Back to original Mesa 12ax7A, tired of tube rolling

[bandit2013]

It is amazing how well this amp responds to different preamp tubes. The Mark IV is not as forgiving. Found many combinations that sounded great for a while. From Tung-Sol, EH, JJ, 5751, and so on (excluding the high cost NOS tubes). Amps sounds great for a while. Then you thing "what was that combination I did the other day?" Oh well.... For a while I was set on EH 12ax7. Tried Tung Sol for a while, just not satisfied. At least I had a point of return, the original stock Mesa 12ax7a tubes. ( However, I put most of them to use in the Mark IV). I had three not being used, swapped what was removed from the V into the IV. Now I have all stock original Mesa 12ax7a tubes (excluding the PI [v7] tube).

Amp never sounded better. I have often returned to the stock tubes just to get a feel if better or worse. As the power tubes get some use, the tone will change gradually. Since I play in the 45W most of the time, I decided to switch the power tubes (inner to outer and vice versa). My not thing that would make a difference, but Mesa does have a slightly different bias on the outter tubes compared to the inner pair.

Note: Reason why I pull the chassis is to let my eyes see what I am doing, not let the hands feel for what I cannot see. I have been successful in changing tubes without pulling the chassis. However the last roll, I damaged the long V1 shield. Will have to order a replacement (I will get a short one like the others, the longer shield is harder to install, resulting in a split spur on the end, aluminum a bit on the soft side).

 

[bandit2013]

Forgot, it sound kick ass now. Better than it did when I brought it home. Power tubes are still performing well, no red plating, tone loss. Too bad the original Power tubes died early, the amp sounded good before they crapped out. SED wing C with stock mesa 12ax7 and one sovtek LPS in V7 sounds the best so far. Trebble not over the top, gain is satisfactory in both CH2 and CH3. I will leave it this way for a while since it sounds great.

 

[exbest182]

Dude.. I feel you..

I went from all stock, to Tung Sol in V1, and Mullard in V3, with the sovtek in v7
then Mesa stock in v1, tung sol in v3 - mullard in v1, mesa in v3, all sorts of different combinations...

It's exhausting.

 

[cradlefish]

The NOS tubes IMO are Hard to beat. You can get them for good prices on eBay. You just need to check the sellers feedback. I've had good luck with most and gotten great deals on some. I would suggest you look into it. They can be had for the same price as new current production tubes.

I've tried the new tubes as you've mentioned - not impress by they.

 

[bandit2013]

For the time being I am satisfied with the overall tone. I did take out the Mesa tube in V1 and installed a Tung Sol, that is much better. I have not lost that great sound from the SED's yet and I hope they last for quite a while.