PowerTube™ Specifications

The PowerTube is a microphone amplifier that takes on a traditional 'vintage' approach to generating gain. In other words, instead of using the latest technology, it goes back to the glory days of analog audio by employing a transformer coupled input, high voltage tube gain stage and class-A output. And although one can find mic preamps that 'out-spec' the PowerTube, there is no denying - once you give it a listen, you will find that it sounds spectacular.

Block Diagram
Powertube Block Diagram
Frequency Response
Powertube Frequency Response
Specifications are subject to change without notice.
*Refers to use with Radial Workhorse rack and mixer
Microphone Input  
Circuit type: 100% discrete class A with 12AX7 tube drive
Microphone Input: Transformer coupled, Jensen JT-115KE
Current draw: 235mA
Frequency response: 20Hz ~ 20KHz +0/-1dB
Input Impedance: 900Ω
Mic preamp gain: +60dB
Maximum gain: +75dB when used with Workhorse*
Maximum output: +22dBu
Output impedance: 200Ω
Output type: 100% discrete Class-A FET
Common mode rejection (CMRR): >84dB
Equivalent Input Noise (EIN): -128dBu @ maximum gain
Dynamic range: >93dB
Total Harmonic Distortion (THD+N): 0.05%
Intermodulation distortion (IMD): 0.011%
Instrument Input  
Omniport input Impedance: 150kΩ, unbalanced*
Instrument preamp gain: +55dB, unbalanced*
Equivalent Input Noise (EIN): -95dBu, unbalanced*
Total Harmonic Distortion (THD+N): 0.1%
Control Panel  
Meter: 10 segment peak indicator with hold
Pad: Variable
Polarity: 180°
High-pass filter: 250Hz cut-off, -3dB at 150Hz
Air Control: Presence boost @5kHz
Phantom power: 48VDC - 10mA (as supplied by 500 frame)
XLR configuration: AES spec: pin-1 ground, pin-2 (+), pin-3 (-)
Ground lift (rear panel): Lifts ground on front panel XLR input only
Weight: 1.5lbs (0.7Kg)
Shipping size: 9 x 6.5 x 2 (inches)
Compliance (API): Yes
Compliance (WHOS-Doc): Yes
Warranty: 3 years, transferable
Conditions: For use in dry locations only between 5°C and 40°C
Click to view larger