Archive for the ‘Guitar & Bass’ Category

After a career working with computers and lots of other high-tech and cutting-edge stuff, it’s ironic that I’m back into the vacuum tube biz. It’s been decades since Dad and I took lunch bags of suspicious tubes to the local drugstore to test them on their console tube tester. What goes around sometimes comes back.


Since I bought an Ampeg tube amp from a fellow guitarist, I’ve learned more about those finicky, fragile, lethally high-voltage tubes than I ever expected to know. Here’s my latest observation:

My amp has two EL84s in the power stage, is rated at 15 watts output, and is just plain loud. I toned it down a bit with a pair of EL844s (a lower output version of the EL84). They sound fine and breakup occurs just a bit sooner.

I tried to adjust the pre-amp stage as well by replacing the one 12AX7 with a 12AY7, a tube with a lower gain factor. This swap hasn’t gone as well as the EL844s. The 12AY7 makes the amp sound oddly soft in terms of response and overall sound (can’t think of a better way to describe it). Having gone back to the 12AX7, the amp sounds better.

Back to work (on tomorrow’s sermon) and maybe a little time later for some guitar . . .