Ayon Audio Stratos DSD REFERENCE DAC

32 bit, PCM up to 192k, 64xDSD, 128xDSD (Ultimate high end DAC's can't beat 32-bit processing and powerful DSD engine firmware upgradeable!)

Full-featured Tube D/A converter 

Class-A triode vacuum-tube output stage for single-ended & balanced operation

S/N > 120db

Quad differential gain stage is composed of 2 high performance tubes per channel. The Stratos DAC features a vastly overrated, high capacity power supply for the analog output stage with tube “bridge” rectification, choke coupling and two oversized power transformers. 

The sound is powerful with fantastic bass speed, extraordinary dynamic, airy, finely detailed and outstanding 3D holographic. 

Some unique features:

2 separate R-Core / Low noise – insulated power transformer for digital & analog

Tube rectification

Choke – filtered power supply and coupled with special film caps

High speed  & high quality audiophile grade coupling capacitors

Superior capacitors ( MKP 1% )

Gold-plated industrial grade PCB

Reviews:

Ayon Stratos DAC, "Audiophile-Magazine“

STRATOS is without any doubt one of the best DAC I ever listened to. It makes Music, and in the best possible way. It is comfortable in any situation, from Rock dynamics, to Opera sweetness or Blues laments. With DSD, simply on USB, it takes advantage over SACD players that cost twice or 3 times more. With PCM, Stratos is very close to the wonderful Ayon S5 streamer.

The Absolute Sound

"Long Term Satisfaction" - Stealth DAC (one level lower than Stratos)

http://www.theabsolutesound.com/articles/ayon-stealth-dacpreamplifier/

Ayon Stratos DAC, Haute Fidelite N°2

“The Stratos DAC/preamp is among Ayon’s latest designs.

As is now the norm for Ayon the layout brings together tubes and state-of-the-art conversion circuits. It results in one of the most remarkable sound reproductions ever met in a DAC so far.