Need some Mark III help ...

[rvschulz]

I have been "tube collecting" recently and decided to try retubing the Mark III green stripe. Ran into a couple of issues.

First, I was perusing the downloaded document from the website and it said that I have 5 pre-amp tubes - v1-v5 ... i look in the back of the chassis and i see 4. behind the 4 power tubes - one 12AX7, then 3 with the one closest to the input (v1 i think) having a metal cover.

next, v3 for the lead channel - i put my favorite old Penta from a different amp in and ... no lead channel. I check it, and voila' ... it is broken. What i have left is some generic chinese and sovtek 12AX7. someone suggest their "favorite" tube for v3. i am looking for more of a Santana creamy lead - no metal brutal stuff ...

 

[Boogiebabies]

If your amp has reverb, you will have four tubes up front and on at the back. If it does not, you will have three up front and on in the back.
The V1 in the can is the closest to the output transformer and the V3 would be your lead channel. the tube closest to the power tube would be your phase inverter. For cream with current tubes, try a JJ or GT 12AX7M. For NOS you can try an RFT, Mullard or the oldest Ei you can find. The smoothest IMO in the Boogie's is a NOS JAN 12AX7WA, basically a Phillips preamp tube made to military spec.

 

[edward]

...
next, v3 for the lead channel - i put my favorite old Penta from a different amp in and ... no lead channel. I check it, and voila' ... it is broken. What i have left is some generic chinese and sovtek 12AX7. someone suggest their "favorite" tube for v3. i am looking for more of a Santana creamy lead - no metal brutal stuff ...

Needless to say, tube choices (like what constitutes "great tone") is a very personal decision. That said, I do not play metal or use heavy gain and found NOS Mullard CV4024 (12AT7s) in V2 and V3 get me a much more creamy and smooth OD in the Lead channel. It is more lush, round, and shaves off that upper-end bite which is perfect for less-modern/more "old-school rock" feel. I "think" I also put an AT7 in the PI spot, too, but I can't recall at this point ...could get back to you on that if you like. Just a bit of food for thought

Edward

 

[Buddy]

Yup , +1 on the oldie Mullard's & 12at7 phase inverter .