Series 1 Rectoverb Head cutting out...

[Rectogroove]

Hey guys, I have a '99 Series 1 Rectoverb head and it's been having some issues... It's been consistently played on for the last 10+ years, with no issues before. I've recently put a Groove 12ax7 R2 in the v1 position. The rest are Mesa 12ax7's. The power tubes are a little over a year old and I'm running Mesa 6L6's. When I crank the output past 12 o'clock, it cuts out in certain spots. This is with the master volume matching the output, and even cranked. I watched the power tubes recently while this happened and one of them was flickering and the glow was inconsistent. They both have been glowing blueish purple recently. I tested all of the preamp tubes as well and I noticed the Groove R2 in the v1 position was noisy but I think this is generally a noisy tube in that position anyway. Any ideas?

 

[Rectogroove]

TTT

 

[domct203]

Have these symptoms just started since changing V1?

Dom

 

[Rectogroove]

No sir. This was going on before the change in v1. I have recently purchased a new set of Mesa 6L6s. Going to see if this will fix the problem...

 

[clutch71]

New tubes do not always = good tubes. If your cutting out specifically at a certain point on the gain knob only you could have a bad pot. Relatively cheap to fix.