How to use multimeter

Dewald,
Thanks again

Hi there,

It is not impossible to measure voltage with a load connected - it only gives you a more accurate voltage measurement with no load or a shunt-load. Remember - as the frequency changes the IMPEDANCE of the speaker also changes.
Also remember to disconnect all other channels - both source cables and speaker-loads - all other channels (exept the one that you're measuring) must be 'mute'.
This is the defacto way to measure channels.

I would recommend connecting the shunt-resistor. Go to a radio-shack and let the technitian make on up for you. A 8 ohm, 100 watt resistor (with heatsink) with two short leads soldierd to it and the ends of the leads also soldierd. Use it in parallel with the Multi-Meter.

Sorry - My description might have been a bit skimpy.

Kind regards,
Dewald Visser

Dewald,
Thanks for the detailed response, still I wanted to clarify a few points;
When you say: "Disconnect speaker and connect the MM to ch. A."- wouldn't it be a problem to have an amp running with no load on one channel and a load (speaker B) connectd to the other.
I guess you are saying it's impossible to measure an output voltage with the speaker connected.
Thanks again.

Hi

Just hook up your multimeter to the speaker terminals set it in Volt AC mode. Don't know how pink noise will work, if you have a signal generator connect it to a input on your amplifier and set at 1kHz adjust output on the tone generator so it is not too loud and then measure.

Good luck

1 Disconnect the speakers
2 Connect the multi-meter (MM) to channel 'A'.
3 Feed the amplfier a sine-wave (1000 Hz) through a pre-amp or pink-noise.
4 Set the MM on the AC Voltage setting. 1 - 150 volts range.
5 Turn up volume and take note of voltage on channel 'A'

Note - leave volume on this mark (ie. voltage will read 3.25 volts & use this to compare the other channels)

6 Mute amp or turn off and connect MM to next channel - 'B'
7 Repeat step 3 - 5 for ch 'B'
8 Advance through all channels and take voltage-level notes.

Make shure that you leave the volume control on the same setting when testing to get a correct reading. Always use the MM on the "V AC" setting. I would recommend using a shunt-resistor (8 ohm, 200 watts) in parallel with the MM.

You can also use a oscilloscope to check the channels... but alas, much more difficult.

Best of luck,
Dewald Visser

NB - Why don't you take the amp to a qualified technitian to get it checked. Accidents happen all to quickly!