AXPONA 2017: Doshi takes a balanced view of tubes

I first met Nick Doshi in 2013 at the Rocky Mountain Audio Fest where he was showing a prototype of his v3.0 monoblocks, a push-pull design that used four KT-150 tubes to produce 160 watts per channel.

The sound, driving Wilson Audio Specialties Alexia speakers, was both dynamic and sweet. High-power tube amps are a tricky proposition. This young engineer seemed to have nailed it, however, even though the v3.0 was still a pre-production effort.

I had a nice chat with Nick, who was especially patient and good at describing technical aspects in terms a journalism-degreed audiophile could understand. I made a mental note to follow his progress.

Doshi Audio has grown considerably since then, both in the numbers of products in its catalog and in proud owners worldwide.

Nick rolled out another new creation, a stereo amp ($17,000), at AXPONA 2017. The company occupied the Paragon Sight & Sound room with Wilson.

The new two-channel amp, part of the v3.0 line, will begin shipping this summer.

“My goal was to see if I could build an amp with as few gain stages as possible and still be able to adequately power most speakers,” Doshi told me. “This one has two gain stages producing 75 watts per channel. It’s fully balanced from input to output, and has zero overall feedback.”

The component also has an interstage transformer that is differentially driven for optimum phase-splitting to the push-pull output stage.

The v3.0 stereo amp shares many of the top-drawer parts used in Doshi’s monoblocks. In fact, there are so many similarities that the two-channel unit could almost be considered a half-power version of its bigger brother.

Unfortunately, the v3.0 stereo amp was on static display. Doshi’s v3.0 Jhor monoblocks ($29,995 a pair) — the current model of the unit I saw at RMAF 2014 — were up front, driving the relatively new Wilson Yvettes ($25,500).

In addition, there was a Doshi v3.0 preamp ($16,995), Doshi v3.0 phono stage ($16,995), Doshi tape preamp ($16,995) and a Mara Machines MCI JH110 reel-to-reel tape deck ($8,000).

Also in the rig was a dCS Rossini DAC ($23,999) with a Rossini Master Clock ($7,499), as well as a Brinkmann Spyder turntable ($17,490) with a Koetsu Rosewood cartridge ($4,995). Cable was Transparent Reference (totaling $40,310, plus $3,795 for the Transparent Power Isolator 8). Bases and stands were from Harmonic Resolution Systems.

A tape playback of Sonny Boy Williamson’s “The Sky Is Crying” was so good it was spooky, but a Steely Dan track with a Roger Nichols-recorded driving bass groove overloaded the room a bit. This, I believe, was no fault of the system, but rather could be put down to the acoustics exhibitors battled throughout the Westin O’Hare.

Doshi shows no signs of slowing down. After the v3.0 stereo amp comes out in July, he’s got two more products ready to jump off the drawing board.

“I’m working on an integrated amp, and then I’ll be doing another preamp,” he said. “We are growing really rapidly.”

It couldn’t happen to a nicer guy.

AXPONA coverage generously provided by NOBLE AUDIO.

About John Stancavage 196 Articles
Contributing Editor for Part-Time Audiophile