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Also the second extreme of the bandwidth was slightly subdued. The bass was very nice, vivid, fairly well defined and endowed with a highly agreeable timbre. But the low bass was not as potent as over the more expensive Krell amps or my reference Luxman. Interestingly the Accuphase E-450, apparently the more powerful, went no lower either. Its low bass was fatter and slightly underscored to result in the impression of deeper reach and potency. The Accuphase is a very good machine with splendid timbre. Alas the Krell sounded cleaner and smoother when it came to bass and its transition to the midrange was more even. Still this bass was not as massive as I know it from my M-800A. One must pick the right loudspeakers to circumvent it. This is why the Harbeth Super HL5 with its splendid timbre and strong mid bass was a very good choice at least for me.



The only problem you face in this price range is a slightly hard upper midrange. It is not bright per se but its attack is somewhat hard. We perceive it as a slight nervousness to the sound, as additional energy in the attack of voices and similar. This can be heard best in commercial recordings. When listening to better recorded material like Isao Suzuki Blow Up 2 and Count Basie Plays and Joe Williams Sings Satnards, it is in no way annoying although it can be heard even there in a slight underlining of the lower cymbals. The Harbeth handled this better than my Dobermann although the latter are objectively much better speakers. I think this was simply the result of a better match of characters. The HL5 are not especially resolving, hence things revealed by more expensive designs don't matter with them. It is also important that the Krell (which itself isn't ultra-resolving to finally have the people from Krell not emphasize this single aspect) did not highlight the Harbeths' shortcomings as though it were specifically developed to match them. I will only add that the S-300i sounded fantastic with the Kuzma Stogi S, Stabi tonearm and Dynavector Karat D17MkII cartridge (the phono preamp was a RCM Audio Sensor Prelude IC).

Description: This Krell amplifier has a form factor close to what are accustomed to with its KAV-300i and KAV-400xi predecessors. This is a flat, very deep and truly heavy device with very high output power not only for an integrated but in general - 150W at 8Ω and 300W at 4Ω. It isn't just powerful but has high-current capabilities. Halving impedance results in power doubling to behave as ideal current source at least into 4Ω.


I talked about predecessors but this amplifier inherits only their general shape. The external design and insides more resemble the Krell FBI and Evolution series. This means a volume knob with holes like a revolver's cylinder (a bit similar to what Michaelson does at Musical Fidelity); a big blue display to its right; and small buttons for source selection. The display is not the only item to date this as a 21st century unit. There is also a menu button. There are not many inputs on the back but the sockets are very high quality. We have three unbalanced RCA inputs, a balanced XLR input and a dedicated iPod port. As we learn in the company materials, the Krell docking station can extract the analog signal from the iPod's digital-to-analog converter and forward it balanced.


This is important because the S-300i preamplifier section is fully balanced - the incoming signal right behind the RCAs converts to dual differential. The loudspeaker outputs are single and gold-plated and identical to what we find with Rotel, Canor and many others. There are DC trigger sockets and a RS-232 port for computerized controllers. The really big surprise is the silk screen: "Manufactured In China Under ISO 9001 Quality System". Yes, the cheapest Krell integrated is made in China in a modern factory with ISO certification.


The inside is typical for a high-class modern integrated. The input signal runs to a big PCB near the back plate. Almost all of the parts are SMD and the inputs are switched to ICs. The signal from the RCAs leads out with short shielded cables and the XLRs are soldered directly to the PCB. The analog-domain volume control is regulated by a bank of chips. The preamplification circuit is built around four ICs per channel using the Analog Devices OP177 in the starring role. This is one of the newest and best ICs of its kind, with low distortion and noise. It is also characterized by very good linearity. Although two Wima capacitors are visible at the inputs, those are employed only for voltage filtering. This amplifier uses no capacitors anywhere in the signal path. Between sections, the signal progresses in current mode to allow for extended high-frequency response. In the menu we can set input names, gain, balance and fix a given input at unity gain to integrate it with a home cinema system.


The output sections are bolted directly to the lateral heat sinks. Each is based on four multi-emitter Sanken LAPT transistors in push-pull. Voltage gain and current buffer stages both operate in class A but the latter employs 'floating' mode, indicating a dynamically tracking bias. A very big shielded 750W toroid takes up center stage. It runs separate secondaries for the output stage, preamplification stage and control units. The filter capacitance is a significant 38000μF. The
power supplies for the respective sections are placed on the PCBs they serve. The remote control is big, metal and solid. Beyond the S-300i, it can also control a CD, DVD player and the iPod while the display can relay messages from the iPod. Because this is a very competent and compact amplifier, it can also be used in studios, hence rack mount wings are available as accessories.

Technical data (according to manufacturer):
Output power: 2 x 150W/8Ω; 2 x 300W/4Ω
Frequency response: 20Hz – 20kHz (0dB/-0.14dB)
S/N ratio: 90dB (weighted)
Gain: 32.5dB
Input sensitivity: 0.82V
Input impedance: 47kΩ (RCA) / 94kΩ (XLR)
Power consumption: 20W (without input signal)/1800W (max)
Weight: 19.5kg
Dimensions: 438.2 W x 101.6 H x 444.5 D mm
Krell website
opinia @ highfidelity.pl