Leben CS300XS Tube Rolling
Of course there are older threads, here and elsewhere, that cover the subject. But I’m looking for fresh takes from new users (and given how quickly used units move, I’m guessing there are a few of us around) as well as feedback from seasoned experimenters (maybe even some dating back to those mind numbingly long threads of 10+ years ago).
Some say the Leben CS300XS is responsive to different tubes, both EL84 and 12ax7. Others say only the signal tubes noticeably impact the sound. Given that versions of the amp have been around for ~20 years, this seems like something that should be already settled, but here I am…
New production or NOS and no hard budget, I’m open to trying anything anyone else enjoyed. What am I trying to achieve? Occasionally, I hear some random graininess and/or hardness at higher volumes (could this be tube related? I don’t know). Beyond that, I’m really looking for anything that brings more of the Leben’s great qualities forward (like when I added A23 cables to the mix, *everything* improved).
Speakers are Klipsch Forte IV and sole source at the moment is a Chord Qutest DAC. Thanks in advance for any advice/help you care to share.
@bjesien Thanks again! That's *really* good to know... Tomorrow I'm supposed to receive my second, new Leben CS300XS (hence the original purpose of this thread). Don't want to go into the long, boring details of my Leben saga here (at least not yet), but I'll soon be able to compare two different units and better distinguish amp behavior from tube behavior for myself ('cause there's no substitute for experience, right? Lol.) I promise to report back..
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@ghasley Unfortunately, I don't have wired headphones. But yeah, definitely shopping 5751s from Brent or VTS (good point on the speakers). In addition to the GE version, the Sylvania 5751 black plate, triple mica get some great feedback. |
I've got a Leben CS300xs going into a Forte IV too. The Leben came with Genalex EL84s and 12ax7s. I'm not much of a tube roller, but I have replaced the EL84s with NOS Sylvania's that added a bit more "glow" to the sound. I've been itching to upgrade to upgrade the 12ax7's. Brent Jesse has never done me wrong with tubes and figure that his "butt ugly" tubes would make sense since the tubes are not visible. |
@djspinner Thanks for the engagement. Since you mention owning the same Klipsch/Leben combo, can you hear any tube hiss/buzz/noise from the tweeter? |
I had previously heard some intermittent noise from the Gold Lioins - almost a grinding sound - coming out of just one channel. I switched the tube positions and the sound switched channels. So clearly had one bad tube. When I changed them all out, that noise was gone. At normal listening volume - with the music paused - I currently hear no noise/hiss. If I cranked the volume knob up well past where I would ever do so with music coming through - I can hear some faint buzz. That's fairly normal for tube gear though. Brent Jesse has some good reading on the subject: |
