Classic 30 Dropping Resistor

[mikeboone]

I have a Classic 30 with a burned dropping resistor (R58). The markings are gone and the schematic it is listed as 400W5FP. It is a power resistor of at least 5W or so. Can anyone clarify the value? Is it 400 ohm? The one in question is now an infinity resistor which doesnt fare well for the rest of the power supply that is starved for V.

[Albert Kreuzer]

400 Ohms 5W flameproof.
Have you checked the reason why it burned up? Could be a problem with the power tubes or the filter caps.

[Enzo]

And since 400 is not a standard value, if your supplier doesn;t have those, use 390 ohm. Even Peavey does that in some production runs.

Albert is right, of course. resistors never burn up by themselves, they burn up because something dragged too much current through them. And here that something is almost certainly a shorted power tube. A shorted cap or something is a possibility but way lower in probability.

[mikeboone]

Thanks guys... Thats exactly what I needed. My guy downtown has a 390 in stock. I will give the caps and tubes a look to see who the guilty party is.