Accuphase P-5000, P-5921 Brochure

m Powerful 6-parallel push-pull output stage in each channel delivers
linear power down to very low load impedances m Input stage with MCS topology m Current feedback circuit combines excellent sound quality with total operation stability m Bridged connection mode allows upgrading to true monophonic amplifier m Massive Super Ring toroidal transformer rated for 1 kVA m 4-step gain control
The P-5000 continues the distinguished design policy of the M-8000 and P-7000. This stereo power amplifier uses carefully selected top quality parts throughout and is an ideal match for the C-2400 preamplifier. MCS topology in the input stage reduces noise even further. Refined technology and inspired design result in superb performance and flawless sound quality.
In order to drive any kind of speaker with precision and authority, a power amplifier must provide extremely low output impedance (Note 1) and be capable of supplying a constant drive voltage at all times (Note 2). To realize these design goals, a power supply that fully meets the demands of the output stage is necessary. In the output stage of the P-5000, six pairs of high-power transistors with a rated collector dissipation of 150 watts are arranged in a parallel push-pull configuration for each channel. The devices are mounted to large heat sinks for efficient dissipation of thermal energy. Rated output power into 1 ohm is 650 watts per channel (music signals only). Power remains linear also when impedance changes, as exemplified by the rating of 400 watts into 2 ohms, 200 watts into 4 ohms and 100 watts into 8 ohms. Even speakers with very low impedance or with drastic impedance fluctuations can be driven effortlessly and accurately. By using the P-5000 in bridged mode, it is possible to create a monophonic amplifier with even higher power reserves. This performance is sustained by a massive high-efficiency Super Ring toroidal transformer and large filtering capacitors.
The important input stage also has been given due attention. Another Accuphase innovation called MCS (Multiple Circuit Summing) helps to minimize noise. Current feedback topology assures totally stable operation up to very high frequencies. Balanced inputs shut out external noise. The copper foil side of the PCBs and all input and output terminals and major signal carrying points are gold plated, for enhanced signal purity.
Stereo power amplifier is ideal match for C-2400 MCS technology in input stage improves S/N ratio, distortion ratings and other characteristics. 6 pairs of wide-band high-power transistors in parallel push-pull configuration for each channel. Massive 1 kVA toroidal power transformer supports 650 watts of power into ultra-low 1-ohm impedance. 4-step gain control effectively reduces noise.
Note 1: Low amplifier output impedance
When forming the load of a power amplifier a loudspeaker generates a counterelectromotive force that can flow back into the amplifier via the NF loop. This phenomenon is influenced by fluctuations in speaker impedance and interferes with the drive performance of the amplifier. The output impedance of a power amplifier should therefore be made as low as possible by using output devices with high current capability. This absorbs the counterelectromotive force generated by the voice coil and prevents the occurrence of intermodulation distortion.
Note 2: Constant drive voltage principle
Even when the impedance of a load fluctuates drastically, the ideal power amplifier should deliver a constant voltage signal to the load. Figure 2 is a graph plotting the output voltage versus current characteristics. Even when the load changes, the output voltage remains almost constant, showing linear current progression. Actual measurement of clipping power at the extremely low load impedance of 1 ohm yields 660 watts. At 2 ohms, the figure is 500 watts, at 4 ohms 310 watts, and at 8 ohms 171 watts. This demonstrates the impressive performance reserves of this amplifier.
6-parallel push-pull power unit delivers guaranteed linear power output of 400 watts into 2 ohms, 200 watts into 4 ohms and 100 watts into 8 ohms
The output stage uses high-power transistors with a rated collector dissipation of 150 watts and collector current of 15 amperes. These devices boast excellent frequency response, current amplification linearity, and switching characteristics. The
transistors are arranged in a 6-parallel push-pull configuration (Figure 1) for ultra-low impedance and mounted on a massive heat sink made from diecast aluminum. This assures effective heat dissipation and reduces the impedance of the output stage. Power linearity is maintained down to ultra-low loads, which demonstrates the impressive capabilities of this amplifier.
MCS topology in input stage reduces residual noise and drastically improves S/N ratio
The input stage features Accuphase's original MCS (Multiple Circuit Summing) design. Three separate
unit amplifiers for the input signal are connected in parallel, minimizing noise and distortion and greatly improving other performance parameters as well. This approach yields further improved sound quality.
Output current (A)
Output voltage (V)
* 1-ohm operation possible with
music signals only
Fig. 2 Output power vs. load impedance
(output voltage/output current: actual measurements)
BIAS STABILIZER
CIRCUIT
BIAS STABILIZER
CIRCUIT
BIAS STABILIZER
CIRCUIT
Fig. 1 Circuit diagram of amplifier section (one channel)
NFB switching type gain control reduces residual noise
Because the current feedback type amplifier circuitry is very stable and introduces little phase shift, an NFB switching gain control has become possible (MAX, –3 dB, –6 dB, –12 dB). With this approach, reducing gain also results in reduced noise. This is especially beneficial when using highly efficient speaker systems where the noise floor could be a problem.
Current feedback circuit topology prevents phase shifts in high frequency range
The P-5000 employs the renowned current feed­back principle developed by Accuphase. At the sens­ing point of the feedback loop, the impedance is
– Input
Buffer
+ Input
Buffer
Fig. 3 Current feedback amplifier principle diagram
Current adder
I-V
converter
Trans-impedance
amplifier
Current NFB
network
Amplifier
Output
kept low and current detection is performed. An impedance-converting amplifier then turns the cur­rent into a voltage to be used as the feedback
signal. Since the impedance at the current feed­back point (cur­rent adder in Figure 3) is very low, there is almost no phase shift. Phase com­pensation can be kept to a minimum, re-
Fig. 4 Frequency response with current
feedback
sulting in excel­lent transient response and superb sonic transpar­ency. Minimal amounts of NFB are used to maximum effect, providing natural energy response. Figure 4 shows frequency response for different gain settings of the current feedback amplifier. The graphs demonstrate that response remains uniform over a wide range.
Robust power supply with "Super Ring" toroidal transformer and high filtering capacity
The P-5000 features a massive toroidal power trans­former with a maximum rating of 1 kVA. The trans­former is housed in a non-resonant alu­minum case filled with a material that transmits heat and absorbs vibrations. This completely pre­vents any adverse influences on other circuit parts. A tor­oidal transformer uses heavy-gauge copper wiring on a doughnut-shaped core, resulting in low impedance and high efficiency while allowing compact dimensions. Two ul­tra-large aluminum electrolytic capaci­tors rated for 47,000 µF each serve to smooth out the pulsating direct current from the rectifier, providing more than ample filter­ing capacity.
nn
n Power amplifier assembly with 6 parallel push-
nn
pull transistor pairs per channel mounted directly to large aluminum diecast heat sinks, MCS circuitry, and current feedback amplifier
Bridged connection allows upgrading to a true monophonic amplifier with 1,300 watts into 2 ohms (music signals only), 800 watts into 4 ohms, and 400 watts into 8 ohms
Bridged connection results in a monophonic amplifier with four times the power output than during stereo operation. Dynamic power with an almost unlimited feel is the result.
Easy switching between dual mono/stereo/bridged
A mode selector on the rear panel makes it simple to switch between dual mono, stereo, or bridged operation. A mode selector on the rear panel makes it simple to switch between dual mono, stereo, or bridged operation. Dual mono can be used for example to drive subwoofers or to obtain the same single-channel signal at both speaker terminals, for bi-amping with dedicated low­range and high-range devices.
n n
n Front panel
n n
nn
n Oversize speaker terminals accept also Y lugs
nn
or banana plugs
The sturdy terminals can handle even very large gauge speaker cable. The connectors are made of extruded high­purity brass material and are gold-plated for utmost reliability and minimum contact resistance. Y lugs or banana plugs can also be used.
nn
n Balanced connection prevents induced noise
nn nn
n Input selector button (balanced/unbalanced) on
nn
front panel
nn
n Large analog power meters with on/off switch
nn nn
n PCB copper foil and all major signal path
nn
components are gold-plated
Gold-plated
parts
Unbalanced and balanced input connectors
Assembly with meter and protection circuitry
High-quality, high-reliability parts
n n
n Rear panel
n n
A
Left/right-channel power meters (dB and % scale)
B
Meter operation/illumination switch ON OFF
C
Input selector BALANCE UNBALANCE
D
Power switch
E
Gain selector MAX – 3 dB – 6 dB –12 dB
Remarks
This product is available in versions for 120/230 V AC. Make sure that the voltage shown on the rear panel matches the AC line voltage in your area.
The shape of the AC inlet and plug of the supplied power cord depends on the voltage rating and destination country.
F
Unbalanced inputs
G
Balanced inputs
a Ground b Inverted (–) c Non-inverted (+)
21
H
Left/right-channel speaker output terminals
22
I
Mode selector
23
DUAL MONO NORMAL BRIDGE
24
J
AC power supply connector
25
n Supplied accessories: • AC power cord
GUARANTEED SPECIFICATIONS
[Guaranteed specifications are measured according to EIA standard RS-490.]
m Continuous Average Output Power (20 - 20,000 Hz)
Stereo operation 0,650 watts per channel into 1 ohm(✽) (both channels driven) 0,400 watts per channel into 2 ohms
Monophonic operation 1,300 watts into 2 ohms(✽) (bridged connection) 0,800 watts into 4 ohms
m Total Harmonic Distortion Stereo operation (both channels driven)
m Intermodulation Distortion 0.003%
m Frequency Response At rated output: 20 - 20,000 Hz +0, –0.2 dB
m Gain 28.0 dB (GAIN selector setting: MAX)
m Gain switching MAX (28 dB), –3 dB (25 dB), –6 dB (22 dB), –12 dB (16 dB)
m Output Load Impedance Stereo operation: 2 to 16 ohms
[ With music signals, load impedances of 1 (stereo) or 2 Ω (mono) can be driven.]
m Damping Factor 270 (also in stereo operation)
m Input Sensitivity Stereo operation 1.12 V for rated output
(with 8 ohm load) 0.11 V for 1 watt output
m Input Impedance Balanced: 40 kilohms, Unbalanced: 20 kilohms
mm
m Signal-to-Noise Ratio 120 dB at rated output (A-weighted, input shorted)
mm
mm
m Output Level Meters Logarithmic scale, dB/% indication
mm
mm
m Power Requirements AC 120V / 230V, 50/60 Hz
mm
mm
m Power Consumption 75 watts idle
mm
mm
m Maximum dimensions Width 465 mm (18-5/16”)
mm
mm
m Weight 31.2 kg (68.8 lbs) net
mm
0,200 watts per channel into 4 ohms 0,100 watts per channel into 8 ohms
0,400 watts into 8 ohms
Note: Values denoted by () symbol are for music signals only.
0.05%, with 2 ohm load
0.03%, with 4 to 16 ohm load
Monophonic operation (bridged connection)
0.03%, with 4 to 16 ohm load
At 1 watt output: 0.5 - 160,000 Hz +0, –3.0 dB
Monophonic operation: 4 to 16 ohms
Monophonic operation 2.25 V for rated output
(Voltage as indicated on rear panel)
630 watts in accordance with IEC-65
Height 221 mm (8-11/16”) Depth 461 mm (18-1/8”)
37.0 kg (81.6 lbs) in shipping carton
0.11 V for 1 watt output
• Specifications and design subject to change without notice for improvements.
K0305Y PRINTED IN JAPAN 850-0134-00 (AD1)http://www.accuphase.com/
Loading...