INTRODUCTION
The Tubeopto 8™ is the ideal Eight Channel input/output expander for any ADAT Lightpipe equipped audio
interface, direct-to-disc recorder or DAW. Eight high quality second-generation discrete class–A vacuum tube
microphone preamps are packaged in a single rack space unit with eight channel 24-bit digital I/O. The mic
preamps drive internal high quality A/D converters and a standard ADAT Lightpipe digital interface. ADAT
digital input is coupled to internal high quality D/A converters that drive eight balanced 1/4” outputs.
Every input on the Tubeopto 8™ offers full control of the signal path with pad, phase and low frequency roll-
off switches. Input gain and variable output level control of each channel allows up to 70dB of clean gain with
incredible sonic transparency and the tube stage can be dialed in for warming effects and soft clipping. Each
channel has wide range LED meters that monitor the preamp output levels to the A/D while clip indicators
monitor preamplifier peak levels. Balanced 1/4" phone or XLR inputs are available on each channel and high
impedance 1/4” instrument inputs are available on channels 1 and 2.
ADAT Lightpipe I/O handles eight channels of 24-bit audio input and output at 44.1KHz, 48KHz, or externally
set sample rates. Wordclock in and thru-puts allow multiple Tubeopto 8’s to be synced in complex system
configurations.
INSTALLATION
The Tubeopto 8
™
may be used in a wide variety of applications and environments. In a rack-mountable, all-
steel enclosure, the unit is designed for continuous professional use. Mounting location is not critical. However,
for greater performance reliability we recommend that you not place the unit on top of power amps or other
sources of heat, or strong magnetic fields. The tube circuitry needs about a minute to “warm up” and stabilize
from a cold power up.
AC Power Hookup
The Tubeopto 8
™
has an internal power supply. Only connect the unit to mains power of the type marked on
the rear panel. The power source must provide a good ground connection, and the ground pin on the mains
plug should never be defeated.
Analog Audio Connections
Audio connections to and from the Tubeopto 8
™
are:
Rear balanced combo input:
[XLR] Pin 2 = Hot (+), Pin 3 = Cold (-), Pin 1 = Ground
[1/4”]
Tip = Hot (+), Ring = Cold (-), Sleeve = Ground
Rear balanced 1/4” output:
Tip = Hot (+), Ring = Cold (-), Sleeve = Ground
Front 1/4” instrument input:
Tip = Hot (+), Ring = Cold (-), Sleeve = Ground
