Impedance Mismatch Prohibited?

[Beck-Ola]

Steve:

The JMD:1 owners manual makes a strong statement about using the correct speaker impedance load and implies possible damage if mismatched. Seeing as many tube amps are fairly tolerant of impedance mismatches, e.g., 2:1, does this mean the JMD:1 is more susceptible than usual to damage from this and it should really be avoided?

I often like to daisy chain a couple of 2x12 cabs and the lack of a 4 ohm output jack makes that problematical. Not a big deal though. Just wondering if it's really ill advised to run from the 8 ohm output into a 4 ohm load?

[SteveD]

The impedance mismatch section is standard text in all of our valve amp handbooks. It is a recommendation accompanied by a warning of possible damage.

If you want to take the risk then that is your prerogative. I would personally not recommend a mismatch on the JMD.

[Beck-Ola]

Thanks, Steve. If you don't recommend it in this case, then I will avoid it. I noticed with the Class 5 it was a "go for it", but then 5 watts is a lot less than 50 watts. Your wording seems to imply a greater risk than usual though.

[SteveD]

The Class 5 is a different beast entirely.

[Beck-Ola]

That's for sure! Different "beasts" is about right too.

I am digging the JMD a whole lot. Excellent and inspiring amp!