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This review first appeared in the May 2010 issue of hi-end hifi magazine High Fidelity of Poland. You can also read this review of the Leben CS660P in its original Polish version. We publish its English translation in a mutual syndication arrangement with publisher Wojciech Pacula. As is customary for our own reviews, the writer's signature at review's end shows an e-mail address should you have questions or wish to send feedback. All images contained in this review are the property of High Fidelity or Leben. Ed.

Reviewer: Wojciech Pacuła
CD player: Ancient Audio Lektor Air 
Phono preamp: RCM Audio Sensor Prelude IC
Preamp: Leben RS-28CX 
Power amp: Luxman M-800A
Integrated amp: Leben CS300
Loudspeakers: Harpia Acoustics Dobermann
Headphones: AKG K701, Ultrasone PROLine 2500, Beyerdynamic DT-990 Pro 600 Ω
Interconnects: CD-preamp Wireworld Gold Eclipse 52, preamp-power amp Velum NF-G SE, speaker cable Velum LS-G
Power cords: Acrolink Mexcel 7N-PC9100 (CD) and 2 x Acrolink Mexcel 7N-PC7100 (preamp, power amp)
Power conditioning: Gigawatt PF-2 Filtering Power Strip
audio stand Base
Resonance control: Finite Elemente Ceraball under the CD, turntables change continuously, as do cartridges
Review component retail: zł 25.900 in Poland

The Leben Hi-Fi Stereo Company—that’s indeed the full name of this manufacturer—has been quite close to my heart for several reasons. Foremost of these is that Leben broke into Poland thanks to our September 2006 review of their CS-300 amplifier in our first-ever Japanese issue. There was another Japanese amp that also enjoyed its Polish premiere with us (the TRI TRV-300SE) but that's a different story. To get these machines for review wasn't easy. Their firms were not that open to the world outside Japan and most of them were represented by free-lance agents. Fortunately Leben's agent was the MuSon company, their foreign ops representative a Mr. Yoshi Hontai. His personal involvement and kindness made possible a review loaner, no questions asked, no security deposit required, to a faraway Eastern European country foreign to most Japanese and to be most specific, to little me at the helm of a Polish/English online magazine. It was all quite a long shot but blessed by good fortunes. The CS-300 proved to be fantastic as both speaker and headphone amp. The latter function made it very popular with headfiers. I myself couldn't resist and the CS-300 became part of my personal system for quite some time, to be replaced later by the CS-300 X custom-made for me and based on the Toshiba EL84.

I should also mention that for some time another essential part of my system came from Leben, their RS-28CX preamplifier. It represents very high value and was finally replaced only by the 60.000zł Ayon Audio Polaris II with DC Regenerator power supply, also custom-built for me. Of course I had crossed paths with several preamplifiers earlier that offered somewhat better sound here or there but only at far higher prices. Their small performance increases did not justify replacing the Leben so it stayed on and on. In short, Leben occupies a significant place in my audiophile history. This company is also a great example for how advanced technology can be brought together with good industrial design and fanatical attention to detail. Unusual is that against what they compete, Leben’s pricing is actually quite low for high-end hifi devices.

Hence I couldn't fathom why our Polish Leben distributor did not introduce to our market other Leben products except for the already mentioned CS-300, the CS-600 I tested for Audio and the preamplifier I personally ordered. I knew that Mr. Hyodo—Leben's owner, chief designer and former Luxman engineer during their Golden Age—-was most proud of his power amplifiers. But then what do I know about sales and distribution concerns. Perhaps I should know more about them to broaden my audiophile horizons? Regardless, I boldly demanded a Leben amp for review and must have been annoying enough because our importer finally delivered the CS-660P, making it another Polish premiere.

This machine is based on Hyodo-San's favorite valve, the KT66 beam tetrode made by Classic Components Inc. Four GE 6CS7 twin triodes occupy the first amplification stage. The power supply runs semi-conductors, a 6CJ3 dumper tube delays the high B+ voltage to the output tubes to protect them from in-rush current damage and increase their life expectancy. This stereo amp is quite big and covered in a wonderful golden-hued lacquer. One can roll power tube types from EL34 to 6CA7, KT77, 6L6GB, 6L6GC/5881, 350B, KT90, KT88 and 6550A.  Bias and heater current voltages are selectable via two back-panel switches while differently colored LEDs also confirm proper bias help (the owner’s manual describes all the details). Mr. Hyodo loves the KT66 because his favorite amp is the original Quad II which ran with them. So I quite logically refrained from any tube rolling and just went with what the designer considers best – the supplied NOS KT66.

The CS-660P is equipped with a potentiometer to make for a multi-tiered review approach: with CD players, phono stages and preamplifiers as an integrated amp or fixed-gain power amp set to a specific input voltage. Power delivery is 40 watts stereo into 4/6/8/16Ω or 80 watts monaurally via rear-panel selector. Claimed bandwidth is 10Hz-100kHz at 0.7% THD @ 10 watts.