Variation on clean module modification procedure....

I bought my Blackface module (silverface front panel) pre-modded and was looking it over last night. I found that there were TWO resistors in position R1. I searched the web trying to decode the different color bands to find what value the resistors are. Here is a decent resource for that. See section 6.1:

http://www.teamsaber.com/john/ee/resistor.html

Turns out that one is a 470 ohm (most likely the factory resistor) and the other is a 220 ohm. By using this calculator (another great resource....would also be handy for calculating speaker wiring impedances, etc.):

http://www.1728.com/resistrs.htm

I found that the total resistance with those two resistors in parallel is......150ohms.....the desired value.

Just thought that was kinda interesting and was gonna pass the info along. If a person has trouble finding a 150 ohm resistor, but can find a 220 ohm, then this appears to be a workable alternative.

Most likely the Fab ran out of 150 Resistors and they used the two resistors in Parallel to give the desired value.

FM

Exactly.

Also, it appears they soldered the second resistor in from the top, which should be easier to do as it looks like a really tight fit to fit a soldering iron tip in between the bottom of the circuit board and the bottom plate. I know people have done it, but wow that looks like a tight fit.