charlesdavid75

I noticed that my SV HD100 had Sovtek 5881WGCs installed when I bought it. Since then it has undergone tube replacement. Besides the cup, is there any tonal difference in the Sovtek 5881WXT vs Sovtek 5881WGC? How much of the tone actually comes from the power tubes vs the preamp tubes? I understand that there is a very specific set of rules for preamp tubes in the SV HD100 as well. Should you always have the same preamp tubes ion V1 and V2? I recently was informed by a Line 6 team member that I could really only safely use SHU GUANG 12AX7B, SOVTEK 12AX7LPS or electro-harmonix 12AX7EH. This amp really impressed my when I played it in the store, but soon after I discovered that after about 20 minutes of playing the sound becomes less edgy with a loss of volume. I can adjust the knob and the volume returns, but the original clarity and bite are no longer present. Could this be a tube issue? As I said I had the tubes changed with a match quartet of Sovtek 5881WXTs and bias adjusted. I would love to have the that original presence and crisp sound back.

Thank you so much. Many thanks. I'm really glad you have warnings of possible issues noted on the forum. I'm rather new to tube amps and bought the Spider Valve MKII used and it sounded fantastic, but now it's not as it once was. I'd just like the best possible tone like everyone. I truly believe it's possible with this amp, though it may take many hours of fine tuning.

I have read and completely understand, a lot of engineering went into what makes the Bogner/Line 6 amp. I respect it's differences and what makes it unique. With that said I intend to keep it stock so it can run long and strong. I have a matched quartet of Sovtek 6L6/5881WXT tubes and a pair of 12AX7B China tubes on the way. My question, what is the specified bias value for the Line 6 Spider Valve MKII power tubes?