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Finding joy in a 1-watt-per-channel amplifier -- is that even possible?

The Audiophiliac delves deep into the sound of Linear Tube Audio's astonishing MicroZOTL2.0 headphone/speaker power amplifier.

This is no joke: Can a one-watt amplifier possibly sound any good? If it's a headphone amp, one watt per channel is plenty, but can a one-watt amp play louder than a whisper with speakers?

It's the sound quality of the single watt that makes this amp special, but if you crave power and glory, the Linear Tube Audio MicroZOTL2.0 one-watt-per-channel amp won't cut it. Then again, for very small rooms or used with desktop speakers one watt might be enough -- it was for me.

Before we go any further, the MicroZOTL2.0 is sold primarily as a headphone amp, and that's how I used it most of the time. But since it has speaker outputs, I hooked up a pair of highly efficient Klipsch RP-150M bookshelf speakers, and the sound was vital, lively and rhythmically alive. Even with just one watt, the RP-150Ms could play fairly loud, but the puny power output limited bass oomph and dynamic impact. That was expected, but with quieter acoustic music the sheer clarity of the MicroZOTL2.0's sound floored me.


The Linear Tube Audio MicroZOTL2.0 amplifier

Linear Tube Audio

The MicroZOTL2.0 is a Class A, no feedback, output transformerless design that uses one 12AT7 input tube and one 6SN7 output power tube per channel. The MicroZOTL2.0 is a "reconfiguration" of David Berning's original MicroZOTL amp that was manufactured from 2000 to 2007. Berning's electronics were first coveted by audiophiles in the 1970s, and he continues to handcraft his own company's electronics in Washington D.C.

The MicroZOTL2.0 is manufactured by Linear Tube Audio in Washington D.C., which licenses David Berning's designs and sells them for much lower prices than Berning's own creations. David Berning personally tests Linear Tube Audio's prototypes to make sure the amps perform to his standards. The MicroZOTL2.0's compact chassis measures 9.5 by 4.75 by 7.8 inches (241 by 120 by 198 mm) and weighs 5.35 pounds (2.5 kg).

The amp's rear panel offers two pairs of stereo RCA inputs and one pair of stereo preamplifier outputs, heavy-duty speaker connectors; upfront there's a 6.3mm headphone jack, input selector, volume control and power switch. The MicroZOTL2.0 doesn't come with a remote control.

Peering through the clear top cover the MicroZOTL2.0 looks well put together, and uses top quality parts including hand wound coils and metal film resistors. The designer estimates the tubes should have a 10- to 20-year lifespan before replacement.

I started my evaluations with my Audeze LCD-X, Beyerdynamic T1, Grado GH-1 and Hifiman HE400S headphones, and the MicroZOTL2.0 was an instant hit. Man, it's so clear but also rich and warm, the sound was robustly alive.


A look inside the Linear Tube Audio MicroZOTL2.0 amp

Linear Tube Audio

While listening with the AudioQuest NightHawk headphones I compared the MicroZOTL2.0 with the Schiit Ragnarok amp. The MicroZOTL2.0 was warmer and fuller, there was more body to the sound, and the stereo soundstage was more spacious. The Ragnarok was even more transparent, bass definition firmed up, and when I cranked the volume louder, the Ragnarok's dynamics kicked harder than the MicroZOTL2.0's.

Continuing with the Oppo PM-3 headphones with a few Jesus and Mary Chain songs, the MicroZOTL2.0 unleashed the band's screaming guitars and melodic hooks with real gusto, the Ragnarok was brighter, and more immediate in its presentation. It rocks!

I'd say the Ragnarok was more accurate, the MicroZOTL2.0 added a bit of extra gravitas, texture and body to the sound of every tune. Which amp is better, that's in the ear of the beholder. The Ragnarok is a superb, and much more powerful solid-state integrated amp for speakers and headphones, but the MicroZOTL2.0's tube-enhanced sound will have its admirers.

The one downside to using the MicroZOTL2.0 with headphones and speakers is the speaker outputs are always on, so when you listen to headphones, the speakers will still be playing sound. I worked around this by unplugging the speaker cables when I listened to headphones, which I admit isn't ideal. That said, I assume most MicroZOTL2.0 owners will only be using the amp with headphones, but even so a headphone/speaker output switch would be a nice feature.


The Linear Tube Audio MicroZOTL2.0's rear panel

Linear Tube Audio

The MicroZOTL2.0 may look rather plain on the outside, but the sound is something else again. Linear Tube Audio also offers a few more-powerful amps, I hope to review one early next year.

The MicroZOTL2.0 is sold with a one-year warranty (and that includes the tubes). The price is $1,100 in the US, and Linear Tube Audio ships direct to the UK and Australia for approximately £728 and AU$1,564 respectively, plus shipping.