Quick B+ question

[navdave]

About how much B+ would I need to get 100 watts out of a pair of KT88's?

[stingray_65]

"With an anode to anode load of 4,000 Ohms and 550 volts on the anode a pair run in ultra linear AB1 will deliver 100 Watts at 3.5% distortion"

http://www.r-type.org/exhib/aad0118.htm

Quick answer.

[PRR]

> About how much B+ would I need to get 100 watts out of a pair of KT88's?

Don't you also need to know B+ current demand, current variation, screen voltage, load impedance...?

Didn't some junior engineer, long ago, write-up a cheat-sheet for the tube so it would sell well?

http://www.mif.pg.gda.pl/homepages/frank/vs.html

[navdave]

Thanks stingray wouldn't I get a little more power and harmonic
distortion running in pentode? Got 550vdc under load.

"With an anode to anode load of 4,000 Ohms and 550 volts on the anode a pair run in ultra linear AB1 will deliver 100 Watts at 3.5% distortion"

http://www.r-type.org/exhib/aad0118.htm

Quick answer.

[stingray_65]

Another quick answer,  Yes.

As far as more power, It wont be noticeable, aurally that is.

Here's the thing, how often are you going to run it wide open?

More than likely, what most guys do is turn the knob till it's a bit louder than they think they can get away with  how many watts is that?

Not to forget that volume is logarithmic, all things being equal (same input signal, same speaker efficiency) a 1 watt amp is XdB, a 10 watt amp would be 2XdB, and a 100 watt amp 4XdB, that is to say a 100W amp is twice as loud as a 10W amp, at say an even 10% power gain by not running in UL will not make a aurally noticeable change in volume.

As far as distortion, it will be noticeable, UL is not just for audiophiles who can tell the difference between oxygen free speaker cables and lamp cords.

And it will come in sooner too, most guitarist feel this is good.

But the REAL question here is..

What do you think you want to build?

are you looking to build a PP KT88 amp and need to find a tranny or do you have a tranny that you're looking for some useful project?

Ray



 

[navdave]

Been building em for a while but been using 6550's and OT's rated
at 60 watts. Just thought I might be running those 60 watt
output trannys a little hard. They get pretty hot after a while.
So if I can get a lil more power and head room that's what I wanna do.

What do you think you want to build?

are you looking to build a PP KT88 amp and need to find a tranny or do you have a tranny that you're looking for some useful project?

Ray