Leben CS-600X Integrated Amplifier - Page 2 of 4

For this review I'll be evaluating the new Leben CS-600X with its stock complement of tubes.

I have tried a lot of power tubes over the years in my Leben CS-600, finally settling on the Sophia Electric EL-34ST as my favorite.

I'll also be delving into the tube swapping aspect of the Leben CS-600X in a future article, where I'll tell you about my listening impressions of Sophia Electric EL34-ST and KT88-ST power tubes in both my CS-600 and the new CS-600X, so stay tuned for more Leben CS-600 / CS-600X tube swapping fun.

The only nit I have to pick with the Leben CS-600X is that I would like to have an optional taller top cover offered that could be left in place when using the taller tubes that I prefer.

Review System

My Leben CS-600 has been in my audio-visual system for years, originally with my Harbeth Super HL5 loudspeakers, and now with my vintage Altec A5 Voice of the Theatre loudspeakers.

I started my vintage Altec Lansing A5 Voice of the Theatre loudspeakers project on December 31, 2016. Gary Fischer did a beautiful job of restoring my vintage Altec A5 Voice of the Theatre loudspeakers, and you can read more details about Gary's work with my A5's in Jeff's Place posts here: Part 1, Part 2, and Part 3.

The Altec A5's were originally optimized to provide ample sound reinforcement specific to the needs of small-to-medium sized movie theaters, so the stock crossovers are not really suitable for home listening environments, where they actually sound quite dreadful.

So, to address the stock crossover issue, with advice from friend Yazaki-san, I developed crossovers that optimized the big beasts' performance for smaller domestic listening environments.

My crossover solution was to utilize a Hiraga-san inspired crossover circuit, modified with an adjustable high-frequency crossover circuit that allows blending of the high- and low-frequency drivers & horns to match rooms of various sizes (more information HERE).

So equipped, the Altec A5's are impressive loudspeakers that are surprisingly flexible and room friendly, and they have adapted remarkably well to their new home, which happens to be a spare bedroom in my home that I use as an audio-video room, with the rather small dimensions of 11-feet x 12-feet x 9-feet (ceiling), with a 6' x 3'5" x 9' foyer on one end. I have my Altec A5's installed on the long wall in the room corners.

You'll hear people say that large vintage Altec loudspeakers like the A5's won't work well in smaller rooms, which is of course not the case at all if you are using appropriately designed crossovers for them, like the adjustable Hiraga-inspired crossovers I use that allow for optimization of the horn & driver integration for the room size.

You might wonder why I would go to the trouble and expense of restoring vintage Altec A5 Voice of the Theatre loudspeakers, and then developing specialized crossovers for them to make them suitable for home use.

The reason is that the vintage Altec A5 Voice of the Theatre loudspeakers provide a magnificent and immersive presentation of audio from music & film sources that once heard is rather addicting.

The big vintage Altec A5's have a refined, immersive, spacious, and dynamic presentation that makes film and music sound & feel spooky real, and I constantly marvel at their performance in my audio-visual system.

My Altec A5's are the 16 Ohm versions, so I set the Leben CS-600X integrated amplifier's speakers impedance switch to 16 Ohms, the best match for the A5's impedance.

I have a new Apple TV as one line source for streaming Netflix, Amazon Prime, etc., and an OPPO UDP-203 Blu-ray player for spinning DVD or Blu-Ray movies, or an occasional CD, as a second line source.

For a vinyl source I use my Artisan Fidelity restored Thorens TD124 (above), now equipped with a Thomas Schick tonearm, a Thomas Schick graphite headshell, Acoustic Revive PC-TripleC/EX Headshell Leads, and a Soundsmith Carmen Mk II phono cartridge.

Besides being a great sounding phono cartridge, the Soundsmith Carmen Mk II phono cartridge is a high-output design that doesn't need a step-up transformer to work its magic, so I can run the Schick tonearm leads directly into my Leben RS-30EQ phono preamplifier (above).

For the Leben RS-30EQ phono preamplifier and Leben CS-600X integrated I used Acoustic Revive Power Reference TripleC AC power cords to connect to the AC supply (above).

For the OPPO UDP-203 Blu-ray player I used an Acoustic Revive Absolute Power Cable to connect to the AC supply (above).

I used Belden 8402 microphone cable interconnects to connect the Philips TV to the Leben CS-600X, and the Leben CS-600X to the OPPO (above).

To connect the Leben RS-30EQ phono preamplifier to the Leben CS-600X I used Acoustic Revive RCA Absolute FM Interconnects (above).

For speaker cables for my Altec A5 Voice of the Theatre loudspeakers I used Duelund DCA16GA tinned-copper wire, which is an exceptional good match to my A5's.