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Power Meter Adlustment

I don't see any unplugable cable. Where would it be located? Damn manual gives the procedure in 3 steps.

1. Connect AG set to 1 khz and dummy load to aux jack and speaker terminals respectively

2. Connect AC voltmeter across dummy load

3. Adjust pots VR3 (VR4) when AC voltmeter indicating 21v/8ohms fior 50 watt reading on power meter.

They make it sound so simple. :screwy:
 
You can make a 1Khz sine wave test tone using the PC with some software like Audacity. And then you can burn this tone onto a CD and voila you have the 1Khz test tone.
 
I did that Chan. Much cheaper than a signal generator. I tried the procedure again but the way echo and peter described but still no soap.
 
anal people like me should not have amps with meters. I always want things right. I should take this KA-405 and the non-working KA-3500 I have and find a KA-601 or 701 or 7100 or 7300 to trade for.
 
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chan tran said:
You can make a 1Khz sine wave test tone using the PC with some software like Audacity. And then you can burn this tone onto a CD and voila you have the 1Khz test tone.
Click to expand...

Damn, you were so close!

Here I was thinking, "is everyone on AK living in the 50's?", signal generators are a thing of the past. So are CD players (and CD [and even DVD] burners, for that matter!). Why would you burn the test tone to a CD when you can connect the computer directly to the amp? There is a lot of dedicated signal generating software out there, with very useful features, no need to create a tone with audio editing software. ****, even computers are unnecessary, just use your phone! There's an app for that.
 
something is odd .. wondering if record level was down on burnt cd .
have you checked your dummy load is actually 8 ohms ?
no mute or filters engaged
 
I took my ohm meter and checked the resistor and it came out at 8.1. No filters or muting are on. Loudness is off. The mp3 file I am using to create the cd was recorded at 44/160
 
Why are you compressing to mp3? Just record it as a wav file, uncompressed.

And unless you've made a second attempt to adjust it, I'd certainly not give any sort of accuracy to the first. And as a reminder, 1KHz is pretty much out of the AC response band of most 'inexpensive' meters. I'd do 240Hz.
 
It was already an mp3 file is why I did that. I'll get a 240 hz tone and decompress to a wav then burn
 
I got a 240hz wav and made the audio cd. I tried a more expensive meter and still couldn't get the right reading. The scale was set at 200v because the next choice down was 20v and I need to be able to hit 21. Didn't work right something is rotten in denmark.
 
I disconnected the left side ic from the aux jack. I hooked up dummy load to speaker a right. Set Voltmeter to 200 scale AC and connected leads to each side of dummy resistor. I turned on amp a played a 250 hz tone and raised volume trying to get 21v. I got volume knob to about the 12:30 position and it read 2.1 and I didn't try any farther. I stopped at that point.
 
This may seem like a lot of hoops to jump through, but you need to verify all conditions. One at a time.

You need to verify that the level of the test tone CD is sufficient to drive the amplifier (via your CD player) to the level required level.

You need to verify that all connections are made correctly and all ICs are good.

You need to verify that all settings on your meter (DMM) are correct.

BTW way, just a reminder, always start any of these tests with the volume control set to MINIMUM.

Where did you get your 240 Hz wav file?

Do you know at what level it was generated?

Is it a stereo wav file or mono or possibly just one channel, if so do you know which channel, left or right.

Does your CD player have an output level control? If so where is it set?

Any and all of these things can affect the level of the signal from your CD player.

And this will affect the loudness (signal level) at any given position of the volume control on your amplifier.

There are several things that you may try, any of them will help to lead you in the correct direction.

Replace the dummy load with a speaker, if you are sure no damage was done with your first test methodology.

Set the volume control on your amplifier to MINIMUM. Play your test CD and slowly increase the volume control on the amplifier.

Based on your test results, your amplifier was putting out just a little over half a watt (0.5 watts), with the volume control at the 12:30 position, when playing your test tone CD.

If all is working as it should be, your 240Hz tone should be very very loud before you reach the 12:30 position ( the condition that produced half a watt in your test) on you volume control on the amplifier.

You can also measure the output of your CD player when it is playing the test tone.

Just connect your meter to the outer part of the RCA connector on the end of the interconnect, and the inner part (be sure not to short the two together) and play your test tone. You can start with your meter on the 2 VAC range.

Compare that reading with a reading taken when playing a music CD that has some loud passages on it (the reading will "bounce around). If the reading that you got with the test tone CD is not in the ballpark with the music CD, then the level of the test tone is to low and that is why you had a low reading with your test.

You can also measure the signal across the dummy load when you are playing a music CD that has some loud passages.. Of course the reading will "bounce around", but if you can get a reading more inline with what you are expecting, then all is working as it should be.

Double check you connections for the dummy load and the amplifier. Double check your meter settings and lead connections.

BTW, what was the indication on the meter on the amplifier when your DMM reading was 2.1 VAC? Remember you test indicated just a little more than a half a watt, or about 0.55 watts. Did the meter on the amplifier correspond to this power level.

Here is a link to a simple Ohms law calculator..

Ohms Law Calculator.
 
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I got the 240hz file off the web. The meter checks out fine and my interconnects are in good shape. The CD Player I am using is a Kenwood CD404 5 disk carousel. It has no output level control on it. Using your figures JBL Guy I set up the dummy load and equipment and played the file at 12:30 where it read 2.1 v. Using your 0.55 watt figure I adjusted the meters to that mark on the units power meter. I repeated for the other side. I then disconnected the test equipment and hooked up the speakers. I played a music cd and slowly turned it up till I reached the rated 55 wpc according to the units power meters. That occurred at the 1:30 mark. The sound was clear and not distorted and definitely loud. This sound about right? I have a kenwood KR-9050 receiver that also doesn't hit top power till that point so this isn't uncommon for a kenwood unit. Let me know what you think
 
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