The Amp Garage

ypaulvogel, I completely get what you're saying about installing 3-phase equipment. For guitar amps and similar gear, I'm thinking that a 2 pole power switch and 2 pole circuit breaker (like this ) would completely eliminate the problem along with worrying about whether or not the plugs in public sp...

That's a good point. Only one of the two wires is protected with a circuit breaker. I'm not sure how that should matter to us at the guitar amp end of things, but it's a reasonable point. I apologize if I sound argumentative. I'm just trying to convince myself one way or the other that the two wires...

Well one is more earthy than the other. The neutral wire is connected to earth somewhere in the circuit. Whether it is at the power generation facility or in your home. It is referenced to earth and said to have 0 potential. Right, but what benefit is there in knowing this, or which of the two wire...

And yes, neutral doesn’t mean ground. It’s just current return, sometimes it is connected to earth early in the return path but it doesn’t have to be. "Current return"? What does that mean? Exactly the same current flows in both wires - opposite directions, of course, but there's absolutely no way ...

"Neutral" wire? What's that? I am aware that in some countries one of the two power wires happens to be connected to ground back at the breaker box, but really that's not a good reason to treat it differently, at least not as far as I'm concerned. Start out by thinking of both wires as equally hot, ...

If you go to the Welcome page of that site, there's a line near the bottom that reads:

"email for comments or questions: uneumann at gmail dot com"

The load on triodes is not nearly as critical as with pentodes. By that I mean that there's no danger trying wildly different loads. In general, with triodes as output tubes, higher resistance loads give lower distortion and lower power... and vice-versa, but don't be afraid to try every combination...

printer2 wrote: ↑Fri Sep 27, 2019 10:43 pm [...], tie the diode pins to the plate.

Or the cathode.

Since the 6J5 is an octal tube, you could rewire the socket for 6SL7. That's a dual triode with more gain than the 12AY7 originally used in the 5E3, but less than the 12AX7 that many people substitute. They can be microphonic, but as Stevem said, they have a nice beefy sound that should work well wi...

The Blackstar is cathode biased, so the resistors around the switch are connected to ground. It should work with fixed bias where the resistors are connected to the bias supply. I don't think it's important to use different size resistors (200k & 220k.) The big resistor (2.2M) is to reduce noise whe...

It seems to me that grid current through a 10M resistor will bias the tube very cold... until you plug in a guitar with ordinary pickups. Then the grid current will go through the pickup and restore normal bias - probably not a big deal. I don't know what will happen when you plug in an acoustic wit...

Think of magnetic shielding as channeling the flux around what ever you're shielding more than blocking it. By that I mean that it won't work to put up a wall hoping it will leave a "shadow" free of flux. You need to make a full enclosure; the flux enters the shield on one side, stays in the high mu...

The idea is that it needs to be fully annealed after bending, which amounts to heating it in an oven to some temp after bending and then letting it cool slowly.

I don't know what the magic temperature is, but it's almost certainly hotter than the oven in your kitchen will go.

Have you tried removing (or changing) the voltage divider?

Rob's Blackvibe has 220k/270k resistors forming a voltage divider to mimic the reduced gain of the AB763 normal channel (he calls them "mixing" and "Vib Ch load".) You can remove them for more gain. It won't necessarily add the flavor of the third stage in the trem channel, but it's easy to try. You...