Sino 12AX7B in the Herbie

[TCRS]

I was wanting to try a pre amp tube with a little less gain in the Herbie to get a tad less saturation. I had some Sino 12AX7Bs laying around and decided to give them a shot in it. I was shocked. There wasn't really any less gain or saturation to my ears, but it really woke channel 2+ up. Before it had a looser round bass note. Now it is as tight as channel 3 and is just as aggressive. Weird. I switched my rhythm and also boosted solo channel on my midi and effects to channel 2+ now I like it so much. Anyone else swapped pre amp tubes and had the same result? I'm using all Sino 12AX7Bs in all six slots. I thought the amp had muscle before, but now it is a monster.
It had TAD 7025 in V1 V2 and then TAD 12AX7Cs the rest of the way.
I'm also running Ruby EL34BHTs and I highly recommend them. 7 months of solid studio/stage use with no fade or issues.

 

[Peter Diezel]

12AX7´B is same is 12AX7A. We would like
to use it but no none microphonics available
at the moment. Triode A on V1 makes the
difference.

 

[TCRS]

12AX7´B is same is 12AX7A. We would like
to use it but no none microphonics available
at the moment. Triode A on V1 makes the
difference.

So the triode A on V1 is what made channel 2+ tighter and meaner? I'm a novice when it comes to how tubes make an amp react/sound different. I thought 12AX7B tubes were a lower gain version of the 12AX7 preamp tube. Are all the 12AX7A,B,C tubes the same? Are they just putting different letters on them? I have also seen 9th generation 12AX7 tubes advertised. What exactly is the difference in them? I'm curious since they all have different prices ranging from $5 to $25 and they seem to be the same tubes. Any advice Papa Diezel?

 

[Peter Diezel]

You don´t know what You get because every
distributor renames the tubes from Shuguang.
The most used name is 12AX7A-C. "C" is for
China. You are right with different "generations".
They have also silver plate versions
which have a slightly lower output often marked
as 7025 which is only an industrial name for
12AX7. In European countries the name ECC83
is used. Of course all this types will sound
different. If You check a bunch of 100 "same"
tubes out of a box You will hear also differences.

 

[TCRS]

I wish they would just have one type of Chinese 12AX7 and one name for it. It gets really confusing with all the different names and brands. I know what you mean about them sounding different. My silver plates do sound different than the 12AX7B. The silver plates have a thinner tone to my ears than the 12AX7B. I don't really hear a gain difference, but tone wise they aren't as fat. The 12AX7B tubes I put in the Herbie are tested and balanced according to the seller. They sound really good, so I guess I got a good batch of them. Thanks for the information on the Chinese 12AX7!
Thanks again for the replacement logo also!