Seeking Feedback from Leben CS-600x Owners

Hi all. Looking for advice from anyone with Leben 600x experience and experience with traditional 300b set design amps. 
 

I have the 600x and considering adding a 300b set with tube rectifier and western electric 300b’s to my system as a 2nd amp. 
 

I use Devore 096 speakers. My question is- is adding a good 300b to my collection going to be too similar to the Leben for it to warrant the purchase?. 
 

my other upgrade I’m on the fence about is a new tone arm to better match a lower compliance cart I’m running. 
 

any thoughts on the above are welcome 

Finally past the break-in period, and I am super happy with the 600x. A few things helped eliminate some grit and glare: swapped the line stage tubes with NOS Sylvania and CBS tubes, which mellowed things out. Amp is warm, rich, musical, and while it sounds odd, transparent and clear too. Tall and wide soundstage, manages to reveal wonderful detail, with body and weight. 
It isn’t a fat tubey sounding unit in the style of a VAC Avatar SE, and I am having trouble thinking of an EL34 integrated that really sounds like it at all. I’m more reminded of VTL gear.

I just picked up my 600x today and only have about 4 hours on it, but I’ve heard I may need 50+ hours to let the caps fully burn in before forming an opinion. But until then:

- very gutsy amp, with plenty of power for Devore Nines. Really turns them into a dynamic speaker with great control. It even powered a pair of YG Carmel v1 speakers, though I didn’t quite like that pairing as much as I did the Devore.

- I’m not a fan of the stock EH EL34, it has a bit of a glare. I quickly swapped for a Gold Lion KT77 and quite liked the sound. I have an NOS set of Winged C tubes I am tempted to try.

- super transparent and detailed, not a syrupy classic sound but it does have warmth, just not at all rolled off.
- in contrast to my Woo WA5 300b integrated, which is 8wpc, the Woo has that delicate and intimate 300b sound that is seductive, until you try to rock out and it gets a little flat at higher volumes. The Leben gives up some immediacy and sweetness but you get better body, more detail, more life like soundstage, and wow what a soundstage.

curious to see how the amp changes in the first 50 hours.

@ghasley  Perfect description to help me sort out the comments I've read.  I do indeed think any criticisms I've heard on lack on tubey sonics are likely from those seeking a very wet euphonic texture.  I will certainly look into the Leben further.  Much appreciated.

What do you mean by tubey sonics? It is rich and musical, responds to tube rolling and yet, it isn’t a set amp. It sounds right to my ears but YMMV. 
Side by side with say, a Primaluna dialogue premium integrated with el34’s it sounds more powerful than the PL on ultralinear and more rich than the PL on triode. The 600x controls the bass where you wont miss the ss control and yet, the mids and top are undeniably top notch tube sonics. But dont confuse it with an overly euphonic kind of amp but an overly euphonic amp is usually deviating considerably from optimal performance. Big round tone while being faster than most el34 tube amps. You really should go listen to one on several speakers. Its worth the money to travel to do so. Besides, even if you fall in instant love, you will have to wait for yours given the backlogs and the wait typically experienced when buying a Leben. They hand build them and demand exceeds supply, even during a pandemic.

Thanks for both responses.  I'm considering pairing with Devores although I've heard that the Leben may not have the most "tubey" sonics.  Does that ring true with you @ghasley ?

I owned a CS600 and currently have a CS600x in my office system. The Cs600x is better in every way but read up on the cs600 for speaker matches, its just a better and improved version. To me it seems to have more presence and snap. Maybe some power supply improvements, but it isn’t so different that speaker recommendations that were applicable to the 600 no longer apply. I enjoy Devores with the Leben but I have also connected it to my Wilson Sashas and it did a surprisingly good job, just a little loose in the low bass.

Hi,
this is a terrific amp full of nice timbre, acepting either el34 or 6l6. I have heard it with Blumenhofer Genuin FS2, FS3. I will have a listen to them again this week some time when i visit my dealer friend so i can give you more details about any additional matchings.