[Mh996]

To those owning both, how does the performance with KTs as powers compare to the EL39? I’ve gone back to stock since I had a 39 die on me, and I’m debating between waiting for another to show up or going in on some KT88s from Upscale. Where can adapters for these be found?

 

[LoryWiv]

I can't speak to the KT versus EL39 comparison as I've only tried former, but can recommend headfier @Deyan for good KT adapters. Another option is ebay seller xulingmrs.

 

[mordy]

Hi cf...yo, but at the moment I'm more dumbfounded by these GU50s than actually being able to enjoy them lol!! ...(you know the trials and tribulations of assessing new tubes!! ). Hopefully this weekend I'll be able to have some more relaxed, proper listening time, rather than analysing time (which is much more stressful ).

Re. adapters, Mrsx should be able to make them look no worse than others - they would just need external wires for connecting to the heater power supply (and would also need a clear positioning marker for correct tube insertion, as there's no locating lug on its glass base...nothing too difficult IMHO!). And the sort of 12V power supply I posted recently normally has either 5 or 6 amp handling, and with each GU50 only needing 0.7 amp there's plenty of spare capacity lol! If using 4 tubes, I reckon the neatest approach would be to simply take all 4 wire pairs to a common connector towards the back of the tubes' area, fed by a single (pair) from the power supply...easy....
And their strange look does indeed grow on you...but only gradually lol!!...(and yes, better after a glass or 2 of good wine!! ). Actually, it appears the metal top can in fact be removed, which I'm sure would make it look much better. However, softening the adhesive with a hairdryer is one thing, but prising off the rounded edge would be another entirely! Still, at their silly cheap price, it might just be worth a try!!

Ah well mon ami, the web does indeed keep getting more tangled by the day...but at least I'm keeping true to my word and not leading folks into bankruptcy...yet!!

Time for supper, so it's BFN...CJ

Hi h1,
How do you know how to position the GU50 in the sockets if there is no guide pin or markings?

 

[Johnnysound]

*

 

[connieflyer]

Just wanted to drop a note to remind folks here about the fires in Australia, and the concern we have for especially one of our members here UntilThen. I dropped him a PM this morning, to see how he is doing and if he is impacted. Over 23 people have already been killed in the fires, and oveer 1400 homes destroyed. If you get a minute you that know Matt drop him a PM.

 

[hypnos1]

Hi h1,
How do you know how to position the GU50 in the sockets if there is no guide pin or markings?

Hi m...good question. The 'guide' for this GU50 tube is in fact a raised section that runs 2/3rds the way down its side, denoting the cathode position, and which would therefore fit correctly in the corresponding guide in bespoke holders. But going straight into a socket would need this position marked clearly on the socket itself, so as to marry up with said raised section on the tube. This would obviously have to be pointed out to any 3rd party maker of adapters.... :



The raised guide clearly visible above.

The tube's pins are unevenly spaced, so there are in fact only 2 ways it will fit in the socket, which should limit the chance of incorrect insertion.

And as for that rather strange metal top cover, it obviously can in fact be removed and looks much better for it IMHO!! ...as can be seen below :



(Shan't bother with the LED lights from underneath though, even if it does look 'pretty'!! ).

All I need to do now is work out just how to remove the curved metal cap without breaking the tube lol! ...(just as well I've got some more tubes coming...eventually!!!).

ps. Actually, with these GU50s costing just a few bucks each I'm sorely tempted to make up a neat (not 'Frankenstein!) 2x tube array for each power slot, which should be easy enough to slip in a couple of small leds...with McKintosh blue!...(sounds better the more I think of it lol!! ).

pps. And now with these GU50s beating all comers, I must thank you mordy for providing the extra push for me to test the JAC Music guy's assertion that this tube is 'better' than the KT88...was undecided until then...CHEERS!...CJ

 

[connieflyer]

Okay, CJ, you are tempting me more and more with these tubes, I have been resisting hard, but I feel I am starting to weaken. Sounds like you are getting excellent results, so may have to bite the bullet. Now, should you decide to make the above alterations, ESPECIALLY the Mc blue, I am afraid I would again have to follow you done the garden path! After watching the blue meters on the pair of McIntosh 600 watt amps in the demo room, still want to avail myself of the magic. I know that they used to offer a pair of the meters as a stand alone option years ago, should have bought them then and saved my self some money. Were you contemplating four Gu50's power and a pair as drivers?

 

[connieflyer]

Now this one is hitting close to home!

 

[hypnos1]

To those owning both, how does the performance with KTs as powers compare to the EL39? I’ve gone back to stock since I had a 39 die on me, and I’m debating between waiting for another to show up or going in on some KT88s from Upscale. Where can adapters for these be found?

Hi Mh996.

As usual, a certain amount is going to depend on one's system, but I personally found the KT88s to provide that bit more in most areas compared to the EL39...something I never actually thought possible lol ...especially in the bass, mids and soundstage/positioning. Adapters are available either from member Deyan or xulingmrs as previously mentioned. I myself have tried one of Mrsx's adapters and found it worked perfectly : https://www.ebay.com/itm/1pc-Gold-6...155772?hash=item2cf82b69fc:g:20wAAOSwZ15dlpRl And at $27 a pair incl shipping is actually a very good price indeed IMHO!

ps. Just to make things even more difficult for you(!), I probably have a spare EL39 (at a reasonable price)...decisions, decisions lol ...

 

[hypnos1]

Okay, CJ, you are tempting me more and more with these tubes, I have been resisting hard, but I feel I am starting to weaken. Sounds like you are getting excellent results, so may have to bite the bullet. Now, should you decide to make the above alterations, ESPECIALLY the Mc blue, I am afraid I would again have to follow you done the garden path! After watching the blue meters on the pair of McIntosh 600 watt amps in the demo room, still want to avail myself of the magic. I know that they used to offer a pair of the meters as a stand alone option years ago, should have bought them then and saved my self some money. Were you contemplating four Gu50's power and a pair as drivers?

Oh dear, cf...resistance is futile, don't ya know??!! But as my deputy-in-chief new tube tester, you do have a certain responsibilty to our comrades lol!

But seriously, it's always good to have others' views on tubes that I rave about especially...even though each different system is bound to vary somewhat in its delivery.
To be fair to others, it would need 3rd party adapters to be commissioned and tested...Mrsx has always been obliging in this, and so I'm happy to ask her once more if seriously interested.

With regard to trying a quad as powers, this is further down the road as yet...but will keep you updated on the project (and will definitely consider some 'Mc blue' adornment lol!). As for GU50 drivers, I'm really keen to see just how they match up to the GEC TT21s but am still waiting for more tubes!!...(have ordered another 4 - at $3 each!! - this time from Moldova...any ideas on their postal system @OctavianH ?!! )....BFN...CJ

ps. How did you know that just now I was looking at the very amp you showed that uses the GU50?...and a nice one it looks too lol!!

 

[connieflyer]

Could be we think alike!

 

[Mh996]

Hi Mh996.

As usual, a certain amount is going to depend on one's system, but I personally found the KT88s to provide that bit more in most areas compared to the EL39...something I never actually thought possible lol ...especially in the bass, mids and soundstage/positioning. Adapters are available either from member Deyan or xulingmrs as previously mentioned. I myself have tried one of Mrsx's adapters and found it worked perfectly : https://www.ebay.com/itm/1pc-Gold-6...155772?hash=item2cf82b69fc:g:20wAAOSwZ15dlpRl And at $27 a pair incl shipping is actually a very good price indeed IMHO!

ps. Just to make things even more difficult for you(!), I probably have a spare EL39 (at a reasonable price)...decisions, decisions lol ...

Ah, how you guys make upgrading such a challenge with all these options! I almost can’t believe the soundstage could be wider than with the EL39s. It’s nice that this thread is circling around to a lot of tubes that are readily available. I searched for a month before I could find a pair of 39s and I’ve been looking for some EL11s to show up since before my Euforia delivered in July! Have any of those you’re trying to get rid of?

 

[connieflyer]

I have more great combos of tubes then I'll ever be able to use. I have a pair of e l 11 if you're interested. How about $10,000 a tube! Or best offer!

 

[barontan2418]

Ah, so I can't blame you then OH!... But yours is cold comfort re. their not-so-imminent arrival then . Fingers crossed, nonetheless...(and what chance from The Russian Federation I wonder?!! ).



I understand fully LW. And which is why, I'm sure, this amazing tube hasn't been taken on board by more folks...more's the pity lol . But for those used to tinkering, this GU50 is without doubt the bargain of the century...way better than any reissue tube to be sure, and for peanuts! Their appearance is also probably a factor, which no doubt is one reason why the AudioValve amps hide them in enclosures lol!...(but are obviously rated very highly, with the Assistence model at $11,000 and pair of mono blocks at $7,800!!).

I'm certainly getting on board H1 and have a quad winging their way from Russia. Might/will ask you for a step by step on sorting the external power at a later date as this is totally new to me. Hope this is OK.

 

[hypnos1]

I'm certainly getting on board H1 and have a quad winging their way from Russia. Might/will ask you for a step by step on sorting the external power at a later date as this is totally new to me. Hope this is OK.

Hi bt...and congrats on biting the bullet re. this GU50 project. With @connieflyer also interested I'll get under way with contacting Mrsx and giving precise instructions for the adapter. And of course I'll give more details on the 12V power supply...cheap, and a piece of cake...if you can strip a piece of wire and stick it in a connector lol!

And to whet your appetite even further, with well over 100 hrs on both mine as powers, I can now officially say that IMHO :

.......................................

And is something I'm still trying to get head around lol! ...CJ