[g0ldl10n]

Recently, I got an amazing deal on a huge lot of 6GW6/6DQ6B sweep tubes and put together a couple adapters this morning, and with the bias switch in the negative position the plate current safely stabilizes out at 55mA, and these are easily my favorite for my needs out of the 3 types I have tried.

Also, their shorter stature, especially the RCA made tubes look at a lot more fitting in the Mini.

Must state though, without the bias switch in the negative position the plate current reaches into the mid/high 70s, so wouldn't go this route unless your Mini has this ability.

I also have a pair of Miflex and Jupiter caps on the way - so anxiously awaiting those!

But right now, the Mini is sounding great the way it is!

 

[UntilThen]

Matt, where is the EL12 or a “Psvane KT88-T-II” on the scale from 1 (EL12N) to 10 (EL12 Spec)

EL12 would be a 9 and Psvane KT88 Tii a 8.

EL12 is mite warmer than EL12 spez. I have enjoyed both tubes a lot.

Once you switch to Psvane KT88 Tii, the sound is more transparent and neutral and the tone is incisive and hard hitting.

GEC KT88 is more organic and natural sounding. One of the best power tube I have heard in Ultimate. Imo the holy grail.

 

[UntilThen]

2 other power tubes I would love to get my hands on are:-

Mullard EL38
GEC / Cossor 807

 

[albertmuc]

EL12 would be a 9 and Psvane KT88 Tii a 8.

EL12 is mite warmer than EL12 spez. I have enjoyed both tubes a lot.

Once you switch to Psvane KT88 Tii, the sound is more transparent and neutral and the tone is incisive and hard hitting.

GEC KT88 is more organic and natural sounding. One of the best power tube I have heard in Ultimate. Imo the holy grail.

Thanks Matt, now I can see the whole picture

 

[Deleeh]

Could the ps vane be more manageable in terms of costs and perhaps more worthwhile on balance.
If they come close to an EL12.
Even if it is said that the mid-range slips back a little, I don't think you should have any problems with Mundorf/Milfex.

@g0ldl10n

Looking forward to hearing the Jupiter impressions.

@UntilThen
Here's a post about the 807 in case you didn't know:
http://www.r-type.org/addtext/add029.htm
Explains why yours may have gone up at the time.
Seems RCA did the best here in terms of longevity.
Also note that US Cossors are still available today, so don't be lazy at this point.
Good Cossors cost money and are UK made but there is nothing to say about their longevity and endurance.
On Ebay there is a little something, the most where sold is the Indian.
I've bought from him before and the tubes are ok, funnily enough my 2nd pair of Nec 6sn7s sounded better than his.
I don't know why although they are the same.

@mordy I can think of another tube for you 12AU7 Tungsol Blackglass absolute go if you can find them in the US.
It has a nice sub bass where it delivers, and generally warm, nice midrange and clean highs where smooth and sweet and not annoying.

 

[UntilThen]

@Deleeh until you try 807 you cannot speculate on its tonal quality. @OctavianH has been through the most types of 807. Ask him which he likes best.

 

[mordy]

Could the ps vane be more manageable in terms of costs and perhaps more worthwhile on balance.
If they come close to an EL12.
Even if it is said that the mid-range slips back a little, I don't think you should have any problems with Mundorf/Milfex.

@g0ldl10n

Looking forward to hearing the Jupiter impressions.

@UntilThen
Here's a post about the 807 in case you didn't know:
http://www.r-type.org/addtext/add029.htm
Explains why yours may have gone up at the time.
Seems RCA did the best here in terms of longevity.
Also note that US Cossors are still available today, so don't be lazy at this point.
Good Cossors cost money and are UK made but there is nothing to say about their longevity and endurance.
On Ebay there is a little something, the most where sold is the Indian.
I've bought from him before and the tubes are ok, funnily enough my 2nd pair of Nec 6sn7s sounded better than his.
I don't know why although they are the same.

@mordy I can think of another tube for you 12AU7 Tungsol Blackglass absolute go if you can find them in the US.
It has a nice sub bass where it delivers, and generally warm, nice midrange and clean highs where smooth and sweet and not annoying.

Celebrating a tube birthday today:

This is an RCA 6K6GT/G. Can you read the date code? K1E - let's see what the early RCA codes chart says:
Z - 1936
U - 1937
T - 1938
X - 1939
R - 1940
Y - 1941
S - 1942
K - 1943
H - 1944
V - 1945
F - 1946

1 - JAN-FEB
2 - MAR-APR
3 - MAY-JUN
4 - JUL-AUG
5 - SEP-OCT
6 - NOV-DEC

E stands for OEM

It is the 81th birthday for this tube - Jan-Feb 1943. The price I paid for this tube was he same as the EIA code for RCA - how's that for a coincidence?

The drivers subscribe to the entanglement theory which accurately explains why some tube combinations sound better than others:

"Quantum entanglement is a bizarre, counterintuitive phenomenon that explains how two subatomic particles can be intimately linked to each other even if separated in space.
Despite their separation, a change induced in one will affect the other.
Quantum entanglement is the phenomenon that occurs when a duet of particles are generated, interact, or share spatial proximity in such a way that the quantum state of each particle of the group cannot be described independently of the state of the others, including when the particles are separated by distance."

If the above sounds like Chinese to you, you are right - these tubes are Shuguang 6C8P.

As ugly and crude as these tubes look, that's how good they sound. Available on AliExpress for less than a song.

 

[OctavianH]

@Deleeh until you try 807 you cannot speculate on its tonal quality. @OctavianH has been through the most types of 807. Ask him which he likes best.

It is hard to say which one is the best, all are different enough to make sense try them. However, I will try to make a very short summary of what I remember about them. I have listened in the last months only to my RCA pair. Some photos of different types I have tried are here on the dedicated thread. I think the best start on these is the RCA 807, but only if you have not bought already the RCA 6L6 metal which, honestly, on my amp sounds 90% the same. I have a feeling that RCA 807 is an idea more airy while 6L6 metal base sounds more punchy and articulated in the bass area. So in my view, and on my amp, owning both does not make sense and if you want to get an idea about how RCA 807 sounds you can just read here what people said about the metal 6L6. Mullard 807 is an idea sweeter in the mids while loosing a bit of control in the bass. Bass is an idea more fuzzy, but the mids and overall presentation is sweeter. GEC ATS25 has the typical old GEC sound (GEC ST shaped L63 grey glass is a similar tone). Besides these, I tried some russian 807 which sounded an idea more sterile, less flavour, but not very bad either. More dry. Sylvania 5933 was also nice, if you like a thinner presentation. I guess it is the most neutral of them all. There are also other manufacturers like Westinghouse or Hytron who produced these. I do not have a pair of those, only singles and one day I might pair them and try.

Regarding reliability, I only heard about problems with Westinghouse, on several forums, but of course I might be wrong. There are debates related to quality of newer Westinghouse production, while some claim the older ones are not problematic at all.

 

[albertmuc]

This 6j5 Sylvania sounds silky and warm. The age can unfortunately be seen from the condition of the housing, I don't think it's really bad. The seller only has two pairs left…

 

[triod750]

This 6j5 Sylvania sounds silky and warm, in the photo the tube is just burning in, therefore with EL12N. The age can unfortunately be seen from the condition of the housing, I don't think it's really bad. The seller only has two pairs left…

They are superb for rusty blues voices. I would not be surprised if they are all made by RCA and then rebranded. And your source is a good one to deal with.

He has a lot more outside of that bay. He also has more than you find in his shop Analogkontor. You will have to ask.
https://analogkontor.com/

 

[albertmuc]

„Mod House Audio Tungsten“ on the UltimatE, I'm tempted, but only a little

Are there any fundamental arguments against or in favor of this combination?

 

[mordy]

This 6j5 Sylvania sounds silky and warm, in the photo the tube is just burning in, therefore with EL12N. The age can unfortunately be seen from the condition of the housing, I don't think it's really bad. The seller only has two pairs left…

Don’t worry how the metal tubes look - even the rusty ones work well!

A little black electrical or silicone tape will help to improve the aesthetics...

 

[triod750]

If the above sounds like Chinese to you, you are right - these tubes are Shuguang 6C8P.

As ugly and crude as these tubes look, that's how good they sound.

They make JAN-CG-6Y6G sound cleaner = synergy.

 

[g0ldl10n]

Looking forward to hearing the Jupiter impressions.

I was/am planning on installing the Jupiter caps first, however, it looks like the Miflex caps will be here tomorrow, and the Jupiter caps haven't shipped yet..

Was just writing this up and got an email from Jupiter stating these were shipped too.. and what do you know, both Miflex and Jupiter caps (ordered from different places) are scheduled to be delivered tomorrow - Jupiter going in first! Annnnnnnd, if there is by some miracle enough room in the Mini's chassis, I will likely install both with a switch, but I am thinking there is not enough room - we shall see.

 

[carlosgab]

After following this forum for months and hundreds of kilometers driven, me and my headfi friend have finally tried this amp from the man himself. The experience of this amp with the Utopia was sublime! There was more impact and deeper bass. It was pure amazement! Now we are talking to Eric about getting one for each of us! Thank you Eric, it was so nice of you to let us in!