Amp issue?

[Twincam]

So I've noticed when my amp is off at the amp switch but still on at the plug socket, if I put my ear right up to the speaker I can hear some noise a slight hiss, as said it's very very faint almost inaudible. The amp seemingly works great.
When the plug socket is off no noise.

It seems odd that possibly some parts of the amp are getting power even if the amp switch is off? Surely it would switch off the power completely. Or is this maybe interference from the mains being somehow amplified by the off amp. I'm tempted to open it up check the switch is ok and how it's wired, the switch is working fine tho no noises, no weird burning smells etc
Amp is the Bugera bvp 5500 hybrid. One that I recently gave a glowing review off. And being from the behringer family I don't want it blowing up haha!
An issue or not.

[luckydog]

Making the leap of faith that the power section is class D and the PSU is switch mode, it's possible that the PSU remains ticking over whenever connected to the mains, and the power button is really a soft start. In which case, yes there could be a trace of residual noise in standby mode (off), or the noise could be the PSU itself 'cycle skipping' in low power (standby) mode ?

HTH !

LD

[Twincam]

[quote name='luckydog' timestamp='1465898605' post='3071893']
Making the leap of faith that the power section is class D and the PSU is switch mode, it's possible that the PSU remains ticking over whenever connected to the mains, and the power button is really a soft start. In which case, yes there could be a trace of residual noise in standby mode (off), or the noise could be the PSU itself 'cycle skipping' in low power (standby) mode ?

HTH !

LD
[/quote]

Nope valve pre and class a/b power section. But I see where your coming from.
Oddly with a new cab it does not do it. Seems fine anyhow.

Wonder if I should put a multimeter on the speaker cable, with the amp off see if anything is coming through?