The Wombat* bias meter is a compact, innovative solution to allow anyone to properly bias a tube amplifier. First announced way back in 2000, this revolutionary biasing meter was the first of its kind to give a digital readout of the actual power dissipated in the output tubes. This is the only truly accurate method of biasing.
- Provides a digital readout of plate voltage and plate current, and automatically calculates and displays the actual plate dissipation in watts - no more math or guesswork!
- Eliminates dangerous multimeter probing of internal amplifier high-voltage wiring
- The only truly useful biasing tool, because it takes into account actual plate dissipation.
- Eliminates error-prone, inaccurate biasing methods such as the oscilloscope "crossover-notch" biasing method
- Eliminates the need for expensive digital multimeters and having to add 1 ohm "current sense" resistors in amps in order to measure bias current..
- Uses only the highest quality components and construction.
- Features high-resolution 12-bit analog-to-digital converters and 0.1% tolerance voltage sense resistors for unparalleled accuracy of measurement. No other bias meter can come close to this accuracy.
- Measures plate voltages up to 750V, current up to 500mA. Internally protected against voltage/current overloads and ESD (static) discharge.
- Ultra-compact size - only 3.8" x 2.4" x 1.1" - doesn't take up valuable bench space, easily portable.
- Works on both fixed-bias and cathode-biased amplifiers.
- Easy to use - simply adjust the amplifier bias potentiometer until the desired plate current is obtained, and check to make sure the max recommended plate dissipation for the tube is not being exceeded as indicated on the display.
- Rear panel has overlay showing power ratings for most common tube types, for ease of use.
- White backlit LCD display to allow easy viewing on dark stages
- Runs on two AA alkaline batteries (not included), easily accessible via the rear panel snap-on cover. Low-power backlight for long battery life.
- RoHS-compliant, currently pending CE certification for EU markets
Specifications:Socket adapters, not included, available separately in any combination:Dual octal probes with 24" leads to allow biasing of all common 8-pin guitar amplifier output tubes, including EL34, 6L6, 6550, 5881, and others. Each of the probe assemblies has dual octal sockets, so with one probe you can measure and display voltage, current, and power for up to two tubes at once, or with two probes you can measure and display up to four tubes at once.Display:
Dual noval (9-pin) probes are also available, to allow biasing of amplifiers using two (with one probe) or four (with two probes) EL84 output tubes. Note: Noval probes are currently out of stock, undergoing changes for CE compliance, available soon.
There is also a special dual-triode bias probe to allow measurement of bias current in low-power amplifiers using a single 12BH7/12AT7/12AX7/12AU7 or other dual-triode tubes. One probe will display the current, voltage, and power for both triode sides simultaneously. Two probes will allow the measurement of two dual-triode tubes simultaneously. Note: Dual-triode probes are currently out of stock, undergoing changes for CE compliance, available soon.
The display automatically recognizes how many probes are connected. If two dual probes are connected, it will cycle between probes 1/2 and 3/4 every few seconds to allow bias measurement and display on up to 4 tubes simultaneously.LCD display readout of plate current in mA, plate voltage in volts, and plate dissipation in watts. The LCD display is backlit to allow easy viewing on dark stages.Dimensions:3.8" long x 2.4" wide x 1.1" tall.
A. "Harry" Marsupial
Official "spokeswombat" for Aiken Amplification
* Wombat stands for "World's Only Metered Biasing Ampowerometer Tool" - well, we *had* to think of something catchy!
Copyright © 2000-2010 Aiken Amplification. Photo used without permission (I don't know where it came from, but the critter is kinda cute!) - credit given to photographer in photo.
