I have a Delta Blues 1x15 that I bought back in the 90's, right when they first came out. It sat for a number of years while I used my Classic 50 2x12, until recently when I wanted something a bit lighter to lug to gigs. Swapped the speaker with a Weber model and have settled on a tube setup that works for what I need (I use the clean channel and get all my gain from pedals, switching them off to go back to clean etc...) V1 = 5963, V2 = ax7, V3 = ax7LPS and JJEL84's. I've noticed that when I'm playing some gainy stuff and am boosting the signal (I use a DLS MKIII for the gain platform and a RAT to boost it for solos) I can hear something weird when I play higher up the fretboard, especially when bending, sounding like another faint note along with the note being played. I do recall this with the original speaker, which was part of the reason I swapped it out. I do not notice it as much if the RAT is off, though the signal isn't as loud either (I have also tried a few other boost pedals and the problem is still there). Any ideas? It's not like it's obscenely loud either, loud enough to cut through a 5 piece band but not deafening....... Thanks for any insight.