Europa is our all tube tone control preamp, based on the 6922/E88CC family of tubes.
All preamp circuits are on one pcb with their respective power supplies.
All components are housed in an all metal chassis, this makes it easy to place this preamp in shelves.
Europa is another excellent design cooperation between by our circuit guru Ray Waters and Erhard Audio, it is an all tube, Baxandall tone control preamplifier, with a classic cathode follower circuit, tube output buffer and a transistor based constant current source. The tone controls allow the user to adjust for not-so-perfect recordings and to compensate for room acoustics. With the tone controls in the cut/center position, there is no influence to the signal.
With the Tone Defeat engaged, the Baxandall circuit is completely bypassed, resulting in a classisc line preamp.
The optional phono preamp is a hybrid 6922/E88CC circuit, using a pair of hand matched ultra low noise LSK170 JFET as the input stage and the 1NK60ZR-AP MOSFET as the output buffer, resulting in a dead quiet MM phono preamp stage!

Care was taken in this design to keep the circuit as straight forward as possible to avoid manipulating the signal more than is strictly necessary. The result is this outstanding tone control preamplifier.
Power Supply:
We have completely re designed the high volatge B+ power supply, using the excellent LR8 high voltage regulator, resulting in a more stable and extremely low noise B+, one for each channel.
The regulated DC filament supply is based on the excellent LD1085V voltage regulator, one for each channel!
The low-noise toroidal transformer is  our own design and custom made for us. It is housed in an aluminum housing creating a full shield.
Europa can be wired for 120VAC 60Hz or 220-240VAC 50Hz.
Only high quality components are used in the construction of Europa. Low-noise Vishay +/-1% variation metal film resistors are used throughout the signal circuit with high quality Panasonic metal oxide resistors in the power supply circuit. WIMA film and Panasonic/Nichicon/Wurth electrolytic capacitors are used throughout.
All printed circuit boards are designed in house, manufactured to FR4-TG standards, and are double-layer with a full ground plane on the component side to ensure complete screening of the circuits.
RCA sockets are gold plated and mounted directly onto their dedicated printed circuit board, which also carries the selector switch, keeping wiring within the preamp to an absolute minimum. The selector switch is connected via a stainless steel shaft and supported by a miniature ball bearing running through the front panel to the selector knob.
Tubes are factory new JJ 6922 triodes for the tone control preamp as well as the optional MM phono preamp.
General specs:
Main preamplifier gain with tone controls centered - 12dB (x4)
Frequency response is  20Hz to 30KHz, +/-0.1dB
Output impedance, between 80 to 100 OHMS OHMS (Variation of the output tube buffer); Input impedance 1M
Tone controls, boost and cut of 12dB
Optional phono preamplifier gain - 41dB - for MM cartridge only. For MC cartridge, see our SUT (Step Up Transformer)
Optional phono preamp frequency response is accurate to within +/- 0.1 dB of the RIAA curve from 10Hz to 40 KHz
Power consumption: 34W, 40W with the phono option
Chassis size: 13"W x 11.25"D x 3.25"H / 330W x 285D x 82H mm / 2U
Weight: 10lb / 4.5kg
The optional MM phono preamp is on the far left
preamp pcb with the optional AMTRANS caps, all the black ones in the image