Leben cs300xs & Integrated amp demos: to tube or not to tube?

Welcome to tubes. Glad you had the chance to audition. Typically, you hear people talk about “tube watts” right before they are chastised with the “watts are watts” retort, and it usually ends with something along the lines of—you just like distortion. And yes, current is an issue. However, generally, less power in a tube amp can work better for whatever reason.

You may ultimately find you want a little more power, but that is an issue you will come to grips with over a long period of time, AND a 30 watt tube amp will only have a little more power than the 10 watt. It is something you notice more with symphonic music and big swings. My speakers are also known as easy-to-drive, but in the end, I am very happy to know where the boundaries of my speakers are, as opossed to the boundaries of my amp. I can’t really tell you why, exept that I am usually content with normal listening volumes, if that makes sense.

 

Distortion is the last thing that comes to mind when thinking about the sound out of the Oto. Transparency? Yes. Distortion or euphonics? No. Not with this amp anyway, I can't speak for all tubes. I don't listen to big orchestral works, but lots of dynamic swings in my music and I was amazed at the speed of this amp.

 

In my experience, solid state has a certain sound and tubes have another, with many variations and flavors within those parameters. If, for instance, your were listening to a symphonic work that featured a very low-volume solo part that shifted instantly into a full orchestra hit with timpani etc (which often happens), you might find that the soundstage would flatten out at that moment. Bigger transformers and larger output tubes maintain that 3D realism under greater stress. It really is not about playing louder.

This is it, really. Solid state seems to sound 2D by comparison, and some recordings just sound kind of flat anyway.

Some people are not much interested in that wide, deep, tall aspect of sound. Some speakers are more capable of creating that sound. In fact, you can get so much of that that a recording sounds too broken apart and too disparate. The tubes control, to a degree, how much of that element you can have.

I am repeating myself, but in an valve integrated, the preamp is the thing. If a designer can make knockout preamps, they probably make a good tube integrated.

 

Yup. You nailed it.

 

I've found that tubes can do some cool things to music, but color your sound, which wasn't something I enjoyed over the long haul. Sometimes that color, even to the smallest degree, can sound really cool and can be addicting, but that color doesn't work on every recording. I got burnt out on tubes and wanted neutral. I haven't heard a tube amp that can do neutral like a great solid state design.

 

It certainly is interesting. The amp I have now, in its stock configuration, is pretty close to neutral with only a little additional depth to the soundstage to give it away. What I truly do not understand is this coloration. If the frequency response is measurably flat, and the signal-to-noise ratio is known, what is left? Even-order harmonics? Outside the audible frequency range? Is this what gives us the spatial information that tells use there is physical space separating the sounds? I have some opinions formed over the years, but I truly love to change them. For me, at my level of understanding, there is still a great amount of mystery.

My old integrated had a Mosfet pre, that would get very warm and soft as it got hot over several hours. I always thought that was the tubes, but now I know it was the solid-state preamp adding coloration.

 

I think some of it depends on the tube type...KT88 and 120 tubes are more neutral and linear than some other designs. But I think most tube users want some mid-range magic that other tubes can offer. I also found that the best solid state designs can make music jump out of darkness where tubes can get near there but you can never get as "black" of a background. Again, that is a tradeoff.

 

I have enough ambient noise in my room that I could hardly know if I had a black background. What are some tube amps you have owned and liked?

 

I've only owned Prima Luna, but have heard Fisher, Octave, Marantz, Mcintosh, Conrad Johnson, Audio Research, Wavelength, Manley, Luxman, and others in a variety of systems. My favorite are EL34 based with great monitors, because of the midrange...it really made electric guitar pop. Sometimes unnaturally, but that is what I loved about el34's. It was a pretty consistant trait across el 34 amps...Jerry Garcia's guitar tones were fantastic. Other music, like Portishead, didn't sound as good to me through el34's. I never heard el 34's sound as good with bigger speakers, so I had to decide what I really valued.

 

Yep. Had an EL34 integrated for 20 years. So the Prima Luna and the Audio Note in this thread both have a circuit that adjusts the bias on the fly, so as the tubes age, the bias is always spot on? I read that some people feel this is great for keeping the amp working in top condition, but that these circuits also have sonic negatives.

 

The Oto should arrive in a few weeks, I'll post more once I get it set-up in my system.

 

Welcome to the EL84 world!

One thing caught my eye though. The SE and the SE Signature versions have much larger output transformers. In fact, I have never seen such big output transformers in an EL84 amp. This can only be a good thing...

 

It could be too late at this point, but might this thread be retitled?

It's turned into a very interesting discussion about integrated tube amps in general (and the audition process in particular).

Anyone curious about the Leben CS300XS, however, wouldn't find many posts directly about the amp.

 

Maybe it's time to try some Shindo amps. ;-)

 

My main concern with trying other tube setups going forward: with my room size, main musical interests, and sonic preferences, I think I'm going to need my REL subwoofer in the setup (though the bass boost on the Leben would do in a pinch). So the first question I'd ask a dealer/seller would be how the Shindo (or Line Magnetic or Audio Note, etc.) would interact with a subwoofer in the chain...

 

Everybody designs circuits differently so is hard to tell of an auto bias chip really helps or hampers sound. In some ways it would be cool to be able to control your own bias, especially if you prefer it to be lower or higher than what the auto bias is set at.

I also found that once I switched back to solid state and floor standers, my Dead recordings sounded more like an actual concert vs the midrange vividness of tubes. I listened to some Octave gear, thinking that the more neutral nature of it might be what I desired, but there wasn't the low range resolution or top end detail that I was craving. It would be nice to be able to switch systems on the fly while listening at home, but that wouldn't work out in my listening space. A side note is that my utility bill went down when I switched back to solid state...and I only used tubes on the weekends.

 

raferx, you're getting me to do a little thinking about upgrading my integrated amp. The Oto sounds like an almost affordable option. Hmmmmm

 

Was seriously considering a couple-months old one of these from a Canadian seller...

 

Lovely!!

 

That Shindo Apetite integrated or an Aurieges preamp/Montille poweramp would be the Shindo gear I'd consider next; Matt at Pitch Perfect Audio was great to work with on the Leben and DeVore gear

 

+1

Perhaps we could re-title it: Integrated amps: to tube or not to tube?

 

Single ended output transformers are almost always larger for a given wattage, compared to push-pull. They have to be physically bigger because of inductance losses etc.

jeff

 

They sure got grunt in the bottom end...

 

Any ideas on how long this amp (it's tubes really) should take to break in? 200 hours?

 

Power tubes are usually done by 50 hrs. Some of the fancy big triode tubes are supposed to take longer. When I built my Pete Millett amp, I really didn't notice it changing much over the first 50 hrs. There's always exceptions, and of course people's opinions will be vary whether there is perceived "break-in" or not.

jeff