Wyred 4 Sound ST-250 Power Amp

Really nice amp.  125 wpc into 8 ohms, 220 into 4 ohms. The speaker connections on this amp have been
upgraded to Cardas connectors.  The amp
is 3 years old.  PayPal - please add 3%.  Below is one of the many positive reviews for the ST-250.

Wyred 4 Sound's entry level – and most detailed – stereo power
amplifier, the ST-250 offers outstanding performance at an unbelievable price.
Stable to 4 ohms, there are few speakers this amp can't handle. 

The ST-250 is a true dual mono design, using the same ICE based
amplifier modules as the $1695.00 Bel Canto S300 and Jeff Rowland $1800.00
stereo amp. The ST-250 is then modified to sound better. Modifications include
extensive use of Dale resistors and Muse audiophile grade capacitors as well as
other upgraded parts.

These amps also feature a custom buffered dual FET input stage
designed by Bascom King. This very high quality input stage has an input
impedance of 61k to work with both solid state and tube preamps.  You will
find all specifications listed below, but it is worth noting that these amps
have a distortion level below 0.02% and a damping factor of 2000 for tremendous
woofer control.

Sonics are exceptional with superb low level resolution,
exceptional transparency and tremendous bass detail and extension. There are a
number of big name 100-150 watt ICE based amps that have received excellent
reviews all over the world. Rest assured that the ST-250 is as good as the best
and better than most.

All the parts used in the ST250's input buffer are of the best
quality: Dale Rn55D copper leaded resistors, Wima, and MUSE audio grade
capacitors, and a thick traced PCB to connect everything. Audio signal doesn’t
sound as good through standard magnetic steel leaded resistors, and
electrolytic capacitors. Inside the FETs on all of Wyred 4 Sound input buffers,
there is a voltage to current conversion for a 'sweeter’ sound. The way a FET works
is the current that flows from the output (the drain to source current) is
controlled by the voltage on the input (the gate). This has a softening effect
that complements the slight brightness and edgy sound of the Class D amplifier.
It tends to make everything softer, smoother, and accurate. 

• 125W into 8ohms
  (conservatively),


• 220w into 4 ohms


• Gold plated unbalanced (RCA)
  inputs


• Neutrik Balanced (XLR) inputs


• Custom buffered input stage
  
  (61.9K ohm input impedance)


• Custom insulated binding
  posts


• Dual mono design


• Full Output THD+N


• 83 % total efficiency


• Intermodulation distortion =
  0.002%, 19kHz/20kHz


• Damping factor = 2000, 100Hz,
  8 ohm


• Factory Selectable mains
  115/230VAC


• Stand-by power consumption
  4.1W


• Thermal protection


• Over current protection


• DC output protection


• Sound optimized soft clip


• Rugged construction


• Laser Etched Milled and
  Anodized Aluminum Front panel


• Dimensions: 430mm (W) x 100mm
  (H) x 370mm (D)


• Weight: 11.8kg