About 9 months ago I purchased a 2 year old Mark V. It is a great amp, very versatile with tons of great tones. I found Channel One’s Clean and Fat modes, Channel Two’s Edge, and Channel Three’s Mark IV all easy to access and very usable with great tones throughout each mode. However I did find Channel One’s Tweed, Channel Two’s Crunch and Mk I, and Channel Three’s Mk IIC+ challenging to dial in tones that felt “right” to my ear.
So I decided to try some ANOS (Used) preamp tubes. I started by changing just V1, then overtime replaced V2-V7. Wow, what a difference. Every aspect of the amp improved, more articulated cleans that are very 3d, gain structure is tighter with less graininess and the modes are more distinct from one another. All the modes that were good are now better and the modes that were challenging are now accessible and engaging. I am using a Mullard I61 in V1, RCA 12ax7 Long Black Plates in V2 and V3, the rest (V4-V7) are Sylvania Long Grey Plate 12ax7. All are ANOS (used) tubes, said to be at or above 1450 Mhos. To compare as best I could, periodically I re-installed the original Mesa preamp tubes. They sounded worse than I had remembered. To be fair, the original 2+ yr old Mesa preamp tubes may be getting weak and thus contributing significantly to the difference I hear. But I really think that NOS tubes are awesome in the Mark V. Btw, I also have a Fender HRDX. I installed three NOS tubes in that, big improvement to the tone, but nothing like the improvement to the Mark V.
I have not tried other brands of ANOS tubes such as; Raytheon, Phillips, Telefunkens, Amperex, Tung Sol, or RFT, and am curious if other Mark V owners have experimented with NOS pre-amp tubes and what they have experienced....
So I decided to try some ANOS (Used) preamp tubes. I started by changing just V1, then overtime replaced V2-V7. Wow, what a difference. Every aspect of the amp improved, more articulated cleans that are very 3d, gain structure is tighter with less graininess and the modes are more distinct from one another. All the modes that were good are now better and the modes that were challenging are now accessible and engaging. I am using a Mullard I61 in V1, RCA 12ax7 Long Black Plates in V2 and V3, the rest (V4-V7) are Sylvania Long Grey Plate 12ax7. All are ANOS (used) tubes, said to be at or above 1450 Mhos. To compare as best I could, periodically I re-installed the original Mesa preamp tubes. They sounded worse than I had remembered. To be fair, the original 2+ yr old Mesa preamp tubes may be getting weak and thus contributing significantly to the difference I hear. But I really think that NOS tubes are awesome in the Mark V. Btw, I also have a Fender HRDX. I installed three NOS tubes in that, big improvement to the tone, but nothing like the improvement to the Mark V.
I have not tried other brands of ANOS tubes such as; Raytheon, Phillips, Telefunkens, Amperex, Tung Sol, or RFT, and am curious if other Mark V owners have experimented with NOS pre-amp tubes and what they have experienced....