When we developed the Limited Edition line of affordable valve amplifiers as proof of concept that you did not need a megabuck and/or kilowatt amplifier to drive a pair of Genesis loudspeakers, they garnered rave reviews, and sold out quickly. Reviewers took to calling them "reference quality" (Srajan Ebaen - on 6moons), conveying "all the benefits of tube amplification with virtually none of the drawbacks" (Jason Victor Serinus - Secrets of Home Theater and Hifi), "robust, powerful, and full of life" (Jack Roberts - Dagogo).

However, much more than how "reference quality" they are, the objective of the design is to play music with true verve and emotion - not just satisfy some specification. "I was surprised how musically enjoyable the Genesis I60 was" (Jack Roberts - Dagogo) "...the M60's delivered. Drenched with feelings, I wiped away a few tears and ironed out plenty of goose bumps." (Srajan Ebaen - 6moons)

A new Genesis amplifier had to be better than the M60s in all aspects. The design brief was simple, a load invariant, high-current, wide-bandwidth amplifier that would allow the musical performance to come to life. In addition, the new amplifiers had to be capable of driving any model in the Genesis range, from the Genesis 7.1 petite to the towering flagship - the Genesis 1.1.

The Genesis Reference Amplifier challenges the status quo of music amplifiers by marrying the advantages of tube (imaging, soundstage, and portrayal of tonal colors) with solid-state (control, dynamics and accuracy).

Technical Details

The Genesis Reference Amplifier challenges the status quo of music amplifiers by marrying the advantages of tube (imaging, soundstage, and portrayal of tonal colors) with solid state (control, dynamics and accuracy). To achieve this, we had to develop some ground-breaking technologies.

Dynamic Power Delivery Supply (DPDS)

Traditional DC power supplies developed with established design principles are usually specified into a constant current draw with a resistive load. However, except for Class A amplifiers (and Class AB at low power), the load is not constant. The power supply is hence specified for the maximum current drawn, but such a huge power supply is often slow, resulting in a dark, brooding, muscle-bound sound.

The Genesis DPDS, on the other hand, is designed to deliver current into a non-linear, dynamic musical load, leading to a sense of power with finesse. The result is that the Genesis Reference Amplifier has the dynamics, extension and drive of high-power transistor amplifiers without the muscle-bound sound, and the elegance, emotion and tonal colors of flea-powered single-ended triode tube amplifiers without being weak or flaccid.

The origins of the DPDS comes from the principles of tube amplifier design – some of the qualities of tube amplifiers were as much to do with power supply design as the choice of tubes over transistors. Because of the high voltages involved, tube amplifiers use relatively small capacitors and chokes to produce smooth DC power.

Transistor amps use cheaper/larger electrolytic capacitors to do much the same job. From this we discover a very simple fact, smaller capacitors usually sound better. There is good science to predict that the high frequency performance of large capacitors will be poor.

There are lots of very small solid-state amplifiers that have excellent sound. They all had tiny power supplies, and the smaller the power supply, the “faster” they sounded. On the other hand, very large power amplifiers with huge capacitors, or even large banks of smaller capacitors in their power supplies tended to sound dark and slow.

This is the issue of speed vs power. The sprinter is not able to sustain the delivery of power for very long, but the marathon runner is not able to deliver very quick bursts of speed. The DPDS is like a relay team with sprinters, medium-distance, and long distance runners in the team. Thus, it is able to deliver high sustained power, as well as very quick bursts of speed.

Such a “relay team” is what gives the Genesis Reference Amplifier the excellent micro-dynamics, tonal contrasts and timbre textures of low-powered amplifiers, and yet is able to deliver huge dynamics and the sustained deep bass of muscle amps.

The basic DPDS in the Genesis Reference Amplifiers has a “relay team” of seven. This was the point at which further enhancement of the “relay team” produced diminishing returns. Nevertheless, this is also assuming that the amplifier is used to drive a pair of Genesis loudspeakers with its built-in servo-controlled bass amplifier.

Super Silent Low Voltage Supply

We recognized that published specifications for noise rejection of opamps and even discrete small-signal amplification circuits did not always tell the whole story. The problem is that PSRR is usually measured at one frequency – usually 1kHz, but then rapidly gets much worse as the frequency rises. Hence the necessity for line power conditioning.

For the Genesis Reference Amplifier, a low-current regulated power supply was developed that has broad bandwidth noise rejection so that RFI coming in over the power lines do not intrude on your music.

Other Features

• A grounded Faraday Cage chassis for RFI and EMI rejection improves micro-dynamics and tonal colors and contrast.

• Balanced components, in the push and the pull parts of the power supply, and having critical components toleranced to less than +/- 1% results in a sense of aliveness and ease in the music.

• Special circuitry to “keep things warm” without wasting a lot of electricity means that your system is ready for you to listen to whenever you are.

• Add-On options & modules.

MDHR sits on top of the amplifier

Maximum Dynamic Headroom Reservoir

The Maximum Dynamic Headroom Reservoir (MDHR) is an add-on power supply upgrade for the Genesis Reference Series amplifiers. It is an extension of the Dynamic Power Delivery Supply (DPDS) that is inside the Genesis Reference Series of amplifiers.

Frederic Beudot of 6moons.com said in his review that the improvement the MDHR brings to the Genesis Reference Amplifier is what would normally cost 5 to 10 times its modest asking price.

The MDHR adds another eleven members to the team. This extends the ability of the amplifier to drive loudspeakers with impedances down to less than 1 ohm. In addition, it adds the ability to deliver more dynamics in the lower midrange and upper bass, and adds detail and extension in the upper frequencies. The lowest bass registers are also enhanced so that even speakers without a built-in servo-controlled bass amplifiers will sound like they are able to play deeper and with more authority.

A resonance control circuitry ensures that the “baton handover” from one team member to the next is handled as smoothly as possible.

This results in increased dynamics from having more current available into lower impedance loads and better micro-dynamics – one listener described it as “having cream in your coffee instead of non-fat soy”.

One MDHR can be used for any one single amplifier module – including the GR180 stereo unit, the GR360 stereo unit, the 2-channel servo-controlled bass amplifier module, the 3-channel servo-controlled bass amplifier module, and the GRM monoblock amplifier module.

Acoustic Syspension System

The Genesis Reference Amplifier comes with an acoustic suspension system that isolates the amplifier from floor or structure borne vibrations. Designed like the suspension system of a race car, the acoustic suspension is made of an acrylic suspension frame, neoprene shock absorbers tuned to the weight of the amplifier module, and steel spikes to anchor the suspension frame to ground. The Acoustic Suspension System is also available as an optional upgrade to the Maximum Dynamic Headroom Reservoir.