AGD Announce The GaNTube88KT Mk III

All Image Credit: AGD Productions

For those of you who are not familiar with Gallium Nitride (GaN) technology, a very brief introduction. GaN technology is a relatively new kind of semiconductor material that is ideal for the manufacture of high speed MOSFET’s used as power devices in switching amplifier (better known as Class-D amps). GaN amplifiers use very efficient circuits to create a switching amp (often incorrectly described by many as “digital amps”). The semiconductor material has the following advantages when used in devices associated with a suitable amplifier design:

• These devices operate at a far higher pulse width modulation (PWM) frequency (800 kHz for GaN versus 400 kHz for traditional Class-D amplifiers). This results in well designed GaN amplifiers creating a near-perfect square wave at the switching node feeding the main output filter, eliminating almost all of the artifacts, oscillations and other distortion effects from the output signal.
• They are very efficient, producing very little heat when compare to convectional Class A or Class AB linear amplifiers.
• GaN amplifiers are generally relatively small even to deliver large power levels.
• They use less power than a traditional linear topologies such as a Class A or Class-AB.
• When designed correctly, GaN amplifiers can easily drive the most complex impedance loads down to 2 ohms and lower
• GaN amplifiers are said to sound very close to conventional single-ended Class A tube amplifiers.

AGD Productions of Los Angeles have just unveiled the GaNTube88MkIII. Their latest development of this technology that resides within a KT88 sized glass envelope. This latest design is said to be the “culmination of two years of relentless development and an unyielding dedication to achieving acoustic perfection” and a “Quantum leap in Acoustic Excellence”.

At the core of this redesign of the MKIII GaNTube amplifier module PWM stage (notably the Voltage-Time converter block) and the LC output filter have had a complete update. This MKIII version extends the designs power stages frequency response to 60KHz, with slew rate improvements due to new layouts and the re-engineered output filter. Still maintaining its 800KHz operating frequency the revised design is said to; “result in reduced distortion, lowered noise, expanded bandwidth and lightning-fast response times”.

With a peak output current capability of 30 amps, this new MKIII design now supports 250watts into 4 ohms when paired with AGD’s Vivace MKII mono blocks and 200watts into 4ohms using their Audion MKII power amplifiers.