The Leben CS300XS Thread
Mar 18, 2009 at 3:23 PM Thread Starter Post #1 of 2,302

Gu Sensei

500+ Head-Fier
Feb 20, 2008
I have been on the hunt for an out-of-production Leben CS300x since bringing home and falling in love with my standard CS300. A few days ago, while following my well-beaten path of audio ‘recycle’ shops in Osaka’s electronics district, I noticed a dusty Leben sitting on a shelf near the entrance of one of my favorite haunts. As my eyes widened, the little ‘x’ jumped out as I simultaneously shouted, “Woo-hoo!” It had just been dropped off earlier in the day and had yet to be processed. These things do not stay on the used shelves very long (think hours at best, or minutes for on-line listings). Being at the right place at the right time is the only way I figured to grab one without paying an exorbitant amount through an auction on the rare occasion they show up there.

Ecstatic is pretty good word for how I feel right now. However, it is not in my possession at the moment. The shop is giving it a thorough cleaning and check-up and should get back to me in a few more days. Hopefully, it will be all okay, but there is a little twist. I forgot about the two different versions: the CS300x (S) with Sovtek EL84s and the CS300x (Limited) with NOS Mullard EL84s. I did not check when I was at the shop and am obviously hoping for the latter. Regardless, I am happy as a clam as both ‘x’ versions have all the upgraded bits and pieces and the Mullards can be purchased (although not cheaply or easily).

I will certainly update with the results, but in the mean time, I am curious if anyone has experience with the Lebens or other amps using the EL84s and can make recommendations:

What are good places would be to buy Mullard EL84s?

Are there other brands that are well respected and less expensive?

How much of a difference will I likely notice by going for the more expensive Mullards?

How long would they usually last?

Any thoughts, advice, or comments are welcomed as I have zero experience rolling tubes.


(Ooh freaky, after posting this, I noticed it was my 300th post.)
May 8, 2009 at 3:27 PM Post #3 of 2,302
try the new genelex n709's..... lovely (although i did have to return one because it arced)
May 8, 2009 at 3:45 PM Post #4 of 2,302
Basically, you can not go wrong with Mullards, however depends on what is your taste of the sound of course is, so, you may like Telefunkens or Siemens more. Teles, in general, are great overall tubes with great balance overall, but some folks find them "hard" sounding, while Siemens are very spacey/airy where details are top notch, but can sound bit to extended/sterile. Mullards are warm sounding with nice detail and great mids, bass can be "loosy" with some headphones, but the best ones are NOS from the earlier 50's, actually all of them, and that's make them quite expensive to buy.
Well, if you going tubes you should know that.Not sure if there any EL84 Tung Sols, but if yes, try them to, cos they are like Teles, but with softer/richer touch. Also Brimars are one that have quite rich/musical sound, so you have some work to do, which is very fun, imo.

Check here for more info
May 12, 2009 at 1:58 PM Post #5 of 2,302
Blackmore is of course talking about REAL Mullards, not the Russian re-issues
May 13, 2009 at 2:32 AM Post #6 of 2,302
Tubeworld is a great place for tube info but a terrible place to buy from merely because their prices are so inflated. Look around on the 'Bay for good deals on Mullard EL84's,you'll find them if you look hard enough. Make sure the pictures of the valves in question are clear. You'd certainly notice quite a difference, especially in sound stage and overall smoothness of the sound. Its hard to tell about lifespan as each amplifier puts a different voltage and bias current load on tubes but suffice to say lifespan will be in the thousands of hours.
May 13, 2009 at 8:34 AM Post #7 of 2,302
Thanks guys, very informative and helpful. After I am really tuned into the sound signature of the current set-up, I will try rolling in some of the suggested tubes. It should be fun.

I did luck out and found four lovely Mullards in my CS300X when it finally came in. Leben only sold the Limited version with NOS Mullards, so I am assuming that is what is in there, but since I do not know the history of the amp, they could be re-issue replacements. Is there any way to tell?

As for the Apache comparison, I never really did a methodical comparison, but each and every time I plugged my D7000s into all the amps on hand, the Leben came out on top. It is quite 'musical' and adds a wonderful warmth and sparkle to the Denon sound signature. It is not thick or tubey at all to my ears. The Apache was cooler and more clinical in comparison. There was probably greater detail retrieval with the Apache, but not by much. The Apache is an incredible amp to be sure and it mated very well with the L3000s and HP1000s when I had them. But the Leben has been the best with my go-to D7000s and is a brilliant integrated amp to boot. Great functionality and one of the sweetest looking amps I have seen. It is keeper indeed and has really suppressed any interest I have in purchasing other amps.

This particular amp needs a bit of a make-over though. The CS300X came with gold plated knobs and mine (like many others I have read about) have become corroded. I do not mind so much as I am looking forward to personally dropping the amp off at the Leben factory which happens to be a few towns over from where I live.
May 13, 2009 at 8:40 AM Post #8 of 2,302
So, you have the amp with you already, congrats! Just post some pics of the tubes and sure we can see what ever they are. Normaly, they do have codes which may tell the age. PICS pls

Any AKG K1000 you can try with it?
May 13, 2009 at 10:39 AM Post #9 of 2,302

Originally Posted by Gu Sensei /img/forum/go_quote.gif
Leben only sold the Limited version with NOS Mullards, so I am assuming that is what is in there, but since I do not know the history of the amp, they could be re-issue replacements. Is there any way to tell?

It should be obvious. First of all, the re-issues should have "Made in Russia" on them.

Pictures would be interesting, though.
May 13, 2009 at 12:00 PM Post #10 of 2,302


Originally Posted by Oskari /img/forum/go_quote.gif
It should be obvious. First of all, the re-issues should have "Made in Russia" on them.

Pictures would be interesting, though.

May 14, 2009 at 1:42 AM Post #11 of 2,302
Alrighty, here are some glory shots. It was nice to see "Made in Great Britain." She is definitely a diamond in the rough, but it will be fun to get it restored (and hopefully not too expensive). The one shot of the bottom insides I nabbed from the web.








May 14, 2009 at 1:51 AM Post #12 of 2,302
As for the K1000, Blackmore, I did have a pair (before they got shipped to you
) that I used with my original CS300, but I never used them with any other amp outside of some store demos. They certainly sounded good but with no other real reference points, it would be hard to recommend outside of the nice functionality of an integrated amp with speaker posts for the K1000s and a good headphone jack for other headphones. The Leben's absolutely matched well with the K701s. Those and the D5000s were probably the best synergy I have noticed with the amp. I definitely prefer a more musical presentation and the Leben really adds a nice coloration to more neutral headphones.
May 14, 2009 at 9:20 AM Post #13 of 2,302
Let's not be so quick to reject current production Russian tubes. At least one manufacturer of high end gear uses (i think) the Russian 6P14P-EP (6n14n-EV) in his entry level SE amps, which are tha father of the Sovtek tube.

You might also go over to the tube asylum at the audio asylum forum and search under EL84 to see what people like over there.

On the other hand, I have not found a current production 12Ax7 I like, compared to US 1950s-made long black plates with D getters. I did get some nice NOS 1970s Teslas from Tubemonger, but he sold out of those. He has a few left of a somewhat newer tube and a bunch of military Tungsrams which are not bad. Of course, Telefunken smooth plates and Siemens triple mica tubes are still available, the prices for the latter being astronomical.
May 14, 2009 at 11:51 AM Post #14 of 2,302
Great pics, thanks. You have the real NOS, cool. You may want to change the 12AX7 for some Brimars, but I would try Tung Sols first, cos Mullards and Brimars, all together, could be bit to much

On the other hand, if you like the sound already, don't bother with tube rolling, imo, unless its necessary. Also, Leben did choose these for some reason, isn't, so, I would say enjoy the music...
I don't have that luck with my amp, not that the stock tubes are bad, but I do notice the huge improvements with some NOS I already rolled, so, my search for the best tube set up isn't done yet.
As for the K1000. I am almost sure if you roll some tubes, you will find the good match for them. Tubes don't sound the same in different amps, so, you may still want to try some in the future.
May 14, 2009 at 12:50 PM Post #15 of 2,302
Yup, those tubes are the real deal. And what a BEAUTIFUL looking amp! Congrats. I'm jealous

Users who are viewing this thread