Tube Amp Archive

How about this: It is illegal to sell the amp. So don't sell the amp. Sell the transferable right to use a non-compliant research prototype amplifier loaned to the licensee in perpetuity (or 99 years if "perpetuity" causes legal problems). The licensee would sign a waiver stating that he understands...

Here is a copy of the RoHS directive: http://europa.eu/eur-lex/pri/en/oj/dat/2003/l_037/l_03720030213en00190023.pdf It specifically exempts lead in glass of CRTs or other electronic components. Barium and strontium are not on the list, so it looks like vacuum tubes would be compliant as long as they...

RoHS applies only in the EU (right now, anyway). It may very well be that Sn-Pb solder will be hard to get one day. SnAg or SnAgCu solder are the substitutes, but they have a number of disadvantages. First, they melt about 25-30degreesC higher than Sn-Pb so the components have to be able to withstan...

I have a lot of experience with mass produced electronics and I rarely see boutique amps marked as compliant with FCC Part 15 (A or B), UL, CSA, RoHS, etc. I think it is pretty likely that most well-made amps would comply with FCC Part 15, UL and CSA. But the testing is expensive--about $5K to have ...

Dueling Dumbles. Larry Carlton (335). Robben Ford ('59 Gold Top). Enjoy.

http://www.youtube.com/watch?v=Lwt9eKDx ... re=related

http://www.youtube.com/watch?v=f64XZRRs ... re=related

The speed of the effect of electricity is very fast. However, the actual speed of any single, particular electron in a copper wire is nowhere near the speed of light. http://hyperphysics.phy-astr.gsu.edu/hbase/electric/ohmmic.html It's in centimeters per second, depending upon conditions; called th...

The THD of a tube guitar amp is still quite high (5% or more) even when it is running "clean". So the sound is going to be colored anyway. And there are other components that affect the tone of a tube amp--such as the output transformer--that are not present in a solid-state amp. If you play your gu...

The speed of light down a wire (to first order) is c / sqrt(epsilon), where c is the speed of light in a vacuum and epsilon is the dialectric constant of the insulation relative to a vacuum. For PVC with a dialectric constant of 3.18 or so, the speed of light is 0.56*c. I found an interesting articl...

You are right that it has to do with the high order harmonics but not for the reasons Dumble stated. 1) Harmonics are not "fragile"--I don't even know what that means. Maybe he means if you have an amp full of stray capacitances acting as low pass filters then the higher harmonics would be attenuate...

Dumble: "The more fragile harmonics can survive in a vacuum tube, where they seem to be eliminated or squashed in a solid state crystal lattice. I think it just comes down to that. The physics of it--electrons can survive in a free space vacuum, where they have trouble in a crystal lattice. I think ...