Bel Canto Design eVo4 2, 3, 4 channel dual stereo/mono power amp

Mint condition eVo4 power amp with new box/packing and all accessories. Can be used as a high power stereo amp with 400W/8 Ohms, 600W/4 Ohms or as a 4 channel amp with 120W/8 Ohms, 240W/4 Ohms. Can also be used as a 3 channel amp where one stereo board powers a pair of satellites and the other stereo board (in bridged mono) powers a sub.

The eVo Digital Output Stage and Digital Power Processor

The Bel Canto Design eVo digital output stage is of unique simplicity. The output uses 2 N channel MOSFET switches switching between the power supply rails. These switches turn on and off within 30 billionths of a second and provide an onresistance path to the supplies of a few thousandths of an ohm. These switches switch alternately between the supplies at a rate over 600,000 cycles per second (600 kHz). When no audio signal is present, the ratio between the time at the positive supply and the negative is balanced to provide no audio frequency output. The switching stage is isolated from the loudspeaker by a single LC filter stage. This 80kHz second order filter is used to reject high frequency energy and maintain linear phase response. Furthermore, the digital power processor adds small levels of high frequency dither to insure that an inherently linear output stage characteristic is maintained from very low to very high output levels. The audio frequency information modulates the output stage by changing the time relationship between the positive and negative supply rails. The critical timing information is controlled by the digital power processor and the effective switching frequency is changed over a 200 kHz to 1500 kHz range. This spreads the digital energy created by the amplifier over a wide bandwidth, greatly reducing the energy at any one frequency. This permits using a simple LC filter to remove the high frequency energy and maintains excellent phase response. Feedback is taken before the LC filter and fed back to the digital power processor. This feedback is used to insure that any variations in the switching speed of each output device are compensated for, optimizing the linearity of the output stage.

Output power 4 Ch. @ 8 Ohms 120W/pc @ 4 Ohms 240W/pc Gain 23dB
2 Ch. @ 8 Ohms 400W/pc @ 4 Ohms 600W/pc Gain 29dB

Bandwidth 1Hz -80KHz ˇ3dB
THD and Noise 100, below 100Hz
Input Impedance 100k/200k Bal
Inputs XLR & RCA
Outputs 4 pr. 5-Way
Idle
Power Draw 30 Watts
Dimensions-inches W x D x H 17.5 in x 18.5 in x 4.5 in
Dimensions-mm W x D x H 44.5 cm x 47 cm x 11.5 cm
Weight 40 lbs (19 kg)
Features and specifications are subject to improvements and changes without prior notice.

Conclusion

This amp accomplished miracles with the Quad 989, and I wish I could have heard what it could have done for other speaker designs. However, I did have had the opportunity to hear a few other amplifiers that actually exceeded the eVo's transparency, detail and deep bass control. But I still have yet to hear an amp that is so exceptional in all areas. I have a feeling this amp could steal quite a few tube-lovers' hearts as well as those who are inclined to remain within the solid state. You would expect this from a $20,000 design, but not from $4,000. Call it a miracle, call it a steal or call it a dream. This is the Bel Canto eVo4 in a nutshell-and it's not a dream.