[ThanatosVI]

I can't speak to the pentodes, but I have a couple pairs of KR 300BXLS's (high current 300B). Love them. The first pair has been in my amp for close to 20 years and probably pushing 10k hours. I bought the 2nd pair only for backup, but haven't needed to use them yet. I pop them in every few months just to see if I can detect any decline in the older ones, and so far nothing audible. Very thick glass and built like the proverbial tank. I have few options for rolling the output tubes in this amp -- a high current 300B is required and (to my knowledge) only KR and EML make them. I had a pair of EML's for a bit and liked them, but much preferred the KR's so I sold them off (and got the backup pair of KR's). Seriously not cheap tubes at ~$1k/pair, but if I amortize that over 20 years it's not that bad.

Can you describe what you preferred on the KRs compared to the EML?

I have heard in a few places that the KR tubes have harder vacuum and can last a very long time. I'm hoping that's true because when I get past my current living situation challenge I was planning to buy a pair of KR KT150 as a little pat on the back gift to myself. Given how much more expensive they are than the Tung-Sol they are based on I'm hoping they are worth it.

I plan on getting them as well at some point this year, the price tag is hard to swallow tho.
Please report back if you do

 

[ThanatosVI]

Update to my last post about the "premium" manufacturers of current production tubes.

Seems Like northern electric tubes are just a rebrand of Fullmusic tubes, all produced in the same factory in China. The Reviews of those are just as good tho.
They do look very similar indeed.
I also read that sophia electric is the same, however their glass shape looks certainly different, not sure about internals.

I also read that E.A.T KT88 are the same as KR KT88. Both produced in the same factory in czech republic, but I also don't know if that is true. Apparently reissued Tesla tubes made with old Tesla equipment.

From Sophia Electric support I received Venusodio.de as german dealer.
Prices are what you'd expect when importing + tax.

 

[mordy]

Update to my last post about the "premium" manufacturers of current production tubes.

Seems Like northern electric tubes are just a rebrand of Fullmusic tubes, all produced in the same factory in China. The Reviews of those are just as good tho.
They do look very similar indeed.
I also read that sophia electric is the same, however their glass shape looks certainly different, not sure about internals.

I also read that E.A.T KT88 are the same as KR KT88. Both produced in the same factory in czech republic, but I also don't know if that is true. Apparently reissued Tesla tubes made with old Tesla equipment.

From Sophia Electric support I received Venusodio.de as german dealer.
Prices are what you'd expect when importing + tax.

The Chinese tube manufacturers have embarked on a marketing path where they present the same tube designation under different versions, different shapes,fancier print and fancier packaging, and different brand names, with the concomitant different and higher prices.
Personally, I suspect that the tubes are the same. In the olden days you had regular and long life versions (not necessarily that the long life versions sounded better) and some tubes picked out for better tolerances (usually military versions), but that was it. And of course rebranding and crossbranding.
Now you can buy a Chinese 6SN7 variant in plain vanilla, in fancy packaging at various price points, UK flavour, ST or globe shape etc etc.
It does not make sense to me that the same company would produce so many different versions of the same tube, but maybe I am wrong…
Did anybody compare the sound of a bulk market tube to the same tube in the top-of-the line box?

 

[Xcalibur255]

TJ Full Music produces some nice tubes, but most are no longer in production after their founder passed away last year. In the past Sophia tubes were made by TJ, some were unique designs made specially for Sophia in fact, but this is no longer true of some of their more recent products. I'm not sure who is making their EL34ST and KT88ST tubes for example. I have a suspicion it might be JJ which would mean the markup is pretty wild, but they may be made unique for Sophia to a different design or standard too.

I bought a pair of the Sophia EL34ST and kind of felt foolish for it given how expensive they are. I do think they sound nice though, in fact very nice, but I don't have much experience with EL34 tubes yet so I'm not able to draw comparisons and judge whether the tubes are really a decent value for the performance offered or not.

 

[bcowen]

Can you describe what you preferred on the KRs compared to the EML?

I plan on getting them as well at some point this year, the price tag is hard to swallow tho.
Please report back if you do

In the Jota amp, the KR's have better bass extension, punch and drive, more low-level harmonic detail in the mids, and better macrodynamics. The EML's sounded kind of restrained and a bit boring in direct comparison. This is not to say the EML's were bad, just that in this particular amp they were eclipsed enough by the KR's that I had no desire to keep them.

 

[Isaacc7]

Got the e3375 tubes in today. It's nice to cross another marque off the list, especially one that I never thought I'd be able to afford. I know it's silly but having the boxes and that little sticker makes me happy.

My amplifier (Dennis Had Inspire KT88 Firebottle) is a single ended pentode and it's for speakers only. I know I know, but these forums are a great resource for tube impressions. Anyway, these sound amazing, even brand new they sound really well balanced, solid. The bass is really well defined and the midrange is spot on. I will say this though, the regular Mullard el38 tubes aren't all that different. The el38 tends to emphasize the treble in my amp/speaker combo but I can counteract that with some darker sounding tubes in my preamp and input tube on the amp. I was blown away with the e3375 with 12sx7 in the preamp and a 6bx7 input tube in the amp. For the el38 I switched to RCA 12sn7GTA tubes in the preamp and the top end came back close to the e3375.

The e3375 has the same plate structure as their kt77 but I have no idea of it sounds similar. I will say that the sound they make is exactly what I expect from a legendary tube

 

[OctavianH]

The e3375 has the same plate structure as their kt77 but I have no idea of it sounds similar. I will say that the sound they make is exactly what I expect from a legendary tube

I have a feeling these are similar or close. I will be able to make a direct comparison with GEC KT77 in the following weeks and I will provide feedback. I have also Mullard EL38 so I know how those sound.

 

[Isaacc7]

For all the 807 fans out there, don't neglect the 6bg6! They are generally considered the same as the 807 but with a different pin out. Most people think older tubes sound better but there are some possible exceptions. For example, this set of Philips 6bg6GA has the guts of the Sylvania grey plate 6l6gc! It's another example of tube manufacturers scrambling to fulfill contracts with existing lines instead of recreating old tubes. A 6l6gc can certainly handle anything that the original 6bg6 was designed fr, the opposite can't be said!

I will try these in a few days. I just got back from vacation and am really enjoying the Sylvania 6sl7 and JAN 7c5 combo. I need to bask in stereo goodness for a while, don't want to have to sit through burn in now! I also have a pair of GE 6bg6 with big plates. They look like the GE 6l6gb. A pair of Westinghouse 6bg6 are proving to be more difficult to ID. They are noticeably wimpier looking though. I'm a sucker for the 6l6 family soI will try them all in good time!

 

[OctavianH]

While playing recently with 807 I made some pictures of different brands I own. I think it is ok to share them to you here.

1. Russian G-807 (Uljanovsk factory) rebranded as RSD.

2. RCA 807

3. Sylvania 5933

4. Mullard 807 (Blackburn) rebranded as Philips QE06/50

5. GEC ATS25

In the end some group photo:

All sound different enough to recognize, all share the sound signature of their manufacturers.
I hope you'll enjoy them. If anyone has more or knows more about these, I am all ears.

 

[leftside]

While playing recently with 807 I made some pictures of different brands I own. I think it is ok to share them to you here.

1. Russian G-807 (Uljanovsk factory) rebranded as RSD.



2. RCA 807



3. Sylvania 5933



4. Mullard 807 (Blackburn) rebranded as Philips QE06/50



5. GEC ATS25



In the end some group photo:



All sound different enough to recognize, all share the sound signature of their manufacturers.
I hope you'll enjoy them. If anyone has more or knows more about these, I am all ears.

Great to see all these different tubes.

 

[OctavianH]

Great to see all these different tubes.

Yes, 807 was made by a lot of manufacturers. And I'll add also a nice picture of the GEC ATS25 glow.

 

[ThanatosVI]

Guys can you please go to https://www.westernelectric.com/expand and fill out their survey, stating that you have interest in Western Electric KT88 tubes in the future.

Especially with the current russia Situation we need every western KT88 we can get and Western Electric has the Reputation to maybe give US the best there is!

 

[UntilThen]

I didn’t know Western Electric make KT88. You want GEC KT88.

 

[ThanatosVI]

I didn’t know Western Electric make KT88. You want GEC KT88.

Well they don't make them yet, but they are planning to expand their lineup and ask around what the customers want. (See link)
I certainly want them to make KT88 in the future and hope many of you tell them the same!

 

[bcowen]

Guys can you please go to https://www.westernelectric.com/expand and fill out their survey, stating that you have interest in Western Electric KT88 tubes in the future.

Especially with the current russia Situation we need every western KT88 we can get and Western Electric has the Reputation to maybe give US the best there is!

Done.