Check out www.genesis-usa.net or call the distributor,Select Products, at 954.985.2698 for sales information.
Occasionally we are asked to test audio equipment at Nikola Engineering. This is a hard thing to do because as a designer myself, I hate to give accolades to someone else's design. But in the case of the Genesis amplifier I have to put aside my pride and give it a thumbs-up. I would put this amplifier into the purist category. The purist designs with perfect audio reproduction as the main objective, leaving other amplifier parameters in the background. In consideration of that, I split this review into two categories, "Pro" and "Con". As we'll see with the Genesis amplifier, items that fall in the latter category generally do not affect sound quality. Caveat: I am someone that, for sound quality reasons, would never load an amp below 4 ohms regardless of what it can do. Inputs should be balanced, outputs unbalanced, slew rate should be high, damping is not very important, etc. So readers should take this review in light of that.
DescriptionThe Genesis dual mono is a two channel amplifier with internal crossovers. The high pass crossover can be tuned as low as 20Hz, thus it can also be used as a subsonic filter. (Although the 12 dB / octave slope is too slow for this purpose). It has high and low pass 12 dB/octave crossovers, tune-able from 20 to 200 Hz. An external low pass level control with 5.5 dB is included. Construction is clean and straightforward. The controls and connectors are accessible on the side of a buffed & polished aluminum extrusion. This type of construction does require considerable machining, adding expense.
I am told amp comes with a 12-page manual, a birth certificate and a simple wiring diagram. But I did not receive a manual for the test, but then who reads them anyway? Rest assured that buyer's would get the complete package.
Pro'sDual MonoThis amplifier is actually two separate amplifiers (and power supplies) which results in better than 90 dB separation. Dual mono also means that the RCA grounds are not common and breaks possible ground loops.
ConnectorsThe power connectors are heavy duty, high quality and machined. The RCA input connections are also nicely machined. An extra terminal is supplied for an external fan.
CircuitryThe input circuitry uses Burr-Brown OPA2134 op amps. These are relatively expensive low distortion, fast slewing op amps, a very nice touch. The output stage uses darlingtons for high output current capability. Normally this method causes thermal instability and difficult biasing, but the Genesis employs a clever output resistor / diode trick to overcome this.
The amplifier delivered power as efficiently as an AB can; the power supply was efficient. Input inductors were included to reduce RFI. The power supply is unregulated. The darlington output stage provides super high output current capability.
PerformanceThe amplifier produced plenty of power with low distortion. Four-ohm distortion was under .03% THD at virtually any power level below clipping. Two-ohm THD was < .1% below 240 watts per channel. Because of its unregulated power supply, power dropped to 95 watts per channel at 12 volts/20 Hz @ 4 ohms. Distortion remained very low even at 1 watt power levels.
The bandwidth was limited on the bottom end by the 20 Hz high pass crossover which could not be switched out. The high-end response was only down .7 dB at 100 kHz.
It is hard to measure actual slew rate as an audio equipment's frequency response should always be passively limited before active circuitry. Slew rate appeared to be a very respectable 20 volts/mS. Passive input roll-off may have reduced the apparent slew rate somewhat.