Radial PowerTube

500 Series Vacuum Tube Microphone Preamp


About this item



The Radial PowerTube is a class-A vacuum tube microphone preamplifier that captures the essence of the original sound source while imparting the rich harmonics, warmth, and character of a transformer-coupled tube circuit.

  • High voltage 12AX7 tube drive with 60dB of gain
  • Smooth sounding Jensen transformer input
  • Hand-selected 100% discrete class-A electronics
  • Tube circuitry provides vintage warmth and character

Vintage tube tone in a modern preamp

The PowerTube leverages the warmth and tone of a 12AX7 vacuum tube using an innovative non-radiating charge pump that supplies 140 volts to the tube to deliver the excitement and character of a high-voltage vintage tube amplifier. This feeds a class-A balanced output stage that together, can produce as much as 60dB of gain, making the PowerTube ideal for use with all microphones. For even more character, activating the Air switch adds a slight edge to a vocal track or sparkle on acoustic guitar, while low-frequency resonance is easily tamed using the high-pass filter.

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.

Audio circuit type:100% discrete class A with 12AX7 tube drive
Transformer:Jensen JT-115KE
Frequency response:20Hz ~ 20KHz +0/-1dB
Dynamic range:>93dB
Gain:+75dB when used with Workhorse*
Total harmonic distortion:0.05%
Intermodulation Distortion:0.011%
Input Impedance:900Ω
Output Impedance:200Ω
Common Mode Rejection Ratio:>84dB
Equivalent Input Noise:-128dBu @ maximum gain
Maximum Output:+22dBu
Data Compression:235mA
180° polarity reverse, Ground lift, HPF, Level Control, Phantom Power, OmniPort
Input Connectors:XLR
Output Connectors:XLR
Weight:1.5lbs (0.7Kg)
Shipping size (L x W x D):9 x 6.5 x 2 (inches)
Conditions:For use in dry locations only between 5°C and 40°C
Warranty:Radial 3-year, transferable


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