L-Pad Problem

[simon111]

I got through the post today an L-Pad all in one speaker attenuator to try out on my amp (the volume pot looking ones with three terminals). Unfortunately I ordered the 8 ohm one and my valve amp is 16 ohm.
So three questions.

1, Would using it harm my valve amp? (8 ohm instead of 16)
2, If not how would it differ from a correct 16 ohm one? (sound wise)
3, If it would  harm it, is there anyway I can change it to 16 ohm (remember this thing is sealed up) - would adding an 8 ohm resistor going into the input side work?

I don't want to try it until someone says it will be OK. As I don't really want to blow up my Dads Fender amp!

Simon111

[d95err]

In general, it is better for a tube amp to run with a too low impedance load than too high. So 8 ohm L-Pad with 16 ohm output is better than the other way around. Old Fenders are said to be much more reliable than e.g. old Marshalls, so I think you can risk it. Don't take my word for it though...

Adding a (big power) 8 ohm resistor between the speaker output and the L-Pad could be even better. I think it would lead to a minimum attenuation of about 6dB (not completely sure about this). That is probably a good thing. You'll probably never want to use less than 6dB attenuation anyway, so you'll get a better range for the usable attenuation levels.

I'd ask around on the AX84 or 18Watt forums. They probably know better (than I do).