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My Behringer ACX 1000 seems to have a high noise floor. All is disconnected and channel volume is down. When Master Volume is at 6-7, noise is very evident. Is this normal for behringer and s there a simple fix
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Not normal for anyone, Behringer or otherwise.
I would be wagering you have a noisy op amp. Absent the availability of schematics, I'd be looking down the row of op amp ICs at their output pins for noise signals on my scope.Education is what you're left with after you have forgotten what you have learned. -
Originally posted by dkrause View Post
Op amps are inherently noisy. "Trust me". Not much you can do about that, except don't use them....
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Well, actually all devices which are (a) resistive or (b) amplify are inherently noisy. The only electronic parts that are not inherently noisy are pure capacitances and pure inductors - of which there aren't any.Originally posted by mooreamps View PostAmazing!! Who would ever have guessed that someone who villified the evil rich people would begin happily accepting their millions in speaking fees!
Oh, wait! That sounds familiar, somehow.Comment
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Oh, enough BS already.
Op-amps are considerably quieter than tubes, but they have their best noise figure at a lower input resistance, as low as a few kOhms for bipolar ones like the NE5532, and maybe 10-100k for JFET devices like the TL07x.
I believe the current noise contribution of a JFET op-amp comes from gate leakage current, which increases drastically with temperature, so a TL074 in a black stompbox on stage at an outdoor gig in Florida in June could well be noisier than a tube.
RG: I once saw a document that claimed that pure inductors and capacitors generated noise too. It was part of the series about the development of the Digiphase synthesizer at Dana Labs. (Which Mooreamps will know all about since they were developed for the Deep Space Network. ) I didn't believe it.
"Enzo, I see that you replied parasitic oscillations. Is that a hypothesis? Or is that your amazing metal band I should check out?"Comment
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Gary, there may be some inherent noise in an op amp, as in most parts, however, in the context of the original question, the point made was that one of the op amps had probably gone considerably noisier that the average op amp. So if we think all op amps are noisy, then the term noisy is useless to differentiate any part. So what we mean when we say noisy is that the particular part has failed in a manner to greatly increase the noise it adds. Does that work for you?Education is what you're left with after you have forgotten what you have learned.Comment
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