There is no sound coming from either speaker when the volume control is at minimum. As for the other inputs I’m currently using an Aux cable as I don’t have any headphones or CD player. The audio out of both is fine, it’s just that the right side is really quiet. I have to have the balance control nearly all the way to the right for it to balance out. But as you know, this compromises the volume.
Are you saying that the audio channels are not balanced, and the right channel has very low output?
If so, try reversing the input cables (with amplifier turned off) at the back of the amplifier. Does the problem change sides?
It is possible there is no right channel at all, and you are hearing only "bleed through" from the left channel.
If there is a tape monitor switch, try pushing it a few times to clear the contacts.
But make sure the input cables are working properly.
If so, try reversing the input cables (with amplifier turned off) at the back of the amplifier. Does the problem change sides?
It is possible there is no right channel at all, and you are hearing only "bleed through" from the left channel.
If there is a tape monitor switch, try pushing it a few times to clear the contacts.
But make sure the input cables are working properly.
The most common causes of channel imbalance (generally in any amp) tends to be poor tracking of the the dual gang volume control.
I also see you have an older thread relating to 'cutting out'.
So I think you are going to have to do a proper test to give us some idea of how much quieter one channel vs the other really is.
A DVM on AC volts and a simple lowish frequency sine wave test tone (say in the 400Hz t 1kHz range) is all you need. Set the speaker output (the volume control) to say 2.00 volts on one channel and compare to the other channel. To guarantee identical inputs between channels use just one RCA input plug and swap it between the left and right inputs for the test.
I also see you have an older thread relating to 'cutting out'.
So I think you are going to have to do a proper test to give us some idea of how much quieter one channel vs the other really is.
A DVM on AC volts and a simple lowish frequency sine wave test tone (say in the 400Hz t 1kHz range) is all you need. Set the speaker output (the volume control) to say 2.00 volts on one channel and compare to the other channel. To guarantee identical inputs between channels use just one RCA input plug and swap it between the left and right inputs for the test.
No, the problem doesn’t change sides, it is still the same, hardly any sound coming out the right speaker. It’s quite possible that it is bleed through from the left channel.
There is no tape monitor switch on the amplifier.
Could you possibly explain this a bit more? As I’m not experienced in this. I have a DVM.
You need a sine wave test tone which can be from a test CD or an MP3 file etc. You connect that as an input to say 'CD in Left Channel' on the amp and with the DVM on AC volts you set the volume to give say 4 volts AC on the left speaker output. Now swap the input lead to the right channel and without touching the volume control measure the AC voltage on the right channel output, It should be identical, any difference being an imbalance which we can calculate and see if it seems acceptable or not.
If you want an MP3 test tone I can make one now and attach it.
If you want an MP3 test tone I can make one now and attach it.
Here you go. 440Hz sine. It plays for two minutes.
Connect the meter on AC volts across the speaker terminals of the channel you are measuring. Polarity does not matter for AC.
I recommend you start with the volume on MINIMUM and then turn it up slowly. 4 volts AC on the meter corresponds to 1 watt into 8 ohms and it will be louder than you might think.
Once you are happy its working OK you can disconnect the speakers (to measure in peace and quiet).
It should not matter which file you use but I'll attach both, a single channel mono and normal stereo file (same content on each channel)
Connect the meter on AC volts across the speaker terminals of the channel you are measuring. Polarity does not matter for AC.
I recommend you start with the volume on MINIMUM and then turn it up slowly. 4 volts AC on the meter corresponds to 1 watt into 8 ohms and it will be louder than you might think.
Once you are happy its working OK you can disconnect the speakers (to measure in peace and quiet).
It should not matter which file you use but I'll attach both, a single channel mono and normal stereo file (same content on each channel)
Some little things to look out for.
First do not turn the level up to high. 4 volts is only 1 watt and 20 volts would be equal to 50 watts into 8 ohms. Most listening is done at levels of 1 watt and below.
Channel imbalance due to mis tracking of the volume control is usually much worse at low levels so test over much lower volume levels as well if your meter can reliably show low AC voltages. Accuracy doesn't matter as long as the result is repeatable.
First do not turn the level up to high. 4 volts is only 1 watt and 20 volts would be equal to 50 watts into 8 ohms. Most listening is done at levels of 1 watt and below.
Channel imbalance due to mis tracking of the volume control is usually much worse at low levels so test over much lower volume levels as well if your meter can reliably show low AC voltages. Accuracy doesn't matter as long as the result is repeatable.
Okay, I think I have done this right, please correct me if I’m wrong.
I have used the sine tone via the aux cable and attached only 1 RCA connector to the left channel. I tested the left terminal using the probes and I turned the volume up to get a reading of 4 volts. Then I switched the RCA cable over to the right channel and tested the right terminal and I’m only getting a reading from the DVM of around 0.5 - 0.6 volts.
Also there is a fuzzy sound coming from the right speaker whilst playing the sine tone.
I have used the sine tone via the aux cable and attached only 1 RCA connector to the left channel. I tested the left terminal using the probes and I turned the volume up to get a reading of 4 volts. Then I switched the RCA cable over to the right channel and tested the right terminal and I’m only getting a reading from the DVM of around 0.5 - 0.6 volts.
Also there is a fuzzy sound coming from the right speaker whilst playing the sine tone.
That sounds like you are doing the test correctly. We swap the single input lead simply to ensure 100% repeatability and that nothing in the source component playing the file plays any part in the result.
So it sounds like you have problem with the amp.
Two points.
1/ Have you tried the test using a different line input? (do NOT use a phono input for a record deck as the gain is to high on those).
2/ Does it sound as bad as these results suggest when playing music normally?
Hazy thinking and I'm wondering if the speaker relay could be at fault... that usually improves if you turn the volume up but that would only apply with a speaker attached as a load. The high load current temporarily 'cleans' the contacts until the next time.
Beyond that you would have to repeat the test but this time move into the amp to measure.
So it sounds like you have problem with the amp.
Two points.
1/ Have you tried the test using a different line input? (do NOT use a phono input for a record deck as the gain is to high on those).
2/ Does it sound as bad as these results suggest when playing music normally?
Hazy thinking and I'm wondering if the speaker relay could be at fault... that usually improves if you turn the volume up but that would only apply with a speaker attached as a load. The high load current temporarily 'cleans' the contacts until the next time.
Beyond that you would have to repeat the test but this time move into the amp to measure.
No I have not.
not really, it sounds okay apart from the fuzziness that’s coming from the right channel.
I think it is. I’ll explain how this happened: my Marantz amplifier is connected to two Tannoy Mercury m2 cherry speakers. The aux cable was set up to a 4 port digital to analog audio converter, which then was connected to my smart TV via a digital audio cable.
One day I turned the tv on, the amp and the audio converter. Then I heard a boom, there was no sound coming from the system. I turned it on and off and there was no ‘clunk’ sound like before when it was turned on.
I read some forums that this was to do with the relay, the only way I’ve been able to do these tests is to hold a small stylus on the relay so that sound plays through it.
If it is relay (which I think it could be) how would I rule out any other causes of this issue and also how would I fix this issue?
Hmmm...
That sounds like something else might have happened but we need to prove whether it has or not.
Looking at the circuit and the headphone feed is from before the relay. I'm assuming plugging headphones in also disconnects the speakers. If the sound is distorted/low/fuzzy on headphones then it is not the relay. If the sound is OK on headphones (and the speakers are automatically disconnected and so no heavy load on the amp) then it may or may not be the relay.
If you were to repeat the sine wave test but this time instead of measuring across the speaker terminals you were instead to measure to a point before the relay then that would be conclusive proof.
Low signal before the relay and the relay is NOT at fault.
Normal signal (so 4 volts) before the relay and a lower signal after the relay and the relay is faulty. You can see the relay and also the speaker terminals to the right of the relay in the diagram. This time you would measure between ground and L751 or R769 and L752 or R770 to the left of the relay. Those resistors should be easy to spot and measure to. Either end of the resistor would give the same result. If the signal is low on the resistor then the amp itself has a problem and not the relay.
This is the relay:
That sounds like something else might have happened but we need to prove whether it has or not.
Looking at the circuit and the headphone feed is from before the relay. I'm assuming plugging headphones in also disconnects the speakers. If the sound is distorted/low/fuzzy on headphones then it is not the relay. If the sound is OK on headphones (and the speakers are automatically disconnected and so no heavy load on the amp) then it may or may not be the relay.
If you were to repeat the sine wave test but this time instead of measuring across the speaker terminals you were instead to measure to a point before the relay then that would be conclusive proof.
Low signal before the relay and the relay is NOT at fault.
Normal signal (so 4 volts) before the relay and a lower signal after the relay and the relay is faulty. You can see the relay and also the speaker terminals to the right of the relay in the diagram. This time you would measure between ground and L751 or R769 and L752 or R770 to the left of the relay. Those resistors should be easy to spot and measure to. Either end of the resistor would give the same result. If the signal is low on the resistor then the amp itself has a problem and not the relay.
This is the relay: