2. amps-preamps
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How much DC is considered safe?

If you measure the DC voltage at the amp's speaker output terminals, how much DC is considered safe? I have a pair of monoblocks that I measured a maximum of -32mV on one amp, dropping to about -21mV on the other. Will this small amount of DC cause any harm to the speakers?
plato
clueless
763 posts
 
Plato:
In short-0
But-My understanding is that measuring dc with ac present usually results in unreliable readings. Especially true with most garden variety digital meters. Probably not to worry over those readings. Tweeters generally safe from low amounts because of the caps. Do you hear any pops from the woofs when you fire them up?

There are more tech oriented forums than here. As a failsafe try asking your Q at the Asylums DIY page or bottlehead.

The world ain't right when Plato is taken rif from Clueless.
gregm
3,021 posts
 
Great parting comment, Clueless :^)! Anyone here monikered Aristotle??? Cheers.
plato OP
1,543 posts
 
Thanks guys. I think I'm fairly safe at the level of DC the amps exhibit, but was just wondering at what DC voltage threshold would one need to be concerned?

If anyone here can answer that, by all means do so, otherwise I may do as Mr. Clueless suggests and pose my question in a more technical forum. BTW, that parting comment should have read, "takin' riff" not "taken rif." ;P
vantageaudio
182 posts
 

Don't take these figures as "gospel" (there are far too many variables out there) but figures around and under 20mV are fairly innocuous, figures from 20 to 50mV should probably be adjusted out and figures above 50mV can often be classed as a fault condition. Hope this helps.

Regards, Richard

clueless
763 posts
 
Plato:
Fuley apreciate da Engleash Leson. Duh..., youve redemed youself as intelagent as fer as me are cuncrned.

As soon as i saw it posted I shook my head. Have you ever noticed how careless e-mail makes you? Maybe it is just me.I have an immediate liking of anyone named Plato as I live in a cave and spend lots of time looking at the shadows on the walls. Have you ever noticed how poor the sonic qualities of rock is.

Anyway. I still think you want 0 (or very close) dc and your reading is not reliable. I am not an amp person (i do like to make speakers) but i assume the real issue is sound. dc running out is not going to help the coil make sense of what it is trying to do and well... all the cable up grades in the world will not help. A well designed pre/amp should block the dc and it becomes an issue long before you have to worry about the health and welfare of your speakers if you want music.

Do me a favor, if you find an answer post it back here. It would be appreciated. Maybe we can publish a dialogue about it.

Sincerely, I remain
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