Zener diodes - 5W rated

Add a zener diode (in the opposite polarity to the rectification diodes in your power supply) and you can drop your B+ voltage. Very useful if you just want to trim some power valve dissipation. I use one in the WF-55 4W Tweed-style amplifier – you can see it in-place in the second photo on the right.

The type I supply here is rated at 5W. You can use them in series if you want to drop more voltage and stay within their power rating. I stock 10V and 20V versions.