Sony DPS-V55 multi-effect processor & Alto HPA4

Technical specifications Sony DPS-V55 multi-effect processor

A/D Converter
20 bit resolution

D/A Converter
20 bit resolution

Sampling Frequency

unbalanced switchable +4/-10 phone jack (X4)
Max input level +20dBu

unbalanced switchable +4/-10 phone jack (X4)
Max output level +10 dBu (for -10 dBu reference output level) and +20 dBu (for +4 dBu reference output level

MIDI Input/Output
5 pin DIN (IN X 1, OUT/THRU X 1)

Frequency Response
20~22kHz (+0, -1 dB)

Signal-to-noise Ratio
Greater than 93 dB

Less than .005% (1kHz)

Effect Algorithms
45 (9-4channel; 27-2channel; 9-mono pair)

200 factory presets (001~200)
200 storable presets (201~400)

Power Source
AC 120 V, 60 Hz

Power Consumption
11 W (120V)

Technical specifications Alto HPA4

The Alto HPA4 4-Channel Stereo Headphone Amplifier is a professional headphone amplifier system for studio and stage applications. This universal, multi-purpose processor features 4 independent high-power stereo amplifiers in one rack unit, and delivers maximum audio quality - even at high volume levels. No studio should be with out the HPA4. 
  • Four input/aux sections provide four mixes
  • Direct adjustable on the front panel for stereo signal source
  • Each channel has treble/bass controls
  • Each channel has output level control, mono/stereo switch, and left/right mute control.
  • Three headphone outputs on earch channel (one on front panel, two on rear panel)
  • Each channel has LED output meter