Over a full year in design, complete with innovations never dreamt of at this price point, we were nonetheless shocked to see how closely the Crimson 275 performs next to our 350 series monoblocks which sell for $9,500/pr.!


As with our more expensive amplifiers, Bob employs his unique twist on a DC restorer circuit which has two main benefits —lower distortion without dissonant side effects and extended tube and amplifier life.

Totally cool.  Almost literally!

   Our amplifiers simply do not run as hot as any other tube-type amplifiers. In fact, they are the coolest running tube type amplifiers in history, allowing you to actually touch the tops of the mighty KT120's and never be burned! While we caution against grabbing the sides of the output tubes (they must be hot to function), the internal temperature of our amplifiers is a bit warmer than the inside of your mouth, resulting in an indeterminate lifespan.

   Due to the unique design, all the components in the amplifier undergo much less stress than in conventional designs. Due to the efficiency of the concept, our transformers can be lighter and despite Bob Carver specifying esoteric steel for their cores, it helps us sell a $4000 amplifier for under $3000. Transformers are traditionally the most expensive component so if there’s no compromise in performance, this is a genuine benefit.


Although Bob Carver has been demonstrated to be at the leading edge of amplifier design, introducing, through the years, patented and unique approaches to efficiency and performance, many engineers believe power supplies may be one of his great strengths. As with his legendary SunFire tracking power supplies, the bottom line is that you may expect our amplifiers to outlive any other brand, and our extended warranties underscore that fact.

We warrant the Crimson 275 for a full five years; that’s the amplifier and the tubes! We love the fact that our finest competitors warrant their tubes for three months. It’s all about economics. If your tubes tend to fail, limit the warranty. A manufacturer has no option; they must. Since our tubes last for years, it costs us nothing to be heroic.

There is a meter on the front of the amplifier which can indicate the health of the tubes — get a bad reading, get free tubes! Aside from the extended circuit and tube life, it’s the sonics that blew us away. One of the reasons for this is our proprietary use of two separate feedback loops. One, typical of what you’ll find in many fine amplifiers, ensures stability and linearity. But the other is quite fascinating, dedicated to using the back-EMF, preserving depth and staging.

An amplifier that actually listens to the room.

All loudspeakers generate voltage as they play. It’s generated from the driver movement necessary to reproduce music but also all loudspeakers technically “listen” to the room. Did you know that the loudspeakers in prisons are also microphones? It enables the authorities to monitor the prison’s pulse in real-time. All loudspeakers are microphones. You might not want to use one for recording but conceptually, they are microphones in reverse.

Loudspeakers are also electric motors. Electric motors all kick voltage back to the power source whether it’s a loudspeaker, a refrigerator or an electric drill.  Manufacturers of line conditioners have a point. Your refrigerator motor not only adds noise to the AC line, they actually send electricity back through the wall outlet. We call this Back-EMF and it's unavoidable, due to the theorem of reciprocity. What's in the back-emf? The room sound!


With a tube type amplifier, when back EMF appears at the output terminals to the loudspeaker, the output transformer’s secondary becomes a primary! The back EMF enters the amplifier through the transformer and affects frequency response downstream. With ordinary tube type amplifiers, speaker matching becomes critical. Our amplifiers are load-invariant. Through decades of experimentation and some pretty heavy mathematics, Bob Carver has been able to use the Back-EMF to increase efficiency in the mighty SunFire subwoofers, and to improve the depth, soundstage and openness of our amplifiers. Solid-state amps discard the Back-EMF.


This is done in a unique fashion, and, as in the case of our extended tube life, unique to our products. The amplifiers listen to the room through the loudspeakers and preserve a large soundstage. It took literally decades to get the circuit right without creating artificial coloration. If you’re concerned about naturalness, consider that Harry Pearson, the founder of Absolute Sound Magazine, noticed this phenomenon, pointed out to Bob (who already knew about it) and kept our Silver Seven amplifiers as his personal reference for years. Dick Olsher from Stereophile Magazine  and Absolute Sound, called this series the most important tube amplifiers in decades.