Mar 272010

I fell in love with the Leben Hi-Fi electronics back in February of 2007 when I wrote an article about the Leben CS600 integrated amplifier for 6Moons.

I ended up buying the review unit (the ultimate recommendation) and have been using it nearly every day in my second system, which is in a small “BBC-sized” listening room that works best for my Harbeth Super HL5 monitors, and makes for a great system for listening to music or for watching movies.

One of the great things about the Leben CS600 is its ability to use a variety of vacuum tubes, which makes it extremely flexible, and a lot of fun to experiment with. I get a lot of e-mails asking about vacuum tube settings for various tube types, so I thought I’d go ahead and post the settings table as a resource.

Be sure to let me know if you find a tube type you really like for the CS600, and I’ll let others know via this blog as a way to share the fun.

Below is the tube settings table for the CS-660P from the Leben web site (the ‘O’ indicates the correct switch position for a particular tube):

Leben CS-660P Switch Settings Table

Here’s my table for the CS-660P that says the same thing in a different format, which I tried to make a little easier to understand than the Leben website table above:


 Posted by at 10:47 am

  140 Responses to “Leben CS600/CS660P Vacuum Tube Settings Tables”

  1. Hi Jeff, for CS600, I just recently got a pair of Raytheon japan 6cs7 and a pair of Sylvania 6cs7. How should I put them in the amp? Currently, I have it as Ray Syl Ray Syl.


    • Hi MK,

      You should run quads of the same tube for inputs, if you run two different manufacturer’s pairs the results could be unpredictable.



  2. Hi Mr. Jeff,

    I have already got Canterbury SE and Leben CS660P. Please therefore kindly advise a combination of what Preamp?
    Thank you for your attention.


    • Try a Leben 28 Preamp. It is with a phono section….
      Maybe a good match with you power amp.

      Kind regards


    • Hi Thanh,

      I’ve always had the best luck with combining preamplifiers from the same manufacturer as the amplifier, so I would think that Leben RS-28CX would be a good choice. Another one to consider is the Leben RS-100U preamplifier, which is warmer, smoother, and more laid back than the RS-28CX, which might make for a nice match with the Tannoy high-frequency driver.

      I hope that helps.

      Kind regards,


  3. Hi Maik,

    Thank you for your advise.
    I also have planning with Rs-28cx as it may go with Cs660p. But other brand introductions has caused hesitate, such as: Conrad Johnson ET5, Audio note M3…
    By this so large section, I do not expect to get about technique relation or comparation. But I really concern of it’s most effectively performance… Beside of positive specifications of Rs-28Cx we have ever read, please kindly help with your privacy brief reasons or ideas for my decision…
    Looking forward to hearing from you soon.
    Thank you very much.
    Kind regards,


    • In the most cases you should pair pre and poweramp from the same factory.
      The electrical output from the pre is in some cases very difficult. Maybe other brands can’t handle it.
      On the other hand you must see the thinking of the whole chain.

      I had tried to couple Leben with Shindo. This wont work. But if you drive Leben gear as pre and poweramp,it works really good!
      Maybe Shindo runs better…;-)

      You have the decision to buy a Leben RS-28 with phonostage or you can use the RS100 pre. In this case you need a extra phonostage Leben RS-30. My advice: take a Auditorium23 T1 Step Up and a really good Ortofon SPU. This runs perfectly with a Leben phonostage.



  4. Dear Jeff & Maik

    Thank you for your kind response with useful details. This may enough for my decision.
    Just looking for the Rs-100 for now.
    With love and hanging on to Leben…

    Thank you for your help to step up my system.
    Kind regards,


  5. Hi Mr.Jeff
    I very happy to read your review and advise about Leben CS-600 and Harbeth SHL-5 in which I have both of them as my favorite system. There is one thing that make me confuse that Harbeth has impedance 8ohm ( but in some article you had mention 6ohm) then in Leben CS-600 has selector 4-6-8 ohm so what is most suitable impedance that I will select in Leben Cs-600 for Harbeth SHL-5 ?

    Your kind advise will be highly appreciated

    • Hi San68,

      That’s a really nice combination you have, I really love my CS600 & Harbeth system too.

      Harbeth specified the Super HL5 as a nominal impedance of 6 to 8 ohms (the new HL5plus is specified as 6 ohms), so I would recommend that you try both the 6 and 8 ohm settings, then choose the one that you think sounds the best. I ended up using the 6 ohms setting, but you might prefer 8 ohms.

      I hope that helps.



  6. Hi Jeff,
    I’m new to tube rolling and Leben so it was very helpful to read all your blogs/articles about Leben.
    I’ve just upgraded my amp to Leben CS600 (I used Primaluna before), now I’m looking for some 6CS7 tubes to start rolling.
    For the preamp stage, I’m trying to look for Sylvania 6CS7 but I couldn’t find a matched quad. Can I buy single tubes and put them together?
    Otherwise I have found these on Ebay which has GE 6CS7 and Matsushita 6CS7, what is your thought on this? Should I buy these tubes or keep looking for the Sylvania?

    Thank you for your help.


    • Hi Kyle,

      Welcome to the Leben CS600 club! It’s a great amp!

      My favorites are the Sylvania’s, but I’ve got lots of others too. I’m not sure there is a ‘best’ as different listeners will prefer different tubes.

      If you’re wanting to experiment a little, just give them a try and see how they work out for you. I haven’t tried the Matsushita, so that could be interesting.

      Also Radio Electric Supply normally has a good stock of 6CS7’s of various types, it would be worth checking with them as well.

      Let me know how you like what you try!

      Kind regards,


      • Hi Jeff,

        I have emailed Radio Electric Supply, however they don’t have Sylvania 6CS7 tubes any more.
        I have bought 4 x Matsushita tubes on Ebay, I will give them a try and write a short review to keep you updated



  7. Hi Jeff, another question re the 6SC7 tubes. I have a matched quad of Sylvania’s arriving soon, but one thing I’m trying to get my head around is: are these tubes ‘active’ when I use an external pre? I think I read something years ago about this, but just can’t seem to find anything around the traps.
    Also, while I’m here: I’m wondering if anyone has run a CS600 with Audio Note ANE speakers? I am, and have to say the match is amazing. Difficult to believe how good it is. In fact I’ve put my Shindo Concertino away for a rest after bringing the Leben out of hiding – really after reading your recent updates.
    Thanks Jeff.


    • Hi Peter,

      I’ve never heard that about the CS600. The CS600 is basically an amplifier with a volume control, and the 6SC7 tubes provide the first stage of amplification for it. I wouldn’t think a line preamp would change that first stage of amplification any more than a phono preamp would.

      The Sylvania 6SC7’s are by far my favorite 6CS7’s in the Leben CS600, giving a smooth & natural HF presentation that I find really addictive. I think you’ll enjoy them! The Sophia EL34 ST’s take a while to run-in, but they are a phenomenal match for the CS600 too.

      I’ve really been impressed with my CS600 driving my vintage Altec A5’s. I was using my vintage Mac gear on my A5’s, but I ended up replacing it with the Leben CS600 and I’ve been marveling how good the combination is. The CS600 has been around for a while, and I think people tend to forget how really good it is.

      That’s really cool about your ANE speakers (I’ve always liked their musicality), and they strike me as loudspeakers that would be a perfect match for the CS600.

      If you haven’t tried the Duelund DCA wire as interconnects & speaker cables yet, I suspect they too would be a really nice match with the ANE’s.

      Kind regards,


  8. Hi Jeff, Thanks for the very prompt reply and clarification on the 6CS7’s – make sense.

    Being an avid reader of ‘jeffs place’, I’ve followed many of your tips, particularly with the very affordable Duelund and Beldon cables, but only tried with my Shindo amps as the Leben was packed away and really was an out-of-site out-of-mind situation, but now I’m rediscovering the Leben it will be time to get the Duelund in place.

    At the moment I have WE16GA speaker cables running (another one of your tips) and find these really musical, so will be interesting to compare with the Duelund. Surprisingly my Shindo speaker cable just doesn’t seem to work anywhere near as musically with the Leben. Just shows how effective the right match is – price aside.

    I’m currently running vintage Mullard EL34’s, but definitely have the Sophia EL34 on my shopping list – and being a lover of the EL34 and 300B valves, I reckon these could be the cats whiskers!

    I’ll let you know how the Duelund goes – in a day or so.

    Thanks Jeff.


    • Hi Peter,

      If you already have the WE16GA speaker cable, the differences between it and the Duelund DCA16GA as speaker cable are fairly subtle. You will hear a bigger difference between speaker cables if you compare the Duelund DCA12GA to the WE16GA.

      The Belden 8402 microphone cable interconnects (shielding grounded on the source end only) are terrific “vintage tone” interconnects for applications where shielding is needed.

      Where the Duelund DCA20GA excels is as unshielded interconnect, although I do think that DCA20GA made up as shielded interconnect (shield grounded on the source end only) makes for a better interconnect overall, it makes for quite a bit of extra work compared to just using the Belden 8402 which is already shielded.

      Keep me posted on your results.

      Kind regards,


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