The Leben CS300XS Thread - Page 2

Hey Gu Sensei -

My interest in this amp has been piqued again. How have you liked yours?

Thanks very much for that! Unfortunately for me, there is no Chicago area dealer than carries them. The bummer is I was just in Tokyo 2 weeks ago, but didn't have time to get to Akihabara, which I usually do on my business trips to Japan. I know I could have picked on up there. In the US the CS300XS is $3,495. So I have to consider it very carefully, especially since I would be using it just for headphones.

But I like the circuit topology and tube complement - and yes, the wonderful cosmetics!

We shall see...still considering it...

I don't claim to be an expert on circuit design, but the CS300XS uses tubes I consider to be excellent sounding (12AX7 gain, EL84/6BQ5 power), and is transformer coupled, so should be able to drive low impedance headphones as well as high, although I note that several people, including you I believe, did not think they were very good with the low impedance Grados. The amp is very nicely point-to-point wired, and the circuit appears to be, and is touted to be, quite simple. Given the rated output power, I assume the Leben is using the EL84 in their native pentode mode, which IME will give is a robust, "meaty" sound, without being overly tubey, all other things being equal.

Here is an interesting post (and thread) from Audio Asylum about tube-rolling and the CS300: http://db.audioasylum.com/cgi/m.mpl?...ht=leben+cs300

There have been a LOT of amps that use 2 x EL84 and 2 x 12AX7 - including my $400 Ming Da MC84C-07, which sounds quite good. But I'm sure there is a much higher level of performance that can be had from an amp of this design.

Now if only I could get one at a reasonable price. Oh well. The US Distributor, while polite, doesn't seem to see my point that I shouldn't have to pay a dealer in Cleveland 35% margin on a $3,500 when he won't be giving me any support at all - just taking my payment and passing my order to the distributor. So unless I find one used, I will have to admire this amp from afar, I'm afraid.

Well, I am not sure that anyone cares but me and Gu-Sensei, but through a twist of good-fortune for me, I was able to acquire his CS300X, as he bought a new one. It arrived yesterday.

I had not really thought through the fact that the Leben is transformer-coupled - and after getting over the surprise, I realized what a good thing that is for me, as all my other top tube amps are OTL. The Leben gave me the chance to use a tube amp with the low-impedance Denon D7000 and Ultrasone Ed 8. And based on just one day's listening, this is going to be a VERY good thing The CS300X sounds fantastic - it is really incredibly good sounding as a headphone amp. I need to do some comparisons, but it may well be the best sounding headphone amp I have. It is certainly among the best.

Someday I may try it as an integrated amp - but as a headphone amp - it's terrific.

Great buy, great amp, pity you dont own K1000, would be interesting read your opinion, cos at 15w p.ch. can be a good match to. Gongrats!

Skylab how it fares with your T1?

Haven't tried that combination yet - but will soon.

Agreed, I like it very much. I bought it for K1000 but later found that it works very well also with HD800. Actually I can have both connected and switch between them with the headphone/speaker switch. The problem with HD800 is that there are few usable steps on the volume control, but is is a continuous potentiometer and you can set it between the preset steps. I have no problem with the slightly emphasized treble of HD800 with the Leben amp - at least not with the right tubes. The treble can sometimes be a little tiring and unnatural with other amps.

There have been some demo and used CS300 floating around in Sweden for about 1500 Euro and I found a demo and it is a very good value at this price. It feels like a keeper and I have bought rather many tubes - most moderately priced. I am cautious with NOS output tube that are expensive (e.g. Mullard), hard to find and will worn out. I assume the rarity is the reason that the CS300X model (with Mullards) has been discontinued.

The stock GE Jan 5751 is not my favorite, although it has a very pleasant and elegant sound with the Sovtek EL84 that are stock tubes in the standard model. As I understand it the same GE 5751 is used also in the more expensive models and giving at a beautiful, smooth coloration in my taste, IME and IMO. Just now I have a Telefunken smooth plate that I prefer and it was not especially expensive as used. I am so satisfied with this and the new stock Gold Lion EL84 that I not yet have fully tried all the tubes I have bought. But tube rolling will go on and is in a preliminary stage. The Leben amp is sensitive to tubes and that makes it difficult to say exactly how it sounds but there are many tube combination that make it shine.

I also happen to like that the tubes are not visible and the amp is simple to place. Of course it needs some ventilation but it never runs especially hot.

I'm using all Sylvania tubes - 5751's and 6BQ5's - grey plate in both cases. The sound is very smooth, but not overly tubey. Very, very nice. It's a very robust, organic, involving, and detailed sound. I'm highly impressed.

Obligatory pics :

Very nice, Rob. Sweet amp - congrats.

Thanks for sharing with pics!

Thanks man! I'm really digging it. I've gone a little nuts with the head-fi purchases this year...my ears are thanking me, but my wallet sure hates me

never realized how big it is. know what the weight is roughly.