Power amplifier clip indicator

[August Karlstrom]

How come power amplifiers for the consumer market typically never
include a clip indicator? Would such a feature have a negative impact on
the fidelity?


-- August

[Peter Wieck]

Many of the higher-end amps did have such indicators. But when fidelity started taking a back seat to costs, and when two-channel stereo essentially died in the consumer market, both conditions mitigated against this feature.

I keep two HK amps with lead displays for power-out, right up to clipping. Dynaco, McIntosh, SAE, Phase Linear and quite a few others used either meters, LEDs, indicator lights and any of several other means to convey clipping. Until a few years ago, I also had a Dynaco ST416 with an LED display, and its older brother, the 400, had meters as an option.

These days, I believe that Yamaha, Onkyo and a few others still offer this feature.

Note: Other than making a nice display, for most actual audio purposes, such a display is very nearly meaningless in actual use. I remember speaking with an HK rep at the introduction of their CItation 16. He stated that it came with and without the LED display - which was about a $200 option in the early 80s. With the display sold 4:1 over without. Go figure. The 19 (which I also keep) did not come with a no-display option. They learned.

Peter Wieck
Melrose Park, PA

[August Karlstrom]

On 2016-04-13 23:29, Peter Wieck wrote:
> On Wednesday, April 13, 2016 at 2:57:03 PM UTC-4, August Karlstrom
> wrote:
>> How come power amplifiers for the consumer market typically never
>> include a clip indicator? Would such a feature have a negative
>> impact on the fidelity?
>>
>>
>> -- August
>
> Many of the higher-end amps did have such indicators. But when
> fidelity started taking a back seat to costs, and when two-channel
> stereo essentially died in the consumer market, both conditions
> mitigated against this feature.
>
> I keep two HK amps with lead displays for power-out, right up to
> clipping. Dynaco, McIntosh, SAE, Phase Linear and quite a few others
> used either meters, LEDs, indicator lights and any of several other
> means to convey clipping. Until a few years ago, I also had a Dynaco
> ST416 with an LED display, and its older brother, the 400, had meters
> as an option.
>
> These days, I believe that Yamaha, Onkyo and a few others still offer
> this feature.

Then there are more models with this feature than I thought.

You sometimes read discussions about "How many watts do I need." A clip
indicator is an honest way for an amplifier to say "I give up, you need
a more powerful amplifier" rather than trying to camouflage the problem
with technologies like soft clipping etc. If the music doesn't sound
right at higher volumes, how can you tell if it's clipping or if the
problem is elsewhere?


-- August

[Peter Wieck]

Well.... How may worms are you prepared to herd based on how many cans of such are you willing to open all at once?

There is clipping, and there is clipping. I keep Maggie speakers rated at about 83dB at one watt at one meter. 83dB is a reasonable but low average listening volume. If I am playing one or two of the very few sources I have with a 30dB P/A (peak to average), then I would need an amplifier capable of 100 watts for the peaks, and also capable of producing clean sound at 0.1 watt. That covers the 30dB range.

I have two (2) amplifiers capable of doing that for *BRIEF* peaks, and two capable of delivering a clean 100+ watts all day and all night. Note that at the peaks, I am delivering 103dB of sound. And, my ears will not be bleeding.

Or, let's suggest that I am playing a very compressed source such a Heavy Metal, where the P/A seldom exceeds 10dB. And I want it LOUD - so, I am *averaging* at 100 dB. Meaning my amp will need to give something on the order of 75+ watts, average, and peak at 500+/- or so. I have _no_ amplifier capable of doing that safely. I have only two that will make the average safely. Few exist as well.

Now, for the real world:

If I am listening in my radio room, about a 12 x 15 x 9 *FOOT* cubic rectangle using 86dB @ 1watt speakers playing classical music, orchestra + solo instrument, my systems in that room are perfectly comfortable with 30, 75 and 100 watt amplifiers (WPC/RMS) respectively as I will NEVER even wish to play loud enough to clip. In point of fact, my flea-power Dynaco ST35 (17 very anxious WPC) is effective for 90% of my listening in that room.

And the Maggies seldom pin the LED display, again unless I am playing one of my few very wide range sources. I very nearly never play heavy metal.