[triod750]

Yes, it was a common getter type. I don't know a 'correct' name for it either. But pill getter makes one think, or pill foil getter...

 

[TLO]

I have seen many people calling it dimple pan.

 

[OctavianH]

I also measured today some EL38. I said I'll give them another chance.

Anyway, this tube looks brutal, I almost forgot how it was looking.

These are double ring getters, I had in the past double D-getters and also those grey glass french ones. Sold them. These I will not sell, they deserve their place among others, even if I was never into these. Who knows, preferences might change, today I know more about pairing and about Eternity.

 

[OctavianH]

View from the top of the world.

 

[OctavianH]

Time to try something new. They say electric guitars sound spectacular, no problem, I am here to confirm this. HEDDphone TWO incoming. I wanted to buy 2nd hand but nobody sells these. A good sign, I am sure they will be interesting. ZMF and Meze are everywhere in Classifieds, HEDD, well... Germans are good for weissbier, let's hope also for headphones.

 

[Isaacc7]

Time to try something new. They say electric guitars sound spectacular, no problem, I am here to confirm this. HEDDphone TWO incoming. I wanted to buy 2nd hand but nobody sells these. A good sign, I am sure they will be interesting. ZMF and Meze are everywhere in Classifieds, HEDD, well... Germans are good for weissbier, let's hope also for headphones.

The website says preorder. Is the reason you couldn’t find any second hand is because they aren’t out yet? Hope they sound amazing. I didn’t see any tech specs as far as how difficult they are to drive etc.

 

[OctavianH]

Is the reason you couldn’t find any second hand is because they aren’t out yet?

They are out, they sell in batches and now they prepare batch 4. They are not second hand because not many resell them. I'll know more when I will try these, I stopped believing in reviews a long time ago. But these guys seem to make interesting equipment. If not, we have Classifieds. There are a few words on youtube or several websites but well, I prefer to hear them.

Some tech specs:

 

[OctavianH]

January, freezing cold outside. What does the tube roller? I tell you, tries to understand what Master Isaac tells him for a few monts. I've started analyzing loctals. LOL

First conclusion is simple: I definitely need a 4K monitor. I cannot see anything on my 2K one and I scroll 90% of the time. Monitor rolling? Cool!

Some people smoke to see things, I've put a few hundreds of pinouts on a table and saw more than them. What I saw is that there is a lot of potential and uniformity in P8A and loctal sockets. If you build an amp for these, well you will be able to use natively a lot of tubes. Of course, wiring it an idea wisely.

I never understood these american "number named" tubes. But now I start to have an idea.

PS. It's funny, I am at least 50 years behind with audio and I need a 4K monitor. LOL

 

[Isaacc7]

January, freezing cold outside. What does the tube roller? I tell you, tries to understand what Master Isaac tells him for a few monts. I've started analyzing loctals. LOL



First conclusion is simple: I definitely need a 4K monitor. I cannot see anything on my 2K one and I scroll 90% of the time. Monitor rolling? Cool!

Some people smoke to see things, I've put a few hundreds of pinouts on a table and saw more than them. What I saw is that there is a lot of potential and uniformity in P8A and loctal sockets. If you build an amp for these, well you will be able to use natively a lot of tubes. Of course, wiring it an idea wisely.

I never understood these american "number named" tubes. But now I start to have an idea.

PS. It's funny, I am at least 50 years behind with audio and I need a 4K monitor. LOL

That’s a great spreadsheet! One more local you might want to put on there is the kt81. Same pin out as 7c5 but is actually the equivalent of a kt61.

 

[OctavianH]

That’s a great spreadsheet! One more local you might want to put on there is the kt81. Same pin out as 7c5 but is actually the equivalent of a kt61.

KT81 is already there if you look closer. But these loctals are hard to find in Europe and my will to invest is minimum. I have too many tubes and I do not really need new ones. So I am receptive to prices like 5-10 EUR / piece. I left these at the end because are the newest ones and I always go towards "the older, the better"... and by the way, 90% of the loctals I find are Sylvania (312). LOL

And I have to be careful because we have loctals with 8 pin and loctals with 9 pin (EL60 for example).

 

[OctavianH]

That’s a great spreadsheet! One more local you might want to put on there is the kt81. Same pin out as 7c5 but is actually the equivalent of a kt61.

By the way, if it is useful I have no problem to export it from my Google Drive and share it. I have many spreadsheets. Of course, I take no responsibility for any mistake or crazy think anyone will do based on what he thinks he found there. But if this helps someone I am happy. There are also some "stuff" from many years ago on the second page, mostly all data is collected from Radiomuseum/Valve Museum or strange forums.

Document is attached. It has, most probably, some mistakes, so please double check if you want to use some info.

 

[OctavianH]

Today I have renounced on my usual suspects because I had a leftover from the 807 area. At that time I was not able to find these at a decent price and renounced on them. I civilized myself putting in place clear rules related to pricing and priorities in my experiments. But as always happens when you are patient, an opportunity will come at an end.

So let me present you Csf 5933S (P17W). A brother of the beloved 807, this one produced in France.

This tube is very small compared to the usual 807 I have listened before, even with Sylvania 5933. Has 3 rectagular getters placed sideways? I neved saw something like this since the GEC KT88 which has 3 ring getters, 2 sideways and one on top. Anyway, interesting tube. I said it's small:

Now, bias is the same as 807, these ones around -18.2V for 200V/20mA (RCA normally are around -18.5V). Nothing unusual.

Soundwise these seem nice but sound an idea diffuse. I think these were indeed new. I'll let them there and form an opinion later. They are promising, that's all I can say, might be better than the other 807 I've listened because they seem more fluid and coherent. Csf/Thomson tubes are nice, I have a pair of EL90 and I love it and I am not the only one liking those. I heard good things about Thomson 6080 from several persons. So there is big potential here. I'll say more about these one day when I will be confident that I understood something.

 

[OctavianH]

The Csf 5933S evolved a lot in only a few hours, but I still find them a kind of "wet" signature. What's nice is that it is a fluid wet one, this reminding me about the SFR EL90/6AQ5. Because Fivre 6SL7 was not the most inspired pairing, put that just because it's a good all rounder and I can start from there, I decided to pair it with a "dry" Brimar 6SL7 to remove an idea those "shouty" mids.

French masters never disappoint. Csf 5933S is definitely a very good sounding tube. I will put it against RCA and Mullard 807 one day. At the moment I just think it has something from the sound of Fivre. Maybe this is why I like it. The older pieces of these from 50s are branded SFR, in 60s we have Csf and Thomson, but in my view all are the same company. These will definitely remain close to me.

 

[Isaacc7]

Sigh, fell off the wagon and bought some tubes. Decided that even though at the voltages I run them the gu50 will likely run forever I should get some spares. I really am smitten by them in triode, I could easily restrict myself to just them and be happy. I had been idly thinking about ordering for a while. Noticed that the place I had been eyeing them now says they have more than 10 available. They used to say 100+. FOMO gripped me. They are so cheap so why not? Of course shipping from over there is not. Realized that I could add some more to the order without the shipping going up so… Bought some Svetlana 6j7 as well. I already have the adapters, I had heard good things about them, and they are only $3 a piece. God only knows when I’ll get all this. Maybe by that time I’ll actually have my amp fixed. I’ve been enjoying my other amp so much I haven’t felt the need to rush. Think I’ll look into it seriously tomorrow.

 

[OctavianH]

Sigh, fell off the wagon and bought some tubes. Decided that even though at the voltages I run them the gu50 will likely run forever I should get some spares.

You have made the right choice because they will not be at this price forever. I know about GU50 in triode for a long time and you are not the only one praising them.

It seems tubes with "50" have something. I am also not really interested in anything else than the tubes I already acquired. I buy from time to time, at very low prices, tubes which might be interesting from construction point of view, usually bulk boxes. I am not really sure I have something more to discover, at least on this amp. But I think about future amps and made some plans to expand my experience. A part of them was the new headphone. Not really that I needed it, I just wanted to explore 2 headphone signatures on EL50 and my current amplifier, then sell it, most probably.

I stopped buying tubes because I still have tube pairs I never got the energy to try because I already know how they will sound and why I will be bored about them. Who knows, maybe winter mood. EL38 still sits in a box, prepared. Csf 5933S is really good but I miss my EL50. I also have some "surprises" on the P8A and a pair of Mullard EL86 I always wanted to try, EL86 fascinated me at some point. No real energy, so I put it also in the box.

Regarding 6J7 and 6SK/SJ7, all these types have lower screen voltage rating and quite low plate dissipation:

But I guess if 6SL7 works and you strap them triode should work. There was a time I wanted to go towards this path but renounced because these were already too expensive. With amplification factor around 20 I guess strapping them you obtain a 6J5. LOL