P 4 Mono-Class A - Hybrid Poweramplifier

This appliance has been developed in order to reproduce music as lifelike and pure as possible. We are protectionists of the minimalist and extremely puristic construction/assembling. A lot of piece parts or devices will not automatically mean a better sound: less often is more. This can also be said for correction and regulating circuits, which will be applied only if absolutely necessary or if they do not have any negative sound effects. Otherwise we prefer other possibilities; e.g. to construct the power supply more extensive and oversized. An expensive way, of course, but the result shows: we are right.

With the same effort we constructed the other part of the conception: the single piece parts and the internal wiring have been determined in particular hearing sessions; the chassis is being optimized mechanically ex works and other – Audio Exklusiv-own, resonance absorbing measurements are implanted in order to take care that the music signal will be available – without any modifications – at the output of the appliance.

Nevertheless other measurements for decoupling (e.g. under-cover bases or feet by Audio Exklusiv) will be able to optimize the sound.

This can also be applied for the current supply: Even though the power input has been provided with a high quality line filter an additional line filtering can be useful in some regions.

After the successful introduction of the two stereo-poweramplifiers P 1/ P 11 the desire for a pure Class A-conception came up. Such amplifiers are characterised by an extremely fine and pure sound pattern. Not existing transient distortions as well as a perfect distortion shape arrangement ensure a very special sound experience. Already during the phase of development the circuit as well as the boards had been drafted that way to realise easily further conceptions. Furthermore interesting modifications concerning the current supply (transformer, capacitors) can be realised.

The P 4 is a Mono-Class A hybrid-poweramplifier. For each channel it has got one E88 CC/6N6 tube in the amplifier-/driver-section and high-performance-transistors with tube-similar characteristics as source-follower. In order to reach the best possible channel-equality and noise- and distortion-values  the tubes are strictly selected.

Should you ever want to experiment with other tubes we kindly ask you to notice that, due to the missing selection, the sound characteristics can extremely modify.

The greatest modification has been realised concerning the supply voltage: In the P 4 we work with approx. 30 V (P 14 by comparison: 60 V). Less voltage means a better current delivery capacity – which has been doubled in this case. And so the P 4 can be seen as ideal for low-impedance- loudspeakers and/or loudspeakers which require a little higher damping factor.


As we have already realised it with our P 14 even here we chose, concerning the power supply, unconventional ways. In the standard version the six pairs of endtransistors are provided with a 500 W transformer and 60,000 µF filter capacity. In the S-Version (optional for extra charge) we added one 500 W transformer as well as a capacitor bank.  This second transformer is connected with reverse polarity and so the elkos can be loaded twice as fast. All this means not only an unbelievable stable and fast power supply with force, velocity and control in the result, but even more space, airiness and resolution.  


Concerning the circuit we chose a three-step hybrid concept. As known tubes are excellent for voltage supply, transistors however for the current supply. The combination of tube and transistor makes it possible to exploit the technical advantage as well as the acoustical advantage without having to take their disadvantages. Because of tonal reasons we abstained from overall negative feedback as well as from negative feedback in the transistor section, which will lead, to our mind, to a particular good sound.


The power supply is built up with a RC-filter. So, in combination with the high quality line filter, mostly of the line interferences can be eliminated – the audiocircuit works under the best possible conditions.


The used piece parts have been determined separately and in cooperation in long lasting listening tests. Noninductive resistors with only lowest tolerances, MKP-capacitors, mica-capacitors and oilpaper-capacitors or the high quality internal wiring are only a few examples for the final selection of piece parts.


As we use them for all other Audio Exklusiv products even here the special patented measures for resonance elimination have been applied. Specially applied they considerably reduce artificial artifacts and clearly improve the demonstration of finest detail resolution and room information


Thanks to all measures we reach a very special soundpattern for the real connoisseur: extremely fast, airy, nearly three-dimensional, best possible stability and current delivery power; excellent structured, but nevertheless emotional sound pattern, which is, above all, signed by a best possible finest drawing as well as by authority.


Finally THE amplifier when not exorbitant power is required.

Technical data and dimensions

  • Output power (8/4 Ohm):
    50 / 90 W
  • Frequency response:
    10 Hz - 200 kHz (-3dB)
  • S/N Ratio: 101 dBu
  • THD+N (1 W/8Ohm):
    0,014 %

  • IMD: 0,083 %
  • Input sensitivity /
    output level max. 8 Ohm):
    800 mV
  • Input impedance:
    100 kOhm

  • Power consumption:
    138 Watt
  • Dimensions:
    480 (B) x 475 (T) x 125 (H) mm
  • Weight: 18,5 kg