The Feliks Audio Elise headphone amplifier is becoming quite popular amongst forum members and I thought it would be a good idea to start a thread to concentrate on the different tube options for the Elise. A very nice budget option might be: 1960's RCA 6080 with Foton 6H8C, should render a nice soundstage with good depth and bass extension and smooth highs, might be slightly diffuse but is still hard to beat for the price! Tubes found to be compatible with the Feliks Audio Elise are: Power Tubes: 5998 6080 Spoiler: RCA 6080 Bought a matched, well-tested pair of RCA 6080 from a trusted seller for the crushing sum of $14 to my door. Though the sound lacks the large scale of 6AS7G, the tube is very smooth on top, relatively transparent, sweet mids with a good projection of depth and space around the instruments, slightly loose bass without the [ultimate] extension of the Chathams, somewhat laid back overall and dead-quiet. A very nice sounding tube. - Shaffer 6080WA 6080WB 6080WC 6AS7G/CV2523 Spoiler: GEC 6AS7G/CV2523 Although I may have hinted previously that the GECs didn't seem to be bringing a GREAT deal more to the table, with further listening I'm beginning to change my mind. As I am able to turn up the volume almost with impunity on these tubes (short of destroying my eardrums!), by doing so changes the ball game quite dramatically. The slight 'politeness' I mentioned takes on the full dynamism of the Russian tubes, and adds greater 3- dimensionality plus micro-detail to die for (not that the Russians were lacking in any way at all, lol!). Plus something that really got my head spinning - the male vocal lead in Genesis's 'Behind the Lines' has always been well-placed in the recording (with decent equipment) but had a very slight 'aloofness' to his voice. With the GECs in situ, he suddenly appeared as if surrounded by a protective 'cushion' of sound, from which he would occasionally almost float upwards into the air and then gradually descend once again. I almost thought I was hallucinating! I have NEVER experienced anything like this before in music production (apart that is from the soaring voices of a Church choir, but that's more obviously the ensuing tremendous echo/reflection - this was different), or REproduction...totally amazing, not to say weird (and no, I hadn't been hitting the bottle or smoking something exotic!). So from now on, most of my listening is going to be with these beauties in the hot seat. - Hypnos1 Spoiler: Shuguang 6AS7G On first listen, the 6AS7Gs sounded just like the driver tubes - lean and mean. 50 hours of burn in did nothing. Gave them another 24 hours; nothing changed. These tubes sound like crap. I guess I'll keep them for a spare pair. Not even worth the $20, as for the same money one can have a decent pair of 6080s. - Shaffer Spoiler: 6n13H (Elise Stock tubes) The Russian tubes are decent; I'm listening to them right now with 7N7 drivers. They're slightly less resolving than the Chathams, but it's not a night and day difference. Compared to my Chinese tubes, they sound quite smooth, very extended, good sense of body, admirable dynamics, and a pretty rockin' low-end. I like them, albeit, not as much as the RCA 6080 and the Chatham 6AS7G, but a lot more than, say, Sylvania 6080WC - Shaffer Driver Tubes: Spoiler: Shuguang 6SN7 On first listen, the 6SN7s sounded lean and mean. Talk about sibilance! OMG. One could slice bread with the sound. ~100 hours of burn in, and the highs mellowed considerably, the mids became sweeter and slightly more transparent, and the bass stayed just as lean. I'm going to give them another 100 hours in hopes of the tubes becoming more transparent and the bass being more fleshed out. There's definitely some promise here. - Shaffer 6SN7-GT 6SN7-GTA Spoiler: Sylvania 6SN7GTA Initial impressions after, maybe, 20 hours of listening paint the tube as very smooth on top, yet extended, grainless, detailed mids, and relatively weak bass. Less weight than a 7N7, but without its definition and articulation. - Shaffer 6SN7-GTB 6SN7WGT Spoiler: Foton 6H8C/6N8S '60s NOS. Everything is there, but no magic. Unexciting. The system doesn't beckon one to listen to music. Edit: coupled with early/mid-50s Sylvania 6AS7G (possibly made by RCA), the sound is no longer dull and uninvolving. Dynamics are more fleshed out. There's a sense of life. Male vocals gain more body. It's as if there's an actual full-size human singing, rather than a voice stemming from dead space. - Shaffer Spoiler: PsVane CV181-TII Everytime i put back in the PSVANE CV181-Tii, can't help but notice the deeper tinier details coming thru. This is my favorite tube, no doubt. - Lorspeaker ECC32 ECC33 ECC35 Driver Tubes with adapters: C3g (Commercial adapters not available) 7N7 Spoiler: RCA 7N7 RCA made Delcos. After a bit more than 100 hours of burn in, the tube finally came into its own: it sounds wonderfully clear - and I mean clear - very detailed, no grain, a vivid presentation and bass that deserves its own mention. While the bass lacks the weight of some of the other drivers, it's beautifully articulated. No overhang, just a detailed portrayal of the bass. Nothing missing. It's the non-Rap-loving audiophile's low-end dream. - Shaffer Spoiler: RCA 7N7 I'm totally loving the 7N7s. I don't know whether the amp broke in, or the tubes benefited from an extra 100 hours of burnin, but these things are brutally clear sounding. Every note starts and stops in time - no overhang. They sound fast and highly articulated. The issue I had with bass weight is highly diminished to the point of almost being a non-starter. So far, they're my favorite drivers with the stock 6AS7Gs and the Chathams, followed by Sylvania 6SN7GTA and CBS 6SN7GTB. - Shaffer ECC31 ECC40 E88CC Spoiler: Sylvania 6A6 However, even though the Sylvania 6A6 had only 6 hours of burn-in, last night, I decided to chill out and just listen, and was very pleasantly surprised. This is a very musical tube with holographic imaging and a wide and deep soundstage. The bass isn't up to the ECC31, but in that regard, the ECC31 is in a class of its own. Still, the Sylvania 6A6 is a very nice tube. And given that it was actually designed for use in audio, unlike 6SN7 and 6DJ8, maybe this shouldn't be a surprise. - gibosi This list is in no way complete but we can add to it as we discover more compatible tubes. Along with some impressions of the different types of tubes. If you would like to share your experience with a certain set of tubes on the Elise please feel free to do so, your input will be appreciated!