[davehg]

Does cs600 use own headphone amp or is it the same amp as the speaker output? If you change tube, will the change apply to headphone out too? So will it deliver the same sound quality level through head just like the speaker out or is it different with degrade sound quality?

Iam really interested in this cs600 as both speaker and hradphone amp.

I just put my name down for a new 600x so it will be a while, but happy to report when it comes in. I’m Using a Woo WA5 as my current headphone and speaker amp, and it will be fun to compare it’s 10wpc 300b to the Leben’s 28 wpc

 

[davehg]

I am stocking up on tubes to try.out in the Leben. So far, I’ve assembled the following:

JJ KT77
Genelex Gold Lion KT77
Winged C EL34

various NOS 6CJ3/6DW4 rectifiers

JJ and EH ECC82/12AU7a and 12BH7a tubes.

Trying to keep from going too crazy. What’s a good NOS 12AU7a or 12BH7a?

Does the 6CJ3 have any real impact on sound?

 

[Nikos K]

I am stocking up on tubes to try.out in the Leben. So far, I’ve assembled the following:

JJ KT77
Genelex Gold Lion KT77
Winged C EL34

various NOS 6CJ3/6DW4 rectifiers

JJ and EH ECC82/12AU7a and 12BH7a tubes.

Trying to keep from going too crazy. What’s a good NOS 12AU7a or 12BH7a?

Does the 6CJ3 have any real impact on sound?

Greetings, have you received the Leben? curious to hear your impressions

 

[davehg]

Not yet. There was a post on positive feedback about problems with the substitute NOS 6DN3 damper tubes Leben was sourcing, which supposedly were causing some issues. Leben was said to be changing the circuit, which was designed originally for 6CJ3 tubes which are not in production. I wonder if this will delay some outstanding orders. I stocked up on older 6 CJ3 damper tubes in anticipation, but would welcome if there was a change to accommodate the use of current production tubes.

 

[Nikos K]

Not yet. There was a post on positive feedback about problems with the substitute NOS 6DN3 damper tubes Leben was sourcing, which supposedly were causing some issues. Leben was said to be changing the circuit, which was designed originally for 6CJ3 tubes which are not in production. I wonder if this will delay some outstanding orders. I stocked up on older 6 CJ3 damper tubes in anticipation, but would welcome if there was a change to accommodate the use of current production tubes.

I spent a few hours yesterday at Solid Foundation in Athens, the distributor, amongst may other nice stuff, for Leben. Stelios was very happy to let me listen to the CS600 he had on display. Unfortunately he does not have any CS300, they are on back order. What a wonderful sound. I always remembered the Leben house sound as amazing with sensitive speakers and so immediate, effortless and enveloping in the musical happenings. (Bonnec CD player and Blumenhofer 1722 hybrid horn speakers where the other system ingredients)

I had my Focal Utopias with me to verify that the headphone output is as good as it is reported. YES IT IS! same sound, wonderful timbre, probably the best I have heard with the Utopias. Super detail, normal but enveloping soundstage are given with the Utopias. However the lifelike vocals and the lack of any piercing highs are the highlight that I was looking for. This air between the voices and the instruments and this pulsating whole.
After this I do not see the reason for a dedicated tube headphone amp if you can get an integrated amp combined as a bonus. I am sold. I have to sell a lot of things and start saving for the CS300sx. I remember I have heard this many years ago and was also very much impressed, so I am assuming the headphone amp is of similar quality.

 

[davehg]

 

[davehg]

Picked the 600x up over the weekend and still warming in the capacitors and tubes. I hooked the LCD3 up briefly in between speaker listening sessions and confirmed it sounds wonderful. Will post up a longer review once the Leben is fully broken in, and may do a comparison with the Woo WA5.

 

[davehg]

I’ve spent more time with the Leben and it continues to improve. The stock tubes are adequate but like all modern tube amps, the 600x seems to greatly benefit from tube upgrades. I’m running new Gold Lion KT77s, and the line stage tubes are NOS Raytheon and Westinghouse 12BH7 and 12AU7. The tube swap gives the 600x a more fluid, less gritty sound. The stock tubes are Electroharmonix and JJ, which sound a tad brittle and grainy vs the upgraded tubes.

I am really noticing lots of micro detail - the Leben has warmth but it doesn’t sound like a classic EL43 amp. It has a big soundstage and nice depth (though not as much body as my Woo WA5 300b SET, which has a nice depth and immediacy, fleshy, ”you are there” vocals). Both of these integrated amps sound great, but quite different. I’m not sure I have a favorite yet.

I’ve got a bunch of different power tubes to play with, including EL34 and 6L6GCs. I think the Leben supports up to 8 different tube types including KT66s so it is fun to be able to play around.

i‘ve not put much time in with headphones as I’ve had so much fun listening to speakers. It drives the DeVore Nines with ease.

so far, very happy.

 

[davehg]

I spent quite a bit of time rolling the line stage tubes. I’ve ordered NOS Tungsols, GE triple mica, RCA black plates, and Sylvanish black plates, as wells as CBS Hytrons. I’m currently running the Sylvania 12BH7A with the CBS Hytron 12AU7A substitute and it is a nice combo, if perhaps more polite than the Raytheon and Westinghouse combo above.

I also sourced some coin base Russian 6CN3-e tubes, which are rumored to be excellent 6L6 GC substitutes, but not yet tried, nor have I tried the Winged C EL34s.

I did do more listening with Audeze LCD3 headphones. The Leben is really nice with these phones, though it lacks the epic bass of the Woo WA5.

 

[davehg]

Finally spent time listening to the CS600x as a headphone amp. I own a Woo WA5 and WA22, and I spent 22 months listening solely to headphones on both amps, including the Focal Clear and Audeze LCD3f. Both are great amps and both are very tube sensitive, preferring NOS tube over new production. The Leben is no different, and I’ve had great luck with Sylvania and CBS - Hytron and Ratheon line stage tubes, and new production Gold Lion KT77s.

starting with the Focal Clear, I enjoyed the midrange immensely but the bass was quite heavier. I checked the bass boost just to be certain I hadn’t bumped it up inadvertently. The top end lacked openness, which is not how the Clear sounds. The sound resembled my HD650 (absent the bass), glorious vocals but polite top end. In short, it didn’t sound at all like the Clear I knew from 22 months of listening.

Next up - the Audeze. The LCD3 fared significantly better partnered with the Leben. Detail, clean and clear top end, beautiful midrange, and nice firm bass, if not a bit soft compared with fat sound of the Focal. I adored this pairing - super musical, and my toes were tapping.

Of note - the Audeze was used with Cardas Clear cables well broken in, and I listened to the Focal with its stock cable that I hadn’t yet used (owing to using the stock Focal balanced cable with the Woo). I’ve used Cardas Clear on my HD650 and the sound is more transparent than stock cables on Sennheiser and Audeze. Meaning, it’s possible the stock Focal cable is not broken in or not a great match with this system. That might explain the polite top end but not the fat low end.

I enjoyed the Leben, and it is simply stellar as an integrated amp for my speakers. If I just owned the Audeze, I‘d be content with it as a headphone amp, and I’d prefer the Leben over the Woo WA22. But the WA22 is a better match with the Clear when used in fully balanced mode with a balanced source. And the WA5 used with both headphones eclipsed the Leben. so while I’m tempted to part with the WA22, I‘m keeping the WA5.

When used as an integrated speaker amp, the Leben gives the Woo one heck of a challenge for the immediacy, transparency, and body that you get with a 300b. With the right NOS tubes, the Leben eclipses the Woo in bass control, slam, dynamics, and wide tall soundstage on my Devore Nines. The Woo is super special, and has such a special presence and really strong overall balance but at only 8wpc it can’t quite push a speaker the way the 28wpc Leben can.

Where does that leave me? When used solely as a headphone amp, I’d have to give a clear nod to the Woo WA5. I don’t know the output impedance of the Leben, so I wonder if the lack of synergy with the Clear might be because the Focal is a super low 55ohm headphone, vs 110 ohm for the Audeze, and much higher for the HD650. But the Woo WA5 pushed both the Focal and Audeze with sheer dynamics, but with musical warmth and body. In contrast, the Leben partnered beautifully with the Audeze but left the Clear with a gooey warm midrange but overly fat bottom end and too-polite top end.

I’m keeping the Leben as my main integrated - it’s that special. I’m also keeping the Woo WA5, though I’ll be playing less as I am throughly enjoying listening to the speakers.

 

[davehg]

I wrote up a more detailed review here.

 

[davehg]

I’ve done some big upgrades to the system - replaced my Lumin D2 with a T2. Big upgrade and it showcases how well layered and textured the Leben can sound. A bigger upgrade was to ditch the Devire Nines, which I enjoyed, with the Devore O/96. The Leben -Devore synergy is stellar and everything I’ve read about is true - great pairing.

The T2 helped bring the pairing of Leben with Audeze up to expectation. Still not better than the WA5, but more enjoyable now. I regrettably sold the WA5 to clear space on my audio rack, so now the Leben duels with the WA22 for headphone duty.

 

[kasperbergholt]

Clever people,


If all goes well, I'll receive a Leben CS600 next week. Something I've waited for for a long time

The preamp stage uses a quad of 6CS7 tubes.

I've got two questions -

How symetrical measurements do the tubes need to be in this specific amplifier?

Which brands of tubes do people have good experiences with - either in general or with this Leben product in particular?

Supply seems to be somewhat limited - at least in comparison to other NOS tubes like the ECC82.

I'm looling at the following brands now: Sylvania, GE Canada, CBS-Hytron, Marconi Canada, Fivre.


Huge thanks in advance,

Kasper Bergholt

 

[arturo71]

Hello Kasper. I found your question here when I was looking for something.

I have a Leben CS600 since circa 1 year and I also have a CS300XC. These amps are stellar and well above their price category.

Now coming to your questions. I love tube rolling. The Leben does not need a quad, on paper 2 pairs are enough. Having said that, my experience is that it is very tolerant to un-matched tubes, I merrily change tubes without caring too much about which tube pairs with with other.
the Leben accepts so many tubes that a short answer of which are the best ones is not possible. If you put EL34, the best ones seem to be NOS Telefunken (neutral and refined), Mullard (sweet), Amperex/Philips (amazing mids, closely mic recordings), also look for Matsushita that sound like Mullard and cost a fraction (they were machined with Mullard tools as part of a joint venture in Japan, or something similar). Also Tesla that were copycats of Telefunkens and RCA black plates.
Instead for KT88 he king seems to be GEC. People say good things of the current production Genalex Gold Lion KT77 but I do not know them. i stick to the EL34, they are more refined and I do not need the extra power of the other tubes.

Harder to find are the 6CS7, but you can find them if you search enough in the net. some brands are Sylvania (beteer with black plates, other grey plates are OK), Raytheon, General electric.

Good luck and enjoy the journey!

 

[agustinf]

How nice to have a lively thread on the 600! I turned here to ask a question, ready to wake up a dormant thread, and found people actively exchanging.

My experience with tubes in the 600: I tried several types with close and not so close matches, and in this room I'd keep the 77s by a thin margin as they give a more balanced presentation. In other rooms I preferred the original Russian 5881 because I they were a bit more bright and forward. I don't have a tester so I can't say when my tubes go bad, but now I've tested a bunch of those that would alternate in and out as the amp is in service and I know a few were bad! The amp didn't do anything espectularly bad (perhaps I was lucky) just a very minor crackle if you placed your ear at the speakers tweeter. Which brings me to a second point.

My experiences with power supply and switches: Without great evidence about it, I believe that Leben (as perhaps most tube gear) can be sensitive to mains voltage (level, stability etc). Also, as I was (as perhaps everyone else) babying tubes as the weak link, I didn't realize dust and humidity can affect switches and rotary knobs (of which we have a few). My amp is perhaps better off with new switches and pots, as some are oxidized and apparently can't be cleaned up properly.

So the question: Do any of you know how to source OEM parts for a Leben amp? As I said, I need a few pots and switches. The service people I worked with tried contacting Leben Japan but got no response (so far, after a week, perhaps that's normal waiting time, I don't know). I contacted Tone Imports in the past for questions and advice and they've been stellar, but they distribute in the USA and I'm not there anymore (I don't have a Leben agent in this country) and I didn't want to bother, again, not yet at least

Thanks a lot in advance!