Really stupid question, but how do I change ohm setting of JCM 800?

[rocksoldier]

I've never used it with another cabinet than my own, so I haven't bothered to find out how to change the settings.

Is it just to turn that thing with a screwdriver (see picture) for the right ohm (I guess left to right: 4, 8 16?) or?




Not my amp in the pic as i does not have it here at home, but i guess it should look the same, and i really have to know before soundcheck tonight.

[Dreamland_Rebel]

use a coin. and the 12 O'clock posistion is the indicated impedance level.

[rocksoldier]

I think the white marking may be gone on my amp, so if the amp is set for 8 ohm as it is now, which way to turn for which impedance?

[DonP]

I think the white marking may be gone on my amp, so if the amp is set for 8 ohm as it is now, which way to turn for which impedance?

If the amp is set for 8 ohms now, then the impedance is 8 ohms.

I think an explaination is needed.

You have a speaker cab. It has X number of ohms impedance.

You have an amp. Your amp has a selector to set the amp impedance to match the speakers you have.

If speaker cab is 16 ohms, set the ohms on the amp to 16.

* Special case - if you have two cabs, add the ohms together and divide by 4. and set your amp to this value. i.e. 2 16 ohm speaker cabs = (16 + 16 = 32) / 4 = 8 ohms for the amp to be set to.

[rocksoldier]

use a coin. and the 12 O'clock posistion is the indicated impedance level.

Worked out great, easiest thing in the world.

It was just that i had not done it before, and didn't have the amp avaible until the soundcheck today, so i was a little worried.

Thanks!