Recent content by raiken

Those look like standard gutter guard material you can buy at Lowe's or Home Depot. They are good for rear panel vents on heads, but would be too thin for an unsupported front panel like the one in your original picture. For that, you need expanded metal. Do a search for expanded metal and...

There's a Fluke 87V on my bench.

You should get one of these and sweep the impedance curve of each speaker in the enclosure to see the differences and correlate them to frequency response differences: https://www.daytonaudio.com/product/1650/dats-v3-computer-based-audio-component-test-system It will store up to 20 different...

Anything worth doing, is worth overdoing.

Weller.

It may be magnetostriction, which is a normal noise caused by the vibration that occurs in an output transformer due to the magnetic field produced by the signal. Normally you don't hear it because the speaker volume masks it, but when playing into a silent load it becomes audible.

Has anyone mentioned Reaper?

Note that we are talking about two very different things here, balance in normal operation, which is designing the circuit for equal amplitude signals on the two outputs when the PI is npt overdriven, and duty-cycle balance when the PI is overdriven, to prevent asymmetrical drive to the output...

It reduces the amount of duty-cycle modulation that occurs when overdriving the phase inverter. Typically, values in the range of 330k to 390k give the best results, but 470k may be enough. It will not affect the normal, non-overdriven PI balance of the two sides. Duty-cycle modulation...

Purple.

High altitudes are also bad for electrolytic capacitors. They can fail if transported in unpressurized cargo holds, or if they are used in certain avionics equipment where they are subject to high altitudes. There are special hermetically sealed bulk capacitors that are used in military aircraft.

Tube amps have built-in heaters. Not only do they sound great, they keep you warm and toasty all winter long. Modeling amps, on the other hand, not only sound cold and lifeless, they don't care if you freeze to death. All kidding aside... Most electrolytic capacitors are rated in the -40C...

One thing to note: just because a tube is microphonic doesn't necessarily mean you have to throw it away. Microphonic tubes can sometimes live long and productive lives in other tube positions, most notably, in the phase inverter. You can try swapping tubes around to find the worst and...

Purple tolex has the best tone.