accidently i switched my 4x12 cab to 2x16 ohm stereo mode and my amp (box was in 8 ohms ) ran really really hot (i run it with 8 monos again). fortunatly i saw it early enough to switch the amp off. now all my tubes are little black from smut. apart from all that my amp runs as usuall as it cooled down and sounds as usual but i dont want to ruin it completly. should i exange the black tubes or ist it ok to go ahead and keep playing ?

thanks alot

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As long as the tubes are still working you should be fine. You might have shortened their overall life, but if they work and you have no other problems then I think it is ok. You will have to eventually replace them, and sooner then the ones that didn't burn.

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let me see if i get this.

your cab is 16 ohm per side(2x16 ohm) or 1x8 ohm mono.

you normally run your head at 8 ohms..

so you ran your head at 8 ohms into a cab set up for 2x16 ohm.

if so, basically you only pushed one 16 ohm speaker with your head at 8 ohms.

you're fine, you mismatched the safe way... if your cab would have been set to 4 ohms and you ran the head at 8 ohms, you could create problems.

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mismatching the safe way is only safe if the poweramp is a solidstate poweramp..

mismatching with tubes ain't safe..



source? some tube geeks

how is it not safe with tubes? I don't know.. it's just something I've heard... could be something about the signal going back to the amp, + and - ..

is this true? I don't know

why did it burn then ... i didnt have it on standby that prob why ... man i really donno

maybe someone could explain that ohm shit to me ... i really havent a clue.

my amp got 4 ohm parallel , 8 ohm parellel and one 16 ohm in

box has and input and a through ofc and that bitchy stereo to mono switch

i thought there is no safe mismatching aswell. omg help

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Did you switch it while the amp was on?

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nope did it the day before while the amp was not running

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Having twice the impedance on a tube amp causes reflected power from the output transformer to overheat your tubes (as you have noticed). Basically, instead of the full power load being absorbed by the speakers, half of it is transferred back and becomes heat. As Soul pointed out you have reduced the life of your tubes, but they are OK to use until they die a natural death.

As far a solid state goes, mismatching either way can be bad in some situations but most solid state audio amps are designed to be OK with a higher impedance.

god damn, i dont know shit about this ohm jibber jabber, if i ever get a good amp ill probably blow it up the first time i play it.

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its not hard. An idiot proof method is just make the numbers match. 8 ohm head into 8 ohm cab. 16 into 16. OMGOSH EAZY!!!!11!

mismatching the safe way is "usually" fine with both tube and s.s. amps.... alot of high end/botique amplifiers(thd,mesa,bogner,ect..) have even suggested trying it for tonal exploration....

your safest bet is always to match them though.

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i talked with the engl hotline and they told me that mismatching with tube amps is always very dangerous. you should always match it the correct way if you got a tube amp or depending on what master and presence you got the amp might burn ( like it did in my case)

if i only knew that before

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well, i'm not suprised they say that... it's not a gaurantee that your amp is safe from doing it. they don't want to tell you to do something if there is a chance it'll hurt your amp.

but i've talked to alot of amp makers(egnator,suhr at CAA,thd,ect) about it. with their amps they say it's fine, and have from time to time mentioned experimenting with it so get different tonal results. but then again, that's their amps, and they know better than anyone else if it's safe or not with their stuff.

tough break man.

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What amp do you have?

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i got an saveage 120 ... and fucking up with the ohms just sucks

i'll never do that again. i thought i knew everthing i need about amps but you never know

finally im happy that it still runs perfectly and nothing is broken ... you only learn from all that. never play with cables when ure drunk and bored

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Obay the Law of Ohm: Current(I) is directly proportional to voltage(E) and indirectly proportional to resistance(R). I=E/R.

What that means to us is always match ohms, unless your amp has specific instructions that let you mismatch a tiny bit

The worse that could happen is you burn your home and everything within into a Pagen ash waste wonderland.

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