Power Meter Adlustment
- Thread starter moejr
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ryuuoh
FFXIV Summoner
1kHz is the signal you send to the amp, usually into an 8 ohm dummy load to generate a voltage that corresponds to the full power output of the amp.
You would connect a signal generator to the aux in, the dummy load to the speaker terminal, AC voltmeter to the dummy load and set the signal generator to 100 mv output, raise the volume control until you measure 21 volts AC, then adjust the trim pots to set your meters to read 50 watts.
Ebay has dummy loads and signal generators.
You would connect a signal generator to the aux in, the dummy load to the speaker terminal, AC voltmeter to the dummy load and set the signal generator to 100 mv output, raise the volume control until you measure 21 volts AC, then adjust the trim pots to set your meters to read 50 watts.
Ebay has dummy loads and signal generators.
4seatPilot
"Broker"
Jon_Logan
Addicted Member
You should be able to make the adjustment with no load attached.
The next question is, "Where do you want the meter to be accurate for steady state signals?".
I'd adjust it for -0dB or whatever a high reference is on the scale. You might find that the accuracy changes across the meter scale. This is pretty normal for most 'affordable' meters.
The next question is, "Where do you want the meter to be accurate for steady state signals?".
I'd adjust it for -0dB or whatever a high reference is on the scale. You might find that the accuracy changes across the meter scale. This is pretty normal for most 'affordable' meters.
moejr
Super Member
I was looking online and the signal generator i looked at would do 1khz. Found a dummy load too. I just wanted to get an idea of the stuff I need. I have a very good DVOM already so that's taken care of. Not going to happen right away anyhow as I got a KA-3500 in that was supposed to be 100% working but not even close. Got some money refunded and am going to use the amp to learn some basic repair procedures
petehall347
the brandy coffee man
on other amps i have set meters by looking for clipping on the scope then turning vol down to clipping barely there and setting meters accordingly . i set so meters look like maxed out before clipping happens as i know folk like to turn things up that bit more .
moejr
Super Member
I just wanted to set it per the manual. Plus it gives me practice to get used to doing stuff on these vintage units.
moejr
Super Member
Ok I got my self a 120w 8ohm resister for a dummy load. Now I soldered a pair of speaker wires to it. 2 on one side for negative and 2 on the other side positive. I hooked them up to speaker a and put my volt meter across the terminals. Now I was told I could use a 1khz test tone and run it thru the cd player. I did that. Now the manual says to turn the volume till the DVOM reads 21V and adjust the meters to the 50 watt mark. I could not even come close to 21 volts. Full volume produced only 12v. The amp sounds fine and I can tell it is putting out the 55 WPC it's rated for. What did I do wrong? 
All help is greatly appreciated.
All help is greatly appreciated.
petehall347
the brandy coffee man
sounds like your input is maybe too low to achieve maximum output .if you have a scope then you could use it see if the waveform is clipping or not .
Why two wires on each side of the resistor?
petehall347
the brandy coffee man
wrong if using for both outputs at same time ..:nono: i thought the extra wires were for hooking up your test meter .
petehall347
the brandy coffee man
one side at a time should be fine and balance in centre . ideally both sides should be loaded .
Wow! Really?
Ummm...don't do that.
You're actually damned lucky that you didn't destroy the amp.
I also see no reason to drive the channel that you are not adjusting. Just unplug the IC cable from the channel that is waiting its turn.
