DirtyErnie

Raw rectified DC, without the tubes in their sockets. If you put the tubes in, you'll get the ~48v. You're both right. 😉

If they sound great, does it really matter? There are some decent frequency sweep videos on the YouTubes, running those seem a little more practical for in-room checks.

^^^ This first. Electrolytics, selenium rectifier, clean & tension sockets. Don't worry too much about voltages being 'over' as long as the heaters are 7v or less. I'll look up what I did to make the bias voltage variable. I think it was a couple of 10-turn precision resistors, will check the value.

I changed the 1.2K series resistor (screen grid voltage, with the 8K/20w shunt resistor) for 3.3K, lowered my screens to ~315v. The stock ~360v made the JJ EL84 have a 'harsh/busy' kind of sound, now they're smooth.

Mine has a black cable running front-to back by the selenium rectifier. gotta get back to soldering on that one.

There is the notion that an amplifier is a modulated power supply. From that perspective, everything from the power plant to your speakers has an effect.

I think the surface temp limit referenced in most of the spec sheets I've seen is something like 250*C. Capacitors should be at least 85*C. That's a lot hotter than you can handle.

Toy Hauler? aim them out the back and enjoy the closest thing to perfect acoustics.

With? Con: More Gear. Pro: can tune the system and the room to something resembling 'perfection'. Without: The opposite of that ^^^^^^^^^.

8-ohm drivers, should meter out about 6.3 or so. maybe a bit more...

Yup, that would do it. used to play bass for a guy that gigged with one. the bar would let us turn it up to 0.8-1.1. Mesa V-Twin pedal for tone. Apocalyptically loud. 😁

If you were doing it right, they got hit so hard they broke in instantly. 😉

Did you notice both the lows AND the mids cleaned up?

Some of them. Then you get the older-school stuff with naked paper cones and tiny motors. Few things are black-n-white. Most things are closer to 'on a scale of 1-to-10...'

I'll go with 'Yes.' Whether that's due to equipment or ears adjusting is open to debate. I've definitely heard new vacuum tubes 'open up' after a few hours of use. Guitar speakers are quite well known for loosening up after several hours, I don't see why any other cone speaker should be different.