Excellent condition Krell KST-100 Amplifier with original manual. Second owner selling, it has worked flawlessly and remains fully operational as shown in the video which can be seen at youtube.com/watch?v=Thk90iShHFQ. Balanced and unbalanced inputs tested as well as the bi-wire capable speaker outputs. While the sound is excellent with the source and KRC-2 in unbalanced mode, with balanced sources and preamp, the amplifier achieves another level. The amplifier is bridgable and when bridged runs as a mono 400w amp into 8 ohms and an 800w amp into 4 ohms. The amp is not rated for 2 or 1 ohm operation when bridged. Please note, the speaker outputs ARE NOT switchable. The outputs are internally wired in parallel and cannot be controlled individually. The intent is to provide for bi-wiring of capable speakers and NOT for running two pairs of speakers. Any such use is AT YOUR OWN RISK. Stereophile reviewer Martin Colloms had this to say about the KST-100:Possessing a fine tonal balance (to be discussed separately), the KST-100 was also capable of a strong presentation of perspective, with convincing layering of players in large orchestral recordings. I do not believe height is a property of electronics which are inherently neutral; however, certain combinations of room acoustic, phase, and perceived system frequency response, particularly in the 2–8kHz range, can give rise to sensations of image height which may be enhanced by the accurate and transparent reproduction of recorded ambience. In this latter respect, the KST was very capable.The KST-100 conveyed a dynamic, lively quality well beyond its class, remaining interesting and alive over long listening sessions.Dynamics do not only relate to inner vigor but to an overall feeling of power, specifically dynamic range. Technically, this can be described as the range in dB between the inherent background noise and the maximum level possible with a given loudspeaker load. Subjectively, this also concerns an amplifiers ability to reproduce low- and moderate-level detail while being exercised by powerful ones, and its ability to sound unchanged and unstrained when crescendi arrive.The power amplifier passed this test with traditional Krell imperturbability. The much more expensive KSA-150 does have more authority, notably expressed in the bass as an additional measure of slam and extension. I rate the KST highly, but on the bigger speakers it lacked a little in gut-wrenching ability. Nevertheless, the KSTs bass was taut, agile, tuneful, and had good extension; I doubt that there is a class rival for bass precision.The broad midrange was highly neutral, in the KSA-150 mold, and this continued way into the treble register. This formed the foundation for its ability to portray perspectives. The mids sounded easy on the ear, very low in solid-state artifacts. Glare, hardness, etc. were all at very low levels.Please note, due to the nature of vintage components, NO WARRANTY IS EXTENDED OR OFFERED. Returns will only be considered if the KST-100 Amplifier is significantly not as described. Please note: Shipping is at flat rate and includes professional packing and shipping as well as insurance at full value for our mutual protection.