Specifications
Callisto is our new generation 6922/E88CC based premium phono preamp. 6DJ8's can also be used.
After many months of re design and testing, Callisto is a superb tube phono preamp offering a range of options from MM only, to MM & MC with the choice of a number of Lundahl SUT's (Step Up Transformers) to pretty much suit all MC cartridges available on the market today.
Up to eight user selectable cartridge load resistors will allow the fine tuning of the cartridge in use. The value of these load resistor will vary depending on the Lundahl SUT chosen.
The final step up gain is also user selectable via a small toggle switch.
Circuit:
Callisto uses a combination ultra low noise LSK380 JFET (dual LSK170) and tube cascode input stage with an Aikido-style output buffer. A solid state CCS (Constant Current Source) is used in the second stage.
Power Supply:
We have completely re designed the high volatge B+ power supply, using a far superior MOSFET based circuit, resulting in a more stable and extremely low noise B+!
Tube filament is also regulated DC for extra low noise operation.
The low noise toroidal power transformer is our own design and custom made for us. This is potted inside an aluminum enclosure for full shielding.
A 120V/240VAC 60/50Hz selector switch on the rear panel allows Callisto to be used anywhere in the world.
Components:
Only high quality components are used in the construction of Callisto. Precision +/-1% TE Connectivity Holco metal film resistors are used throughout the signal circuit with high quality Panasonic metal oxide resistors in the power supply circuit. WIMA film and Wurth electrolytic capacitors are used throughout. Coupling capacitors are Mundorf MCap EVO series.
The printed circuit boards are designed in house , manufactured to FR4-TG standards, and are double-layer with strategic ground planes in sensitive areas to ensure low noise operation..
The SUT's are the superb Lundahl Transformer units, with optional Silver Wire available at additional cost.
Tubes are factory new quad set of matched Genalex Gold Lion Gold Pin E88CC's.
General specs:
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
