Audio Research 330M Monoblocks | Munich 2024

This ain’t your daddy’s ARC. The Audio Research 330M monoblocks are the first Audio Research Company’s first product to market since being acquired by Val Cora of Acora Acoustics. The unit was on static display in the open area in Hall 4. This KT170 based amplifier promises to be a beast, both in performance and in price.

Words and Photos by Graig Neville

The Audio Research 330M was also playing in the Wadax listening room on Magico speakers. Wadax had their CD/streamer driving the system. The sound was very promising and perhaps had the most “tube” sound of any tube system I heard at Munich. Not in a sloppy rolled-off tube way, but with all the magic of tubes. The rich midrange, the holographic imaging, and the slightly warm soulful sound we associate with tubes.

I had an opportunity to speak with David Gordon, Brand Manager, to get more details on the Audio Research 330M:

The Audio Research 330M amplifier was originally imagined to be a larger, more powerful version of the Reference 160M amplifier, but it turned out to be a much more sophisticated amalgam of designs incorporated in other Reference amplifiers. What was shown in 2022 was an idea, not a product; this is a very different beast, producing 330 watts per channel.

The Audio Research 330M is unique, combining new thinking, new designs and new parts with the best ideas derived from other Reference amplifiers. The new front end is using a 12AX7 tube rather than a JFET at the input. The 12AX7 has a buffered output, the buffering accomplished with special bipolar transistors that have tube-like qualities.

The output tube drivers are new Silicon Carbide (SiC) JFETs, which give the driver stage more headroom. Output tubes for the Audio Research 330M are new KT170s, which have increased plate voltage margin, peak cathode current, and plate dissipation. They sound wonderful, with an incredible musicality. In a properly designed circuit, the KT170 provides an elevated level of performance that is unequaled.

The power supply features solid state regulation for the front end and tube regulation (6H30 and 6550) for the output tube screens and driver stage. It also has a Pi filter using a large choke, reducing output stage supply ripple.

The Audio Research 330M is a fully-balanced amplifier, from input to output. Operation is pentode only because this offers the highest performance. The rear panel includes balanced XLR and single-ended RCA inputs, 8Ω and 4Ω output taps, 12V Triggers, RS-232 control, tube hour meter, 20A IEC, and fan speed adjustment.

In addition to the GhostMeter®, the front panel of the Audio Research 330M includes Power, Meter light adjustment, Tube Monitor, and a reduced voltage standby mode to preserve tube life while allowing quick startup.

In addition to the technical description above, there are a few behind the scenes information about the Audio Research 330M. For example, the 16Ω tap was deleted because it sounded better without it. Better transformers, ground up circuit design, and a 4-layer board are just a few of the details that new ARC Chief Engineer, Dylan Wahl, put into this design. ARC has an in-house professional listener that guides sonic signature of all their products and the Audio Research 330M definitely carries the torch of the ARC sound. Production should be starting soon with a hefty price tag of $90,000/pair. This is above the current production 750M at $85,000/pair.

Other developments at ARC include hiring of seven engineers, including Chief Engineer Dylan Wahl, who was the technical lead designer for the Audio Research 330M. David mentioned there were three more products ARC intends to release this year, but for now what those are remains a secret.

ARC is claiming this is their best ever amplifier, which is high marks, but from what I’ve heard at Munich they present a strong showing.