Tube swapping (part 1)

In my never ending quest for tone I decided to do a comparison of different tubes on my 93' Fender Blues Deluxe. It came stock with 6L6GC's which produce approximately 40 watts RMS @ 8ohms, but it was too much power for bedroom playing. As all tube amp lovers know, the amps sound their best when they're cranked up, but you can't always stand to be in the same room with 'em.

Anyhow, being that this amp was designed with a glaring flaw in it that prevents you from being able to bias it without having to change capacitor values, I used my bias-probe to check the bias with the generic tubes it came with to see where it was registering. It should have been around 38-42 mA to keep it idling properly and out of crossover distortion, however my reading was around 23mA! Waaaay too low. It was no wonder the poor thing sounded anemic. I ran out and bought a hotter duet of Groove Tubes 6L6GC's which biased at a more respectable 30 mA. Better, but the amp was still running too cold. (I have since purchased a do-it-yourself kit to allow me to bias the amp with the simple turn of a potentiometer, but that's another story...)

So, the GT tubes made the amp sound much better but I was pretty sure there was room for improvement. I scoured the Internet forums for some other possible solutions and discovered that by using 6V6 tubes you can lower the wattage of the amp by as much as 12 watts while still maintaining a respectable amount of clean headroom. With that in mind I ordered a re-tube kit from www.eurotubes.com and installed them in the amp to see what the difference would be.

The kit came with a matched duet of JJ 6V6 power tubes, a balanced JJ ECC 83s for v1, a hot JJ ECC 83s for the distortion channel in v2 and a standard JJ ECC83s for the clean channel in v3. I noticed right away that the volume knob was way less sensitive than before (a good thing) and I could turn the amp up to 3 before it blasted me out. The clean channel still had tons of headroom, but the dirty channel was still brittle and useless. Bummer. All said and done I was very pleased with the new power tubes. It comes in handy to swap the tubes based on what gig you're going to play. If I'm playing someplace where I need the extra power, then I drop in the 6L6GC's, but if I'm practicing at home or playing at church then the 6V6's are the way to go. I have yet to explore the myriad possibilities of swapping preamp tubes, but again, that's another story...

Stay tuned for the next exciting installment in my tube swapping adventures... (rolls eyes)