided enabling the loudspeakers to be cut out when using headphones. Two tape recording outputs are provided allowing full tape to tape dubbing as well as the ability to listen to a different source (from the one that is being recorded) by using the "listen" control.

 

Power

The amplifier section of the Delta 90 will drive any real loudspeaker load, for great care has been taken to ensure that power output and current delivery is maintained into low impedance and reactive loads. The amplifier's high current capability is made possible by the use of superior quality MJ15003/4 complementary power transistors fed from high value, low ESR reservoir capacitors and a generously rated toroidal mains transformer.

In order to maintain the highest standards of fidelity, no fuses are used in the loudspeaker outputs or the DC supply lines. Instead, the Delta 90 is protected against overload and abouse by a quick acting electronic protection system. In addition to this, a pair of heavy duty relays serve to protect the user's loudspeaker system; these will mute the output at switch-on and in the unlikely event of a malfunction in the Delta 90 's power amplifier stages.

 

Styling, quality and reliability

The Delta 90 uses custom high quality aluminium extrusions for cool running and to produce a strikingly elegant case that will grace any home both aesthetically and musically. Styled in conjunction with a top industrial designer the Arcam Delta looks as good as it sounds.

Great care has been taken in every aspect of the design, which was only finalised after intensive listening tests. Internal wiring, apart from connections to the transformer, is almost eliminated by the use of a single fibreglass printed circuit board. Every amplifier is rigorously checked at all stages of production and great pride and care is taken in its construction and appearance. All testing is carried out using advanced computer controlled ATE (automatic testing equipment). Finally each amplifier is burnt in and retested before final inspection, packing and despatch in order to ensure a long and trouble free life.

 

"From the outset the amplifier showed itself capable of a very soild dynamic performance. It also took and kept a grip on the subtleties of the stereo signal. The amp looks well set for as long and honourable a life on the hi-fi market as the A60 has had"

 

Specifications

Output Power (both channels into 8 Ω , 20 Hz - 20 kHz, 0,5% T.H.D.):  70 W

Single Channel (into 8 Ω ):  typically 85 W

Single Channel (into 4 Ω ) :  typically 130 W

Peak Current Deliver:  ±16 A

Total Harmonic Distortion:  0,02% (60 W, 8 Ω  at 1 kHz)

Frequency Response

Disc :  better than +0,3 -0,5 from 40 Hz - 20 kHz (typically -3 dB at 20 Hz)

Line :  ±0,5 dB 20 Hz - 20 kHz (typically -3 dB at 8 Hz - 50 kHz)

Tone Controls:  ±6 dB maximum at 20 Hz, 20 kHz (fully bypassable)

Crosstalk:  65 dB at 1khz (all inputs)

Inputs Sensitivity/Impedance

Disc :  2 mV/ 47 k Ω  /100 pF

Noise CCIR :  73 dB

Overload Margin:  at 1 kHz is 38 dB

Switchable universal loading module (ULM/M) available provides: 30 k Ω , 8 k Ω  200 pF, 320 pF, 420 pF and user programmable option.

Disc (Moving Coil)

100 µV/330 Ω

Noise CCIR :  -66 dB

Overload Margin :  at 1 kHz is 38 dB

Tuner, Tape 1, 2 :  100 mV/20 k Ω 

Noise CCIR (ref. 1 W output) :  -77 dB

Overload Margin :  at 1 kHz is 50 dB

CD :  220 mV/6 k Ω

Noise CCIR :  -77 dB

Overload Margin :  at 1 kHz is 50 dB

Outputs Level / Impedance

Tuner, Tape 1, 2 : 100 mV (nominal)/3 k Ω 

Headphones Impedance :  Suitable for headphones of 80 0hm to 2 k Ω 

General

Power Supply:  240 V nominal ( adjusted to 220 V, 120 V and 110 V nominal)

Power Consumption:  300 VA

Dimensions (W x H x D):  430 x 90 x 265 mm

Weight:  6,5 kg (net)

Arcam Delta 80 tuner

 

"The tuner performed well and was simple to use. With strong FM signals it gave a clean and detailed stereo sound. The Delta 80 is thoroughly competitive and can be recommended as good value for money."

FM/MW/LW Digital Preset Tuner

With some of the best music now available from radio broadcasts and with live concerts providing the most natural listening material, the demands made on a quality tuner have increased A&R Cambridge has responded to this need by introducing the Arcam Delta 80 FM/AM tuner. Suitable for use with all stereo amplifiers, the Delta 80 produces a natural, smooth and detailed sound on FM, without the harshness or sibiliance associated with some other tuners. The Arcam Delta 80 combines its excellent sound quality with a modern appearance, the convenience of presets and a digital frequency display. As part of the new Arcam Delta range of electronics, the Delta 80 is the ideal complement to the Arcam Delta 90 integrated  amplifier and the Arcam Delta 70 compact disc player to be designed and manufactured in Great Britain.

 

The tuner's controls have been deliberately kept to a minimum to ensure simple, fuss free operation. Three interlocked push buttons are used for selection of the wavebands, each band using the flywheel assisted rotary tuning control for smooth, precise tuning, in addition a total of 12 programmable presets, 6 for FM and 6 for MW/LW, are always available for the convenient tuning of your favourite stations.

An easy to read, blue tinted 4-digit fluorescent display provides an accurate frequency readout across all three wavebands. A useful, logarithmically scaled, two colour LED signal strength meter is fitted. ( the first two LEDs glow amber when the signal strength is sufficient for good mono FM reception, with the first green LED also lit up the signal to noise ratio is good enough for stereo FM reception. The strongest and best FM or AM signal is of course indicated when all five LEDs are illuminated). On FM , A&R's proprietory three colour traffic lights LED tuning indicator makes accurate tuning really straightfor ward; in addition a green LED indicates when a stereo programme is being received.

For FM reception an AFC button is fitted to compensate for small drifts or any slight mistuning which may occur. A mono switch is provided to ensure better reception of weak FM stations.

 

Technical Design

The design of the Delta 80 has been realised using the highest quality components, selected for optimum sonic performance. Detailed theoretical analysis and extensive listening tests have produced exceptional results, the sound quality on FM in particular being firm, precise and clear.

In accordance with our experience in making some of the world's most acclaimed hi-fi amplifiers, liberal use is made of the best passive components, including precision 1% metal film resistors and close tolerance polystyrene and polycarbonate film capacitors. The tuner's front end uses dual gate MOS FET transistors for good RF performance and great care has been taken with the tuner's decoder circuitry and all power supplies in order to achieve the best sound. In addition an active low pass "birdie" filter is fitted before the stereo decoder to minimise the annoying whistles from adjacent stations which can sometimes interfere with stereo reception. A highly efficient multiplex output filter removes the 19 kHz and 38 kHz high frequency tones produced by the stereo decoder, preventing interference with the bias oscillators and Dolby encoders of tape recorders.

On the long and medium wavebands ceraful design has improved reception, especially on the "crowded" night time air waves resulting in a clearer, more informative sound.

 

Quality and reliability

Great care has been taken in every aspect of the design, construction and alignment of the Arcam Delta 80 tuner to ensure years of consistent, trouble free operation. The electronics are built in the traditional A&R manner using a single large fibreglass pcb fitted with proven high quality components, operated well within their ratings for long life and ease of servicing. Every tuner is rigorpusly checked at all stages of production, both for performance and appearance. Each unit is tested and aligned using advanced custom built equipment and is then "burnt-in" and finally retested before despatch to ensure ultimate reliability.

The Arcam Delta 80 tuner is provided with a ready made 75 Ω  dipole wire aerial for FM reception and a specially designed loop aerial for AM use. Nevertheless, for best results, in areas of anything but prime reception it is nearly always better to add appropriate external aerials in order to provide th etuner with the best possible input signal.

 

Specifications

FM Tuner Section

Tuning Range:  87,5 to 108 MHz

Sensitivity (IHF):  1,4 µV

Total Harmonic Distortion (95 MHz , reference 22,5 kHz deviation at 1 kHz):

Mono :  better than 0,15%

Stereo :  better than 0,25%

Ultimate Signal-to-Noise Ratio (CCIR/ARM)

Mono :  better than 74 dB

Stereo : better than 70 dB

Frequency Response:  20 Hz - 20 kHz ±0,5 dB (typically -2 dB at 15 kHz)

Channel Separation:  better than 40 dB (1 kHz)

Pilot Tone Supression:  better than 50 dB

Capture Ratio:  1,5 dB

Alternate Channel Selectivity:  better than 60 dB

AM Supression:  better than 50 dB

Signal Strength Meter:  5 LED type, logarithmic scale, usable from typically 10 µV to 2 mv aerial signal

AM Tuner Section

Frequency Range

MW :  530 - 1600 kHz

LW :  160 - 270 kHz

Distortion:  0,4% at 50% modulation

Ultimate Signal-to-Noise Ratio :  50 dB CCIR weighted, ref. 30% modulation

Genaral

Output Impedance:  2 k Ω

Recommended load:  20 k Ω  or greater

Output Level:  800 mv at 75 kHz deviation

Power Supply:  200 - 250 V AC only; 8 VA (100 - 120 V AC convesrsion possible)

Dimensions (W x H x D):  430 x 60 x 265 mm

Weight:  3 kg

A&R Cambridge C200 Pre-Amp

A good sound system is more than just a set of highly impressive technical specifications, the listening quality itself is more important than a list of figures. With our 200 series audio equipment we believe we have achieved an extraordinarily good balance between performance and cost, between theoretical design and practical audio quality.

The 200 series combines the very best sound performance with superb standards of construction and a highly attractive modern appearance.

The combined system produces a notably clean and beautifully neutral sound and yet preserves a large number of undeniably useful features.

A unique mixture of careful kistening tests and quality control measures during development and production have combined to present a superbly felxible high performance sound system.

The C200 Stereo Control Unit

The C200 satisfies all the demanding criteria set by systems requiring a control unit of top quality yet with versatility and flexibility in its

Readily upgraded at some later date to keep pace with future developments in audio systems.

The C200 includes a number of useful features not always found on modern high quality pre-amplifiers.

The unit is provided with a variety of tone and signal routing controls without loss of quality in performance. The bass and treble controls are factory set for a perfectly flat response in the 12 o'colock position; soft clicks of the knobs provide a guide for nominal one decibel steps up to a maximum of five decibels boost or cut. The tone controls are non-inverting, which allows a true by-pass cancel switch to be used without phase reversal.

A switchable low frequency, sub-sonic filter is fitted to minimise the effects of possible turntable rumble; it also helps to protect small loudspeakers from low frequency overload. A mono switch is also included.

The headphone socket is driven from a separate internal high quality amplifier. Thus, whatever the final speaker system might be, headphones can always be used. The main pre-amplifier outputs are automatically muted when the headphones are plugged in . Two extra switched and fused mains outlets to IEC standards, invaluable when connecting up a complete hi-fi system, are provided at the rear of the case.

There is a choice of module cards for the two modular inputs, including low output moving coil cartridge, moving magnet cartridge and line level. The cartridge input boards have switchable load and gain facilities, access to which is through apertures underneath the unit.

A tuner input and two tape inputs are also fitted. Full tape-to-tape dubbing is possible and adjustment is provided for the tape return levels.

Within the C200, provision has been made on the output card for fitting electronic cross-over units for use with active loudspeakers. One such system, using a C200 and two SA200 power amplifiers is shown on page SA200

The C200 Control Unit is primarily intended for use with the SA 200 Power Amplifier, nevertheless it is suitable for pairing with any other high performance power amplifier if required. Also, matching it with units of the A60 series can provide a number of different, highly imaginative sound systems.

Specifications:

Inputs:

Inputs 1 and 2 : labelled Disc and Aux, are programmable and their function depends on the input boards selected.

Moving Coil Cartridge

Input Resistance (switchable):  330/100/30/10 Ω

Input Capacitance (switchable):  1/100 nF

Input Sensitivity (switchable):  60/160 µV at 1 kHz

Noise:  less than -60 dB (high Gain); less than -66 dB (low gain)

Overload Margin:  better than 38 dB

Moving Magnet Cartridge

Input Resistance (switchable):  47/30/8 kΩ

Input Capacitance (switchable):  50/150/270/370 pF

Input Sensitivity (switchable):  1,5 / 3,0 mV at 1 kHz

Noise:  less than -70 dB (high Gain); less than -75 dB (low gain)

Overload Margin:  better than 38 dB

Other Inputs - Tuner, Tape 1 and Tape 2

Input Sensitivty:  100 mV

Input Impedance:

Tuner, Aux :  20 k Ω

Tape 1 and 2 :  10 k Ω

Outputs

Tape 1 and Tape 2

Nominal Output Level :  100 mV

Output Impedance :  2 k Ω

Main Output

Nominal Output Level :  1,0 V

Output Impedance :  350 k Ω

Noise (using line input):  less than -90 dB

Crosstalk (any input):  less than -60 dB at 1 kHz

Distrotion:  less than 0,01% (20 Hz -20 kHz at 1,0 V RMS)

Maximum Output:  better than 8 V RMS

Performance

Frequency Response

Via Line Inputs:  +0, -0,5 dB, (20 Hz -20 kHz)

Via Disc Inputs:  +0,25, -0,5 dB , (20 Hz -20 kHz)

High Pass Filter:  -3 dB at 30 Hz  12db/oct

Tone Controls:  ±5db at 20 Hz and 20 kHz

Phase

All stages are non-inverting providing phase integrity under all operating conditions

Power Supply

200 - 250 V AC, 48 - 63 Hz, 25V A max. The unit may be adjusted to work in the range 100 - 125 V AC.

Maximum capacity of switched AC outlets 5A RMS

Dimensions (W x H x D):  430 x 44 x 305 mm (17" x 1-3/4" x 12")

Weight:  4 kg (6,8 lbs)

I like

A&R Cambridge SA200 Power Amp

The SA200 is a high performance stereo power amplifier that will satisfy the most demanding listening tests and measurements.

Internally the SA200 consists of two identical mono power amplifiers, each with its own separate DC power supply fed from separate secondary windings of the massive toroidal mains transformer. This design approach ensures the very best isolation between the two stereo channels without the extra weight and expense of using a second transformer.

Each amplifier channel can deliver in excess of 100 watts continuous power into 8 Ω  loads or  160 watts into 4 Ω  loads with negligible distortion. The unit will also drive well over 200 watts into 2 Ω . 

Considerable care has been taken to ensure that power output is maintained into low impedance and reactive loads. The amplifier is thus extremely tolerant of different loudspeaker loads. A bridging module is available to connect the two channels to produce over 320 watts into a single 8 Ω  speaker.

The unit is very well protected by quick acting electronic protection systems and fuses. The fuses are placed inside the feedback loops to eliminate their effect on the quality of the sound output. The sound quality is further maintained by the direct hevy duty wiring between the boards and the output terminals. A novel feature of the SA200 is the input-output comparator which detects any amplifier distortion such as clipping. It then momentarily changes the colour of the front panel indicator from green to red as a warning to the user.

The SA200 is built to the highest standards with the minimum of internal wiring. The electronics are housed inn a heavy duty steel tray which also forms the base of the casing. The front panel is made from a custom aluminium extrusion and the rear panel is a single  massive casting which also acts as the heat sink for the output stages. The steel top plate slides into place and is therefore easily removed for quick access to the electronics and the loudspeaker fuses.

The solid wood and cheeks can be supplied in a larger size for stacking the SA200 with a C200 control unit. A rack mouting kit for professional use is also available.

The SA200 is ideally partnered by the C200 Control Unit although it is, of course, suitable for use with any other high quality audio pre-amplifier to form the heart of a system giving the very best performance.

Specifications

Inputs:

Sensitivity:  1,0 V (reference 100W/8 Ω  at 1 kHz)

Input Impedance:  20 k Ω

Noise (unweighted or CCIR/ARMweighted reference 100W/8 Ω ):  less than -100 dB

Gain to Loudspeaker Terminals (29,0 dB at 1 kHz):  phase non-inverting

Outputs

Loudspeakers : 4 - 16 Ω

Nominal Output level:  100 watts into 8 Ω

Performance

Power Output an Distortion

Both Channels into 8 Ω :  100 W at 0,08% Total Harmonic Distortion 20 Hz -20 kHz

Distortion

at any level up to 100 W into 8 Ω , 1 kHz less 0,03% (typically 0,01%)

at any level up to 160 W into 4 Ω  , 1 kHz less than 0,05% (typically 0,02%)

Output Power at 1 kHz at clipping (0,1% Total Harmonic Distortion ) with both channels driven is typically 125 W per channel into 8 Ω  , 195 W per channel into 4 Ω

Frequency Response:

10 Hz - 20 kHz +0, -0,5 dB (It is recommended that the pre-amplifier's high frequency response be curtailed to at least -3 dB at 50 kHz

Power Supply:  240 V AC, 48-63 Hz, 600 VA maxcimum (the unit may be adjusted to work at 220 V or 120 V if required)

Dimensions (W x H x D):  464 x 95 x 350 mm (18-1/4" x 3-3/4" x 13-3/4")

Weight:  10,0 kg (22 lb)

I like

Arcam Delta 60 amplifier

The Arcam Delta 60 is a powerful, versatile and thoroughly modern hi-fi amplifier.

The Delta 60 is a worthy successor to the famous A&R A60. England's "classic" integrated  amplifier of the late seventies and early eighties. Famed for its reliability and long life, as well as its fine sound quality, over 30 000 A60s are in everyday use worldwide. By making use of the advances in technology that were not available when the A60 was designed, the Delta 60 retains all that was best in that amplifier, whilst improving on it in terms of sound quality, aesthetics and ease of use.

The Delta 60's clean design makes it a perfect match for the Arcam Delta series of hi-fi components. These include the Delta 70 compact disc player (with its optional Delta Black Box outboard D/A cenverter) and the Delta 80 FM/AM Tuner. the Delta 60 is also ideally suited to driving Arcam's range of loudspeakers.

Versatility

The Delta 60 can accept inputs from up to 5 different sources. These include 4 line inputs, normally compact disc, tuner and two tape recorders (one of which can be a VCR). A full tape monitor facility for one of the tape recorders is provided, allowing offtape monitoring of the recorder signal when a three head tape recorder is used. Two tape outputs are available.

the disc input caters for all Types of pickup cartridge. As well as normall MM cartridges, even the highest quality low output moving coil types can be accommodated via the Delta 60's built in low noise MC preamplifier stage. this is switchable from the rear of the amplifier. In addition, the user's chosen cartridge may be optimally matched to the disc pre-amplifier by thw addition of our optional switched loading modules. Versions are available to suit both MC and MM cartridges.

All inputs to the Delta 60 are made via good quality phono sockets. All the line level inputs are fed directly to the volume control, enabling any source to be accepted without distortion, as the overload margin is virtually infinite. The volume control itself is a high quality, friction locked "dual" type. This removes the need for a separate balance control (with a consequent improvement in sound qualit). A mono switch is provided; this is operative on all inputs and can yield significant improvements in noise performance when playing old records or receiving weak FM broadcasts.

Ingenious loudspeaker switching is an Arcam speciality. Two pairs of loudspeakers may be used with the Delta 60 - these are connected via heavy duty, silver plated 4 mm sockekets. The main speaker sockets are hard wired directly to the amplifier's outputs to obtain the best possible sound quality. Headphones can be used in parallel with these. A second set of switched loudspeaker sockets is also available; these can be muted via a front panel switch when not required. This is particularly useful for someone who wants to listen to headphones without disturbing the neighbours.

Quality and Reliability

Great care has been taken with every aspect of the Delta 60's design to ensure first class sound quality and reliability. All components are operated well within their ratings and are laid out on a single large fibreglass p.c.b. (printed circuit board). This virtually eliminates internal wiring and connectors, both potential sources of inconsistency and long term unreliability. Most components are soldered using Arcam's military standard flow soldering and p.c.b. washing equipment. This is followed by a rigorous visual inspection procedure. 100% testing of all major parameters is carried out on every amplifier using advanced computer controlled automatic testing equipment both before and after a gruelling 24 hour burn in procedure. After this every amplifier is given a functional listening test by our final inspection department before packing and despatch.

As with all Arcam electronics, the Delta 60 is warranted for 2 years from date of purchase against failure in normal use.

Styling

The Arcam Delta 60 looks as good as it sounds. This is no accident, because great care was taken from the outset with all aspects of both the mechanical and electronic design.

The elegant, slimline cabinet is construced entirely from aluminium alloy with extensive and imaginative use being made of custom extrusions. Aluminium was chosen because of its excellent thermal characteristics (for cooler running) and nonmagnetic properties (for better ssound quality), in addition to its ease and consistency of fabrication. The cabinet is finished in attractive and durable black epoxy paint.

Power

The Arcam Delta 60 is an extremely well behaved amplifier which has a sufficiently high peak current capability to drive all practical loudspeaker loads down to 4 ohms nominal impedance. Electronic protection in the power stages safeguards against  any incorrect loads or short circuits. This short term protection is backed up by easily replaceable output fuses should a fault persist.

The Delta 60 amplifier is guaranteed to deliver its continuous rated output power of 50 watts per channel into an 8 ohm load at any frequency from 20 Hz to 20 kHz. In practice, under normal music conditions, considerably more power is available. Given loudspeakers of at least moderate efficiency, surprisingly high volume levels are attainable without audible distress.

Electronic Design

The Delta 60's electronics incorporate high gain, high current power amplifiers whose inputs are fed directly from the amplifiers's volume control. By eliminating all line amplifier and tone control stages from the circuitry Arcam have ensured that all the Delta 60's line inputs are always routed straight through to the power amplifiers, eliminating the need for such marketing handles as "CD direct" switches and the like. Due to the amplifier's straightwire input the number of series coupling capacitors has been dramatically reduces with consequent improvements in dynamics and clarity.

The power supply meets Arcam's usual high standards with substantial twin 10,000 uF reservoir capacitors fed from a generously sized 200 VA Holden and Fisher toroidal mains transformer. This has excellent regulation and a very low radiated magnetic field for optimum sonic performance.

The phono pre-amplifier stages of the Delta 60 are of a high standard for an integrated amplifier. They feature fully regulated power supplies and a passive equalisation section between the two main stages which are themselves D.C. coupled to each other. This system provides audibly better resolution and imagery. The input buffer amplifiers use precision Op27 amplifiers for improved noise performance and liberal use is made of 1% metal film resistors and high grade polystyrene and polypropylene film capacitors. In addition the Delta 60 incorporates a high quality switchable MC cartridge pre-amplifier stage fed from its own totally separate regulated supply. Provision is made for customised cartridge loading on both MC and MM inputs via Arcam's unique user adjustable universal cartridge loading modules.

Specifications

Output Power

Both Channels :  50 W at 8 Ω  (20 Hz to 20 kHz , 0,5%)

Single Channel :  60 W at 8 Ω , 95 W at 4 Ω

Peak Current Delivery:  ±10A

Harmonic Distortion:  0,02% (50 W, 8 Ω , at 1 kHz)

Frequency Response:

Disc :  better than 40 Hz - 35 kHz  +0,3 -0,5 dB

Typ. -3 dB  at 20 Hz

Line :  30 Hz  to 35 kHz  ±0,5 dB

Typ. -3 dB  at 10 Hz , 80 kHz

Inputs

Disc (Moving Magnet)

Sensitivity :  1,8 mV

Noise (CCIR) :  -75 dB

Overload Margin at 1 kHz  :  35 dB

Input Impedance :  47 k Ω /100 pF

Switchable Loading Module (type ULM/M) available to provide the following additional loads; 30 k Ω , 8 k Ω , 200 pF, 320 pF, 420 pF and user programmable option

Disc (Moving Coil)

Sensitivity :  160 µV

Noise (CCIR) :  -67 dB

Overload Margin at 1 kHz  :  35 dB

Input Impedance :  220 Ω /4,7 nF

Switchable Loading Module (type ULM/M) available to provide the following additional loads; 100 Ω, 30 Ω, 10 Ω, 100 nF and user programmable option

Tuner, Tape 1, 2

Sensitivity: 160 mV

Noise (CCIR) ref. 1 W output -95 dB

Input Impedance: 10 k Ω

Overload Margin at 1 kHz :  50 dB

CD

Sensitivity :  260 mV

Input Impedance :  6 k Ω

Outputs

Tape 1, 2

Nominal  Output :  160 mV

Input IMpedance :  2 k Ω

Crosstalk (all Inputs):  -70 dB at 1 kHz

Power Consumption:  250 VA maximum

Dimensions (W x H x D):  430 x 64 x 295 mm

Weight:  5 kg Net (6 kg Packed)

I like

Arcam Alpha 2 amplifier

The improvements that have been taking place in turntables, CD players, and loudspeakers demand a new level of performance from the amplifier - the heart of every hi-fi system. The discerning buyer expects that today's amplifier should combine a natural yet dynamic and powerful sound quality with good looks and ease of operation. above all, the amplifier's standard of manufacture and quality control should promise years of consistent, trouble free performance.

Until now, only a handful of designs were able to meet all of these stringent criteria. Unfortunately the prices of amplifiers in this select group often made them incceassible to those on a limited budget. Arcam, recognising this unfulfilled demand, has now designed and produced  a modern, top quality amplifier that is truly affordable - the Arcam Alpha 2.

Offering many of the sonic benefits of more expensive models, the Arcam Alpha 2 would be regarded as a fine amplifier at any price. However, when its outstanding performance, facilities and construction are compared with other amplifiers at its price level, it is clear that the Alpha 2 is destined to become a classic, setting the new standards by which all others will be judged.

Philosophy

The Arcam Alpha 2 is a product of Arcam's many years of experience in amplifier design and manufacture. Detailed theoretical analysis and extensive listening have produced a design that is technically outstanding. This design has been realised in practice using high quality components selected for optimum electrical and sonic performance. The result is an amplifier that maintains the full dynamics of a musical performance while reproducing the subtleties and emotion both accurately and naturally.

Power

Not only does the Alpha 2 produce a generous 30 watts continuous output per channel into 8 ohms,  but its special high peak current output stage will drive loudspeakers whose impedance dips as low as 2 ohms. Unlike many other amplifiers the Alpha 2 can be run continuously at high levels because its coolrunning aluminium chassis will not overheat.

Versatility

As well as working properly with all commonly available loudspeakers, the Arcam Aplha 2 is fully compatible with a wide variety of programme sources. Five inputs are available; four are selected by a rotaty switch and the fifth by the nearby tape monitor button. all the inputs use a high quality and robust design of phono socket.

The Alpha 2's cartridge input is specialy optimised for use with any moving magnet cartridge or high output moving coil cartridge. The highest quality low output moving coil cartridges can also be accommodated using our optional plug in MCA pre-pre-amplifier board.

There is a dedicated input for a CD player, further inputs for a Tuner and Video playback and finally a set of line level input and output sockets suitable for use with a tape recorder.

Fexibility

A quality domestic hi-fi amplifier can and should possess those genuinely useful facilities which can improve the performance of the complete system. Typical of Arcam's attention to detail is the Alpha 2' volume control which has been psychoacoustically designed to allow ease of adjustment at the low volume levels often used in the home. limited range bass and treble controls of advanced design are also provided. These allow precise adjustment of the frequency extremes without coloration of the critical midfrequency band. Used sensibly they can help correct for imperfections elsewhere in the system, particularly those associated with cartridges and loudspeakers. The constant power law balance control also helps in this respect. The tone and balance controls all have a centre click stop to provide a reference response in the centre position.

The Alpha 2 has a front pabel socket which will suit a wide variety of stereo headphones. The headphones and loudspeakers will normally work together as the main loudspeaker sockets are wired directly to the amplifier's output to obtainthe best possible sound quality. However  a second pair of loudspeaker socket is also fitted enabling the loudspeakers to be muted automatically whenever headphones are plugged in.

Electronic Design

The disc pre-amplifier uses a low noise professional IC and employs audiophile grade 1% metal film resistors and polypropylene capacitors in the critical RIAA equalisation network. This ensures a clean, accurate sound.

Uniguely the Alpha2 is also configurated to accept out plug in moving coil cartridge pre-pre-amplifier board, the MCA. The MCA and Alpha 2 combination has a much lower noise level and correspondingly greater fidelity than other similarly priced amplifiers. This allows the Alpha 2 to be used successfully with some of the world's finest MC cartridges.

All other inputs are fed directly to the Alpha 2's volume control to ensure a virtually infinite overload margin. The preamplifier stages which follow the volume control again employ low noise professional quality ICs and make minimal use of coupling capacitors to avoid degradation of the sudio signal. All preamplifier circuits are powered by two lownoise, low-impedance regulated power supplies.

The Arcam Alpha 2's power amplifier is an advanced bipolar, high slew-rate design with direct coupled fully complementary class AB output stages. Constant bias circuitry for the driver transistors maintains a clean, dynamic output throughout the entire operating range. The amplifier has a very high transient current capability, made possible by use of 100 watt power transistors combined with high value low ESR reservoir capacitors and a generously rated toroidal mains transformer. Together these permit instantaneous peak output levels of some 250 watts from a single channel into a 2 ohm load. Nevertheless the amplifier is effectively protected against overload. readily accessible fast-blow output fuses are also fitted for loudspeaker protection. They are connected within the main  feedback loop to prevent degradation of the signal. In addition the layout of the PCB has been optimised for such factors as maximum transient power capability and minimum on-board interaction.

Finally, the loudspeaker outputs use ultra high quality PCB mounted 4 mm sockets. These employ silver loaded contacts amd are soldered directly to the PCB to ensure integrity of the signal path. High quality matching plugs are supplied as standard.

Specifications

Output Power: 

30 W  - both channels into 8 ohm (20 Hz - 20 kHz at 0,5%THD)

40 W  - single channel at 1 khz into 8 ohm

60 W  - single channel at 1 khzinto 8 ohm

Total Harmonic Distortion:  0,02% (at 25 W into 8 Ω at 1 kHz)

Overload Margins: 

Disc Inputs :  32 dB at 1 kHz

Other Inputs :  50 dB

Frequency Response:

Disc Input :  60 HZ - 20 kHz , ±0,5 dB, -3 dB at 20 Hz

Other Inputs :  30 Hz - 20 kHz ±0,5 dB, -1 dB at 20 Hz

Tone Controls:

Bass :  +-8 dB at 50 Hz

Treble :  +-8 dB at 15 kHz

crosstalk:  -65 dB at 1 kHz

Disc Inputs:

Suitable for MM and high-output MC cartridges

Sensitivity :  2,5 mV

Noise :  -72 dB

impedance :  47 k Ω  in parallel with 100 pF

With MCA board fitted, for low output MC cartridges

Sensitivity   250 µV

Noise :  -70 dB

Impedance :  330 Ω

Tuner, TApe, Video :

Sensitivity :  200 mV

Noise :  -95 dB

Impedance :  25 k Ω

CD

Sensitivity :  450 mV

Noise :  -95 dB

Impedance :  10 k Ω

Outputs Nominal Level/Impedance

Tape :  220 mV/2 k Ω

Headphones :  suitable for 8 Ω  - 2 k Ω  impedance

Loudspeaker:  30 W into 8 Ω  at 1 kHz

low frequency daming Factor :  200

Suitable for speaker of 4 Ω  or higher nominal impedance

General

Power Supply:  240 V , 110 V ; 50/60 kHz

Power Consumption :  120 VA

Spares Provided

Two loudspeaker fuses;

Two red and two black 4 mm plugs

Dimensions (W x H x D):  430 x 230 x 84 mm (16,9" x 9,1" x 3,3")

Weight:  4 kg (8,8 lbs)

I like

A&R Cambridge T21

The T21 Stereo FM Tuner

The qualities of the A60 amplifier series demand a tuner that is a complete partner. The T21 is that partner, an ideal match in looks, performance and price.

Great care has been taken in the design of the sound circuitry of the T21 to produce an unusually flat frequency response over the critical listening bandwidth. A "birdie" filter, fitted before the stereo decoder, considerably reduces the unpleasant whistles ("birdies") caused by closely positioned stereo broadcasts it also compensates for phase errors in previous stages which would otherwise add to distortion and crosstalk. A highly efficient ,ultiplex filter removes the 19 and 38 kHz high frequency tones produced by the stereo decoder circuitry, preventing damage to loudspeakers and interference with the bias oscillator in a tape recorder.

Overall, our design and production standards have been carefully maintained with the T21 tuner. We beliwve it is the perfect complement to our range of high performance, value-for-money sound equipment.

T21 also included in the tuning window is a single red LED as a stereo beacon. Tuning can be carried out by either the manuall tuning control or one of the five preset push buttons. Full station search with continuously variable tuning is provided by the rotary knob which has a pleasant and useful flywheel action. For the more frequently used stations each of the five buttons can be individually preset with the controls at the rear of the tuner. A mute facility is provided to remove background noise between the stations. To ensure that a station, once selected, remains accuraattely tuned in, an AFC (automatic frequency control) is fitted.

The  T21 can be used with any amplifier including of course, the A60 itself. A level controll knob on the rear of the tuner allows unwelcome variation in the output volume between the tuner and, say, a record deck to be equalised. Thus only minimal adjustment of the amplifier's volume control is ever needed. Both 75 Ω and 300 Ω balanced serial sockets are provided together with tuner matching plugs, allowing easy connection to all standard FM aerial systems.

Specifications:

Tuning Scale:  21 matched red LEDs in steps of 1 MHz, a gradual changeover in light intensity between adjacent LEDs allows frequency readings of typically 0,2 MHz to be achieved.

Tuning Range:  87,5 - 108,5 MHz

Signal Strength Meter:  bargraph scale using 5 LEDs, 2 red and 3 green

Tuning Meter:  3 LEDs, red-green-red

Stereo beacon:  single red LED

Aerial Inputs:

Socket for 75 Ω and 300 Ω antenna

Performance

Sensitivity (IHF):  1,3 µV

-3 dB Limiting Point :  10 µV

Capture Ratio:  1,5 dB

Alternate Channel Selectivity:  better than 60 dB

Repeat Spot Suppression:  better thann 80 dB

IF Rejection:  better than 80 dB

AM Suppression:  better than 50 dB 

(ref. 75 kHz deviation, 30% AM at 400 Hz, aerial signal  10 µV-10 mV)

Signal-to-Noise Ratio (CCIR/ARM weighted):

Mono :  better than 70 dB

Stereo :  better than 68 dB

Pilot Tone Suppression :  better than -50 dB

Subcarrier Suppression:  better than -40 dB

Total Harmonic Distortion (1 kHz):

Mono :  better than 0,15% (typically 0,08%)

Stereo :  better than 0,25% (typically 0,15%)

Channel Separation:  better than 40 dBf

Frequency Response:  20 Hz - 12 kHz  ±0,5 dB ( typically -3 dB at 15 kHz)

Channel balance:  within ±1 dB

Output Level:  continously variable 10 mV- 1 V at full deviation

Output Impedance:  less than 1 k Ω

Recommended Load:  better than 10 k Ω

Power Supply;  200 - 250 V  AC, 6 VA maximum; (or  100 - 120 V AC)

Deimensions (W x H x D):  450 x 60 x 240 mm (17-3/4" x 2-3/8" x 9-1/2")

Weight (net):  3,3 kg (7,3 lb)

I like