IO TUBE PHONO STAGE
Io is an all-tube phono stage suitable for the most demanding cartridges including low-output moving coils. A proprietary differential circuitry design achieves high gain with extremely low noise. A separate power supply chassis removes any possibility of transformer noise corrupting delicate audio circuitry. Peter Moncrief Stealth Capacitors are used in the Eclipse Edition for unparalleled sound quality. An optional innovative mechanically-switched discrete resistor volume control yields precise resolution at all listening levels.
•High gain / low noise capable of handling low output moving coils.
•Zero feedback.
•80dB maximum gain, internally selectable down to 56dB.
•Flexible user selectable loading on the back panel from 47Kohms down to 10ohms.
•All tube amplification and output (16 tubes total).
•Separate vacuum tube regulated power supply utilizing 8 tubes.
•Two sets of XLR and two sets of RCA outputs per channel.
•Input can be either RCA or XLR.
•Optional: Innovative and unique mechanically switched discrete resistor volume control with 46 positions using Roederstein resistors, one for each channel.
IO Options and Upgrades:-
Mk II, Signature and Eclipse
Io is available in three versions: Mk II, Signature and Eclipse (see tabs above for more detail on each version). The Mk II version uses high-grade Rel-Cap polypropylene coupling capacitors. The Signature version uses exotic and expensive coupling capacitors and other critical parts to bring the performance to a higher level. Eclipse is the ultimate realization of the true capabilities of the Io, incorporating constrained-layer damped machined aluminum panels and Peter Moncrief's Stealth Capacitors. All versions of Io can be factory upgraded to Signature or Eclipse.
Dual Power Supply
Io comes with a single power supply standard, or optionally a second power supply may be added for true dual-mono (see "Power Supply" tab above for more detail).
Volume Control
The Io may optionally be configured with volume controls. This allows the Io to drive a power amplifier directly, negating the need for an intervening line stage. If using a line stage, the front panel volume controls are used to adjust gain.
When configured with volume controls, a further option exists: Two phono inputs or one phono input and one line input (CD player, tuner, etc).
If it is configured with two phono inputs, each input can have its own loading setting, adjusted internally in the Io. The gain / output level is then set by the volume controls.
If it is configured with one line input and one phono input, phono loading is externally accessible at the rear panel. The line input is truly balanced and has both balanced (XLR) and single-ended (RCA) connections. A single ended input will be balanced by the Io. Gain / output level is set by the volume controls.
The volume controls are dual mono and identical to those in the Callisto. Each volume control consists of four silver contact Shallco 46 position switches ganged together in a unique configuration. Each switch consists of 46 Roederstein resistors for a total of 184 Roederstein resistors per channel! All other volume controls sound different at lower levels than at higher levels, due to non-linear elements and the number of solder connections and resistors the signal must traverse. Aesthetix unique configuration means that the sound quality is the same at lower levels as at high levels.
Any Io, of any version or age, may have volume controls added as a factory upgrade.
Faceplate
Io Mk II and Signature available with black or silver faceplate.
IO Technical Specifications:-
Inputs: one phono input, RCA and XLR jacks provided
Inputs (with volume control option): one line level balanced input, RCA and XLR jacks provided
Outputs: 2 RCA (SE) and XLR (balanced)
Gain: 80dB maximum
Volume control (optional): switched resistor network volume control with 46 steps
Frequency response: +- 0.25 dB, 20 Hz - 20 Khz
Signal to noise: 70 dB minimum, A-weighted (ref 1 mv input, 80 dB gain setting)
Input impedance: 10 ohms - 47K ohms (adjustable)
Output impedance: 1K ohms SE, 600 ohms balanced
Recommended load: 10K ohms or greater (SE), 20K ohms or greater (Balanced)
Tubes, each channel: V1-V6 (12AX7); V7 (6DJ8 / 6922); V8 (6SN7)
Power consumption: 350 watts
Physical dimensions:
Main unit, MkII or Signature: 5 5/8" high, 19" wide, 18 1/2" deep including jacks
Main unit, Eclipse: 5 1/2" high, 17 1/2" wide, 18 1/2" deep including jacks
Power supply, MkII or Signature: 5 5/8" high, 19" wide, 18 1/4" deep
Power supply, Eclipse: " high, " wide, " deep including jacks
Shipping weights:
Main unit, MkII or Signature: 32 lbs.
Main unit, Eclipse: 37 lbs.
Main unit, MkII or Signature w/vol: 38 lbs.
Main unit, Eclipse w/vol: 45 lbs.
Power supply, MkII or Signature: 50 lbs.
Power supply, Eclipse: 55 lbs.