Doshi Audio V3.0 Line Stage

Doshi Line Stage V3 up for sale.  Current model and one fine sounding pre-amp.  It is a bargain at its retail price of $17,999.  Downsizing and it is a shame for this to sit unused.  It is in like new mint condition.  No scratches or imperfections that I can see.  About 250 hours of use. 

Priced at $7,499.  Shipping to US addresses only. Seller will pay shipping. Original shipping box and materials will be used.  Buyer pays Pay Pal fees. No trades.

Marshal Nack in his 2018 Posi+ive Feedback review of this pre-amp summed it up this way.  The new Doshi Preamplifier V3.0 may be physically small but, boy-o-boy, it sure can pack a punch. The powerful statement of its low-end was the first thing I noticed—so much so, that I had to dial down my powered subwoofers. That low-end partnered with the unit's extraordinary dynamic headroom gave it the ability to ride in sync with the most challenging orchestral material. This was uncommonly satisfying, and a tribute to the unit's well-designed external power supply.

Similar efforts targeting resonance and vibration elimination were evident in the thorough-going transparency achieved at all signal levels. Obscurity was banished and the soundstage opened up, allowing an easy walkabout deep into the furthest corners.

The Doshi hits above expectations in every category on the audio report card. Its voice is tempered by a pair of valves that add beauty, warmth, and timbral variety. Always acoustic, always ingratiating, you'll find that voice refreshingly far from a solid-state signature.

Marshal concludes that the Doshi Pre V3.0 is the one to beat at $20K and under.

From Doshi’s website here is more detail.  Doshi believes in circuit simplicity.  This concept reaches its full potential in this Line Preamplifier due to its single gain stage, which employs one ECC99 Dual-Triode Vacuum Tube per channel: the first triode provides gain while the second—a “Follower”—minimizes output impedance. Thanks to our elegant circuit design, the Doshi Line Preamplifier offers zero negative feedback, low output impedance and the ability to drive any cable and amplifier load.

The Doshi Linestage includes four differential inputs.  This unit has 3 XLR and 1 RCA but these can be easily and inexpensively changed by Nick.  Inputs are relay-switched into a transformer which provides 31 high-precision, relay-switched volume steps. Home Theater Bypass is also included, further augmenting versatility. Two sets of differential isolated outputs—also specified as RCA or XLR to the customer’s desires—and a 12V on/off Trigger complete our preamp’s comprehensive connectivity. Naturally, all functions of the Doshi Line Preamplifier have been placed under the control of a machined aluminum remote control.

Behind its sculpted aluminum faceplate, the chassis of our Line Preamplifier incorporates Doshi’s Three Stage Decoupling™ technology to virtually eliminate the influence of both external and internal resonances upon our circuits’ performance. Critical audio circuits are point-to-point wired and mounted on an acoustically isolated sub-chassis. The entire sub-chassis is suspended from a ½“ thick slab of laser-cut, DuPont Corian which, in turn, floats upon four vibration absorbing feet that are mechanically decoupled from the chassis. While our competitors build their enclosures from mild steel and aluminum, Doshi uses extremely strong 14-gauge stainless steel to create a chassis that is mechanically and electrically inert; as a result, our components provide an ideal foundation for performance.

As befits a state-of-the-art component, the Doshi Line Preamplifier includes an oversized power supply housed in a separate, resonance-controlled chassis. Connected to the Preamplifier via a custom-made, heavily damped and shielded cable, the power supply includes a purpose-built transformer. Manufactured by Toroid, this transformer is massively over-specified to prevent resonances that occur when a transformer is run at full capacity. Power Supply capacitance in excess of 1,500 microfarads is more typical of power amplifiers than preamplifiers. High speed, low noise rectifiers and three levels of resistive-capacitive power filtering provide total isolation of the high voltage supply from the mains, eliminating current modulation and delivering battery-like purity and stability while avoiding the high source impedance of a battery supply. In order to extend tube life, all Doshi power supplies feature soft-start circuitry.