Modern Drummer’s spin on Drum heads…


Great Advice on Testing Circuitboards


In circuit testing of output transistors: set the meter to the resistance mode and check the base to emitter and base to collector resistance. negative lead to the base for npn and the opposit for pnp. You should read a few Kohms one way and a few tens of ohms the other( the readings depend a lot on the type of circuit you are checking.). If you have a circuit that has more than one output transistor, than compare the readings between them, keeping the same meter lead orientation{polarity). There is a technique that you pick up that gets you familiar with the different values that are shown when checking in- circuit components. I prefered a Simpson 260 analog meter when I did this.

How to fix a Yamaha G series

I ain’t no good at playing guitar, but I have been fixing amps for 35 years. I would, in fact I did twice, buy broken G100 amps to fix them.
In the G100 there are only eight different types of transistor and four different type of diodes in this amp, and that covers everything, the preamp and power amp sections. Last time I bought some, all were still available or they cross to generic replacements.

One of my amps had a fried input FET transistor in the preamp, the other had a bad component in the power amp. Both were easy fixes, and both sound great now. Not selling mine.

My opinion, nice design, well made, good clean sound. If you find one in good condition at a decent price, I say buy it. If you find a broken one cheap, let me know.