Tube rolling thread | UltraSonic Studios

[OctavianH]

I have a pair of original Genalex Gold Lion KT77, the one from which they made the reissue, and it is a very warm and forgiving tube, on Elise. Warmer than KT88 or KT66.
From what I have read, it seems EL34 might be the same, but I never had the chance to try those. I will do it on Eternity.

 

[UntilThen]

I have a pair of original Genalex Gold Lion KT77, the one from which they made the reissue, and it is a very warm and forgiving tube, on Elise. Warmer than KT88 or KT66.
From what I have read, it seems EL34 might be the same, but I never had the chance to try those. I will do it on Eternity.

What I am hearing from KT77 is that it sound like in between KT88 and 6L6GC. Those 2 extremes so it is a very good tone. More so towards the 6L6GC but with very good clarity and details. So far my favourite amongst all these 3.

I have a pair of brand new NOS GEC KT66 clear glass and Philips Miniwatt 6CA7 (EL34) double O rings xf2 coming in a weeks time. I am waiting on adapters from mrsxuling to run Cossor 801 and Telefunken EL12 spez in Elekit TU-8200. It's quite an incredible amp so far. Auto biasing.

There's also a brand new NOS pair of GEC KT88 that I'm thinking but it will cost AUD $1100 ... you only live once.

 

[OctavianH]

When you say KT77 is between KT88 and 6L6GC what is the scale you are referring to? Cold -> Warm or?

 

[UntilThen]

KT88 is north of neutral ie a bit bright. 6L6gc is south of neutral i.e a bit warm. KT77 leans more towards 6L6gc but not as warm.

 

[OctavianH]

KT88 is north of neutral ie a bit bright. 6L6gc is south of neutral i.e a bit warm. KT77 leans more towards 6L6gc but not as warm.

And KT66?

 

[UntilThen]

I haven't got my KT66 and EL34 yet. In a week or more. Will be sampling those 2 tubes for the first time. I.e I have not heard KT66 and EL34... well that's not true... I heard the 2 x EL34 in Auris Nirvana 4 weeks ago at my downtown head-fi shop with LCD-4 and Susvara. EL34 is warm and romantic and I love it. Still details abound. Think HD650 scaling well with a good tube amp, that's what EL34 is.

 

[UntilThen]

KT88 is a very nice tube imo. I love the details and force. There's a lot of punch under control in the right amp. However now hearing KT77 for the first time, I'm very impressed. Have you tried Cossor 801 with white ceramic base? Supposed to be a very good tone. Likewise Tung Sol 6550. I will be trying 5881 as well but most of all I want to try my 4 pairs of NOS EL12 spez in a proper amp now.

My seller has so many NOS power tubes. Pity he sold out on all KT66 smoke glass but some actually prefer the cleared KT66 clear glass. I love the smoke glass look. Like a smokey jazz bar kind of exotic.

 

[OctavianH]

Very interesting, thank you. I do not have any pair of 6L6GC but I have a quad of GE 7581A/KT66 which is, as far as I know, a 6L6GC. This fat one:

Never tried Cossor 801 but I have here a pair of GE 6550A and sounds quite nice, a very neutral and detailed tube, almost clinical. It reminds be about Tung Sol 7236, hard to say why. I know that Tung Sol 6550A are warmer than this one. My Eternity will have stock bias KT66 + 6J5, this is why I am very interested to know about it.

 

[UntilThen]

You can't go wrong picking KT66 as stock bias because it's probably the most beautiful tone of them all, according to feedback from the Elekit thread.... except EL12 spez. This guy just love the EL12 spez. He says only the GEC TT21 beats it. I can't run TT21 in tu-8200 without power transformer replacement.

Your quad of GE 7581A/KT66 is what I am after too. It's getting very expensive now. Also GE 6L6gc. Too many tubes to try. You and DL will have a lot of fun but I've already started here.

This beauty .. TT21.

 

[OctavianH]

I know it sounds funny on a tube rolling thread, but my plan is to find out that GEC KT66 + GEC L63 are perfect and just enjoy music. The tube rolling options are there for safety if I change something or want to play from time to time. Of course, this might not happen so I'll be forced to roll.

 

[UntilThen]

I know it sounds funny on a tube rolling thread, but my plan is to find out that GEC KT66 + GEC L63 are perfect and just enjoy music. The tube rolling options are there for safety if I change something or want to play from time to time. Of course, this might not happen so I'll be forced to roll.

Believe me staying with just 6j6 and gec kt66 won't happen. I know because here I told myself that too. Bought a 2nd hand Elekit tu8200 for $800 and I'm going to spend a bomb on tubes because each of these big power tubes are very unique in their tone. It's a big change from 6as7 / 6080. I can't believe that they are still rolling those big tubes in Elise and Euforia. Get a proper amp to run these big tubes and see them go. Just consider ourselves lucky we're not into 2a3 and 300b tubes yet because those are the killers.

What you can do is keep the NOS tubes as an investment and just run with current production tubes. Every public holiday, Christmas and your birthday roll in the NOS tubes to celebrate.

Even the Genalex Gold Lion KT77, KT88 sound very good. I'm just curious how much better will the NOS tubes be. Well I'm about to find out but that means burning in those NOS tubes to at least 100 hours.

 

[OctavianH]

You are right, but the hope dies last.

GE 7581A/KT66 was around 70GBP at Langrex when I bought them. Now I think twice to buy from UK since they put taxes after Brexit.
And regarding reissues, I've sold or given away all my russian reissues except a pair of Tung Sol 7581A. So I'll stick to NOS and for me, the Reissued KT66 was around 70% compared with the NOS counterpart. Of course this is a very subjective evaluation, but even if the price/performance ratio favors the reissues, the NOS are still better.
Now, if it makes sense to buy NOS, well I think this is the principle of diminishing returns or something.

 

[UntilThen]

Of course. Reissues are like wearing a fake Rolex. Well look at it this way. A NOS pair of GEC KT66 at AUD$600 will last you a life time. A NOS pair of GEC KT88 at AUD$1100 will extend your life by 20 years. Another pair of NOS Mullard EL34 xf2 with D getters will set you back at AUD$400 and extends your life..... forget it just enjoy it. Tubes are for using not for hoarding.

The guy who's selling me these NOS tubes must be laughing because he would have gotten them very cheap some 30 years ago.

 

[OctavianH]

And because size matters, I plan to try these on Eternity:

I do not consider these as reissues since, as far as I know, KT120 and KT150 are new models.

 

[UntilThen]

Those KT150 are what I want to run on my Primaluna Dialogue Premium HP before I sold it off. All 8 of them.

Now there's one for sale and I'm thinking really hard.....
https://www.stereo.net.au/forums/topic/337356-primaluna-dialogue-premium-hp-power-amplifier/