Biasing a Blues Deluxe or Hot Rod Deluxe

[nocaster]

First of all...........

You can die when you play with valve amps. Even if they're switched off. If you aren't confident stop reading. Don't come crying to me when you're dead.

Right, on another thread someone queried about biasing these amps. It's a piece of piss so I said I'd take some pics and post them here. Also, there doesn't appear (as far as I'm aware) to be anything online that's easy to follow and not full of "Yankee" jargon/slang.

This process is correct for Blues Deluxe and Hot Rod Deluxe amps. It may or may not apply to other Fender amps but I don't have any experience of any other models so can neither confirm nor deny this.

Here goes :

Unplug the amp. Lay the amp down flat and take the back off. You need to remove 6 screws and then pull the back cover off :



Ohh scary stuff!

If you are replacing tubes then do so now by simply pulling out and replacing the old ones. Take care to line up the tubes correctly to avoid damaging pins.

The two points you need to know about for biasing are marked below. One is a ground point and one is a special resistor Fender installed to enable you to bias your own amp. We will be measuring the voltage differential between these points and adjust it accordingly. This is called setting the bias............



Here's the ground point in more detail.It's the lower red circle in the pic above :



I personally clamp the black lead of my multimeter onto the little bit of metal screwed to the chassis. Using "clip on" multimeter leads is better in numerous ways. It's a bazillion times safer as you clip the test points on and then your hands are free to adjust bias, pick nose, etc.

Anyway, go ahead and clip your black multimeter lead onto this test point.

Then plug the amp in and switch onto standby. Leave for a few minutes to let the valves heat up, then switch on properly.

From now on be even more carefull then you were being before. Death can occur.

To be continued...........................