36 watt cathode R

[FireLewis]

In a 36 watt,

Wich way is better, between using a common resistor for the 4 tube set and using one R per pair?

Is there any difference in sound?

Thanks.

[Plexi]

Better? their are different ways of doing this, don't know if any are better than the other. You can use one single resistor for all EL84s,
you can do each pair, or you can do each single tube.
Probably the single one for each might be best,not really for tone or sound,but if you were playing and one tube went out,you might get by, pulling the one bad tube. But also, you have more componets that way, and more things to go bad.
I like using one,and one cap. you can use those that mount to the chassis.

[Phil_S]

One is the simplest way to build. More is just clutter, so what's the point?

[Snapcase]

I don't see any practical reason to use individual resistors per tube. It only complicates the building. If anything, using a resistor per side if you are somewhat picky about the push-pull balance. Or using a single resistor followed by a rheostat for further and more precise balance (or imbalance) settings. But a single resistor alone will work good enough and keeps things simpler.

[zaphod_phil]

I kinda prefer the idea of using one resistor per push-pull pair in a 36W amp. That gives you the option to pull one pair of power tubes, and run the amp at 18W whenever you want (with a 16 ohm speaker on the 8 ohm tap or an 8 ohm speaker on the 4 ohm tap).

[krx]

I kinda prefer the idea of using one resistor per push-pull pair in a 36W amp. That gives you the option to pull one pair of power tubes, and run the amp at 18W whenever you want (with a 16 ohm speaker on the 8 ohm tap or an 8 ohm speaker on the 4 ohm tap).

Yes, good idea. Just make sure each resistor is shared by an opposing push-pull pair and that you pull the right tubes.

[rjgtr]

A nice idea when using two pairs with two resistor/cap pairs is to put one p/p pair on a switch for 18watt mode. Then you don't have to pull the second pair. I think Ceriatone does this.