[OctavianH]

Beautiful tubes need beautiful photos. I like the Italy flag on my pair of EBC3.

The STC 5B/254M is a nice tube, I find it very musical and warm sounding. Some claim it is neutral, for me it's sweet and musical. Everyone has different views, but majority agrees that these are quite nice. My version of them are "vintage" with double D-getters.

This is a tube I will keep around. I like it and I am sure I can obtain more from it on my next amplifier with variable Vplate so I can put these to more than 200V/20mA. Until then I will enjoy it here.

Philips EBC3 is a brighter tube, has elevated highs, but it is very detailed and transparent. People who have problems with high frequencies might be careful with these, but for me they add a lot of detail and an idea more aggressivity where I felt D8000 Pro was an idea too polite: top range of the frequency area. But as usual, they have a problem and the problem are some too thin to my taste mids. Combined with the STC 5B/254M they shine. Because both have something which the other is missing.

 

[g0ldl10n]

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.

Aha! You find it incredible too? Different base version of the VR55/EBC33. When I first heard some very old, small blue painted/coated ST Mullard VR55s, I was awe struck. So much so, the VR55 and commercial EBC33 is the tube I have the most of in my collection- I was determined to never go without them. I was lucky enough to find a listing on ebay shortly after I discovered them for a whole box full of the small ST blue Mullard VR55s, in the original military packaging for about $2/ea. I absolutely love the triode inside that tube, it is truly amazing.

 

[Isaacc7]

I got my amp back from the tech. Told my sad tale on the main Oblivion thread. One other thing the tech mentioned is that I should probably start my vt60 tubes at a lower voltage and then move them to operating voltage once they had warmed a bit. I figured that was probably a good idea. The main problem I have is that the adapters I use for one of my favorite input tubes, the c3m, obscures the pot to adjust the voltage. Once I put the tubes in and re-cable it I’ll see if a long, thin screwdriver would solve my problem.

In any case, I’m excited to get back to my amp!

 

[Isaacc7]

Lol. Tried to use a screwdriver to adjust the B+ between the C3M adapters and couldn’t get the screwdriver to lock in place. Shined a flashlight on it only to find the pot isn’t slotted. It’s the only one that isn’t lol. Maybe this particular combo just isn’t meant to be lol.

 

[OctavianH]

Aha! You find it incredible too? Different base version of the VR55/EBC33. When I first heard some very old, small blue painted/coated ST Mullard VR55s, I was awe struck. So much so, the VR55 and commercial EBC33 is the tube I have the most of in my collection- I was determined to never go without them. I was lucky enough to find a listing on ebay shortly after I discovered them for a whole box full of the small ST blue Mullard VR55s, in the original military packaging for about $2/ea. I absolutely love the triode inside that tube, it is truly amazing.

I never tried EBC33 but I do not have the same expectations as for EBC3. Mullard ECH3 is not in the same league and I expect that also the successors are similar.

Lol. Tried to use a screwdriver to adjust the B+ between the C3M adapters and couldn’t get the screwdriver to lock in place. Shined a flashlight on it only to find the pot isn’t slotted. It’s the only one that isn’t lol. Maybe this particular combo just isn’t meant to be lol.

I am glad that you solved your problems with the amplifier but I doubt that the craftsmanship of Tomas was the culprit. He built me this small amp with a lot of functionality and I use it between 12-16 hours per day for almost 4 years and honestly, no problem. The problems might be related to last minute changes in the design and these are the risks of being a pioneer. I do hope you will find a proper solution to fix it and use it as intended, what you have there is unique and I doubt you can find something similar on the market.

PS. Do not let me start on what problems I had with mass produced expensive equiment. I will say a few words about some highly appreciated brands around and I prefer not to do it.

 

[OctavianH]

Let see what Mr. Lion tells us here about EBC33. Well, I guess I'll need adapters for this and I do not want more adapters, but it might work in EL32 or 6J7 ones.

The only problem I see here is that 6J7 or EL32 adapters I have are strapping via a resistor the G2 -> Anode. And I am unsure if D2 on EBC3 will like 180V and make problems. Otherwise, might work.

What do you think @g0ldl10n in trying EBC3 on some adapters with pin 4 tied to anode via a resistor? Will the diode make me problems? For example ECH33/35 should work without problems in any of 6J7 or EL32, of course not advisable to let G3 floating but well, at 4mA I doubt that big problems except maybe some hum might occur.

PS. 6J7 might be perfect for ECH33/35. G2 and G3 are fine and the floating triode anode is perfect, I do not want the triode inside those.

Later edit: Yep well, EBC33 cannot be used in those adapters. Because diodes should not be connected in any way anodes. So a correct adapter should let those floating or maybe tie them to Cathode to cancel their operation? Anyway, I'll not put EBC33 in any of 6J7 or EL32 adapters. So my tests of any EBC33 will not happen soon.

ChatGPT tells us how they were using in radio receivers those diodes: