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

I guess I need to clarify "logarithmic." Basically, this means that our ears require multiplicative power consumption to hear louder sound - not additive. Not to mention that the same goes for different frequencies. Bass notes require more power than treble notes. If you are listening to a violin solo, you only need a couple Watts. If you are listening to a concert, you will need hundreds more Watts to get the dynamic range right. You can use less power but when the tympani hits, you will get distortion. If you can live with that, then you don't need much power. :) When I had my MC7200 playing classical, the meter needles could bounce between 0.1W and 150W every couple seconds without ever touching the volume knob.

Also, I already said that to measure real power, you need voltage AND current. Some meters base it only on voltage which is correct if the impedance is constant but as we all know, speaker impedance is all over the map.

The McIntosh meters from the 1980s up to the most recent amplifiers are true power meters and are accurate if their calibration isn't out of whack. They may be off a few Watts but that isn't a big deal. However, the recent integrateds like the 6500 and 6300 have volt meters and not power meters. This was probably done to lower costs and will not be very accurate unless your speakers are a relatively flat 4 ohm load.

You really need to watch an amp with meters one day. You would find it very instructive - I sure did and often I wish I still had a McIntosh with big blue meters.

Arthur