RADIAL POWERTUBE | 500-series Tube Mic Preamp W/ Jensen Transformer
- Catalog #: R700 0115
PowerTube
500-Series Tube Mic Preamp W/ Jensen Transformer
The Radial Engineering PowerTube Preamplifier 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.
Designed to fit inside the Radial Workhorse and other 500 series racks, the single-wide PowerTube begins with an ultra low-noise Jensen input transformer. This exhibits near-perfect frequency response while producing the warm Bessel curve that is characteristic of a Jensen transformer. The signal is then amplified via a select 12AX7 tube using an innovative, non-radiating charge pump that supplies 140V 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 PowerTube suitable 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 PowerTube Preamplifier is equipped with fully variable trim and gain controls. A 10-segment LED bar graph provides visual feedback. Driving the PowerTube Preamplifier 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 PowerTube Preamplifier comes factory-loaded with a select 12AX7 tube along with a second Tonebone distortion pedal tube for more grit and madness.
- 10-Segment LED
- Provides visual signal status as it monitors average RMS peaks to deliver a clean, distortion-free signal to the mix buss and recording system.
- Trim
- The Trim control lets you set the input level going to the tube and class-A circuit. Set low for least distortion or high to add harmonic content and grit.
- 180° Polarity Reverse
- Used to phase-align 2 signals for greater accuracy or as a creative element during the recording process.
- Gain
- Lets you adjust the overall drive circuit. When pushed hard, the PowerTube adds character and harmonics to the signal path.
- Air
- High-frequency lift used to gently add presence to the signal path for more shimmer and clarity.
- Filter
- The 80 Hz high-pass filter removes low frequencies to help eliminate excessive bass. It is particularly useful when layering acoustic tracks.
- 48V
- Phantom power for condensers is equipped with power-on LED and recessed to prevent accidental use that could damage ribbon mics.
- Mic Input
- The XLR female connector is conveniently located on the front panel and placed at the bottom to keep the cable out of the way.
- Omniport
- Rear-mounted 1/4" instrument input, allows guitar and bass to be recorded direct. It is available when used with 500 series racks.
- Full Enclosure
- 100% steel casing reduces magnetic interference from other nearby modules that may cause pollution.
- 100% Discrete Class-A
- Output stage combines with the transformer and tube to deliver 60 dB of gain, making the PowerTube suitable for just about any microphone.
- Radial Push Switches
- Radial switches feature durable metal outer casing and are rated at over 20,000 cycles for added durability.
- Double-Layer Front Panel
- Steel construction adds rigidity to reduce stress on the PC board.
- Dual Potentiometers
- Doubled-up solder points for durability. Steel casing with steel shaft and retention nut will not bend when under stress.
- Heavy Duty XLR
- Glass-filled nylon connector with ultra-heavy nickel-silver solder lugs for optimal signal transfer and long-term reliability.
- 12AX7 Tube
- The PowerTube employs a select low-noise 12AX7 tube with a non-radiating 140V charge pump to deliver the performance of a high-voltage tube preamp.
