Homebrew Amp Sends Sino-British Combos Packing

I took my new amp to church yesterday? The verdict? Amazing.

One of the guitarists asked if he could use it during services. Mind you, he was going to be putting it up against the lead guitarist’s $1200 Vox AC30. At the end of the day, the guitarists were telling me how great my amp was.

The sound is warmer than the Vox. It breaks up nicely. It sounds way better at low volumes. It has plenty of juice. They didn’t have to turn it past 12 o’clock, even with a single 10″ speaker battling against the Vox’s 2×12.

I put a new part in it: a humdinger circuit suggested in Merlin Blencowe’s book on power supply design. This is a trimmer pot between the heater feeds with the wiper connected to ground. It allows you to balance the voltages in the feeds so they’re identical. This gives excellent hum cancellation. Now the amp is really quiet.

I’m planning to build an amp for one of the guys, and he was leaning toward a Super Reverb, but now he’s thinking two amps, because he likes this one so much. It looks like I can do it for around $400, unless he goes for a Gucci tone-snob transformer set. That will add $300 to the job.

It amazes me that I can use this amp to practice in a small room. And look how God has given new value to the physics education I thought had been wasted.

Two of these would completely solve my church’s guitar amp problems, but I guess they’re stuck with the Voxes. They’ll never sell them and use homemade amps. People don’t like to rub their mistakes in their own faces. When you blow that kind of money on amps, the natural thing is to struggle to make use of them.

Life is sweet. The next project will begin as soon as I can get parts.