B22 noise pickup question...

[Solude]

I recently got a Nugget B22 that had been around so I gave it a good tightening and put it to work. Sounds great no issues there. However I have noticed that like the consumer PC speakers I have at work, it picks up Blackberry traffic and passes it through to the headphone. Has never happened to my KGSS in the four years I've had it.

So the question. What causes that and is there any way to fix it?

[Grahame]

Listen inside a Faraday cage - Wikipedia, the free encyclopedia ?

Your amp is acting like a radio.

HowStuffWorks "How Radio Works"

(it amplifies stuff!) Shield it, so it doesn't

Have you ever heard GSM "handshakes" from a phone near unshielded PC speakers ?

[Solude]

That is exactly what I'm referring to. So short answer is its wired with unshielded cable. Hmm odd that nothing else is picking it up.

[johnwmclean]

The transformer if unshielded is more likely to be the root cause.

[Les_Garten]

I saw a reference about laying it(Blackberry) on top or inside an anti static bag, the kind you would get OpAmps in or a Laptop HD.

[Solude]

Any easy way to shield the transformer? Rather not have to commission another one, though a 4ch once I find a dynamic worth the investment might be interesting Anyone know if Rockhopper, forget the members name, is ok with modding his already finished ones?

[K3cT]

You can try covering the transformer with EMI shielding material but the easiest way would be replacing it with a shielded one.

[mrarroyo]

What? No one is suggesting ERS paper?

[Beefy]

If the noise pickup is coming from a Blackberry polling the local tower, I really don't think that the transformer is the root cause......

[johnwmclean]

Hate it when you do that let’s hear it then what is it.

[Les_Garten]

The other suggestion is Ferrite cores on the speaker wires/interconnects.

[qusp]

quite possibly the case isnt grounded to earth ground (even through a loop breaker) and most likely the reason you havent heard it on the KGSS is because electrostatic amps are inherently balanced by nature. adding a 4th channel to the B22 would also probably solve the issue (or at least mask it) with CMRR. but sure get a better shielded transformer in there.

personally I would only ever use ferrites or a choke on the shield, I just dont like the idea of using them in the signal path when there are other ways to solve the issue. grounding is an area that isnt done correctly all that often and there are fairly straight forward rules that when followed, go a log way to ridding the system of any noise such as this.