Mark V preamp tubes?

[sevycat]

I got some new tubes in today and decided to install them in my mark v. I placed a tung-sol reissue 12ax7 gold pin in the PI v7 position and a RFT ecc83 in the v1 position. I really could not make a connection with it while in the clean channel, meaning the effect was not as prodominate as what I noticed when I switched to the crunch or lead channel. Those two channels were a huge improvment in overdriven tone.

I am wondering if I moved the RFT into another position how it would sound. What does V2-v6 positions do and where would be the best place to move it to? Is V2 the best place to move it to?

 

[domct203]

Page 62 of your manual explains the preamp tube functions.

The best place to move it to would depend on what you want out of the tube swap.

Dom

 

[sevycat]

I would say that I play Rock n Blues mostly. I am looking for the RFT to have the most impact on the 2nd and 3rd channels. Which is where I think it really works best.

 

[eudaimonia02912]

The RFT should have the most impact in V1, since that's where the signal starts. With the exception of the PI, each tube in the path has successively less effect on the tone.

V2 is dedicated to channel 2, and occurs second in the signal path after V1, so it's a good place to put a tube to change V2.

V3 will have most effect, after V1, on channels 1 and 3.

For what it's worth, I run my NOS RFT in V1. I've tried it in V2, V3, and the PI as well, and it made the most audible difference in V1.

 

[eudaimonia02912]

One more thing: Keep in mind that RFTs are dark and crunchy. Many people think of them as improving high gain channels, but as coming at the expense of clean channels.