SMPS Burn In

[rf7]

Is it OK to do a 20 minute 20% power burn in on a unit with a SMPS?

Or is that a bad idea?

I usually do that for SS amps before I let them go back to the customer, just to see if they will hold up in the field.

[olddawg]

Is it OK to do a 20 minute 20% power burn in on a unit with a SMPS?

Or is that a bad idea?

I usually do that for SS amps before I let them go back to the customer, just to see if they will hold up in the field.

20%? I would always "cook" an amp on a load bank at 80% for half an hour after a major repair. You know the customer is going to do it.

[rf7]

I'm running a sine wave at 20%. You're probably running program material (music) right?

If not, wow!

[Enzo]

A sine wave is tough for an amp, so I don;t expect it to do that full out for more than a moment to check clipping. I use music for burn in, but I also run the amp at what I can reasonably expect it to see during use. Solid state or tube makes no difference, the amp still needs to work at the jobs it will be asked to do by its owner. A brief spin at 20% power seems overly timid to me. If it can't spend an hour running at a pretty good percentage of its rating, I want to know why not.

[olddawg]

A sine wave is tough for an amp, so I don;t expect it to do that full out for more than a moment to check clipping. I use music for burn in, but I also run the amp at what I can reasonably expect it to see during use. Solid state or tube makes no difference, the amp still needs to work at the jobs it will be asked to do by its owner. A brief spin at 20% power seems overly timid to me. If it can't spend an hour running at a pretty good percentage of its rating, I want to know why not.

Yes, program material. I was always told to bring it to clipping, then back off about 20%.

[Steve Conner]

Burn in? Usually we are dealing with SMPS burn out.

A solid-state amp actually gets hotter with signals somewhat below clipping. I can't remember the exact figure for max dissipation, but I think it's about one-third or one-half of full output power. So that is the hardest test. I don't think many amps would survive one-third power into 4 ohms for an hour.

This only holds for conventional Class-AB amps: with classes G, H and D it's more complicated. For a test signal, you might like to drive them a dB or so into clipping with "Back In Black" on endless loop.

It also only holds for a sine wave test signal. With music, the bigger the signal the hotter the amp gets, as expected.

[J M Fahey]

As I remember (must check anyway), max dissipation is around 40% max power.
And for amp burn in (tube or SS), your taste runs quite close to mine, my favorite test signal is any AC DC classics, raising volume until distortion is *clearly* audible.
A very good real world stage/rehearsal simulation.
Not only overheats the electronic elements but, *very* important, the transformer.
And kills most poorly specified speakers ... but that's what musicians will do anyway .