Dyad S400 power amplifier

 

Dyad S400 is the world’s first true fully balanced hybrid power amplifier in which voltage amplification is achieved by all vacuum tubes while current amplification by solid-state transistors. It employs patented Dual Balanced Feedback Topology (DBFT) and High Current Buffer Amplifier (HCBA).

S400 is a stereo power amplifier that delivers over 200W to a 8-ohm load and 400W to a 4-ohm load per channel. Vacuum tubes (12AU7 x 2, 6922 x 1 per channel ) are used for voltage amplification. Current amplification is handled by solid-state transistors packed HCBA that produces unity voltage gain but tremendous high current capacity. Due to the balanced nature, two HCBAs are used per channel.


The DBFT has proven to be an excellent balanced design with astonishing sound since developed in 2007. The dual balanced feedback loops can easily allow the performance of the power amplifier to be optimized. Since voltage amplification is handled by all vacuum tubes, while HCBAs have unity voltage gain, the mids and highs of the audio spectrum have retained very much to a tube power amplifier. But S400 has much better bass performance over tube power amplifiers by means of tremendous current drive provided by sold-state transistors.

 


PRODUCT DESIGN
Hybrid stereo power amplifier employed with patented Dual Balanced Feedback Topology and High Current Buffer Amplifier

SIGNAL TUBES
12AU7 x 2, 6922 x 1 per channel

OUTPUT POWER
200W x 2 for 8 ohm load
400W x 2 for 4 ohm load

DISTORTION
0.02% @ 10W, 8 ohm (1kHz)

0.1% @ 200W, 8 ohm (1kHz)

VOLTAGE GAIN
31dB

SIGNAL TO NOISE RATIO
> 90dB

INPUT IMPEDANCE
100k ohm (single-ended input)
200k ohm (balanced input)er channel.

DAMPING FACTOR
>150

OUTPUT CURRENTS
25A (continous)
50A (peak)

INPUTS
One set of balanced inputs
One set of single-ended inputs

BANDWIDTH
20Hz to 20kHz

IDLING POWER
230W

MAXIMUM POWER CONSUMPTION
1000W

DIMENSION
220 X 470 X 576mm (H x W x L)

NET WEIGHT
43kg/95lbs                                                                                 

 

 

 

 

(German)

(Click the icon to read the full review.)

  

 

“Dyad S400 is capable of conveying the sound naturally in an amazingly relaxed way ... absolutely convincing!” Dirk Sommer of HiFi Statement, Germany. (Click the icon to read the full review.)

 

“The sound was breathtaking in the way it layered information -- I was able to hear the space around performers on the stage.” Michael Wright of Ultra Audio. Dyad S400 received the Select Component award from Ultra Audio. (Click here to read the full review.)