Hi everybody
I recently got a vintage amp and have been using it for a couple of months now. It works and makes a very pleasant sound to my ears. Though there is one concern. Almost all the time I hear that one channel is slightly louder than the other. Of course, it may be my hearing. I did the typical cleaning of the unit, including the balance and volume control pots and bias adjustment.
Question: Can I use a tool/equipment to measure the actual levels of the signal coming out the amp to both channels, to confirm or negate my subjective and personal suspicions?
Thanks.
I recently got a vintage amp and have been using it for a couple of months now. It works and makes a very pleasant sound to my ears. Though there is one concern. Almost all the time I hear that one channel is slightly louder than the other. Of course, it may be my hearing. I did the typical cleaning of the unit, including the balance and volume control pots and bias adjustment.
Question: Can I use a tool/equipment to measure the actual levels of the signal coming out the amp to both channels, to confirm or negate my subjective and personal suspicions?
Thanks.
Give it a mono signal and change the wires to the speakers. If the difference in SPL follows to the other speaker, it is the amp. If it stays at the same side, it may be your listening or the loudspeaker.
Yes, I did that. My feeling is the same. But because I hear the difference on a very light scale, I want to base it not only on my hearing, but on a tool more reliable than my ear.
Turbo is correct inserting a mono signal into both left and right input of the amp. Connect a low reading ac multimeter between the positive output terminals of the amplifier. If you see a reading then the sound is not balanced. Turn the balance to read as close to zero as possible. Now they are balanced. if you cannot balance them then there may be an issue with one of the amps.
There could simply be an acoustic issue such as one speaker is closer to a reflecting wall or curtains or a coach and the other in more open space causing an acoustic imbalance. In that case move the speakers around.
Would that be a valid assumption:
- connect a phone based sound generator to the amp input terminals
- connect a low reading AC multimeter to the output terminals of the amp in parallel with the left and right speakers
- measure the volts on both channels
You can connect any mono signal to both channel, essentially you want the exact same input. Yes use your phone if it pleases you. Now connect the multimeter between the two red output terminals of the amp and it will read the difference between them. That should not be to hard? Need a picture?
Now turn the balance control left or right until the meter reads a very small amount say, zero. Look at your balance control and wallah it will tell you which of left or right is the loudest. With a sharpy, or felt tip pen mark the balance control so that you can always put it on the same spot in case you inadvertently moved it from the real centre.
Now turn the balance control left or right until the meter reads a very small amount say, zero. Look at your balance control and wallah it will tell you which of left or right is the loudest. With a sharpy, or felt tip pen mark the balance control so that you can always put it on the same spot in case you inadvertently moved it from the real centre.
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Yes, picture of the output terminals and connected MM will help.
I am not sure about "multimeter between the two red output terminals of the amp". I thought left +/- and right +/- are different parts of the circuit.
I am not sure about "multimeter between the two red output terminals of the amp". I thought left +/- and right +/- are different parts of the circuit.
Goodness, it is harder than to teach my cat to play dead. That only took me 10 minutes.