KrellSolo 575Krell Solo 575 Monoblock Amps - massive!This ad is for a pair of powerful Krell Solo 575 monoblock amplifiers This pair is BRAND NEW, in the original boxes, NEVER USED. I’ve only opened the boxes to inspect the contents. Why buy used...13990.00

Krell Solo 575 Monoblock Amps - massive! [Expired]

no longer for sale

This ad is for a pair of powerful

Krell Solo 575 monoblock amplifiers

This pair is BRAND NEW, in the original boxes, NEVER USED. I’ve only opened the boxes to inspect the contents. Why buy used if you can get a BRAND NEW pair!

Krell Class A iBias Technology

Krell's history is rich with breakthrough Class A amplifiers that have helped build the Krell legacy of offering the best sounding amplifiers available. Audiophiles have always considered Class A technology to be the best sounding operating state for amplifiers. However, despite Class A's unrivaled sound quality, it has fallen out of fashion because of recent demands to reduce power consumption and heat in home electronics products. Krell engineering took this challenge and redefined the meaning of high performance power amplifier. Our goal - unmatched performance, elegant design, and a compelling array of features. The breakthrough - a patent pending circuit delivering Class A operation without the excessive heat and wasted energy of conventional designs, housed in a striking new form factor, with network connectivity for advanced access and monitoring. The sound is open and unconstrained, in a manner that rivals live performance and the true sound of voices and instruments. Music and dialogue are reproduced with a richness, detail, and startling dynamics that fill a room.

Plainly stated, Class A designs are the most musically accurate circuit topology available. Class A amplifiers do not suffer from the inherent distortions that all Class AB amplifiers experience. In a traditional Class A design, the output transistors conduct full current at all times regardless of the actual demand from the speakers. Often, only a fraction of this power is needed to reproduce an audio signal at normal listening levels. The rest of the power is dissipated through the amplifier’s heat sinks, producing large amounts of wasted heat. With Krell's iBias™ technology, bias is dynamically adjusted, so the output transistors receive exactly as much power - but only as much power - as they need.

Krell's iBias Class A technology allows our latest amplifiers to run in full Class A mode to full power while minimizing heat generation. Previous efforts at using a "tracking" bias, while effective, only measured the incoming signal and set bias levels from this information. Our new patent pending iBias technology significantly elevates the effectiveness of previous designs by calculating bias from the output stage. This seemingly small change in topology results in a dramatic improvement in sound quality, especially midrange richness and purity.


The core of the technology is an innovative, patent pending design for a dynamic intelligent bias circuit. Our iBias Class A circuit directly measures the output current of the amplifier and adjusts the bias to the optimum level. Because iBias Class A measures the output current, the real time demands of the specific speaker connected to the amp are directly incorporated into the circuit function. In addition, iBias Class A even reduces the bias when the signal is at very low levels, making its operation undetectable by ear and even by standard amplifier measurements.

In sliding bias schemes, the circuit merely estimates how much bias is needed based on the input signal and an "assumed speaker load." Compared with iBias Class A, these sliding bias technologies are much less effective - and much less accurate.

Solo 575

Mono Power Amplifier

575 Watt Amplifier Featuring Krell iBias Technology 

Frequency response

20 Hz to 20 kHz +0, –0.15 dB

<0.5 Hz to 100 kHz +0, –3 dB

Signal-to-noise ratio

>108 dB, wideband, unweighted, referred to full power output

>115 dB, "A"-weighted


27 dB

Total harmonic distortion

<0.03% at 1 kHz, at 575 W, 8 Ω 

<0.19% at 20 kHz, at 575 W, 8 Ω

Input Impedance

Single-ended: 100 kΩ 

Balanced: 200 kΩ

Input sensitivity

Single-ended or balanced: 3.03 V RMS

Output power

575 W RMS at 8 Ω

900 W RMS at 4 Ω

Output voltage

192 V peak-to-peak

68 V RMS

Output current

22 A peak Slew rate

40 V/μs

Output impedance

<0.045 , 20 Hz to 20 kHz

Damping factor

>216, 20 Hz to 20 kHz, referred to 8

Power consumption

Standby: 1 W

Idle: 131 W

Maximum: 2660 W

Heat output

Standby: 3.42 BTU/hr.

Idle: 448 BTU/hr.

Maximum: 9097 BTU/hr.


1 single-ended via RCA connector

1 balanced via XLR connector



1 pairs binding posts


17.1 in. W x 7.65 in. H x 21.10in. D

434 mm W x 194 mm H x 536mm D


80 lbs., 36.4 kg (shipping)

70 lbs., 31.8 kg (unit only)

More information here:

The amps are currently in our store in Southern California (San Diego area).

Who’s “Alma Music and Audio”?

We’re a hi-end audio store in Southern California, set in beautiful La Jolla (San Diego area). We do NOT operate by appointment, so you can stop by our store anytime, browse the LP racks (2000+ and counting!), and enjoy our 6 rooms set up with great gear from some of these brands:

ADL/Furutech - Aqua Hi Fi - Audioquest - Audionet - Audiopax - Auralic - Aurender - Avantgarde - Bergmann - D'Agostino - darTZeel - DEQX - ELAC - ENIGMAcoustics - Evolution Acoustics - Hegel - iFi - IsoTek - Kii Audio - Koetsu - Kronos - Kubala Sosna - Kuzma - Linn - MSB Technology - Music Hall - Nagra - Octave - Ortofon - Solid Steel - Sound Galleries Music Server  - Wharfedale - YG Acoustics

We prefer payment to be made by check, cash, or money order. Credit cards OK with a 4% charge. Sorry, no PayPal on this one.

We’ll ship worldwide, please contact us for a quote to your destination!

We’d love to hear from you, so send us your questions, inquiries, orders, etc to: [email protected], or call us at (858) 412-5530, (619) 243 4924, or (619) 243 6615.

Thanks for looking!

almaaudio member since July 2007

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