Head ----> Cab ohms question

Vim Fuego

Hey there,

I recently acquired a head that is 8 ohms mono but for the present time, I have a cab that is 16 ohms mono but 8 ohms stereo.

Is it possible to run the head through only one of the 8 ohm inputs or am I asking for trouble? I'm planning to sell the cab anyway and replace it with an 8 ohm 2 x 12.

Sorry for the possibly stupid question, it's been years since I bought a new head so it's been a while since I looked into impedance and whatnot.

Cheers and happy new year!

Doctor J

It's fine. Once the ohm value of the cab is greater or equal to the value of the head you're fine. There's a good guide to this in the resources sticky.

Vim Fuego

Cheers, I did have a look in there but unfortunately the link to that guide is now a 404 error. I have been running it through the 16 ohm input and it's ok, was just thinking it would be a better match through one of the 8 ohm stereo inputs. Will give it a go anyway.

Voodu Child

The most common answer you'll hear is what Doc has said.

However, you'll hear some very respected and experienced techs answer the exact opposite - because of flyback voltage effects there is much more of a chance of damage running into a cab of higher impedance than lower.

Honestly, there's no right answer - any kind of mismatch has the potential for damage because every amp is different - some will handle an impedance mismatch no problem (Mesa/Boogie etc), others won't fare so well. And it depends on other factors - how hard you're running the amp etc.

The best answer I can give is to match your impedance if possible.

Vim Fuego

Thanks for the advice folks. I will be getting an 8 ohm 2 x 12 as soon as funds allow I might just sell the 4 x 12 as it's really superfluous to my needs right now.