THD Reactive Rectifier

[baddog]

Has anyone tried these? I have a silverface bassman 50 that i was thinking about trying it out on.

thanks

[TD_Madden]

if they're like Weber's Copper-caps, they work pretty well....I think Ted even makes one which is adjustable.

[Old Tele man]

...don't know about the THD device, but Ted Weber's Coppercap™ units provide a linear-approximation of what is actually a power-exponential curve...it's close, but not "exactly" the same voltage "drop" versus current load.

...while some people claim to be able to "hear" a difference between a 'real' vacuum tube rectifier and the Coppercap™, I have to say that I couldn't HEAR any difference, even though I was certainly able to measure and record real-world differences on my o'scope and digital screen captures.

[dai h.]

by "power-exponential curve" do you mean logarithmic and if so, why is it not linear?

[Old Tele man]

by "power-exponential curve" do you mean logarithmic and if so, why is it not linear?

...the actual Child-Langmuir "diode" equation (also called 'Three-Halves' Power Equation) is:

Ip = K*(Vp)^(3/2)

where:
Ip = Plate current,
Vp = Plate voltage,
K = Perveance, a tube coefficient based upon internal physical geometry and spacings.

...as you can see, it's an exponential equation and not a logarithmic equation.

[dai h.]

thanks OTM. Sorry, I'm basically a idiot when it comes to math, so I can only sort of see that the voltage into the tube will be multiplied by the Perveance(seems the bigger the cathode and plate, plus the closer they are the bigger this value?) and I don't undertand the "^(3/2)" coming after that.

[loudthud]

^(3/2) is an old way of entering exponents from back in the days of line printers, teletypes and punched cards (usually called IBM cards). So 4^2 would be 4 squarded equals 16. This board has no way to enter super and sub scripts unless there is a way to do it in html. If anyone can enlighten me, that would be great!

[baddog]

Hi everyone

I didnt understand any of the stuff you guys where talking about but i did order the Weber 5U4GB Copper Cap Moduler and will post my findings after installing it. Im hoping it will warm my amp up a little. at the very least it has to be better than the orignal diode rectifier that is in the amp. I have a silverface 72 bassman head that i turned back to the blackface specs.

SRV baby

thanks
keith

[Old Tele man]

Hi everyone

I didnt understand any of the stuff you guys where talking about but i did order the Weber 5U4GB Copper Cap Moduler and will post my findings after installing it. Im hoping it will warm my amp up a little. at the very least it has to be better than the orignal diode rectifier that is in the amp. I have a silverface 72 bassman head that i turned back to the blackface specs.

SRV baby

thanks
keith

...a man after my own heart! -- when the facts (or theory) make no sense, we just go out and "...TRY IT..." approach.

...looking forward to hearing your results.

[Old Tele man]

^(3/2) is an old way of entering exponents from back in the days of line printers, teletypes and punched cards (usually called IBM cards). So 4^2 would be 4 squarded equals 16. This board has no way to enter super and sub scripts unless there is a way to do it in html. If anyone can enlighten me, that would be great!

...here's how I do it, I use the 'hidden' Microsoft "ALT-key" keyboard method:

1) Turn 'on' the keybord NUM LOCK function to enable the numeric keypad.
2) Then, while simultaneously holding 'down' the ALT-key, enter 4-digit numeric character-code on the numeric keypad and then release the ALT-key; NOTE--the leading ZERO ('0') must be typed.
3) When done, don't forget to turn NUM LOCK 'off' again.

...here are some commonly used codes:

0170 = ª
0176 = °
0185 = ¹
0178 = ²
0179 = ³
0188 = ¼
0189 = ½
0190 = ¾
0248 = ø
0131 = ƒ
0181 = µ
0177 = ±
0183 = ·
0149 = •
0215 = ×
0133 = …
0153 = ™
0169 = ©
0174 = ®

...there are others, here's link to a PDF-table that shows all the 4-digit ALT-key codes: http://www.pgdp.net/c/faq/charwin.pdf

[dai h.]

thanks LT. Sorry for the thread hijack there baddog!

[baddog]

Not a problem. No fees to small

SRV
baddog

[bassman69]

Need a Little Help from My Friends

Could someone please tell me how to hook up the reactive rectifier?
I read that it was to replace the solid state rectifier but I don't see how. It looks as though it is added to the existing circuit. (Is this correct?)