High-End Volume Controller - As a cost-effective alternative to our full-featured Stereo and Surround Monitoring Controllers MTC 2381 and SMC 2489, the SPL volume controllers are dedicated solely to level control. The Volume2 model is intended for stereo applications, while the Volume8 can control up to 8 channels. Both devices are designed with active circuitries to circumvent inevitable disadvantages of passive circuitries that result in impedance variation and therefore degraded linearity in frequency response.

Extended information

Who needs analog level control?
Simply put—most DAW (Digital Audio Workstation) users. A majority of D/A converters and sound cards provide nothing in the way of analog level monitoring control, and this means the necessity of varying signal levels at the converter outputs. The result is a lowered bit rate in the monitoring signal, which can lead to commensurate loss of audio quality.
A further, very interesting application area is in the construction of a straight, audiophile-quality stereo playback chain, where the Volume2 is situated between the playback machine and either power amp and speakers or simply active speaker system. In such cases, the playback machine must offer analog outputs. This provides for minimal financial and electronic efforts through the most direct possible playback path.
Common AV receivers employ VCA and DAC components which tend to produce more distortions, or the signal runs through further AD/DA converters for the volume control. Thus especially with SACD or DVD-A sources, only a high-quality analog, direct control of the source output ensures an unimpaired playback of the original information.

Additional Reasons for employing the Volume2:
* High quality balancing stages with extremely good common mode rejection (minimize interferences and disturbances in the signal paths)
* The mute switch allows for very fast reaction times in cases where loud speakers or ears should be protected (for example, with computer crashes)
* Users of analog summing without monitoring facilities can cost effectively improve their systems

Special Features:
The Volume2 is built only with analog circuitry and performance, and its high quality parts in sophisticated circuitry design are prerequisites to superior audio quality:
* High end volume potentiometer and illuminated mute switch from ALPS; the potentiometer controls signals directly (without VCA or DAC circuitry)
* Balanced XLR in- and outputs
* A high quality power supply with toroidal transformer
* Massive, 45 mm diameter aluminum knobs ensure consistent, refined handling
* The elegant, compact format housing (215 x 80 mm or 8.5 x 3.1 inch) allows for flexible desktop positioning near or under a computer monitor or generally saving space in positioning

Technical specifications

Inputs/Outputs
Instrumentational amplifier, electronically balanced
(differential), transformerless

Nominal Input Level: +4 dBu
Input Impedance: =22 kOhm
Output Impedance: ‹ 600 Ohm
Max. Input Level: › +20 dBu
Volume Gain: ∞ to 4 dB

Measured Data
Frequency Range: 10 Hz-100 kHz
(100 kHz = -3 dB)
CMRR: › 60 dBu@1 kHz
THD: & N (@ +15 dBu Input Level) › -100 dBu
S/N A-weighted: -102 dBu
Crosstalk L/R (@ 1 kHz): › -80 dBu
Dynamic Range: 120 dB

Power Supply
Toroidal transformator: 3,5 VA
Fuse: 250 mA/230 V, 500 mA/115 V
Voltage Selector: 230/50 Hz ‹› 115 V/60 Hz
Power Consumption: ca. 15 W

Dimensions & Weight
Housing:
215 x 80 x 220 mm/8.5 x 3.1 x 8.8 inches
Depth incl. Potentiometer, Sockets:
245 mm/9.8 inches
Weight: 1.6 kg/3.52 lb