View Full Version : Impedence Mismatch question
Phil Divine
08-18-2009, 11:43 AM
I am selling a 16 ohm G12H30 speaker. A friend wants to put it in his Valvestate 8040 40 watt combo. Thing is, his speaker in the amp is 4 ohms, which leads me to believe that's what the amp is designed for. In a SS amp, is there any danger to running a 4 ohm amp into a 16 ohm speaker?
He doesn't mind a volume drop, as it will let him turn the amp up, but obviously I don't want to sell him a speaker that will kill his amp. I am not worried about the speaker at all.
I know there are 2 schools of thought on this one. One says that going up is safe, although gives less power. Like a SS PA. The other says any mismatch will lead to problems.
pgissi
08-18-2009, 12:45 PM
I know there are 2 schools of thought on this one. One says that going up is safe, although gives less power.
thats really regarding tube amps since they are coupled by an OT to the speakers of which then generate EMF or "flyback" of which is dangerous to the OT secondary. SS outputs typically direct coupled, no OT
marshall valvestate= valve preamp and ss output, mismatch all day and all of the night, think of it as a form of attenuation with this 4 ohm amp and 16 ohm spkr arrangement but its not that there is no danger.
Heat is the danger if he wants a 40watt ss amp to compete with a 100watt tube stack, very loud drummer, a bass player with 1000watts, 1000 in the monitors etc. I say this only because the 16ohm speaker is going to dramaticallly reduce the amps output and this would be great in a volume restricted situation but otherwise not.
Its a judgement call from there
strat a various
08-18-2009, 12:53 PM
It's gonna sound like a 10 watt amp. Why don't you just try it? It can't hurt a solid state amp, it'll run cooler and way quieter.
Phil Divine
08-18-2009, 01:47 PM
Thanks folks. That's what I thought. I will try it. I just didn't want to blow up his amp, while trying it out. He mostly plays at home in his studio, so it may just be perfect.
FrankieSixxxgun
08-19-2009, 07:57 AM
I have a Valvestate 8040 and that little thing is kinda bad ass for what it is! Way better than the Valvestate II things they put out.
Phil Divine
08-19-2009, 08:40 AM
So we tried it last night. Not only did it sound 10 times better, it was louder than the 4 ohm G12L that was in it! Too funny. Anyway, he's happy, so it all worked out.
If anyone is considering a G12H in this amp, go for it. Sounds killer.
schmidlin
08-19-2009, 09:10 AM
Thanks for the follow-up, Phil. I wish all folks did that.
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