P 7 Tube-Preamplifier

This product 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 parts or devices will not automatically mean a better sound: less often is more. This can also be said for correction and regulating circuit, 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.  

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

Nevertheless other measures for decoupling (e.g. 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.

The P 7 is a tube pre-amplifier. For each channel it has got one ECC 803S for the high-level-section, and the power supply has been provided with a tube rectifier type EZ90.
These tubes are absolutely selected in order to reach the best possible channel balancing, noise and distortion measured datas. Should you ever experiment with other tubes we kindly ask you to notice that, due to the missing selection, the sound characteristics can extremely modify.

Concerning the circuit we chose a direct-coupling anode-/cathode-circuit. The advantage can be seen in the shortest signal ways with only one coupling capacitor. So possible sound interferences can be held extremely low.

The P 7 is built, up to the transformers, completely channel separated (dual mono). Each channel works absolutely self-governed and is consequently not influenced by the other. The consequence is a best possible stability and an optimal channel separation. The result is an extremely wide-ranging, airy and an excellent structured sound pattern.

The power supply is built up with an “Resistor-Capacitor-Inductor-Capacitor-” filter. So, in combination with the high quality line filter, mostly of the line interferences can be eliminated – the audio circuit works under the best possible conditions.

We have mostly avoided mechanical contacts, through which the audio signal has to agonize in general. The switching of the input, of the gain and also of the nfb will be effected by means of gas-filled reed relays. The only remaining mechanical contact is the volume potentiometer. We use the best potentiometer you can obtain – in our opinion - at the moment: TKD.

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

Technical data and dimensions

  • Frequency response:
    10 Hz - 79 kHz (-3dB)
  • S/N ratio, wheighted:
    106 dB
  • S/N ratio, unweighted:
    98 dB
  • THD+N:
    0,046 %
  • IMD: 0,059 %
  • Channel separation (10 kHz):
    63 dB
  • Input sensitivity:
    142 mV
  • Input impedance:
    105 kOhm
  • Output voltage
    max.: 22 V
  • Output impedance:
    857 Ohm
  • Gain:
    3 / 5 / 7
  • Power consumption:
    29 Watt
  • Dimensions:
    480 (W) x 465 (D) x 125 (H) mm
  • Weight: 16.5 kg