RCA 7025's ??

[kurtsstuff2003]

So..I've been reading about these tubes of the 12AX7 variety and apparently...They are the "best" 12AX7 type ever made?
I have no experience with them well..not knowingly..lol! And wondering what the big deal with them are?.I see them for sale for $100.00-$200.00 for one tube?? Anyone familiar??

 

[psychodave]

I assume you’re talking about the long ribbed plate RCA? I have a bunch and they are cool.

 

[Exo-metal]

For her pleasure...

 

[MetalHeadMike]

So..I've been reading about these tubes of the 12AX7 variety and apparently...They are the "best" 12AX7 type ever made?
I have no experience with them well..not knowingly..lol! And wondering what the big deal with them are?.I see them for sale for $100.00-$200.00 for one tube?? Anyone familiar??

In my experience, tubes have such an insignificant impact on tone/feel that I no longer experiment with high dollar unicorn tubes. Not saying there's not a difference, but to my ears and fingers it's negligible. Having said that...some amps of course respond better than others to tube swaps. Only amp I've ever owned that I noticed a profound difference when tube swapping was the JJ Jr.

 

[fusedbrain]

Yeah, I'm not sure about unicorn tubes either.
I have a few Mullard, Sylvania, and Rft 12ax7s, and they only seem to make a difference in vintage 2 gain stage amps like Plexi's and JTM45's.
My experience has been that with modern, multi gain stage amps, CP 12ax7s get the job done just fine, and often sound better than NOS.
I will say that if you are going to try a 5751 or 12at7 in a modern amp to control the gain, NOS sound way better than CP, but NOS versions of those tube types are cheap.

 

[tonesfoyobones]

I have several types including some RCA's. In high gain amps I do hear/feel the difference when in the v1 slot but most times it's subtle. They really shine on cleaner platforms amps. Where they excel is in a home stereo set up with some really nice tube amps. McIntosh, Marantz, Mark Levinson etc. In guitar amplifiers, especially high gainers, the great little harmonic subtleties, that you pay dearly for, get lost in the wall of sound. With that said I keep a few to try in amp's now and again.

 

[psychodave]

If some of you guys lived closer I’d show you how different you can make an amp sound just by swapping out V1. Some tubes are subtle, so are really drastic.

I made a few videos swapping out different power tubes with a Cameron CCV. You could easily hear a difference.

 

[MetalHeadMike]

If some of you guys lived closer I’d show you how different you can make an amp sound just by swapping out V1. Some tubes are subtle, so are really drastic.

I made a few videos swapping out different power tubes with a Cameron CCV. You could easily hear a difference.

I've tried swapping preamp and power tubes in roughly 30 amps and again the only one that was night/day was the JJ JR. Differences are there, but very subtle to my ears/fingers.

 

[fusedbrain]

If some of you guys lived closer I’d show you how different you can make an amp sound just by swapping out V1. Some tubes are subtle, so are really drastic.

I made a few videos swapping out different power tubes with a Cameron CCV. You could easily hear a difference.

I'm all over what you can do with swapping tubes in V1.
I just haven't heard anything from NOS pre's that's worth the dough in higher gain amps.
Plexi's, yeah OK I get it.
Power tubes are a whole different game. I agree, the difference between tubes ain't subtle.
If I'm spending large $$ on NOS glass, it's gonna be on power tubes, and mostly on EL34's.

 

[skullfxr]

RCA7025's are great in PI in high gainers. Low noise musical response. I have them in that spot in quite a few of my big boys, and a handfull that have never been used.

 

[fek]

Only amp I've ever owned that I noticed a profound difference when tube swapping was the JJ Jr.

Have you posted your findings on this? I would be interested in reading it if so. Have a JJ Jr and like it a lot but if a simple tube swap could tailor it a little more to my liking, that would be cool. Stock tubes in mine at the moment.

 

[psychodave]

If some of you guys lived closer I’d show you how different you can make an amp sound just by swapping out V1. Some tubes are subtle, so are really drastic.

I made a few videos swapping out different power tubes with a Cameron CCV. You could easily hear a difference.

I'm all over what you can do with swapping tubes in V1.
I just haven't heard anything from NOS pre's that's worth the dough in higher gain amps.
Plexi's, yeah OK I get it.
Power tubes are a whole different game. I agree, the difference between tubes ain't subtle.
If I'm spending large $$ on NOS glass, it's gonna be on power tubes, and mostly on EL34's.

I have to respectfully disagree with high gain amps comment. The right tube in V1, in both high and low gain amps, sets the tone (pun intended). I have 100’s of NOS tubes and have been a tube hound since 1990. It’s a curse tinkering with tubes You guys would throw out new production tubes if you were to hear comparisons. (note: I still use 8th generation tubes in other tube spots).

I’ll see if I can get a friend over and go through some tubes and let him provide his experience.

Just wanted to mention, I’ve been buying NOS tubes for so long that most were purchased 30 years ago for cheap and before the internet crazy started. I agree that it is a hard pill to swallow spending so much $$$ on certain NOS tubes these days.

 

[MetalHeadMike]

Only amp I've ever owned that I noticed a profound difference when tube swapping was the JJ Jr.

Have you posted your findings on this? I would be interested in reading it if so. Have a JJ Jr and like it a lot but if a simple tube swap could tailor it a little more to my liking, that would be cool. Stock tubes in mine at the moment.

I did not. Basically found the stock Chinese 12 ax7s to be much more articulate, cutting, present. I swapped them for different cocktails of Tungsol, JJ, TAD 7025, RCA 12AT, 6n4 and probably a couple others I'm forgetting. All other preamp tube combos made the amp sound dull, dark, lifeless. Put the stock tubes back in and it was night/day for the better.