better to run my amp at 16 ohms?

[jamme61]

I've read that it is best to run your amp at 16 ohms. If this is correct and you only have a 2x12 (two 16 ohm speakers in parallel) that is at 8 ohms. Is it better to still run the amp set at 16 ohms, into the 8 ohm cabinet, for best possible sound? What's the pro's and con's? thanks

[Reeltarded]

Don't mismatch the amp and speakers.

Pros: won't blow up or stress anything out.

Cons: won't look like Blackmore playing Highway Star live.

[martin manning]

I'm not sure I understand the question. Do you mean miss-matching amp and speaker, or do you mean choosing to run a 16-ohm impedance setting and matching cab over running at 8 or 4-ohms into a matching cab?

[cbass]

I think hes refferin to something GW said about the 16ohm tap sounding best because it uses the more of the transformers windings or something like that.I don't think he mentioned running mismatched load.
I wouldn't listen to anything he has to say anyway

[Structo]

Yeah, not sure that has ever been proven.

To the OP, the key thing is to match up speaker and output impedances for the most efficient match up.

Easier on the output transformer and power tubes.

[Cygnus X1]

Yep.
So now you hook up to 8 ohm rather than 16.

[jamme61]

I think hes refferin to something GW said about the 16ohm tap sounding best because it uses the more of the transformers windings or something like that.I don't think he mentioned running mismatched load.
I wouldn't listen to anything he has to say anyway

yes, purposely putting the amp on 16 ohms, while using a cab that is 8 ohms.
I know not to miss match the load but, with all the talk about your OT sounding better at 16 ohms (using the full wind Dan Boul talk and weber books) I thought the good might out weigh the bad. I also thought you could run a mismatch of 8 to 16 ohm, as long as the cab was 8 ohm and the amp was more, at 16 ohm. thanks again for the info on this stuff

[Firestorm]

Opinions vary on whether this is BS or not. But the advice among believers is to run the highest impedance tap available into the correct load. Nobody advocates mismatching just to run the highest tap.

[Cantplay]

It's usually ok to put 16 ohm load on 8 ohm tap. This draws half power, and shouldn't be a problem

Running 8 ohm load on 16 ohm tap draws double power, and can damage the amp.

John

[NickC]

Greetings jamme61,

Why not disconnect one of the 12" 16-ohm speakers in your 2x12 cab and try the amp at the 16-ohm impedance setting into a 16-ohm speaker load? See if you like the tone.

Just be careful not to exceed the single speaker wattage rating.

If you don't think it's an improvement, go back to the 8-ohm tap into the 2x12 8-ohm load.

[jamme61]

I wonder why boogie says to mismatch all you want? I had a boogie back in the day( I think it was a DC5?) and remember reading that in the manual. Mesa manual said to experiment but lower loads would ware out tubes faster. I was just wondering about this stuff. You read, yes you can, no you can't, 16 ohms sounds better? drives me nuts. LOL thanks for all the input.

[pdf64]

It's usually ok to put 16 ohm load on 8 ohm tap. This draws half power, and shouldn't be a problem
Running 8 ohm load on 16 ohm tap draws double power, and can damage the amp.

John, the above is generally the case for transistor amps but different guidelines apply to tube amps.
Their inherently high output impedance generally allows them to drive lower than spec loads without too much of a problem.
Unlike most transistor amps, a shorted output can generally be tolerated for a short while, eg the shorting speaker jack on most Fender tube amps.
Doubling or halving the load compared to the spec value will reduce power output a little, assume by about a third as a rule of thumb.
An open circuit load is the worst case scenario for tube amps.
Pete

[JazzGuitarGimp]

I wonder why boogie says to mismatch all you want? I had a boogie back in the day( I think it was a DC5?) and remember reading that in the manual. Mesa manual said to experiment but lower loads would ware out tubes faster. I was just wondering about this stuff. You read, yes you can, no you can't, 16 ohms sounds better? drives me nuts. LOL thanks for all the input.

I have one of the Bruce Zinky Fender Custom Shop Tone Master heads, and the manual for it says the same thing. If fact, the speaker impedance switch on the amp is not labeled with 4, 8, and 16, but rather Lo, Med, and Hi. The manual suggests this switch can be used to adjust the output volume of the amp. A few months ago, I was using this head with my classic rock band, and it was just too loud. I had decided to remove two of the 6L6's, and I had lost track of the manual, so I called Fender tech support, just to make sure I was remembering what the manual says. Mind you, Bruce had been gone from the company for many years at that point. The tech's initial reaction was "oh god no, you can't do that!" But when I pressed him further (I was pretty sure I remembered correctly what the manual said), he decided to go find a copy of the manual. He then changed his tune: "You are right, that is what the manual says. BUT, I would caution you that the tubes may not last as long when running a mismatched load." I don't remember that caution in the manual, but I am getting old!

Now using a BF Vibrolux Reverb with the band and am quite happy with it.

Cheers,
Lou

[Reeltarded]

Any 100% mismatch rule here, but I don't.

[hitchcaster]

well you've got eric Johnson digging his Marshall's at 4ohms..... so it's not a "rule". just going to sound and feel different. also you've got Steve kimock saying he's tried his best to blow trannies using mismatched loads on 60's fenders and just can't do it.... not one time with craploads of hours and hitting the Amps hard. that's all real world stuff...