A blog of my tube amp design and modification work. Primarily my own builds, but occasionally I feature work I've done on others' amps (with their permission.)

Tuesday, May 21, 2013

The next one!

So, still in the process of homebuying, yeah? Brainmeats don't want to stop thinking about amps. This one popped into my head today - okay, I've been thinking about Plexis a lot and it doesn't look like building a Plexi from a kit makes a whole lot of economic sense w.r.t. resale possibilities. And I've got this Crate GT50 Stealth combo that's been begging to be de-Lee Jackson'ed into some proper Marshall thing.

So why not a Plexi? Sounds like a plan, right? Well, my stupid brainmeats got around to thinking about a couple building blocks that it really likes, a couple it really wants to try out, and somehow I convinced myself to build a new "original" design. Well, original in this case means "stolen from Merlin" but... wait, why am I telling you this?! I am a God of Mojo! I invented the pentode!


*cough*

Sorry; I'm a little delirious. I just spent three hours or so typing up this:


Okay, admittedly, the power supply is a little lacking. The rest though... ho ho ho.

So, starting out: the first two stages can be either run in parallel (think: jumpered channels) or cascaded (think: one-wire mod) at the flip of a switch. Then those slam into a small-signal pentode (think: EF86). The sound gets smoothed out by a directly coupled cathode follower and the rest is pretty much "every amp ever made" though I'm going to try to design a lower output impedance long-tailed pair phase inverter so I can ixnay blocking distortion in the FOUR 6V6 OUTPUT SECTION. 

I do have a working OT this time but I've got to pick a PT which means the power supply world is my oyster. I've already started 'funny' for a guitar amp by using a full-wave rectified bias supply.

Okay.

Well, to summarize: this amp is going to be pretty high gain but extraordinarily versatile. Cleans are going to take a back seat to this glorious preamp distortion and who knows what the final result is going to look like considering how many times I changed Bodie around, but man... this'll be interesting.