Orpheus Labs H TWO 33BD OPUS II Preamplifier

The internal architecture consists of 6 levels

1. Source selection: offers a choice between three balanced and three unbalanced inputs, seamlessly adapting to any source while preserving absolute signal integrity.
2. Conditioner stage: ensures that even the most delicate audio signals are brought to the same reference level, delivering identical sonic quality regardless of the input mode—balanced or unbalanced.
3. The gain adjusting stage of each input between -12.7 dB and +12.7 dB by 0.1 dB step. It is also possible to balance the level Right/Left of each input.
4. Volume adjustment between -127.5 dB and +6 dB by 0.5 dB steps.
5. Adjustment of the balance between left or right on a 12.8 dB range by 0.1 dB step.
6. Output driver with very high slew rate (2000 V/us), capable of driving low impedances allowing a transfer of the audio signal to the power amplifier with no quality loss.

The Tri-State outputs provide the option to select between the Inactive, Balanced, and Unbalanced modes. The Disabled mode allows for the output to be switched off when not in use, ensuring optimal and precise management of connections.

Output B can operate in two different modes:

• In the “PREAMP” mode, output B receives the same signal as output A. This configuration is recommended for bi-amplification installations using, for example, a pair of monoblocs per side.
• The “BYPASS” mode should only be used if the next component also has a volume control function (such as a headphone preamp).

At the heart of the system is an attenuator based on CRQL technology, enabling precise adjustment to the desired output levels. CRQL stands for “Constant Resistive Quadrupoles with a Logarithmic distribution architecture”. This internal circuit has the advantage of being inherently logarithmic, thus avoiding approximations like the more commonly used linear R-2R system in this type of application. The CRQL attenuator module uses quadrupoles composed solely of high-quality metal-film resistors with a tolerance of 0.1%. It allows volume adjustment between -127.5 dB and +6 dB in 0.5 dB steps. To guarantee maximum signal integrity, our CRQL module contains no semiconductor components in series with the signal. Additionally, volume changes occur within a maximum of 150 ns after an audio signal zero-crossing.

TECHNICAL SPECIFICATIONS

INPUT general
Independent gain adjustment between left and right channels	±12.7 dB (in steps of 0.1 dB)
Grounding (menu selection)	Grounded: Signal ground is connected to earth Lifted: Signal ground is decoupled from earth

INPUT Balanced
Connections	XLR
Impedance	94 kΩ
Maximum input voltage	18.4 Vrms

INPUT Unbalanced
Connections	RCA
Impedance	47 kΩ
Maximum input voltage	9.2 Vrms

Volume control
Adjustment range	-127.5 dB to +6 dB (in steps of 0.5 dB)
Balance correction range	±12.8 dB (in steps of 0.1 dB)

OUTPUT
Frequency range (+0dB, -0.1dB)	5 Hz to 1.5 MHz
THD+N on a 600 Ω load (22Hz to 44kHz)	< 0.00063 % @ 1 kHz (-105 dB)
Signal to Noise Ratio (input Balanced)	-132 dB
Signal to Noise Ratio (input Unbalanced)	-126 dB
Number of outputs	Output A: 1x Balanced or 1x Unbalanced Output B: 1x Balanced or 1x Unbalanced

TECHNOLOGY USED
Dual monaural analogue fully BD (Balanced Discrete) preamplifier. Constant Resistive Quadrupoles with a Logarithmic distribution architecture Specificity of output B: Can be used in Bypass mode in order to connect, for example, one Headphone Amplifier with integrated volume control.

POWER
Nominal line voltage	100, 115 or 230 Vac
Input voltage range	±8 %
Maximum power consumption	60 W
Standby consumption	Less than 1 W

SIZE & WEIGHT
Height	Device alone: 146 mm Device + spikes: 175 mm Device + spikes + PSU: 301 mm
Depth	440 mm
Width	440 mm
Weight (Power supply included)	50 kg