tesla ecc83... original? new? rebranded?

[Rickey_Dee]

hey guys!

just picked up a pair of these, got them for a very good price, therefore it is also "ok" for me if these are NOT real Telsa ecc83. anyway, i tried these and they sound much better than the tung sol reissue 12ax7. before i tested them i had 2 mullard i61 in v1 and v2 and a brimar cv4004, and switched then to my "live setup" with the tung sol reissue in v1, tad 7025-S in v2 and a tad ecc803s in v3. it's clear that nothing beats the nos tubes, i should have tried the tube with a mullard and the brimar too, so the comparision to the nos tubes is a bit unfair here. but with the new tubes in v2 and v3, this tube sounds a lot more fuller and a bit smoother than the tung sol... the tung sol seems to be hairier, what i THOUGHT i like, but when i A/B'd them, i almost wanted to throw the tung sol in the trash. it just lacks some body compared to the tesla, jj, whatever it is, so here are some pics, maybe someone can identify this tube.

like i said, if it's a real tesla, fine... so my search for a good new tube for v1 continues. if it's a rebranded new tube, i need to know what tube it is... but somehow i think this might be a rebranded JJ...

[Rickey_Dee]

couple pix more

[Rickey_Dee]

2 more pix...

[demonufo]

Hmmm, well it looks mostly like an RFT, but the crimp holes on the left of the plates are bigger and in a different place, and the getter is different too.

Certainly not a Tesla ECC83.


Another possibility is that it's not an ECC83 at all, but one of the other types. How gainy is it?

[Rickey_Dee]

i don't think that it's an RFT, the top is pretty round... compared to the tung sol reissue, it doesn't seem to lack much gain, but it has more body, fuller sounding with more low mids. the tung sol seems to have more bite, but is thin sounding and lacks a lot of low end compared to this tube. it's day and night.

[Rickey_Dee]

i found this at tubemongerlib.com:

http://www.tubemongerlib.com/gallery2/v ... a.jpg.html" onclick="window.open(this.href);return false;

seem to be the same tubes... to me at least. sooo... is this now a real tesla or not?

[demonufo]

You're describing the sound of an RFT.

I'm not so sure now. The plates look like the work of earlier RFT tubes, but the getter doesn't look like RFT.
I guess it's possible that Tesla got hold of them and finished them off.
The glass body doesn't look like RFT either.

Still certain they are NOT Tesla made plates though.

[Rickey_Dee]

so, it might be possible that what is described @tubemonger is right? that this tube has rft-internals? that would explain why i'm describing the sound of a rft.

i've never heard an rft ecc83 before, but if that's the sound of an rft, then i definitely like it.

[demonufo]

RFT's generally don't have a lot of top end extension. Usually a sound a little gainier and compressed.

[Rickey_Dee]

ok, i'll do another comparision tomorrow, when i can crank amp without disturbing any neighbors... but from what i still have in my head, they were not as gainy as the tung sol reissues. the tung sol's seem to have their sweet spot in the upper mids, and these tubes in the lower mids. but as i said, the tung sol's were definitely thin sounding agains these.

let's see, maybe i can record some clips with my phone, if it works... will not sound great though. but the difference was truly day and night, i hope the phone picks up that difference too.

[demonufo]

Well the Tung-Sol are a pretty crunchy tube as modern ECC83's go, so the gain difference may not be drastic. But I wouldn't expect an RFT to have less. But who knows exactly what that thing is, how hard the vacuum is, how it measures up to true RFT's etc.

[jcs]

Who cares...either way they are solid tubes and rarely go microphonic (yes i have some).

I think i have some with gold pins too.

Hey wait a minute, did Rat Shack sell these in the 70s & 80s?

[Rickey_Dee]

i'll do some clips later, after i solved the problem that's goin on right now in this thread:

http://forum.metroamp.com/viewtopic.php?f=24&t=41301" onclick="window.open(this.href);return false;

hopefully soon...

[LUC.key]

ressurecting this thread ...yes it IS a real Tesla from 1958, not just a rebranded RFT. Tesla made their own ECC83 in late 50's and early 60's ...it was later when they started relabeling RFT's, while producing only E83CC and ECC803S