Mark IV preamp tubes

[ThatDamnSG]

I just retubed my Mark IV. It was starting to sound weak and some of the preamp tubes were starting to go (they were 4 years old) I went with a set of Tung Sol 12AX7's across the preamp section. What a HUGE difference in volume and tone. It did wonders for my R2 channel especially. The only gripe I have is that the Tung Sols made my Lead channel noticeably brighter and a bit harsh. Does anyone have any suggestions on 12AX7's to try? I'm looking for a darker, smoother tone in the Lead channel mainly.

 

[dodger916]

I just retubed my Mark IV. It was starting to sound weak and some of the preamp tubes were starting to go (they were 4 years old) I went with a set of Tung Sol 12AX7's across the preamp section. What a HUGE difference in volume and tone. It did wonders for my R2 channel especially. The only gripe I have is that the Tung Sols made my Lead channel noticeably brighter and a bit harsh. Does anyone have any suggestions on 12AX7's to try? I'm looking for a darker, smoother tone in the Lead channel mainly.

A vintage Mullard 12AX7 will help you here. I've also heard RFTs are good tubes and a bit on the darker side; JJs also.

 

[sduck]

I'm very new to boogies and mark iv's (mine arrives tomorrow!), but perhaps these amps work similarly to the dumble clones I've been using? With them, the usual advice is to burn in new tubes for 40 hours or more before passing judgement on them. When I built my ceriatone overtone special bluesmaster 50 watt, I put tungsol 12ax7's in the preamp, and they also sounded kind of harsh at first, but after many hours of playing they mellowed out considerably.

 

[ThatDamnSG]

I'm very new to boogies and mark iv's (mine arrives tomorrow!), but perhaps these amps work similarly to the dumble clones I've been using? With them, the usual advice is to burn in new tubes for 40 hours or more before passing judgement on them. When I built my ceriatone overtone special bluesmaster 50 watt, I put tungsol 12ax7's in the preamp, and they also sounded kind of harsh at first, but after many hours of playing they mellowed out considerably.

I don't see the point in using tubes for "many hours" before having them giving my ears what I'm looking for. I can understand breaking in speakers, but not tubes. I need them to do what they were meant to do and sound the way I need them to sound after I plug them in and flick 'em out of standby. They either sound good or they don't, and that's all subjective.