6N7 ?

[shooter]

so I flunked resistors 
I went here;
http://www.r-type.org/exhib/aaa0902.htm
read
looked at the data sheet below.
294vdc plate, really, not 295    EDIT: (I just found the -g vdc )

the term quiescent bias, I sorta get, in use that would be no Grid R's?
How does the cathode come into play?
the data sheet has an example of Class A driving class B, but I get lost at the CT + battery

[PRR]

> no Grid R's?

That goes with the transformer coupling.

Why are you interested? '53/6N7 was soon obsoleted by better ways to make a 10-Watt amp.

The Class A condition is 294V because the power stage assumed an even 300V and the driver stage wants 6V bias (294V+6V= 300V).

[shooter]

was soon obsoleted

got interested from the dobro thread, It won't get far, re-learning Class B, maybe even BB.  kinda like my only flathead, '46 ford, mercury heads, 100hp!  I passed it on, got built up, then lost to a divorce, buggy whips are my next interest   

[ginger]

6N7 tubes are prone to microphonics, as are the ones in my National... avoid them

[shooter]

I don't have any, I'm just toying with the idea of a Class B amp, still in the re-education camp for now 

[PRR]

> toying with the idea of a Class B amp

Which is, ....what??

I will assert there are NO class B amplifiers.

Class B is an idealized crack between A and C, and no practical device can work there.

The promise of class B is a low idle power consumption with high maximum power. Less tube heat and greater power economy. But we don't mostly run tubes on batteries. And we don't really fret about guitar amp power consumption. Often the electric bill for the lights is greater than that of the amplifier.

So what is this class B attraction?

[shooter]

So what is this class B attraction?
The 10W SS amps I have are Class B
I'm still graplin with the output stage, single B+, stacked transistors as PP, directly driving the speaker.  I'm not interested in direct drive, but the "stacked" feature 

and it's got me questioning myself on what I "thought" I knew about bias;  the closer to 0 the more current, positive n tubes die, the further neg, less current, but in B, 0=no current, the more you drive it positive the more current. So I'm trying to figure out where my brain is mis-firing

[shooter]

switching to SS understanding in hopes I can get back on track 

here's  pic's to help 
I'm trying to "see" current flow in the push, and pull, condition 1 makes sense, condition 2 doesn't

[sluckey]

Think of it like this...

Condition 1... the top Q is on and charges C7.

Condition 2... the bottom Q is on and discharges C7.

[shooter]

 
that is the kinda thing that lit the bulb!!!!!!
thank you kind sir

[shooter]

Ok, back to tubes;
I was following links on Class B from previous link above, got here, took this pic
http://www.r-type.org/articles/art-103.htm

Isn't this PP example basically a self biased configuration, the cathode voltage "shifts"  based on sine-wave swing?

[PRR]

The tube is specially designed to pull a small (idle) current when Vgk is zero, less when Vgk is negative, and more when Vgk is positive (when it also pulls grid current, hence the transformer and beefy driver).

Such things may be good on battery but usually have "queer" distortion profiles.

That's also a now-uncommon interstage transformer.

[shooter]

The tube is specially designed

ok, that helps, and I like un-common, have done 2 builds with  tranny PI's 
and they do produce scary weird scope images, but the guys with strings like it 

so a "modern" Class B would be to take your favorite 5E3 PP, adjustable fixed bias, crank bias neg til current is all but gone, then bring in the signal?