2012 Dr.Z M-12

DR. Z amps are in many ways my favorite boutique amplifiers (Although Friedman is right up there as well). The build quality and sound they produce is as good as any vintage amp and they are one of the few modern amp builders that are making fully hand-wired circuits that will last a lifetime. This one came in with a blown pair of EL84 power tubes. No other issues to speak of.

We selected a matched pair of EL84’s out of the customers backup stash of tubes and installed them. I am able to match my own power tubes with the B&K Dyna-Jet 707 tube tester I have - which comes in handy in situations like this where a customer has a big batch of random tubes but doesn’t know how good they are or if any are pairs/quads. The EF86 pentode in the front end of this amp gives it a unique tone with a lot of high-end clarity. The Class AB Cathode Bias was within factory spec and was not adjusted. Great amplifier!