Is there a difference between these tubes?

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illini

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I posted this at HC, but don't expect anyone to really respond.

Groove Tube 12ax7c
Groove Tube ecc83c

I was using the GT ecc83c but was unable to get a replacement. I was given the 12ax7 version and told that it is basically the same tube. But, it sounded much brighter in my amp. Is there a significant difference between these two, or did I just get a strange one?
 
illini":2189c said:
I posted this at HC, but don't expect anyone to really respond.

Groove Tube 12ax7c
Groove Tube ecc83c

I was using the GT ecc83c but was unable to get a replacement. I was given the 12ax7 version and told that it is basically the same tube. But, it sounded much brighter in my amp. Is there a significant difference between these two, or did I just get a strange one?
Click to expand...

I've never seen a GT Ecc83c. I've seen the Ecc83S, which is the JJ.

Look at the plate structure and getter to see if they're the same.
 
FWIW Ecc83 is the european designation for a 12ax7. I don't know if they are the same tube though. GT has used different manufacturers for their tubes. For example I have some GT's from the 80's made by Tungsram.
 
illini":46daf said:
I posted this at HC, but don't expect anyone to really respond.

Groove Tube 12ax7c
Groove Tube ecc83c

I was using the GT ecc83c but was unable to get a replacement. I was given the 12ax7 version and told that it is basically the same tube. But, it sounded much brighter in my amp. Is there a significant difference between these two, or did I just get a strange one?
Click to expand...


In any case, save your money and buy from a dealer - not someone who buys in bulk, hardly tests them, and slaps their label on them. GT used to be good when they had access to JAN / NOS tubes from miliary stock - that stock ran up a while ago, as well as their quality (ironic how those two went hand in hand) and people still believe they're better due to some kind of mojo they do "testing" them - it's all BS - they test them, but not any more than any other tube vendor, in fact, I'd say they are less stringent.

Buy them from Lord Valve or Doug's Tubes. Either of them will do it right.
 
I was told that the "c" stood for Chinese. I loved the pre-amp tube I had in the amp, and just wanted to replace it, but the new one sounds to bright. Guess I need to try out a few others until I find what I like again. My repair guy replaced the GT that was in the amp with a Sovtek 12ax7wb. Sounds fine, but not as clear sounding as with the GT.

I also had the output tubes replaced. The amp was running JJ EL-34L"s and had them replaced with Russian EL-34 Winged C's. Would this change make the amp brighter?

The amp is an 82 JCM 800 2204. Any suggestions for what pre-amp tubes and output tubes I should check out would be much appreciated. I am a rock player, not metal.
 
I have the same amp and same year, is yours an anniversary?
Anway, I believe the winged C's are brighter than the jje34l's and will have a bit more mids. Nothing wrong with them and as good as any current production el34 IMHO.
For preamp tubes, I recommend either a Mullard ecc83 in V1 or a RFT. Mullard on the bay from a reputable seller should be under $50.
Rft should be @ $30. In v3 the PI find a mullard 4024. Its The miltary version of the 12at7/ecc81.They are around cheap for @ $15 NOS. It will tighten the bass a touch.
Tube swapping is a terrible addiction. I've gone crazy on my 2204 with Mullard xf2 el34's and Mullard ecc83's in V1&V2 and the miltary 4024 in the PI.
Just remember that the tone changes from the tube swaps are subtle, but then these little nuances are the kind of thing that create a lot of threads.
 
yes.. changing power tubes would make your amp sound brighter. the jj e 34 l tends to add a some low mids and lows and has more headroom than the svets. the svets are a great tube for marshall's imho. however i'm running jj e 34 l's in my dsl and i like them quite a bit. it made the dsl sound smoother and added some bottom end.. which is what i wanted. i also replaced v-1 with an rft. imho the sovtek wb sounds a tad bit grainy when pushed hard.
 
"Grainy" is a good word to describe the 12ax7wb.

I will be swapping out the pre-amp tubes until I find that magic combo again. I may just need to get used to running the treble lower than before.
 
Thanks for the tube help. It sounds like the main difference I am hearing is caused by the switching from JJ-EL34L's to the Winged C's.

When referring to tubes what is a "RFT"?
 
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