The Radial PowerTube 500-Series Preamp is an 'old school' 100% discrete class-A vacuum tube microphone amplifier intended to capture the essence of the voice or instrument while adding the rich harmonics, warmth, and character of a transformer coupled tube circuit.
The Radial PowerTube 500-Series Preamp begins with an ultra low-noise Jensen input transformer. This exhibits near perfect frequency response while producing the warm Bessel curve Jensen is legendary for. The signal is then amplified via a select 12AX7 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. This makes the Radial PowerTube ideal for use with all microphones.
Features include an easy-access front panel XLR input with a safely recessed 48V phantom power switch. To optimize signal-to-noise the Radial PowerTube is equipped with fully variable trim and gain controls. A 10 segment LED bar graph provides visual feedback and driving the Radial PowerTube into the red is encouraged. This increases the grit, harmonic content and distortion. For even more character, activating the Air adds a slight edge to a male vocal or sparkle on an acoustic guitar. Low frequency resonance is easily tamed using the high-pass filter. For added pleasure, the Radial PowerTube comes factory-loaded with a select 12AX7 tube along with a second Tonebone distortion pedal tube for more grit and madness.
The Radial PowerTube... the true character of a world class vintage tube preamp without the noise!
Radial PowerTube 500-Series Preamp Features
- High voltage 12AX7 tube drive with 60dB of gain
- Smooth sounding Jensen Transformer input
- Hand inserted 100% discrete class-A electronics
- Single wide module fits all 500 series rack formats
- High voltage 12AX7 tube gain stage
- 10 Segment LED bar-graph indicator
- Sounds absolutely amazing
- Built in filters to optimize signal path
Radial PowerTube 500-Series Preamp Applications
- PowerTube for studio vocals (in cube) - The Radial PowerTube is the ultimate front end for your finest studio microphone. The Jensen transformer-coupled front end quietly delivers the full spectrum of the source into the class-A tube drive circuit for spectacular results.
- Live recording (in workhorse w/o mixer) - The single wide design and innovative powering scheme allows you to use eight Radials PowerTubes in the Workhorse without sacrificing dynamic range. This makes it perfect for the most demanding live music recording sessions.
- PowerTube on bass (in powerstrip) - Nothing sounds bigger and warmer than a tube! Connect your bass to the Omniport instrument input on the Workhorse, Cube or PowerStrip. Feed the Radial PowerTube into a Komit compressor for dynamic control and then a JDX amp & speaker simulator to capture the sound of a 4x12 half stack.
Radial PowerTube 500-Series Preamp Specifications
- 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: 900?
- Mic Preamp Gain: +60dB
- Maximum Gain: +75dB when used with Workhorse*
- Maximum Output: +22dBu
- Output Impedance: 200?
- 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: 150k?, 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
- Mechanical:
- Weight: 1.5lbs (0.7Kg)
- Shipping Size: 9 x 6.5 x 2 (inches)
- Compliance (API): Yes
- Compliance (WHOS-Doc): Yes
- Conditions: For use in dry locations only between 5°C and 40°C
Radial PowerTube 500-Series Preamp Includes
- Radial PowerTube Tube Preamplifier
- User Guide
- 3 Year Warranty