ampeg b-12-nf speaker wiring
Moderators: pompeiisneaks, Colossal
ampeg b-12-nf speaker wiring
Can someone explain what is going on with the grounding/feedback loop on this thing? Someone had already messed with it before me, so i'm not entirely sure how it was originally wired. Is the EXT speaker meant to be left floating when the 4 pin xlr is disconnected, OT is grounded when connected? The EXT jack is isolated from chassis ground. Different NFB settings for different speaker impedances makes sense, I just haven't seen it done this way and want a sanity check.
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martin manning
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Re: ampeg b-12-nf speaker wiring
It's a safety thing. The phase inverter has no DC ground unless the speaker is plugged in.
Re: ampeg b-12-nf speaker wiring
Thanks Martin, that makes way more sense. I was misreading stuff around the PI and the way the last guy wired things added to my confusion...
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Stevem
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Re: ampeg b-12-nf speaker wiring
To prevent operation of the output stage without a load on the amp it would have been far cheaper to do the Fender thing and just use a shorting jack.
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Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Re: ampeg b-12-nf speaker wiring
definitely a weird setup. I guess they really want you to use the internal speaker. I also consider using pin 1 on an xlr for anything but ground offensive.