Aesthetix Callisto - Signature Edition Tube Preamplifier with Dual Power Supplies
This is the Flagship line stage preamp from Aesthetix (Jupiter Series), utilizing dual power supplies (one per channel) along with dual mono construction. These don't come up for sale very often.
Working as it should all around, and a great match to the IO phono preamp that is also currently listed.
It was updated to independent power supplies back in 2002. Aesthetix is still in business and still offers service and upgrades to this model.
CALLISTO TUBE LINESTAGE
Callisto is an all-tube linestage suitable for the most demanding audio systems and listeners. Fully balanced circuitry from input to output, including internal balancing of single-ended inputs, results in common mode signal rejection and cleaner sound. The innovative discrete switched resistor volume control maximizes resolution at any listening level. A separate power supply chassis removes any possibility of transformer noise corrupting the delicate audio circuitry. Peter Moncrief Stealth Capacitors are used in the Eclipse Edition for unparalleled sound quality.
• Fully balanced differential circuitry with ability to internally balance a single-ended input signal.
• Innovative and unique mechanically switched discrete resistor volume control with 46 positions using Roederstein resistors.
• Separate volume controls and input selectors for each channel.
• All tube amplification and output (8 tubes total).
• Separate vacuum tube regulated power supply utilizing 8 tubes.
• Two sets of XLR and two sets of RCA outputs per channel.
• Six inputs: First two single-ended (rca) or balanced (XLR); remaining four single-ended (rca) only.
Dual Power Supply
Callisto comes with a single power supply standard, or optionally a second power supply may be added for true dual-mono.
JUPITER POWER SUPPLY DETAIL
One defining characteristic of the Jupiter Series is separate power supplies. Each main unit, or audio chassis, is dual mono in construction; there are completely separate left and right audio boards and each has its own power connector on the rear of the chassis. Each main unit requires at least one power supply, a single power supply cannot power both an Io and a Callisto.
There are two versions of power supply available: Stereo or Dual Mono. In the stereo configuration, a single power supply powers both audio channels and has two power connectors on the rear. In the Dual Mono configuration, two separate power supplies are used, each with a single power connector. In the Dual mono configuration, the unit becomes pure dual mono, all the way down to the ac wall connection!
The Jupiter Series Power Supply is the size of a power amplifier and weighs approximately 50 pounds. The Power Supply has two main sections, the heater supply and the high voltage plus and minus supplies. At the heart of the heater supply is its massive, low flux, 210 VA power transformer which has fourteen separate secondary windings that are individually regulated and supply both the Power Supply and main unit heaters. The high voltage supply is composed of a similar massive 170 VA transformer which feeds a common-mode choke input filtering network and then high current vacuum tube regulators (one EL34/6CA7, three 12AX7 tubes per regulator). Each regulator is capable of supplying 600 volts at 100mA. There are two such regulators in the Power Supply. Each separate amplification or buffer stage has its own power supply filtering network and regulated heater supply to isolate individual sections and prevent stage interaction.
Inputs: Six inputs: First two single-ended (rca) or balanced (XLR); remaining four single-ended (rca) only
Outputs: 2 RCA (SE) and XLR (balanced), 1 tape RCA
Line level gain: 23 dB single ended (SE), in/out, and 29 dB balanced/out
Volume control: switched resistor network volume control with 46 steps
Front panel controls: Left and right input select, left and right volume
Remote controls(optional): Volume, mute, balance, phase (option)
Frequency response: +- 0.25 dB, 20 Hz - 20 Khz
Signal to noise: measured at 70 dB minimum, A-weighted (ref 1 mv input, 75 dB gain setting)
Line input impedence: 100K ohms SE, 200K ohms balanced
Output impedence: 1K ohms SE, 600 ohms balanced
Recommended amplifier load: 10K ohms or greater (SE), 20K ohms or greater (Balanced)
Tubes, each channel: (line section) V1 (6922), V2 (12AX7), V3 (6922), V4 (6SN7)
Power consumption: 300 watts
Main unit, MkII or Signature: 5 5/8" high, 19" wide, 18" deep including jacks
Main unit, Eclipse: 5 1/2" high, 17 1/2" wide, 18" deep including jacks
Power supply, MkII or Signature: 5 5/8" high, 19" wide, " deep including jacks
Power supply, Eclipse: 5 5/8" high, 17 1/2" wide, 18 1/4" deep including jacks
Main unit, MkII or Signature: 42 Lbs
Main unit, Eclipse: 47 Lbs
Power supply, MkII or Signature: 50 Lbs
Power supply, Eclipse: 55 Lbs
CALLISTO TECHNICAL DOCUMENTS
The SkyFi Testing Process for Preamplifiers:
We start with a visual inspection of all internal components to make sure there are no signs of stress or aging. Capacitors are checked for telltale sings of bulging or leaking, resistors are checked for signs of overheating or cracking, and transistors are checked for signs of stress or damage. Special attention is paid to the power supply which is the most common source of failure for preamps. We then power up the unit and run a simple 1k sine wave while monitoring the low voltage output on an oscilloscope for signs of distortion or noise to get a baseline.
At this point we will lubricate and clean all switches and potentiometers (that are not sealed) with a high quality contact cleaner, and then re-test all functions for any signs of noise or scratching.
Final testing involves putting actual music through the preamplifier We have learned over time that some issues are only noticeable to a trained ear while listening to a familiar source material. Our test bench has reference vintage KEF speakers that we are super familiar with which will quickly reveal any discrepancies. Some preamps will then move into the listening room where they will be tested with our in-house reference system.
Please click here for detailed specifics regarding our specialized packing process that separates us from the rest.
Factory Optional/Not Included
Yes - As Pictured