Adding a speaker to monitor dummy load

[CAS]

Thanks Helmholtz.

Does anyone have recommendations for power resistors for a dummy load?

Parts Express sells wirewound braking resistors as 'non inductive' load resistors. I believe that the Weber Tru-Load uses this style of resistor. The aluminum enclosure, i suspect, has the benefit of acting as a heatsink.

A lot of DIY projects seem to use generic wirewound resistors (the orange or green rectangular type) found on popular e-comm sites.

And Martin, it seems that you used an adjustable resistor for your build.

I'm probably over thinking this but I am stuck on which type of resistor format to purchase.

[martin manning]

I will be working on my AC30 (35Watts max power, I believe). I might eventually begin working on amps up to 100watts.

35W into an 8 ohm load is 16.7 Vrms, 100W would be 28.3. With the 100k/10k division you would have a maximum of 1.52 to 2.57 Vrms at the output with a high impedance load like a scope input, or 94 mV to 159mV into a 600 ohm line input. To drive an 8 ohm monitor speaker you'll need a separate path such as Helmholtz suggests.

Parts Express sells wirewound braking resistors as 'non inductive' load resistors. I believe that the Weber Tru-Load uses this style of resistor. The aluminum enclosure, i suspect, has the benefit of acting as a heatsink.
And Martin, it seems that you used an adjustable resistor for your build.

Parts Express load resistors will be fine, you'll need a couple if you want to have 4, 8, and 16 ohm loads. Yes, my dummy load uses a 300W 16 ohm adjustable, with the tap splitting it into two 8 ohm sections. Its inductance measures 20uH, which is not a big deal, 50 m ohms at 400 Hz.