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mewithoutus's picture
California
Dec 2005
7 years ago

Ok, I have a Peavey Classic 50 4x10 and it has two speaker outputs, 8ohm and 16ohm. In the manual, it states that when both outs are being used, the impedence is 8 ohms. I was recoording today and when I got home, I decided to check on the tubes to see if they needed replacing (they do, they are over a year old AT LEAST), i noticed my speakers (the ones built into the combo) where plugged into the 16ohm output. i was recording with just the combos speakers, not an extension cab, so the impedence was 16 ohms. is that bad? would that affect the sound any? can I damage my amp that way? what output am i even supposed to have my speakers plugged into if im only using the combos speakers, 16 or 8 ohms?

thanks...

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mewithoutus's picture
California
Dec 2005
7 years ago

bump!!!

please help!!!

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firewalk13's picture
Cleveland, Ohio
Apr 2005
5 years ago

I definitely don't know much but if four speakers are connected to the 16 ohm output they are getting 4 each so that should be okay right? I've never heard of speakers running on 2 ohms like they would be if it was plugged into 8 ohm output. should be ok, hope somebody can provide certainty for you.

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NoFroBro's picture
Australia
Jan 2004
3 months ago

Originally posted by mewithoutus
In the manual, it states that when both outs are being used, the impedence is 8 ohms. i noticed my speakers (the ones built into the combo) where plugged into the 16ohm output. i was recording with just the combos speakers, not an extension cab, so the impedence was 16 ohms. is that bad? would that affect the sound any? can I damage my amp that way? what output am i even supposed to have my speakers plugged into if im only using the combos speakers, 16 or 8 ohms?

The answer depends on the impedence of the speakers. Unfortunately I don't have a Peavey Classic 50 to hand so I can't check details (and won't be back online till Monday).

In general Amp Impedance must be less than or equal to Speaker impedence.

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eastwood6's picture
Mar 2004
4 years ago

Peavey Classics are made to deliver a 16 ohm load to the stock speakers. This is true for a C30 and the C50 combo. The extension cab recommended by Peavey is a 16 ohm cab. The outputs are wired in parallel, so 2 16 ohm cabs (the internal speakers and an external cab) in parallel would be an 8 ohm load, as the manual says. Based on what you're told us, your amp should be fine just as it is.

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mewithoutus's picture
California
Dec 2005
7 years ago

Originally posted by eastwood6
Peavey Classics are made to deliver a 16 ohm load to the stock speakers. This is true for a C30 and the C50 combo. The extension cab recommended by Peavey is a 16 ohm cab. The outputs are wired in parallel, so 2 16 ohm cabs (the internal speakers and an external cab) in parallel would be an 8 ohm load, as the manual says. Based on what you're told us, your amp should be fine just as it is.

ah, thanks so much. im new to impedence and series and parralel, its kinda foreign to me. i just wanted to make sure im not gonna damage my speakers or amp. thanks so much.

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eastwood6's picture
Mar 2004
4 years ago

You're welcome. One more thing - I noticed from your sig that you have a Marshall 1965 cab (I have two). Those are 8 ohm cabs, and therefore are not right to use with your Peavey as an extension cab. You might get lucky and not have any problems using it as an extension cab, or it may at some point damage your amp's output transformer. If you are serious about keeping the Peavey, I would recommend either having someone skilled re-wire your Marshall for 16 ohms, or trade/sell it for a cab with a 16 ohm impedence. Cheers.

"It's never too late to be who you might have been."

George Eliot

English novelist (1819 - 1880)

mewithoutus's picture
California
Dec 2005
7 years ago

Originally posted by eastwood6
You're welcome. One more thing - I noticed from your sig that you have a Marshall 1965 cab (I have two). Those are 8 ohm cabs, and therefore are not right to use with your Peavey as an extension cab. You might get lucky and not have any problems using it as an extension cab, or it may at some point damage your amp's output transformer. If you are serious about keeping the Peavey, I would recommend either having someone skilled re-wire your Marshall for 16 ohms, or trade/sell it for a cab with a 16 ohm impedence. Cheers.

i know that the marshall is 8 ohms. the wonderful thing about the classic 50 is that when both the speaker outs are engaged, they are 8 ohms.

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NoFroBro's picture
Australia
Jan 2004
3 months ago

Originally posted by mewithoutus
i know that the marshall is 8 ohms. the wonderful thing about the classic 50 is that when both the speaker outs are engaged, they are 8 ohms.

And so the load needs to be 8 ohms Total. 16ohm + 8 ohms (parallel) = 5 1/3 Ohms which is less than the 8 ohm minimum requirement. 16 ohms + 16 ohms (parallel) = 8 ohms which is O.K. and is essentially what eastwood6 was telling you before.

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