Scope grounded probes

[ELCouz]

Hi,

I have a Rigol 1052E scope.

I would like to verify audio amplifier clipping with it.

I know that probes use chassis ground.

How to hook it to a speaker output?

I know it's AC with variable frequency and voltage but you don't have a neutral and hot like house wiring.

I just want to be sure and not blow my amplifier.

thank you very much!

 

[betwixt]

If the amplifier output is ground on one side, use that side for the probe ground and the other side for the probe 'tip'.

If it's a bridge output (both sides of the loudspeaker are driven), use two probes but don't use the ground on either of them. Connect one 'probe tip' at each side of the loudspeaker and configure the 'scope to "add and invert" the channels so it shows the difference between the probes rather than difference between one of them and ground.

If you don't know the amplifier schematic, you can check what kind of amplifier it is with a testmeter. Measure Ohms between the ground side of one of the input sockets to each side of the loudspeaker connections with the loudspeaker disconnected. If one shows zero Ohms, or very low resistance (less than about 2 Ohms) it indicates you amplifier is single ended, not bridged and the low resistance side of the speaker is the ground side.

There is a way of showing linearity and clipping on a scope by using the X-Y mode, ask if you need help on how to do it.

Brian.