[OctavianH]

By the way the Valve Museum this guy, Patric Sokoll, put on this website is exceptional value. If on the previous link you can see a lot of EL34 photos to identify different types, he has a lot of info. He has also a page for EF6! So my priorities when going next time in Munchen drastically changed. From Andechs beer pub to ask this guy for a beer. I bet he would be intersted in my plans for the Old European Pentode Tribute amplifier, a subject where my girlfriend does not seem to want to discuss too much. LOL

Here EBC3 with video! But he misses a lot of types. I can help.

 

[OctavianH]

Watching mr. Sokoll measuring on Funke W19 the EBC3 I realize how much better is my simple modern tube tester.



This is the one I have and the guy in France was very helpful. Recommended if you want a simple tube tester. Of course, a more advanced one can be this one.

What I can test on this one very easy is emission, current at a specified operating point and this is all I need to determine what settings of my manual grid bias I need to make to put any tube on the amplifier. Well any = which suits the circuitry (6.3v heaters, can be biases, longer story). Transconductance is not measured directly but can be determined via several measurements. For me it is enough, but I strongly consider to go towards a curve tracer.

 

[ARCXENOS]

Watching mr. Sokoll measuring on Funke W19 the EBC3 I realize how much better is my simple modern tube tester.



This is the one I have and the guy in France was very helpful. Recommended if you want a simple tube tester. And this is the website where I am unsure why they do not have a fully built tube tester but for sure you can ask.

How is that duovac supposed to test the 4pin DHTs, a customized adapter?

 

[OctavianH]

How is that duovac supposed to test the 4pin DHTs, a customized adapter?

I never tested a DHT on it, but since I have only octal sockets on my amplifier I also have adapters towards octal for more "exotic" tube sockets. If I want to test for example 807 I wire the tester for 6V6 and put the tube on the adapter. I always measure or determine grid bias for my 200V/20mA operating point, I do not really care if the tube measures something else at other values. This is why I do not necessarilly trust Ebay sellers measuremets, each amplifier is different and they measure like mr. Sokoll, to some "standard" values from those manuals of their tester, it will not necessarilly match what you will find.

PS. That simple tube tester has only octal and noval sockets. But you can measure directly via adapter like on your amplifier. You put the tube with socket X inside the adapter towards what you can use on your amplifier (which has to be octal or noval, my case 6V6 pinout) and then measure something directly triode strapped (in my case). Not the best way for health or other measurements but for what I need it's ok. Octal and noval socket tubes can be measured directly on the amplifier.

 

[OctavianH]

Time for me to go towards something I already consider classic: 4654/EL50 and EBC3. SFR P17C has not convinced me, the "killer" of the 4654 which is not a sibling, a derived PE06/40P french version is not better for me. Of course, debates can exist and I understand why some prefer that one. In my view it's only a more powerful sounding RT EL39 style of tube, a french made PE06/40P.

I think in the future I will return to EBL21 because I never spent enough time with it. EBL21 on input, maybe try some EBL1 on output (I never done than, has to sound in the same way as EL3N). There are a few things I can do with the tubes I already have and which might bring some news.

 

[OctavianH]

Time for me to choose a very unusual combination: STC 5B/254M with Sylvania 7N7. All loctal tubes, metal base. This is something very different than what I am usually listening to, maybe a good point to explore.

 

[Isaacc7]

Time for me to choose a very unusual combination: STC 5B/254M with Sylvania 7N7. All loctal tubes, metal base. This is something very different than what I am usually listening to, maybe a good point to explore.

7n7 tubes mirror the history of the Sylvania 6sn7. The best sounding ones are the tall bottle with the getter flashing most of the way down the sides. Every American loctal tube was made by Sylvania and all had metal bases as far as I can tell. Well, NU did make some round plate 7n7 early on but those are pretty rare.

 

[OctavianH]

7n7 tubes mirror the history of the Sylvania 6sn7. The best sounding ones are the tall bottle with the getter flashing most of the way down the sides. Every American loctal tube was made by Sylvania and all had metal bases as far as I can tell. Well, NU did make some round plate 7n7 early on but those are pretty rare.

Well, this is the only one I have and I do not especially like it, so I doubt I'll try more of them. But I do not like a lot of famous tubes, for example now I switched to RCA 5691 and it's honestly, terrible. LOL

 

[g0ldl10n]

Well, this is the only one I have and I do not especially like it, so I doubt I'll try more of them. But I do not like a lot of famous tubes, for example now I switched to RCA 5691 and it's honestly, terrible. LOL

Actually, the 7N7 you are running there is not the one @Isaacc7 is referring to. Something like this - these internals appear to be the exact internals of the famous metal base 6SN7W, but this is the 14N7, the 7N7s I have like this are exactly the same internally but with no copper rod.

 

[Isaacc7]

Well, this is the only one I have and I do not especially like it, so I doubt I'll try more of them. But I do not like a lot of famous tubes, for example now I switched to RCA 5691 and it's honestly, terrible. LOL

You’ve mentioned before that 6sn7 doesn’t work very well in your amp. The 7f7 is the same as a 6sl7 and might be more to your liking.

 

[Isaacc7]

Actually, the 7N7 you are running there is not the one @Isaacc7 is referring to. Something like this - these internals appear to be the exact internals of the famous metal base 6SN7W, but this is the 14N7, the 7N7s I have like this are exactly the same internally but with no copper rod.

I have one tall bottle 7n7 with a support rod though not copper. I think both my tall and short bottle 14n7 sounds better. Maybe it’s my particular 7n7 that’s at fault but I doubt it since it’s one of my favorite 7n7. I’ve pretty much standardized on the 14n7 as one of my go to *sn7 tubes. Tomas said that my amp was designed around 6sl7 but I could use 6sn7 if I wanted to. Have always preferred 6sn7.

 

[g0ldl10n]

I have one tall bottle 7n7 with a support rod though not copper. I think both my tall and short bottle 14n7 sounds better. Maybe it’s my particular 7n7 that’s at fault but I doubt it since it’s one of my favorite 7n7. I’ve pretty much standardized on the 14n7 as one of my go to *sn7 tubes. Tomas said that my amp was designed around 6sl7 but I could use 6sn7 if I wanted to. Have always preferred 6sn7.

This is very interesting.. I too have found the 14N7 to sound better, like noticeably so actually.

 

[OctavianH]

You’ve mentioned before that 6sn7 doesn’t work very well in your amp. The 7f7 is the same as a 6sl7 and might be more to your liking.

I doubt it is necessarily a limitation of my current amp because I had the same problem with them on the previous one, guess what, built for 6SN7. I never really liked 6SN7 and the same happened later when I started, like everyone, to listen to 6J5. I preferred 6J5 over 6SN7 but they never remained too much on the amp. 6N7 and 6SL7 are for me much better than any 6SN7. 7F7 is hard to find in Europe, and all the loctals made in the US in general. Of course, having very low expectation my willing to spend is also minimal. And I doubt the 14N7 or the tall bottle 7N7 will surpass my usual suspects I always roll here, so I'll go that path only if I'll find one by mistake in my boxes.

 

[OctavianH]

I found a good synergy between the STC 5B/254M and the Mullard ECC35. It is a tubey combo, an idea fuzzy, but sounds good and relaxing. I would prefer more focus and separation but this goes well with records which need a more forgiving sound.

 

[OctavianH]

Putting Philips EBC3 on input near STC 5B/254M made me put directly the ECC35 and 5691 in the storage. Next step is to put also the ECC33, one my old favourites. Life is too short to listen to them and I'll try them on the next amplifier. This is the value of red series and in my view, the triode inside EBC3 is one of the best tubes I ever listened in my life. Next stop and last in the red series will be EF6. Then we go towards loctals and other stuff I'll find in my boxes.