Preamp Tubes to Tame Brightness?


Well-known member
After reading that book, I feel a lot less bright. So much so that I'll have to have his next book read to me.

Agreed on EQ and speakers having a bigger difference than preamp tubes and preamp tubes more than power tubes. I personally have had a lot of good luck with JJ's. I've purchased 4 or 5 12AX7s in the past year and several sets of EL34s lately and have no problems.


Well-known member
In fairness, it does seem like the guy is looking for a zebra to solve a problem that a horse could easily handle.

How exactly do Treble and Presence controls fall short in “taming brightness,“ exactly? The guy hasn’t even mentioned what specific Marshall circuit he’s talking about.

When the circuits aren’t stock.

If it’s a modern master volume Marshall, Treble and Presence should work fine. If you absolutely have to spend money, put an EQ in the loop or something. You’re going to get infinitely more flexibility out of that than the extremely subtle changes you may or may not perceive with preamp tubes, not to mention their modern manufacturing consistency issues. Any given two of the same type could be brighter or darker, fatter or thinner, whatever. You never know with tubes these days. seems like amp or external EQ controls would be a lot more reliable and predictable to me at least.

I asked for preamp tubes because I do not want a drastic change, I want a mellowing out. I own many other amps in my collection that don’t have this problem which means the speakers fit my tone preference. I do want to grab a cabinet of celestion creambacks 75Hz but it’s not a priority anytime soon.

I do agree though - if I was looking for a drastic change, then speakers or pickups would be the most drastic. Another drastic change is more circuit modifications. You have to be careful though as bleeders can kill the dynamics of an amp if not careful.


Well-known member
Mullard CV4004. They're pretty fat. Then I'd put the JJ ECC83S in V2 & V3. If there a 4th, (sorry, I didn't read what Marshall), I'd put a Sovtek LPS in the PI. I think you'd be golden.