Why don't amplifiers have clipping protection?

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[anthonynicholson]

I absolutely love playing your videos at 1.75x speed while im driving. Can hear more topics during my drive and it keeps up with the pace of my driving.

[karltodd]

Look after your ears dude!! I Recently had a mini health scare with hearing loss. Thankfully it returned to normal. During the recovery period I had no spacial awareness at all. Scary stuff for a audiophile.

[dhpbear]

1:20 - The Dynaco Stereo 120 had such a circuit to limit power longer than a certain interval.

[laurentzduba]

During the early 1990s, virtually all entry level NAD amps have clipping protection, but audiobuddies of mine who own such amps say that the amp souns much more open when the clipping protection circuit is turned off - even at moderately loud listeming levels - i.e. 96 dB SPL with a 90 dB per watt / 1 meter sensitive loudspeakers.

[carlosbauza]

No. Hafler did not have a clipping "protector". It was McIntosh. But Hafler had an experimental circuit that demonstrated the presence of distortion.

[andydelle]

A zener or any diode "clipper" is just that, a clipper. The only difference is you are not stressing the amp but you are just moving the clipping to the amp input. You still hear a nasty clipped signal and it's still bad for tweeters. The way McIntosh did it was a true clipping prevention system. They put a Cad cell (same thing inside a lights on at dusk switch) across the input with LEDS or lamps fed from the speaker terminals shining onto the cad cell. As the voltage approached the amps clipping region and the lamp brightened, the cad cell lowered in resistance and pulled down the input voltage. Thus no clipping took place. But this is not without faults. What you have here is a dynamic range compressor and is in fact how early analog compressors worked although they use a much more linear VCA now days. You can also reverse the process and use the feedback increase dynamic range such as the famous DBX processors of the 70s. And there were also several magazine construction articles at the time for making your own range expander/compressor with LEDs and cad cells from Radio Shack. I must agree the best approach is to just stay out of the clipping region all together. Shouldn't be a problem these days with typical amplifier power levels.

[ryantoomey]

Could you use speakers that can handle much more power than the amp can provide? For example, hooking up 500 watt speakers to a 100 watt amp? It seems like having over-rated speakers would give you lots of headroom so you can't blow them even at the loudest volume. As long as the impedance is correct it should be okay.

[weijiantan]

Is this similar to speaker protection?
To protect the audio amplifier and the
loudspeakers during start-up sequence when the amplifier output might exhibit DC voltage, and to protect the
loudspeakers in the unlikely event of an amplifier power stage failure, where DC component would damage the
speaker voice coil.

[marianneoelund]

Many amplifiers have power-limiting circuitry which serves to prevent sustained clipping, as well as keeping woofers from overheating. Commercial amplifiers with DSP such as the Crown XLS series, my old Dynaco Stereo 400, and many McIntosh models have the feature.
Placing a fixed clamp at the input (by the way, the Zeners need to be in Series, not Parallel) is an undesirable solution as it will consistently create distortion at voltage levels which are near but still below the clipping point. Although this is functionally the same as the method NAD uses to implement their soft-clipping feature.

[InsideOfMyOwnMind]

McIntosh has had that since forever. It works really well, though I'm not a Mac amp fan for other reasons.

[ejonesss]

couldnt an auto mute circuit be designed so when the input voltage gets to a certain level it either completely mutes at the input circuitry or trips the overload and startup protection relay?

the relay i am talking about is when you turn on the amplifier a second or 2 later you hear a click.

i assume that relay is so you dont hear the thump and hum when the system is turned on and charging the large capacitors that are connected close to the speakers.

of course i think the relay is a last resort protection as it disconnects the speakers while the unit is on witch is something i have heard is bad as you are taking the amplifier from full load to no load back to full load in a split second so maybe using the mute circuitry may be safer.

you could just turn down your input source like if you are streaming from your ipod or computer you could turn that down so you shouldnt clip and only use the loudness of the amplifier to fill the room.

not just ears but loud parties can draw the police as there are noise laws in some places so if you are in a place near other neighbors you could get complaints..

copyrights could be another problem you could get copyright notices due to public performance.

[ford]

If you can a little bit about sound and amplifiers then you know that you should not turn volume so amplifies clips!
You also need to protect your ears! without them, music is not fun.
NAD amplifiers almost always have soft clipping you can turn off with a switch.

[janinapalmer]

I have to agree with Paul here 100%...!
Though you can get POWER limiters ( which just trip a relay ) at a certain RMS power level ... and others that provide current limiting to the power supply ( bit like foldback ) .. best think is, like Paul just said get an amp that won't clip and speakers that can handle all its capabilities with EASE... let your ears be the judge

[luomoalto]

Old NAD amps had a “soft clipping” circuit.

[benwitt]

Paul could you speak up a bit. Some thing about needing a bigger amp every few years?

[zulumax]

I have a Realistic APM-200 peak and RMS watt meter hooked up to my tube amp system currently, but have had it for years. Best investment I ever made, saved many speakers because your ear is not a good judge of how loud it really is, especially is alcohol and a party is involved. The old Adcom GFA series amps had instantaneous distortion alert yellow led's on the front which were helpful. Many large amps of the past which I have had owned had large VU meters on the front, Kenwood 700M, Onkyo Intergra M-504. Rule of thumb I have used is never use all of your amplifiers power, if you need more than 50% of it's rated power that only leaves you 3db of dymanic headroom. You need a bigger amp like Paul says. Get a hand held sound level meter and pay attention to your listening levels. Safe levels for listening are 85db or less is safe. 95db is safe for 1 hour, 100db for 15 minutes. Of course those are for constant volume levels and music is dymamic so transient sounds that last for fractions of a second might peak higher. Kind of like how you can move you finger through the flame of a candle quickly, but don't hold it there. Of course 130db or higher can cause permanent hearing loss even for short duration, like a gun shot or thunder.

[johnhodgson]

Hi PaulThe Zeners would be in series. The voltage across a Zener in the opposite direction is about .7 volts. So to clip at 2 volts a person would use a 1.3 volt Zener in series with a Zener placed in the opposite direction. The conduction would occur at 1.3 volts for the forward Zener plus .7 volts for the reversed Zener. The problem I see with that idea is the signal is still clipped. Yes, with a R/C network it can be softened. Professional amps have a compressor circuit that kicks in to reduce the amplifier gain as it approaches clipping. I like your approach best though as any of these circuits will affect the sound. I like the idea by Oystein to buy a pro amp for the loud times. When you are listening that loud the loss in quality won't be so obvious and pro amps are cheap new or used.

[Magnulus]

Loud in general is not good for speakers, whether or not the amplifier is clipping. If the tweeters get hotter faster than they can dissipate the heat, it will cook the ferrofluid on the coils. This will vary from speaker to speaker so much it's impossible to generalize.

The best thing is to keep a decibel meter around and not let the music get above 80-85 decibels consistently. Anything higher is not a safe listening volume, anyways.

[zulumax]

Just wanted to add that running too small of an amp loud damages more speakers than running a bigger amp loud, a 20 watt per channel amp can damage tweeters in a set of 100 watt speakers run into clipping ;)

[MarkJones-repo]

Apparently my Cambridge cxa80 comes with clipping mode, but it's turned off as default....I haven't looked into how to turn it on, but I don't think I need it anyway.