Callisto

Callisto is our next generation high end phono preamp, replacing our popular Janis series.

Callisto is a 6922/E88CC tube phono preamp. 6DJ8's can also be used and if you prefer, we would be happy to use your supplied 6DJ8's. In this case, we would of course adjust the final price of Callisto.

It is housed in a custom wooden chassis, various different types of woods are offered, please contact us for details.

Two versions of Callisto are offered.

The first version will have both MM and MC inputs, (selectable) using a pair of Lundahl SUT's (Step Up Transformers), complete with 8 step selectable input loading to closely match the cartridge used, see below.

The following Lundahl SUT's are offered. LL1931, LL1933 and LL1941. This will give user selectable gain range of 8,16,18, 24 or 38dB using a toggle switch accessible via the rear panel, depending on the model SUT used. Note, each model SUT will give TWO sets of gain ranges., HIGH and LOW.

For example, SUT model LL1931 can be configured for a gain of either 8 or 16, so this toggle switch allows the user to choose between those two gain settings. This means that a number of different MC cartridges can be used for any given model SUT.

Each of these model SUT's are also available in Silver Wire for additional cost, see pricing below.

The second version is for MM cartridges only which will have a simplified rear panel with no switches, just RCA in and outputs.

Callisto can be built with all RCA in and outputs, all balanced XLR in and outputs or a combination of RCA and XLR in and outputs, please contact us about your requirements.

Balanced signals are converted & generated using IC's.

For the XLR inputs we use the super low noise INA2134 chip to convert the balanced input signal to single ended signal for the preamp, for the outputs we use the super low noise OPA1632 and OPA1612 to convert the single ended preamp signal to a balanced output signal.
This balanced signal will have a 1:2/8dB signal 'boost'. This 'boost' is pretty standard with balanced XLR outputs and 'adds' to having an extremely low noise level balanced signal.

The 6922 preamp design uses a combination ultra low noise LSK380 JFET and tube cascode input stage with an Aikido-style output buffer. A solid state CCS (Constant Current Source) is used in the second stage.

The power supplies are regulated solid state DC, driven by a Lundahl custom made power transformer for Erhard Audio, LL3737.

Coupling capacitors are Mundorf MCap EVO's, signal path resistors are Vishay and TE Connectivity high precision film types.

This is a no compromise design which will give you hours of amazing vinyl listening pleasure!

Specifications:

MM Gain is 40dB

MC Gain will depend on the SUT used, 55dB+

RIAA response is flat across the audio band, down 1dB at 10Hz and 0.1dB at 40KHz

Input impedance is 47K for MM and user selectable for MC depending on the SUT and cartridge in use

Power consumption: 32W

Chassis size: 14"W x 12"D x 3.25"H

Weight: 12lb