resistor codes

[JC@]

I have a marshall dsl401 on the bench that blew it's filament supply rectifier.
Changed all tubes and the amp won't bias.
Resistor R31 was 1K1 instead of 15K, and that is how it left the factory years ago. I wonder how many owners this amp had, and how could they accept it biased that way (.2 volts instead of 1.4 according on the schemathic)

[Wilder Amplification]

I have a marshall dsl401 on the bench that blew it's filament supply rectifier.
Changed all tubes and the amp won't bias.
Resistor R31 was 1K1 instead of 15K, and that is how it left the factory years ago. I wonder how many owners this amp had, and how could they accept it biased that way (.2 volts instead of 1.4 according on the schemathic)

They use a 5 band color code on a lot of those resistors. A 15K with a 5 band color code would have brown/green/black/red on it as opposed to brown/green/orange like a 4 band would have (the last color band in each is the tolerance % rating).

Are you sure that R36 didn't blow open or drift up way off spec?

[JC@]

For sure, R31 was a brown, brown, black, brown, red instead of a 15K, and indeed measured 1K1, so I guess it was a series E42 resistor (I had to look that on google btw) they plugged there in error.

[Wilder Amplification]

For sure, R31 was a brown, brown, black, brown, red instead of a 15K, and indeed measured 1K1, so I guess it was a series E42 resistor (I had to look that on google btw) they plugged there in error.

OK gotcha...yeah that would be a bit on the low side.