Tube swapping (part 2)

While running rabidly through the endless nirvana that is the NAMM (north American music merchants) show I noticed some cool stuff at the Groove Tubes booth. The thing that interested me the most though was their new 'Substitubes' tube reducer sockets. Basically these little wonders allow you to run your class AB tube amp in an open-ended class A configuration by using EL84 tubes instead of 6L6, 6V6 or EL34s. This also greatly reduces the power of the amp, allowing you to crank it into power amp distortion without breaking the windows out of your house. Too cool! A duet of these babies will run you around $120 while a quartet is $240. Yikes! I decided to check out what eBay had to offer and noticed someone selling a nearly new quartet. My friend Dan offered to split the auction with me since we each only needed a duet of sockets, so I bid on them and won the auction for a whopping $88 including shipping.

I installed the Substitubes in my 93' Fender Blues Deluxe along with a matched duet of JJ brand EL84's. So, how did it sound? Well, it basically left me with no clean channel and the dirty channel was, well.....dirtier. Keep in mind that I was running all 12AX7 preamp tubes which are pretty high gain as well. So, I swapped in a 12AU7 (lower gain tube) in V1 which feeds the clean channel and voila! My clean channel was back. The volume was significantly reduced as well and I am now able to run it up to 5 without it blasting me out. I'm probably pulling around 18-22 watts out of this 40 watt amp.

I don't think that there is anything I can do about the anemic dirty channel in this amp (short of a major modification) so I will just have to focus on getting myself a really versatile pedal to do the job. As I mentioned in a previous post, the Seymour Duncan Twin Tube Classic is a perfect candidate for the job. I'm not looking for seething distortion, just some nice grit for rhythm playing and some smooth sustain for leads. To this amps defense I must admit that it makes every pedal I've ever put in front of it sound awesome. I've run pedals in front of other amps and they aren't nearly as pleasing as with this one.

For the next installment of 'Tube Swapping' I plan to try different preamp tubes to see what, if any, difference they make. Until then...