General Asylum: REVIEW: Krell KAV-300i Amplifier (SS) by Bruce from DC

"Krell" seems to generate a strong emotional response in audio circles, so I will try to be a low-key as possible. This is a compact, solid-state amp rated at 150wpch @8 ohms; 300 wpch @4 ohms. It has a total of five line-level inputs. Four are single-ended and one is balanced. I have not used the balanced input, so I can't comment on what, if any sonic differences, result from its use as compared to the single-ended inputs.
One of the single-ended inputs is configured as a tape loop. Another of the single-ended outputs can be converted into a direct input to the power amp section, so that the 300i can be used as part of an HT setup. The 300i has one pair of speaker outputs, a pair of single-ended tape outputs and a pair of preamp outputs. While it is possible to use the 300i as a preamp to drive another poweramp, I do not believe the "theatre throughput" input feature would allow insertion of an active device, such as a subwoofer crossover, between the preamplifier and power amplifier sections of the 300i. According to company literature, the power amplifier circuitry is "balanced" but the preamplifier circuitry is not.

Input selection is relay activated by buttons on the front panel. Volume control is by a microprocessor circuit, not by potentiometers. Press one button and the sound gets louder; press the other and it gets softer. A row of LEDs indicates relative gain. There is a mute button. The included remote control controls these functions plus channel balance, which is accessible only through the remote.

Operationally, the amp has been flawless. It seems unaffected by the high RF fields that have plagued my phono preamplifiers, microphone inputs and even the subwoofer amplifier. There are no switching transients at any operating volume level; and there is no audible noise from the speakers at any operating volume setting. The unit is partially powered up when plugged into the power. Pressing the "on" button brings the whole unit online after a delay of a few seconds. Krell apparently has decided to use the entire, fairly massive chassis to heat sink the output transistors. In operation -- and even at rest, while turned "off" -- it generates a moderate amount of heat for a non Class A solid-state unit.

Sonically, I would characterize the 300i as neutral, not euphonic. Even through the preamp section (which drives my subwoofer) it displays the characteristic "Krell bass" low and heavily damped. In my system, I would describe the midrange as smooth and grain-free; and the highs as extended but not harsh or spitty. The system shows considerable depth of soundstage, but that is not solely the result of the amplifier. The 300i seems to reflect what you feed it. It's pretty revealing of differences between source material or types of sources (tape, vinyl, CD). There are, undoubtedly, unhappy combinations possible with the 300i. For example, when my main speakers were being repaired, I substituted a set of Paradigm mini-monitors for them. This was definitely an ear-bleeder combination, which displayed a substantial peak in the upper treble that was quite fatiguing. Interestingly, that characteristic is not evident when the Paradigms are driven by a little NAD reciever. On the other hand, when I tested a pair of B&W DM3000 floorstanding speakers that I was selling, the sound was quite spectacular. The prospective buyer was sold on the B&Ws immediately.

Although I did not do a side-by-side comparison in the same complete system and room (so I'm relying on sonic memory), driving the same speakers, the 300i has a more controlled bass and a slightly more extended top end than the tube-powered Audio Research CA-50, which I considered at one time. Other than that, I do not recall significant differences in other characteristics, such as midrange, microdymanics, soundstage depth, air around the instruments and so on. The ARC, at one third the power, was just adequate for the speakers playing symphonic music in a moderate-sized, treated demo room; the Krell is more powerful than needed for these speakers under any circumstances. It has proved an ability to melt the midwoofer voicecoils before any distortion is audible from the system.

Is it "musical"? Well, I can't answer that in the way that the question is usually asked. If you feed it music, music comes out the other end. If you feed it garbage (i.e. most pop CDs), garbage comes out the other end. I was amazed at home much a pop CD sounds about the same on my system as on my daughter's boombox, only louder. In my view, an amplifier should deliver the goods and get out of the way. By that test, I think this is a good amplifier.

REVIEW: Krell KAV-300i Amplifier (SS) Review by Bruce from DC at Audio Asylum