Feliks-Audio EUFORIA - A Wolf in "Sheep's" Clothing...

[teknorob23]

The problem is that I have 2 hobbies: I am a gamer and I like to listen to music. This means I have a quite powerful gaming rig with a lot of storage space for my digital collection (8TB or so).
This means I need a clean way to bring this collection via USB to the DAC. I do not really want to start with streamers or another PC made for audio, it will complicate too much my life. You see, I always start my PC when I am at home and I have a great monitor to use (2K, 27", 144Hz) so I do not want another unit or a player different than my Foobar2000 from this PC. My plan was to add a JCAT (PCIex USB card) and to keep the ISO Regen when needed, but these iFi devices arrived in my possession by chance. Plan is to test them and sell them...

I completely understand and i think I’ve demonstrated with my own recent bout electric and interconnect upgraditis, that my chosen route is no cure-all either, because although usb based noise is no longer much of an issue, it’s removal had just made me more aware of all the noisy bits in my system. That said the my @hypnos1 inspired/informed diy efforts in electric/ interconnect tidying seem to be working in quite a pleasing way. I had my concerns that everything while darkened was also sounding a bit dulled and muted, but with getting on for 250 hours of run in, it’s all opened up nicely, with particular improvements in separation and micro details. Vocal tracks are cutting through the mix in noisy guitar music like sonic youth and my bloody valentine in away that I’ve never hear before. Ive also been able to hear conclusively that over 50% of cocteau twins lyrics are actually nonsense not just due to Liz fraser’s vocals being lost in guthrie’s Swirling soundscapes.

Thanks to a merry-go-round of recent additions, tq usb cable, diy power leads on every device, Nva balanced mains conditioner, diy neotech silver rca’s (Replacing tq black Ultra 2), its hard to tell what’s really doing what, but im starting to get a bit of baseline of the overall performance which fortunately as a whole is very pleasing. I’m going to give it another week or so of just enjoying the music before I start a process of closer inspection of the individual bits, by a-b’ing. them with their predecessors, because i’d love to know what’s pulling it’s weight and what isnt.

Thank god for this safe place where these activities are allowed to pass with to many questions re ones sanity. Look forward to hearing your results @OctavianH and @Scutey any further reports on the the furmans performance?

 

[OctavianH]

Regarding Furman, we all concluded that it added value and quality to our headphone lines. So everyone should try to add at least the small Furman AC210A-E.

Regarding the USB filters, even if my tests are not 1:1 correct because I used:

1) PC -> QED Reference USB A-B cable -> ISO Regen powered by Sbooster -> USPCB adapter (better than many cables) -> Chord Qutest
2) PC -> QED Reference USB A-B cable -> iFi nano iGalvanic3.0 -> included iFi USB 3.0 cable (looks cheap) powered by the included iPower 9V -> iFi nano iUSB3.0 -> included Chord Qutest USB cable (looks cheap) -> Chord Qutest

So we tested ISO Regen with a linear power supply against iGalvanic + iUSB powered by an included supply which cannot match the Sbooster, more than this at the output of iUSB I used a generic cable.
I can repeat the test replacing this generic cable with Chord Signature Tuner Aray one... but anyway I reached @teknorob23 conclusion that Uptone Iso Regen is superior to iFi iGalvanic + iUSB. Maybe iFi micro iUSB might be better but I do not have it.

In short terms the filters were:

1) ISO Regen = darker, crisper, more precise but somehow condensed
2) iGalvanic + iUSB (both nano) = airier, more dynamic but with less precision (clarity)

Overall, I prefer the ISO Regen + Sbooster. Some claim that the dynamics problem of the ISO Regen is caused by Sbooster and it will work flawlessly with LPS 1.2 power supply... but I prefer to add a JCAT instead of buy another LPS which needs DC input so, basically you need a LPS to power the LPS 1.2 and then the ISO Regen. Crazy, isn't it?

 

[DecentLevi]

Crazy indeed, man. A photo of the exact part of the chain in question would be helpful for those interested to visualize it. I myself have been more than satisfied with my chain of USB cleansers: Schiit Wyrd --> iFi ipurifier 2 --> Singxer SU-1 USB interface / reclocker... with my system. But somehow I have a feeling some of it may be a bit overkill if with DSD files.

 

[hypnos1]

I completely understand and i think I’ve demonstrated with my own recent bout electric and interconnect upgraditis, that my chosen route is no cure-all either, because although usb based noise is no longer much of an issue, it’s removal had just made me more aware of all the noisy bits in my system. That said the my @hypnos1 inspired/informed diy efforts in electric/ interconnect tidying seem to be working in quite a pleasing way. I had my concerns that everything while darkened was also sounding a bit dulled and muted, but with getting on for 250 hours of run in, it’s all opened up nicely, with particular improvements in separation and micro details. Vocal tracks are cutting through the mix in noisy guitar music like sonic youth and my bloody valentine in away that I’ve never hear before. Ive also been able to hear conclusively that over 50% of cocteau twins lyrics are actually nonsense not just due to Liz fraser’s vocals being lost in guthrie’s Swirling soundscapes.

Thanks to a merry-go-round of recent additions, tq usb cable, diy power leads on every device, Nva balanced mains conditioner, diy neotech silver rca’s (Replacing tq black Ultra 2), its hard to tell what’s really doing what, but im starting to get a bit of baseline of the overall performance which fortunately as a whole is very pleasing. I’m going to give it another week or so of just enjoying the music before I start a process of closer inspection of the individual bits, by a-b’ing. them with their predecessors, because i’d love to know what’s pulling it’s weight and what isnt.

Thank god for this safe place where these activities are allowed to pass with to many questions re ones sanity. Look forward to hearing your results @OctavianH and @Scutey any further reports on the the furmans performance?

Hey trob...you do realise that at least partial insanity is the minimum requirement in F-A threads?!!! ...(but full is preferred lol ).

Anyway, even though you are being well and truly sucked down this ol' rabbit hole (Heaven help you!), I think you're discovering that going DIY can not only save you plenty of $$$£££, but also prove extremely satisfying and rewarding, non?! And not a little enlightening, I find...So congrats on your impressive work so far...well done! Keep up the good work.

And as you're finding, changing multiple elements at the same time does make it rather confusing for determining just what is doing what alas! But look forward to the results of any A/Bing you manage to do. And to further confuse matters, combined interactions can also determine final outcome...so how many permutations does that make?...don't count!! ...GOOD LUCK!...

And from the look of things, I'm so glad I ditched USB-based audio systems long ago lol! ...CHEERS...CJ

 

[Johnnysound]

A whole army of eight EL38s...the tubes are nothing short of “world class” as power pentodes: big, bold, powerful, expressive and yet relaxed, unstrained, musical, capable of subtle detail, explosive dynamics and the most powerful and accurate bass that I have heard from any tube amp.

All this as an integrated amp (without Euforia) but -I have to admit- with the help of outstanding Brimars CV4004 preamp and Mullards “cryo” CV4024 drivers, some of the very best you can find, no kidding.

I frankly tought that another quartet of those wild horses in the Euforia would be too much...but I was wrong. As H1 said, in Euforia the EL38s work strapped as triodes, and as so, their sonic character is different than as pentodes....even more linear !. This is confirmed by some old literature that says that this particular EL series was designed from the start as dual purpose (pentode/triode) tubes, with higher linearity as triodes, and I think this is relevant, since the tubes are working at their top spec as triodes...

Also read some comments about the sound being a bit “too much” with certain cans...but as a preamp, driving EL38 powers into my hi def speakers, the quartet in Euforia is just pure tube joy, classic triode sound, unsurpassed by any combo that I know of. I mean, deep detail, insight into the music, unlimited extension, refinement and that touch of “darkness” that belong to the true classics.

The synergy with the power amp (as you can imagine being the same tubes) was exceptional, by far the best that I have experienced with this setup, and there was this sensory quality, a sound that “feels” good beyond merely “sounding” good, being three dimensional to the bone as if with a pure triode, SET amp.

Not “perfect” of course, (because there is no such thing) and I could pick some flaws, but as a tube “aficionado” the whole of it is what matters. I do not care about flaws when either a big orchestra, a small jazz or baroque ensemble, an acoustic guitar solo, a rock group, all sounded stunningly real....

Also liked a lot the combo of EL32/EL38...a bit more controlled in the bass, very neutral for some types of music like electronic lounge or similar, that can go really wild (and still extremely nice) with the full 38 quartet. Still, with the EL32 I felt a loss of ultimate transparency, because the sound of the big triodes makes you forget about control, restrictions and the like, so it is best to let them loose...

 

[DecentLevi]

After almost a year away, I'm finally 'back in the game'. I actually was way underwhelmed with EL38+El11 drivers but this is totally blowing me away - by far the best one-tube-per-socket setup I've heard so far (EL38 + my alltime favorite 6SN7, the rare RCA 6SN7GT smoked grey glass). And I have yet to even try any other combos with the EL38, let alone multi-combos. I just can't stop listening. It's big, proud, authoritative, real and non-fatiguing.

 

[hypnos1]

A whole army of eight EL38s...the tubes are nothing short of “world class” as power pentodes: big, bold, powerful, expressive and yet relaxed, unstrained, musical, capable of subtle detail, explosive dynamics and the most powerful and accurate bass that I have heard from any tube amp.

All this as an integrated amp (without Euforia) but -I have to admit- with the help of outstanding Brimars CV4004 preamp and Mullards “cryo” CV4024 drivers, some of the very best you can find, no kidding.

I frankly tought that another quartet of those wild horses in the Euforia would be too much...but I was wrong. As H1 said, in Euforia the EL38s work strapped as triodes, and as so, their sonic character is different than as pentodes....even more linear !. This is confirmed by some old literature that says that this particular EL series was designed from the start as dual purpose (pentode/triode) tubes, with higher linearity as triodes, and I think this is relevant, since the tubes are working at their top spec as triodes...

Also read some comments about the sound being a bit “too much” with certain cans...but as a preamp, driving EL38 powers into my hi def speakers, the quartet in Euforia is just pure tube joy, classic triode sound, unsurpassed by any combo that I know of. I mean, deep detail, insight into the music, unlimited extension, refinement and that touch of “darkness” that belong to the true classics.

The synergy with the power amp (as you can imagine being the same tubes) was exceptional, by far the best that I have experienced with this setup, and there was this sensory quality, a sound that “feels” good beyond merely “sounding” good, being three dimensional to the bone as if with a pure triode, SET amp.

Not “perfect” of course, (because there is no such thing) and I could pick some flaws, but as a tube “aficionado” the whole of it is what matters. I do not care about flaws when either a big orchestra, a small jazz or baroque ensemble, an acoustic guitar solo, a rock group, all sounded stunningly real....

Also liked a lot the combo of EL32/EL38...a bit more controlled in the bass, very neutral for some types of music like electronic lounge or similar, that can go really wild (and still extremely nice) with the full 38 quartet. Still, with the EL32 I felt a loss of ultimate transparency, because the sound of the big triodes makes you forget about control, restrictions and the like, so it is best to let them loose...

Hi J, good to hear from you again...(thought the gremlins had got to you when your posts kept disappearing lol! ).

And WOW...you certainly do have a nice collection of EL38s there, mon ami! And as far as I'm concerned, silly (cheap) money for a tube I reckon outperforms even the legendary GEC/Osram family of the 6AS7G...(depending on the rest of the system, of course). I can only begin to imagine the sound your entire complement brings to your speakers...powerful hardly covers it, I should imagine ...especially with those 38s running as pentodes in your integrated!!

And yes, 4x 38s in Euforia can indeed be too much for some systems/ears, which is why I prefer @connieflyer 's discovery of the lighter, better balanced partnership with the EL11 as driver. But I must admit that mine are the mesh-plated versions which have a bit more of the EL3N's 'fullness'. Plus, the early large 'balloon', black glass, black plate EL38 (which now commands crazy prices alas!), along with the silver-banded, black plate Philips/Dario versions do seem to have more of the sound you describe using them in pentode mode...ie. the best of both worlds!...(and which would probably explain their meteoric rise in price lol!).

Whatever, this combination now sounds as perfect as one could hope for, especially coming out of the mighty Meze Empyrean headphones...everything in the system obviously now in wonderful synergy (which is the final determining performance factor, of course ).

So all in all, J, I'm glad that you too find the EL38 a very special tube...especially given how many of them now adorn your amps!!

ps. Perhaps it's just as well the early 38 versions are extremely rare and crazy expensive...I reckon 8 of them would blow the roof right off your pad!!! ...CHEERS!...CJ

pps. Another peek at the setup that, in the words of one of the Meze guys, is definitely "a match made in Heaven"...(ie, along with Hugo2 as DAC) :

 

[mordy]

After almost a year away, I'm finally 'back in the game'. I actually was way underwhelmed with EL38+El11 drivers but this is totally blowing me away - by far the best one-tube-per-socket setup I've heard so far (EL38 + my alltime favorite 6SN7, the rare RCA 6SN7GT smoked grey glass). And I have yet to even try any other combos with the EL38, let alone multi-combos. I just can't stop listening. It's big, proud, authoritative, real and non-fatiguing.

Hi DL,
What are all the other bits and pieces around the Euforia?
And my I suggest another low cost addition? A drop of white-out in the little cut-out on the volume knob so that you can see the volume settings easier.......

 

[freesole]

Ugh, really need a Euforia. If anyone is looking to sell theirs, look no further

In other news, this thread is very long and I tried to do a search but, is there an adapter needed to fit the EL38's as the power tubes? I'd be interested in an EL38 and 6SN7 pairing when I get my Euforia but wanted to figure out my next steps.

 

[hypnos1]

Ugh, really need a Euforia. If anyone is looking to sell theirs, look no further

In other news, this thread is very long and I tried to do a search but, is there an adapter needed to fit the EL38's as the power tubes? I'd be interested in an EL38 and 6SN7 pairing when I get my Euforia but wanted to figure out my next steps.

Hi freesole...welcome back.

Yes indeed, adapter needed for the EL38...from MrsX at : https://www.ebay.com/itm/1pc-Gold-p...957233?hash=item2f2697fab1:g:jMQAAOSwi3xb9jks

Good luck with your own Euforia...perhaps there might be the odd one or two around when the 'Anniversary Edition' Euforia finally sees the light of day...not too much longer, hopefully .

And yes, the EL38 as powers will save you a lot of money, compared to anything anywhere near. Plus, they bring out the best in a wide variety of drivers lol ...CHEERS!...CJ

ps. And as you already know, Euforia makes the Empys sing like a canary!!

 

[teknorob23]

DIY Peripherals making my Euforia and its colleagues sound better, big thank you again to @Hypnos for technical and moral support.

I had bit of a marathon session and stayed up way too late last night swapping in and out old for new power cables and followed by 3ish hours A-Bing the TQ and DIY rca's to try and get a bit of more of clue on whats doing what. It quickly became clear the Neotech UP-OCC silver/ Eti Kryo plug interconnect, running between the Hugo2 and Euforia is the star of the DIY show. While not cheap at £100 per metre and 175 for the plugs, it has shown a fairly clean set of heels to the outstanding (£430) Tellurium Q Black Ultra 2 in almost every area of performance, separation is stunning and while it has all the clarity you' might expect or hope for from silver, it also has a beautifully natural tone and texture which i'd normally associate with good copper cables, all of which is bit mind twisting.. in a good way.

The ELEC Audio UP OCC /MS HD Power/ Oyaide mains cables (i've made 4 each at about £75) have about 400 hours on them, so probably not completely burned in yet, but they're have a significant if more subtle effect on proceedings. While not as "look at me" as the interconnects, they're giving a noticeable improvement compared to both the stock and MCRU cables. The darker sound floor and consequent ability to hear more of everything is a real improvement. I was initially concerned everything sounded a bit compressed and undynamic, but 2 weeks its opened up almost completely. The Euforia seems to be particularly benefitting from the change, not that it was noisy before, but its completely silent now and i'm still getting all the EL38/11 loveliness but i'm also hearing all sorts of little details i've not heard before and i'm sure the layering/ separation is has improved too

I still cant really comment on the Nene Valley Audio Balance Mains conditioner, but i will try to run some comparisons at the weekend, so far i'm really pleased and can highly recommend taking the the DIY plunge. The money saving is great, but the satisfaction of making something that sounds as good or better than off the peg equivalents is the really pleasing bit, i just wish i needed to make more, but i've just the got the complicated one, the headphone cable to do and thats going to be it..... for a while

 

[DecentLevi]

Hi DL,
What are all the other bits and pieces around the Euforia?
And my I suggest another low cost addition? A drop of white-out in the little cut-out on the volume knob so that you can see the volume settings easier.......

Cool to hear from you again. The other things you may see around my Euforia were the 3-part USB 'cleanser' (LOL) I was mentioning: Wyrd --> iPurifier2 --> Singxer SU1 --> Modi 2 Multibit DAC via coax cable then to Euforia via silver RCA cable. Off to the side are my 6x multi adapter with its' external transformer, and Koss ESP950 electrostat headphone system with an upgraded Stax SRM1 MK2 e-stat amp which works wonderfully for movies and atmospheric/noise recordings with Euforia as a preamp, and finally to the left is my Little Labs Monotor SS amp which though inferior is more transportable and has it's place for neutral studio monitoring.

All the above are what I've had since early last year. And of course I've got a bunch of tubes and now 6 decent quality EL38's which I've just finished cleaning up fairly well.

All held up by a stealthy new work table I picked up from a local Seattle DIY table maker I found very cheap from Craigslist, and below it is the $2800 TOTL Furman power conditioner feeding everything that I got on sale half off. It seems to still be burning in because though not yet having done an A/B, I also haven't noticed any improvement yet.

Granted there is a newer Singxer all the way to SU-6, newer Modi Multibit and newer iPurifier but how much better sound can one really get by further upgrading a digital stream which is already fed by 3 components. There may still be more potential yet with cable upgrades but for now I think I've got a system that is sure to amaze for quite some time, especially with multi-combos I've yet to try.

 

[hypnos1]

DIY Peripherals making my Euforia and its colleagues sound better, big thank you again to @Hypnos for technical and moral support.

I had bit of a marathon session and stayed up way too late last night swapping in and out old for new power cables and followed by 3ish hours A-Bing the TQ and DIY rca's to try and get a bit of more of clue on whats doing what. It quickly became clear the Neotech UP-OCC silver/ Eti Kryo plug interconnect, running between the Hugo2 and Euforia is the star of the DIY show. While not cheap at £100 per metre and 175 for the plugs, it has shown a fairly clean set of heels to the outstanding (£430) Tellurium Q Black Ultra 2 in almost every area of performance, separation is stunning and while it has all the clarity you' might expect or hope for from silver, it also has a beautifully natural tone and texture which i'd normally associate with good copper cables, all of which is bit mind twisting.. in a good way.

The ELEC Audio UP OCC /MS HD Power/ Oyaide mains cables (i've made 4 each at about £75) have about 400 hours on them, so probably not completely burned in yet, but they're have a significant if more subtle effect on proceedings. While not as "look at me" as the interconnects, they're giving a noticeable improvement compared to both the stock and MCRU cables. The darker sound floor and consequent ability to hear more of everything is a real improvement. I was initially concerned everything sounded a bit compressed and undynamic, but 2 weeks its opened up almost completely. The Euforia seems to be particularly benefitting from the change, not that it was noisy before, but its completely silent now and i'm still getting all the EL38/11 loveliness but i'm also hearing all sorts of little details i've not heard before and i'm sure the layering/ separation is has improved too

I still cant really comment on the Nene Valley Audio Balance Mains conditioner, but i will try to run some comparisons at the weekend, so far i'm really pleased and can highly recommend taking the the DIY plunge. The money saving is great, but the satisfaction of making something that sounds as good or better than off the peg equivalents is the really pleasing bit, i just wish i needed to make more, but i've just the got the complicated one, the headphone cable to do and thats going to be it..... for a while

Hi trob.

Glad to hear you not only succeeded in your DIY projects, but also that you too find one can bask in the satisfaction of outperforming very expensive commercial products, and at a fraction of the cost lol! And yes, this can become even more addictive than most other aspects of this hobby!!

With the headphone cable, there are more difficult decisions to be made alas...for example, does one want a nice 'bendy' cable, or is a stiffer one acceptable? The former is easiest achieved using stranded wire(s)...but stiffer solid is generally regarded as superior, sonically. I personally used 1x length of Neotech AWG 24 and 1x AWG 26 UP-OCC silver, plus 1 of AWG 24 copper per polarity...ie 12 in all!! (Although AWG 26 and 28 silver - plus the copper - would be a good bit cheaper, and probably just as good lol). And I only lightly twist them together, which does make for a rather stiff cable...but using longer wire lengths would enable proper braiding and thus be more flexible (but much more fiddly, of course...not to mention more expensive! ).

So, GOOD LUCK mon ami!! ...(any questions, let me know...)...CJ

 

[Johnnysound]

Hi J, good to hear from you again...(thought the gremlins had got to you when your posts kept disappearing lol! ).

And WOW...you certainly do have a nice collection of EL38s there, mon ami! And as far as I'm concerned, silly (cheap) money for a tube I reckon outperforms even the legendary GEC/Osram family of the 6AS7G...(depending on the rest of the system, of course). I can only begin to imagine the sound your entire complement brings to your speakers...powerful hardly covers it, I should imagine ...especially with those 38s running as pentodes in your integrated!!

And yes, 4x 38s in Euforia can indeed be too much for some systems/ears, which is why I prefer @connieflyer 's discovery of the lighter, better balanced partnership with the EL11 as driver. But I must admit that mine are the mesh-plated versions which have a bit more of the EL3N's 'fullness'. Plus, the early large 'balloon', black glass, black plate EL38 (which now commands crazy prices alas!), along with the silver-banded, black plate Philips/Dario versions do seem to have more of the sound you describe using them in pentode mode...ie. the best of both worlds!...(and which would probably explain their meteoric rise in price lol!).

Whatever, this combination now sounds as perfect as one could hope for, especially coming out of the mighty Meze Empyrean headphones...everything in the system obviously now in wonderful synergy (which is the final determining performance factor, of course ).

So all in all, J, I'm glad that you too find the EL38 a very special tube...especially given how many of them now adorn your amps!!

ps. Perhaps it's just as well the early 38 versions are extremely rare and crazy expensive...I reckon 8 of them would blow the roof right off your pad!!! ...CHEERS!...CJ

pps. Another peek at the setup that, in the words of one of the Meze guys, is definitely "a match made in Heaven"...(ie, along with Hugo2 as DAC) :

Hey H1, the EL38 is indeed a very special tube, and -I have to say- that your “discovery” of this tube for Euforia, for headphone duties, opened (for me) a whole new level of power amplification and top notch pre amplification with Euforia.

So yes, the quartet can be kind of wild and OTT sometimes with cans, but in a pre/power configuration there are other stages, cables, circuits, speakers and a room to deal with, so the extra definition is simply a blessing. The 4 EL 38s (triodes) really stand out in the OTL preamp, with a beautifully musical and commanding performance. The synergy was stunning, exemplary, and I was amazed with the delicacy and musical detail of the tubes in triode mode compared to the powerful personality of the same tubes as pentodes. By the way, they run barely warm in Euforia, and quite hot as powers...

Not to mention the Euforia with 4 x EL38s driving my two NAD mono solid state amps, capable of 450 watt peaks. Fantastic. The word is total, absolute domination of the Euforia sound over the amps (that sounded like tube amps) and its powerful, unrestricted OTL output generated such enormous dynamic swings and awesome bass to the point of being dangerous to my speakers !! I was shure to set the amps at 1/4 power...more than enough. But the danger was part of the fun...rock & roll sounded like a live concert, and any music came clean, clear, smooth, “tube like”. My SS amps never sounded better. In fact, I have tried many quite good preamps, but nothing like this. The OTLs do have a special synergy with SS amps, that’s for sure, and I don’t know why, there must be some technical reasons.

Anyway, the magic of the “full tube” setup is another matter, and at this level of amplification the question is how to optimize the rest of your gear to take full advantage of it...

 

[DecentLevi]

I'm happy to announce impressions of EL38 pairings with top-tier driver / power tubes

EL38 AS POWERS

• EL38 + RCA 6SN7GT (smoked grey glass): vivid, lifelike, robust and detailed
• EL38 + Valvo EL12: superb fidelity but a touch too euphonic
• EL38 + EL11: a fairly 'tubey' / euphonic and clinically detailed sound, yet with super fidelity
• EL38 + EL38 Everything is right, but somehow not surpassing other best combos I've tried so far. Outlandishly microphonic
• EL38 + EL32: A revelation! Excels in every aspect, with that special 'x-factor' of energy and emotion. More detailed and airy than quad of EL38. A somewhat 'intricate' / 'delicate' sound and modestly bright so SUPERB with slightly darker headphones
  

EL38 AS DRIVERS

• Quad 6BL7 + EL38: Superb fidelity with that 'x-factor'. Relism and refinement in spades, good soundstage, separation. Slightly bright and comparable but barely trailing the EL38 + EL32 pairing
• GEC 6AS7G + EL38: Realistic and vivid, velvety, full bodied and pristine, yet somehow something leaving something to be desired in the realm of dynamics / slam (as usual)
• Mullard 6080 + EL38 passive, nothing stands out
• GEC 6080 + EL38: great, linear and refined sound with top notch fidelity, but somehow lacking to the Bendix 6080 pairing
• Benxix 6080 (slotted graphite plates) + EL38: Absolute world-class performer!!! Front row seat to unwavering sonic delight. Airy, vivid, detailed, properly balanced performance, impactful, snappy, authoritative and weighty with perfect tonality, layering and good soundstange. MIND BLOWING, UNRIVALED for single-tube combinations
  
  

While the Bendix 6080 slotted graphite plates are quite an exceptional and unique tube, I've never heard them perform to such great heights until paired with the EL38's. It's a marvelous world class combination and after literally years experimenting is by a great margin the best single-tube per socket combination I've heard to date on either Elise or Euforia. Do note however YMMV depending on one's system and hearing; though as usual I had put the above all through fairly thorough testing (multiple takes with multiple headphones and various test songs and comparisons of the top contenders.)