Power amplifier safety modifications

[diydidi]

A true RMS meter? I have a fluke multimeter that say true RMS on it. I also have a Brymen multimeter that can measure Crest factor.
How do I go about measuring current with these meters?

[nickb]

A true RMS meter? I have a fluke multimeter that say true RMS on it. I also have a Brymen multimeter that can measure Crest factor.
How do I go about measuring current with these meters?

The Fluke is perfect. Just put the meter in series with the 230VAC power wiring. Note series not parallel A 10A range should be fine.

[diydidi]

The primary object of fusing the equipment is to prevent fire. Therefore when you have two transformers it is best to fuse both primaries. You can achieve finer control by fusing the secondaries too.

As a very rough but practical guide, to size you fuse you need to know the maximum current consumption during normal operation and choose one that is (arguably) 1.5x that current. First try a quick blow and move to an anti-surge if it keeps blowing.

Nickb! You are a legend!!
Followed your guide and found a fuse value of 4Amp.
Should I use fast or slow blow?. There is an NTC in series with Transformer primary.

[nickb]

Nickb! You are a legend!!
Followed your guide and found a fuse value of 4Amp.
Should I use fast or slow blow?. There is an NTC in series with Transformer primary.

I would go for anti-surge. NTC's don't help you if you switch off and then on again quickly.

[diydidi]

NickB. Getting back to my question
Can I just measure the current draw while driving ONE channel of the amp into clipping, and multiply by two to get the effect of the other channel?
I only have one dummy load. So I can only measure one channel at a time.

[nickb]

NickB. Getting back to my question
Can I just measure the current draw while driving ONE channel of the amp into clipping, and multiply by two to get the effect of the other channel?
I only have one dummy load. So I can only measure one channel at a time.

I think that would be near enough