How Do Digital Amplifiers Clip?

With Scissors?

This got me wondering how digital amplifiers clip and how an underpowered digital amplifier affects the speakers when over driven?

a digital power amplifier is a switching amplifier (a cousin to the omni-present switch-mode power supply in our computers). So, the output is toggling between plus/minus supply rail & ground. This switching waveform is filtered (usually by a LC filter or many LC filters, each of which is/are a 2-pole filter) to produce the average signal, which is the music signal amplified. As long as the input signal is within the power amplification limits the output signal switches with a duty cycle well below 100% & well above 0%. Once you start over-driving the digital power amplifier, the digital switching output starts switching with a duty cycle approaching 100%, which basically means that the switching output stays a long time at plus/minus supply rail for a much longer time than it stays at ground voltage. The average/filtered version of such a waveform is a (near) DC voltage at the output.
So, at clipping levels, the digital power amplifier will output high levels of DC that will be fed to your vintage speakers & THAT (the DC) will be the death of them. The tweeter usually has a high-pass network which means that it has a series capacitor that will block DC but the woofer (& even the midrange) does/do not have a series capacitor so DC will be fed directly to the driver & it'll damage very quickly, if not immediately.
hope that this helps.....

Many thanks, Bombaywalla. Helps a lot.

It's a good question. If my Class D amps have clipped, I have not heard it yet. Avoiding clipping like death is a big reason I went for 500w/ch Icepower amps. I like my music loud and my large OHM speakers are not particularly efficient (87db or so I believe). I've heard a lot of amps both SS and tube clip over the years. If the BC ref1000ms have ever clipped, I am not aware of it. Nothing I throw at them can seem to make them even break a sweat.

I have the bel cantos too. They have a soft clipping feature to smooth the waveform and cut output slightly as clipping approaches. I believe that feature is built into the B and O ICE module. Like mapman above I never run out of steam. I just keep turning it up and the soundstage gets bigger, deeper and wider.

Its manufacture specific.

Yes, soft clipping is built into Icepower amps.

I have a Linn 2250S digital amp I just acquired with one channel down. On inspection, I see no evidence of anything having been fried or any odor that might indicate this. The components in there are awfully tiny. Is it possible to repair this thing short of replacing the entire board? The $800.00 flat rate Linn wants to replace it unfortunately for me, relegates it to the trash heap.

Didn't realize Ice power soft clips. Good to know. I still do not think I have heard any hint of clipping with the BC ref1000ms though. First time ever in 35 years worth of audio I can say that about my system.

One of the first thing I would recommend to most anyone is do whatever you need to insure against clipping with your amp and speakers. The effects can be detrimental to sound way before it even becomes noticeable. Its a fundamental thing that every owner should be alert to.