amplifier DB meters

All the recent McIntosh and some of the new Cary have them.

You need an amp capable of producing your PEAK power demands and not average power demands. There can be hundreds of Watts difference between the two. Don't forget that power is logarithmic.

To measure Watts, you need to have voltage and current readings. Voltage is easy since it is parallel but current has to be done in series so you must "break" the power path. Nice hand-held meters have current clamp probes that wrap around a wire so you don't have to cut it but those get into some money.

Arthur

Most of us only listen at 1 or 2 watts. Theater is a bit more. Besides the fun factor of watching the meters bounce, what is the use?

Bob,

Music is dynamic. An amplifier meter is only indicative of clipping/power. Power is a function of load (resistance/reactance) and load is a function of frequency. More expensive amplifiers will have a high speed soft clipping circuit to protect speakers (often with a clipping warning light) - this is all that is really necessary to assure good sound. A clipping meter is only a ball park device.

If an amplifier does not have meters can you hook one up or use a test meter to find out how many watts you are using?

You can - but measuring power is quite complex - very few test meters can measure this correctly. A device to measure power accurately would probably cost more than the amplifiers. Yokogawa Power Meters

Most power meters (common in the 70's) are just estimates of power - they measure voltage (easy to do) assume an RMS conversion (using a a fixed load factor and sinusoid waveform type) such as 8 Ohms....all very inaccurate and only indicative). You need to measure current very accurately as well as voltage to get power.

They are so inaccurate as to be useless. Some do look cool though!

Hi, So most of the meters are inaccurate? Though they give a reasonable indication of power, is that correct? As I originally stated I use mine for tuning my system, I can see more or less power being used when setting crossover, EQ or listening level. Yes I can hear the changes but seeing them is also a good confirmation and it is repeatable as I freq write notes. Also I guess it is kind of fun to watch them, I will admit to that!
If most of us "only listen at 1 or 2 watts" why such big amps? I know that is true with myself, but how do you know you are only using 1 or 2 watts when you really dont know that without a meter? Arthur says that you need peak power which is understandable but how much more power do you need if you are only using those 1 to 2 watts.? The reason I ask is my subwoofer amps at the most use less the 4 watts or so on the loudest bass I have seen and indeed 90 percent of the time much less than 1 watt as indicated on the meters, with my 200 watt per channel amp, can I use a much less powerful amp?
Bob