Mar 262010

I get to try a lot of really good amplifiers with my Westminsters, but it seems I am always eager to get my Leben Hi-Fi Company CS660P power amplifier back into the system. The CS660P is shown here with Tung-Sol 6L6G reissue vacuum tubes that are made in Russia for New Sensor. See larger image of the Tung Sols below (in the dark).

The Leben CS660P is a ridiculously good amplifier that just brings the music to life and makes it fun to listen to. It has all the good qualities of a DHT SET amplifier, but at about 40 watts it has enough power to make the Westminsters jump when the music calls for it, and I’ve never even came close to stressing it even at very loud levels. Here’s what it looks like during night listening (below) – beautiful!

I’ve been listening to music all morning while drinking some terrific Peet’s Arabian Mocha-Java coffee brewed fresh one cup at a time – heaven!

Westminster + Leben = musical nirvana!

 Posted by at 6:42 pm

  19 Responses to “Leben CS660P – Wow!”

  1. Hi Jeff,

    It’s Arthur again :). Been a while, hope you are keeping well. We are playing so many LPs through our VPI Classic / CS-600 / SHL5 system, it’s simple and it’s just so enjoyable. Thanks heaps for helping us putting that system together. Through a series of fortunate events, with all stars aligned for us, we may be moving house (fingers crossed), and I could finally get my dedicated listening room if it happens, yay!

    So, I would be keeping my CS-600 with the SHL 5 as the living room system and looking at a pre & power Leben combination for the listening room. In terms of speaker choice, I will stick with the SHL5 in the interim and eventually move towards either a Harbeth 40.1 or if the negotiation goes really well with the new place, a Tannoy Westminster Royal Special Edition.

    Having the above in mind, I would like to ask for your opinion in picking out the Leben Pre Amp. Power-amp is an easy choice with the CS-660P. In terms of the Pre, prices aside (and I am happy to buy a separate RS-30EQ phono), what would your pick be between the RS-28CX, RS-100, and the RS-100U for the most musical sound?

    Reading from you past post, I understand synergy is an important factor to consider. Given the likely speaker path would be SHL5 => 40.1 (or) => Westminster, which pre-amp do you think would yield the best result?

    Your thoughts are greatly appreciated as always. Talk soon, and will keep you updated.



    • Dear Arthur,

      I’m glad you are enjoying your system, it truly is a wonderful system!

      My favorite combination for pre-amplification is the RS-30EQ plus the RS-100U, they really make for an astonishingly good pairing, and would work great for your planned speaker progression.

      Kind regards,


  2. My system consists of Macbook as a source,Weiss DAC202,Leben CS660P and Audience ClairAudient 2+2.
    The result is amazing.Except the lowest bass this is unbelievable realistic.I’ll get Velodyne DD12 sub and forget high end for good.

    • Sergio,
      IMHO you should throw in there a good preamp. Please also undertake all tweaks which Jeff has recommended, such as the pot bypass, tube rollings, etc. (f no already done 🙂 ) They all take this to the next level.
      I had the same system such as yours except the speakers, the DAC202 preamp is not as good as we are led to believe.

  3. Hi jeff, here I am again to get your valid opinion? How’s the performance of the 6L6G compared with the KT66 stock in musical and realm departments?. One of the dealer here offering me tube replacement. They are from GE not Tungsol by the way.

    With kind regards,

    • Hi Harry,

      The sound seems to vary as much between different brands of 6L6G and KT66 as much as it does between the two tube types themselves, so it makes it a little hard to compare them unless you have exactly both brands/types to compare. In the case of the GE 6L6G, I haven’t ever had an opportunity to listen to them, so I can’t really offer any valid comments on them – sorry about that.

      The tube that I am really liking in the CS660P (and CS600) at the moment is the EH KT90. It’s big, warm, and powerful sounding, and is a real nice match for the Leben amps when you want/need to warm things up a little. Kind of like an EL34 on steroids. It’s not as articulate, smooth, and detailed as the 6n3cE is, but it is more powerful and warmer sounding, which in some contexts is a really nice alternative. I now consider it part of my standard reference Leben selection of power tubes when trying to voice them for a warmer overall presentation.

      Kind regards,


      Kind regards,


      • Many thanks for your kind reply, Jeff. Hey it was 5.40 am when you wrote the reply!! I much appreciate it.
        I want to increase the level of my satisfaction on leben+Westminster Royal+Nottingham Analogue Dais+Dynavector XV1S so I’d better seek your notable advice on his, just like when I decided to buy the existing gears….I am really happy to follow your preference and choice.

        Happy listening Jeff….


        • Hi Harry,

          I’d love to hear from you about any discoveries you make as well, so if you decide to give those GE tubes a try be sure to let me know what you think of them. Who knows, they might be magic!

          That’s a beautiful turntable you have. I’ve always had high regard for Nottingham turntables, every one I’ve ever heard has played music wonderfully well.

          Kind regards,


  4. Hi Jeff, I currently own the Leben CS300X and the CS660P amps. It’s obvious that the CS660P adds more bottom weight to the table. Anyway, both sound just great.

    Can the CS600 achieve the same solid base as the CS660P?


    Kind regards.

    • Hi,

      The CS600 and CS660P are almost identical circuits, but the implementation of the circuit, the tubes, the transformers, and the parts mix differs somewhat, resulting in somewhat different sound between the two. The CS-660P sounds more powerful, more transparent, and harder hitting in the lower end (this is with the CS660P used with a preamplifier as intended). I tend to prefer the more articulate, sweeter, more laid back sound of the CS600, unless I need the greater power that the CS660P offers.

      Kind regards,


  5. Hi Jeff,

    I just want to give you an update on my experience with NOS GE 6L6GC. By itself it will win over the music lovers’ hearts. The sound it produces is continuous, slightly warm,and musical. There is no etch, screech, or unpleasant sound that causes listening fatigue. I would not pick a nit shouldn’t have I listened to Shuguang KT 66 stock (a common audiophile decease, I guess…..).
    The GE appears to be rounder and less transparent than Shuguang. I could hear things more clearly such as a foot steep and chair shrieking from the musicians through Shuguang than I could hear through GE. Shuguang gives a sense of more spaces/spade and air than GE. It also gives bigger headroom. Shuguang nevertheless can sound thin and brighter on certain instrument such as violin. GE sounds slightly “thicker” and condensed than Shuguang. Both tubes are good and outstanding on their own. GE makes CD is more “listenable”. Another caution is that GE is a slow starter in a sense that it takes longer time to get warm up to sound at their best, so be patient. I initially disliked GE, but now I starts to enjoy them as they get better overtime (they have run slightly above 20 hours from the purchase).
    As usual, I tend to follow you in order to avoid mistakes or trial and error to reach music nirvana. I recently just won a bidding from ebay for the nos mullard EL34 xf1 matched quad and also purchased the NOS Russian 6cn3ce as well as the brand new Valve Art 350B. I can’t wait to install them on my CS660P play some music over a cup of warm Kopi Luwak (mongoose coffee beans, the most expensive and tastiest type of coffee beans from my country, Indonesia). But I have to be patient since the shipment lead time is quite long to consolidate those tubes from UK and States to Indonesia. I hope my effort will turn out fruitful. I feel lucky to accidentally read your music lover series where I started to buy the leben and shl 5.

    Happy listening Jeff,

  6. Hi Jeff,

    I bought a pair of Avantgarde Duo Omega G2’s for just over a year ago and have been on the search for an amplifier for them, that will give me the sound I’m looking for. It’s been a long, joyfull journey so far and I have really been challenged with my preferences in the sound that I’m looking for.

    A couple of months ago I came across the EAR 8L6 that uses EL34 tubes and the sound of these tubes just grew on me – with their ability to express musical timbre and the live feeling it gives. It also removed the over “energized” s-sounds that I have been strugling with. However the bass performance of the EAR 8L6 is at a level where I can’t live with it on a daily basis.

    Since then I have been looking for other EL34/KT66 amps and I am closing in on the Leben CS660, but since I live in a part of the world where it’s not possible for me to try the combo out before I buy, I was wondering if you could share your views on the match of the Avantgarde Duo Omega and Leben CS660?


    • Hi Morten,

      It can be tricky mating amplifiers to the Avantgarde Duos due to the active subs. If I were you I’d keep playing with the bass levels of the Duos to see if you can’t come up with a combination that works well with the EAR amps (which I’ve always like, by the way). The Leben CS660P has a lot of bass output too, maybe more than the EAR, so if the EAR is problematic with your Duos the CS660P is likely to be even more so.

      The best combination of components I’ve ever heard with Duos is the Tom Evan Audio Design components from the UK. With my Duos there was a special synergy with the TEAD gear that was amazing. If you get a chance, you should give the TEAD gear a listen.

      Kind regards,


  7. Is the Leben CS660P a good match for Quad ESL 63 speakers? I listen to vinyl, and use an LP 12 with a Koetsu Rosewood Signature cartridge. Would you recommend an entire Leben system of electronics for use with my Quads. (preamp, phono stage, and amp in either stereo or mono configuration) Have you heard any of the dehavilland electronics? If so what is your opinion in comparison to the Leben gear?
    Thanks for your input.


    • Hi Richard,

      I don’t have any experience with the Quad ESL 63 loudspeakers, so I’m afraid I can provide any first-hand experience on that combination.

      In the most general sense, I have found the Leben electronics to work well with a wide variety of loudspeakers, so I wouldn’t anticipate any issues.

      I have heard the deHavilland electronics and they are very nice indeed. I’ve been very impressed with Kara’s new phono stage and KA-50 amps. I haven’t spent much time with Kara’s line stage, but I have a couple of friends that own them (Pete Riggle and Stephaen Harrell) and they swear by them! They do drive Quads just fine too, as my friend Ron uses has Quads and the KA-50 amps.

      I hope that helps!

      Kind regards,


  8. Hey Jeff,
    Joined the club.
    I am now a happy owner of a CS660P power amp. I run it with a RS-28CX pre amp mostly listening to records played on TD124mkII using the built in phono preamp. Speakers – Blumenhofer FS-2. At the moment I use Tung-Sol 6L6G tubes. If not the best combo than definitely the best one ever had in my living room. Any tips for tuning, upgrades?

    • Hi Johannes,

      Congratulations on the new Leben gear – very nice! You’ve put together a very nice hi-fi all the way around.

      I liked the TS 6L6G, but I eventually went with KT90s because I enjoyed their extra warmth.

      For tuning / upgrades I’d definatly give the Western Electric WE16GA a try for speaker cables, and the Belden 8402 as interconnects. Every system I’ve tried that combination has benefitted, and the plus is that it is inexpensive to do.

      Keep me posted on how things are going when you get more time in on the new Leben gear.

      Kind regards,


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