[LoryWiv]

Feliks Audio Euforia SE won best amplifier of 2019..............https://www.headfonia.com/hfn-2019-awards/2/

Congrats to FA. I have been very happy with the quality and versatility of my Elise!

 

[LoryWiv]

Hi @connieflyer. I also am enjoying GL KT88 very much as powers in Elise. Still evaluating 3 driver options:

1. TS 7581A: Very good overall, nice warmth w/o being excessive or "gooey", stage is wide, at times I note a bit less treble extension than I'd like but this in turn make them very non-fatiguing for long listening sessions.
2. GL KT77: Just arrived, I need more time to evaluate. Key initial impression is that midrange is exceptional, vocals really shine, treble about right, perhaps a bit bass-light. Stage is not quite as wide as TS 7581A but a bit more so than the Sylvanias below.
3. Sylvania 6NS7WGT brown (micanol) base: Bought on Ebay, seller thinks they are 1950's vintage NOS, at first listen they are completely noise free and really quite a treat. Treble is the standout, very well-extended but SWEET and non-sibilant, really quite euphonic and delightful. Mids and bass are no slouch, and integrate well into a musically coherent presentation. The bass seemed light at first but now about 10 hours in Elise it is picking up. Stage is definitely not as wide as nor instrument separation as clean as TS 7581A but perhaps that's adding to the coherence and a certain intimacy.

Bottom line, each of these driver pairs brings something positive to the table with GL KT88 powers. I'm enjoying the Sylvanias too much to roll them out right now, but ihe GL KT88's have proved to be a solid foundation as powers for each option. It's wonderful to have such an abundance of good choices with our amps!

Brief Update:
Have spent more time with the GL KT77 driving GL KT88, which I note above @connieflyer is favoring with Euforia. I think he is on to something great, as the mids remain exceptional but stage, instrument separation, air and extension at both bottom and top end are improving (tube / brain burrn-in or both?). Overall musicality exceeds that of the Sylvania 6SN7WGT drivers, probably led by those euphonic mids, and while the top end sparkle is still a bit behind the Sylvie's high's are clean and present, bass hits hard with percussive impact when called for but never intrusive nor bleeding into mids.

I'm still interested in what a quad of KT88's (@barontan2418 describes great results using this quad with Elise) or a quad of KT77's might bring, but certainly Elise is performing like a champ with the GL KT77 --> KT88 combination and I think i'll stick with it a while and enjoy the music!

 

[hypnos1]

..........................................................................GU50 tube, and...????!!!..............................................................

Hi guys. Had thought my 'Midnight Missives' were at an end...need my sleep these days lol!

However, my GU50s arriving early from Ukraine have been screaming at me, so spent today doing the necessary (very fiddly!!) and one as power has been running for about 4 hours, with a half hour cooling period.

Well, I couldn't get to bed before letting you know that not only have our amps pulled off yet another major miracle, but already I'm not believing my ears...no pops/hum/crackle/hiss/pings/thuds. In fact no distortion whatsoever, even with volume at ear-shattering levels....and once again, deathly black silence (where it should be lol!).

Already it's doing a wonderful job as power to a GEC TT21 driver...and given this is extremely early days for a NOS Russian military tube, it bodes very well indeed. Next will be 2 as powers, which will be a much tougher test of course, without the TT21 power as support! And already I'm eager for the other 2 to arrive and see what they can do as drivers.

And at £7 the pair (but £9 shipping), this sort of early performance is simply bordering on the criminal lol!! ...count me totally gobsmacked...for the moment, at least......

Anyway, time for zzzzzzz, so BFN guys...and hold off spending big bucks on tubes for now - if you're interested in going this route that is! ...CJ

 

[DecentLevi]

Hi Colin, sounds like the GU50 may be a sleeping beauty, and at least they don't need an external power supply. Just curious if you have any idea on a source for adapters with their unusual pin design? The task certainly doesn't seem like too much for @Deyan I would think anyway.

Also a bit of an off the wall question. Have you recently tried going back to stock tubes? I get the impression that every combo you've been trying for a good while has been sounding fantastic, if even each subsequently better than the last. It makes me wonder if perhaps something with your custom upgrades / component burn-in / chain, etc. has taken your rig itself to a whole new level, and if so maybe your amp will even allow stock tubes to shine in their best light as well.

 

[teknorob23]

Thanks, it is really great to read tube rolling threads as an efficient way to save money

I can't order from outside the EU but aren't the Gold Lions made in Europe maybe even Czech Republic? I should be able to find a source...

hotrox in uk £79 per pair of kt77

 

[connieflyer]

Dl I went back to stock tubes three weeks ago, did not mention it as I felt it to be a non event. It sounded okay, but the difference between them and totl tubes was very apparent and not worth putting back in again

 

[hypnos1]

6080'S always ran the hottest on my amp. The 5998's ran it warm but not hot. Now running the Gold Lion KT77 as drivers and Gold Lion KT88's in power position and am extremely pleased with the results. I started with the quad of KT 88's and went to 7581A's as drivers, which had a great sound as well. Now running the KT77's as drivers, so far this is the best I have heard from my amp. Quad of KT66's were also quite good. Using them as Pre amp out really warms up the Anthem amp. Also uses less volume than the 7581A's. Not quite as bright. Bass is a little stronger also.

Hi cf. So, another thumbs up for the KT77...just what can our amps not do lol?!! The choice now is almost mind boggling...and getting harder by the day (especially now the GU50 is also looking yet another giant killer ...more in a minute...).

 

[hypnos1]

Hi Colin, sounds like the GU50 may be a sleeping beauty, and at least they don't need an external power supply. Just curious if you have any idea on a source for adapters with their unusual pin design? The task certainly doesn't seem like too much for @Deyan I would think anyway.

Also a bit of an off the wall question. Have you recently tried going back to stock tubes? I get the impression that every combo you've been trying for a good while has been sounding fantastic, if even each subsequently better than the last. It makes me wonder if perhaps something with your custom upgrades / component burn-in / chain, etc. has taken your rig itself to a whole new level, and if so maybe your amp will even allow stock tubes to shine in their best light as well.

Well DL, don't know about the GU50 being a sleeping beauty...this must be one of the least attractive/impressive looking tubes out there lol!! But what it may lack in looks it sure makes up for in sound! It's still much too early to get a proper handle on it yet, and won't show its true colours until the second one is in as power and had much more burn in of course...Russian military tubes are notorious for needing looong burn in, and that's even when running smaller tubes and much hotter (this GU50 has the case running even cooler than the KTs lol!). However, my single one as power is already showing immense promise .

But as previously mentioned, this tube does need an external power supply for the heater - viz being 12.6V, and as also mentioned recently my 12V laptop charger/power supply is doing the job absolutely perfectly...just as good as the amp itself for stock, and this time I don't even need to connect its negative lead to mains Earth...no hum/distortion whatsoever (with my UK 3-pin mains supply). And with plenty of Chinese sockets available, I'm sure Mrsx will have no problem at all making an adapter for us...nor Deyan, I should imagine. If anyone is interested trying this tube, I shall give her the required pin configuration, with instructions for external heater wires for easy connection...

However, as is always the case with new tubes I suggest folks wait until I complete full and proper trials so as to make sure this tube shows no incompatibility problems with extended use. So far, my Euforia is showing no signs of objection whatsoever...amazingly so in fact lol!!

Re. going back to stock tubes...at each system upgrade that coincides with new tubes, I had always referred back to stock to validate the new tube's findings. But eventually I got fed up with 'backtracking' in performance quality and so lately don't even bother any more. At each stage...and since...stock has always not matched the new tubes' performance...in my system...although the various upgrades did actually improve stock performance (to quite a degree after the mains conditioning/filtering; cables using UP-OCC silver and copper wire, and DAC change...not to mention the Naim server/player!!).

BFN...CJ

 

[Johnnysound]

Well DL, don't know about the GU50 being a sleeping beauty...this must be one of the least attractive/impressive looking tubes out there lol!! But what it may lack in looks it sure makes up for in sound! It's still much too early to get a proper handle on it yet, and won't show its true colours until the second one is in as power and had much more burn in of course...Russian military tubes are notorious for needing looong burn in, and that's even when running smaller tubes and much hotter (this GU50 has the case running even cooler than the KTs lol!). However, my single one as power is already showing immense promise .

But as previously mentioned, this tube does need an external power supply for the heater - viz being 12.6V, and as also mentioned recently my 12V laptop charger/power supply is doing the job absolutely perfectly...just as good as the amp itself for stock, and this time I don't even need to connect its negative lead to mains Earth...no hum/distortion whatsoever (with my UK 3-pin mains supply). And with plenty of Chinese sockets available, I'm sure Mrsx will have no problem at all making an adapter for us...nor Deyan, I should imagine. If anyone is interested trying this tube, I shall give her the required pin configuration, with instructions for external heater wires for easy connection...

However, as is always the case with new tubes I suggest folks wait until I complete full and proper trials so as to make sure this tube shows no incompatibility problems with extended use. So far, my Euforia is showing no signs of objection whatsoever...amazingly so in fact lol!!

Re. going back to stock tubes...at each system upgrade that coincides with new tubes, I had always referred back to stock to validate the new tube's findings. But eventually I got fed up with 'backtracking' in performance quality and so lately don't even bother any more. At each stage...and since...stock has always not matched the new tubes' performance...in my system...although the various upgrades did actually improve stock performance (to quite a degree after the mains conditioning/filtering; cables using UP-OCC silver and copper wire, and DAC change...not to mention the Naim server/player!!).

BFN...CJ

Just look at these little chinese beauties (8 watt) at just $ 190 plus shipping... The whole amp costs less than a single (used) GEC tube !!
And a most interesting comment from the manufacturer:

“FU50/GU50 is a pentode tube with 40W plate dissipation, It is designed for communication application but sound great if connected as triode,It also called as "little 300B" in China. The amplifier can deliver up to 8 Watts stereo output on 8 Ohms load.The sound is very smooth and musical, Great control and very flexible/punch bass, Sparkle treble even better than some more expensive tubes”

 

[Johnnysound]

I am mightily impressed (to say the least) with the sound of the Shuguang WEKT88 Plus quad on my power amp. After only about 20 hours or so of burn-in I ceased trying to find flaws, and simply enjoyed the sound...a lot. To begin with, the bass -while very deep- is also the tightest, fastest and most dynamic, entertaining bass I have ever heard from a power tube, new or old stock...and I have tried many. Mids & highs are ultra extended, very high def (but not clinical) and this is not a “warm” tube: the music sounds wide open, spacious, clear, exquisitely detailed, almost frighteningly real.

Tried it briefly in Euforia, and have absolutely no doubts that this quad will probably break grounds here as a preamp also, but once installed into my power amp, there is no way I will take them out from there. So good that I got hooked, listening to all my favorites for hours...

In fact, had to look for configurations in Euforia for the best synergy...with some unexpected results. With such an extended amp you are not looking in the preamp for bass or the like, but linearity, accuracy...and best results were obtained with (for example) 4xEL11, or 4xKT77. Curiously, the “symmetrical” quads worked the best...harmony between tubes ?

And of course, I wondered how a chinese tube could be so damm good. “WE” stands for “Western Electric”, but this is NOT a reproduction because WE never made a KT88/6550 ! This one is some sort of interpretation on how a “classic” WE KT88 might have been if ever produced...more in the line of the premium Shuguang 300B, 411 or 2A3 “big bottles” than “standard” KT88s. As so, this is a new design, and it sounds, well, modern, fast, accurate while showing a “classic” flair... A great tube !!

 

[hypnos1]

Just look at these little chinese beauties (8 watt) at just $ 190 plus shipping... The whole amp costs less than a single (used) GEC tube !!
And a most interesting comment from the manufacturer:

“FU50/GU50 is a pentode tube with 40W plate dissipation, It is designed for communication application but sound great if connected as triode,It also called as "little 300B" in China. The amplifier can deliver up to 8 Watts stereo output on 8 Ohms load.The sound is very smooth and musical, Great control and very flexible/punch bass, Sparkle treble even better than some more expensive tubes”

Hi J...yeah, how on earth do they do it for such peanuts lol?! Well, reliability is often the problem of course...plenty of tales of incorrect/fake components; mistakes in circuitry; low quality transformers etc. etc. But some of the makers do seem to be getting better reputations these days...higher up the cost scale of course!!

Anyway, they certainly do seem to like their own FU50, and the Russian NOS GU50 is supposed to be much better. Well, all I can say is that with another 10 hrs overnight burning (and still no untoward issues!), it just might be possible the guy at JAC Music was in fact right in putting this tube right up there with the KT88...but "better"?...time will tell. What I can say however is that at £7 the pair(!!), this tube represents unparalleled value if prepared to handle the 12.6V heater supply (dead easy! ). And if it does indeed keep improving further still could possibly beat all comers lol .

And an interim pic of one sleeping not-so-beauty wink...can't wait to hear with a second in the power seat...

Or, rather, would send..if the darned thing would upload lol!!!...(head-fi problem? Or Firefox? Or Kaspersky? Or...??)...

ps. But what excites me most is AudioValves choosing the GU50 for their new $11,000 Assistent amp...without even the option for a KT88 or similar lol!

 

[hypnos1]

I am mightily impressed (to say the least) with the sound of the Shuguang WEKT88 Plus quad on my power amp. After only about 20 hours or so of burn-in I ceased trying to find flaws, and simply enjoyed the sound...a lot. To begin with, the bass -while very deep- is also the tightest, tautest, fastest and most dynamic, entertaining bass I have ever heard from a power tube, new or old stock...and I have tried many. Mids & highs are ultra extended, very high def (but not clinical) and this is not a “warm” tube: the music sounds wide open, spacious, clear, exquisitely detailed, almost frighteningly real.

Tried it briefly in Euforia, and have absolutely no doubts that this quad will probably break grounds here as a preamp also, but once installed into my power amp, there is no way I will take them out from there. So good that I got hooked, listening to all my favorites for hours, under a new and most enjoyable sonic “light”...

In fact, had to look for configurations in Euforia for the best synergy...with some unexpected results. With such an extended amp you are not looking in the preamp for bass or the like, but linearity, accuracy...and best results were obtained with (for example) 4xEL11, or 4xKT77. Curiously, the “symmetrical” quads worked the best...harmony between tubes ?

And of course, I wondered how a chinese tube could be so damm good. “WE” stands for “Western Electric”, but this is NOT a reproduction because WE never made a KT88/6550 ! This one is some sort of interpretation on how a “classic” WE KT88 might have been if ever produced...more in the line of the premium Shuguang 300B, 411 or 2A3 “big bottles” than “standard” KT88s. As so, this is a truly new design, and it sounds, well, modern, fast, accurate while showing a “classic” flair... A great tube !!

Sounds good J. Would love to pit them against my GEC TT21s...and now the GU50, but at about £230 the pair by the time the robbers have finished here I'm afraid I'll have to pass on that one . Glad that you're loving them though...WELL DONE!...CHEERS!...CJ

 

[connieflyer]

Under $200 is pretty cheap, but what if you want a little more power, say, 100 watts per channel? You might want to try the $48000.00 KR Audio Kronzilla with their handmade triode tubes, the most powerful triode tubes out there!!!! Nice pair of mono blocks.

 

[gimmeheadroom]

Let me see if I have the money in my pocket

Made in Czech Republic, btw!

 

[Scutey]

Crackling value, think I'll have two!.