Is Rocker 50 as easy to bias as a TSL?

[vinyl]

Just wondering how to bias a Rockerverb 50 Head. I do the biassing for my TSL Head but I don't know about this Orange yet. Can it be done with a simple multimeter like the TSL or is it more difficult? thanks

[VintageJon]

Actually you need a way the measure the cathode current, at a minimum.
(You could also figure Screen Current and subtract it from Cathode Current but in anything but EL84's it's usually less than 2 mA. Ignoring Screen current makes for a conservative bias in any event...)

Weber Bias-Rite could be very helpful. Another alternative is install 1 Ohm precision cathode resistors.

Ik= Cathode Current
Vp= Plate voltage
IPD= Idle Plate Dissipation
(Look up or ask me for Max Plate dissipation for your tubes. IPD should be no more than 70% of Max Plate Dissipation.)

Ik X Vp = IPD

This is the correct way to bias.

-Jon

[kannibul]

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by vinyl</i>
<br />Just wondering how to bias a Rockerverb 50 Head. I do the biassing for my TSL Head but I don't know about this Orange yet. Can it be done with a simple multimeter like the TSL or is it more difficult? thanks
<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

You need a Bias-Rite or similar, and you have to pull the chassis - both of which is not needed on the TSL.