carbon comp vs metal film..nice little read

http://www.geofex.com/Article_Folders/carbon_comp/carboncomp.htm

Interesting discussion.

One quibble though: the distortion is even-order, mostly, when the bias voltage is larger than the signal voltage. If the bias voltage is low you can still get distortion with big swings but it will be odd-order.

In between these conditions you will get both.

The example he gives is a little unlikely: 100V sine wave (rms? peak? peak-to-peak?) riding on a 50V d.c. level. You wouldn't get this as a plate load R unless the tube is being driven to cutoff, and then you would just approach 100V p-p I think.

So, when it's a plate load resistor it is true that the voltage will be constrained by the peak positive swing to the power supply, unless there's some other funny business going on, so you will tend to get even order mostly as is asserted.

Guitar players are notorious for driving tubes past their rails.
All guitar players, can I get an Amen?

Amen

wot ... who ... where
:shock:
err
:roll:
yeah

oh ... AMEN !


mmmmmm .... even-order distortion ... hommer

I don't think that percentual change of voltage across a resistor due to it's voltage dependance is the same as percentual amount of distortion generated.

amen.

hallelujah even.

dave

It's Holy Ghost power.
Power to change ah.
I got the keys to the kingdom ah.
Church ah!
He did a back flip over the devil ah.
The Apostle E.H. ah.
Too long on the river ah.
:razz: