A sound you never heard before…

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An EL-34 based high-end amplifier.

This amp is directly derived from our second push pull valve amplifier prototype. It’s the result of a lot of readings, testing, rip-and-retries, archeological research, and listening hours. It was designed with one key idea : No compromises !

  • – The topology of a push pull valve amplifier combined with the exceptional Lundahl transformers.
  • – No compromises about the components quality.
  • – No compromises about the capacitors (low ESR, grade 105°).

To name but a few of our choices :

  • – Oversized stabilized power supply.
  • Toroidal supply transformer
  • Lundahl high-grade audio output transformers.
  • – Gold plated professionnal connectors.
  • ALPS Blue velvet 27mm potentiometer.
  • – Only one capacitor in the signal path.
  • – Tube connectors are point-to-point wired, while the rest of the components are located on a high grade double-sided Printed Circuit Board.
  • – Circuit board with 100 microns thick copper tracks.
  • – 1.5 mm steel sturdy enclosure, with 3mm aluminium front and rear plates, mounted on gold spikes to minimize microphony.
  • – NO fancy auto bias solid state circuitry, possibly degrading the sound, but instead an handy metering and adjustment system.
  • – Tripod arrangement of the spike-shaped feet to ensure stability on any surface.

push pull valve amplifier

Ruby II

1.851,30 € — 1.967,46 €

To choose your Output Tubes,
please check our EL34’s info page.


Technical specifications

  • – Push Pull topology, class AB
  • – Mains : 110V-220V selectable
  • – Output Power : 25 watts x 2 in ultra-linear mode
  • – Output Tube : EL34 x 4 (Electro Harmonix as standard, other brands as options)
  • – Input & Driver Tubes : 5670 x 2, 6SL7GT x 2
  • – Frequency response : 7Hz-67KHz +/-3 dB
  • – Signal/Noise Ratio : 102dB
  • – Distortion : Less than 0.5% at full power
  • – Output impedance : 4 or 8 ohms

Why shoud I buy a push pull valve amplifier like the Ruby II ?

One answer would be: it sounds different from transistors amplifiers, but there is much more :
  • – Valve amplifiers will reduce the harsh sound in most hi-fi systems, without losing the treble and musical details.
  • – A Push Pull valve amplifier produces almost no even harmonics.
  • – Valves amplifiers allow you to hear the “silence” between the notes, as tubes are less noisy than transistors.
  • – A valve amplifier allows you to hear a note, followed by silence (or the dying echo of the note in the concert hall).
  • – A tube amplifier has much less components than a transistor amp, and all things being equals, the less components in the signal path, the better the sound and the better the THD+noise figure.

… I’m a Blues man, and I like Rock from the seventies too. Coloseum, Clapton, Santana, Gallagher, Johnny Winter, The Band… This amp really makes my old friends alive again. My Dynaudio Focus 340 speakers have a rather low sensitivity but there’s plenty of juice in that amp to leave me completetly baffled after John Mayal’s “Blues from Laurel Canyon”… As a photographer I need great music, great sound sensations while on a shooting session. It influences both my work and my models’ behaviour. This amplifier is a major improvement of my studio.

Georges G. Lottig, photographer, Münster, Germany

See the owner’s manual here