pop noise from speakers when turning off cr-620

Kittyhawk

New Member
When I turn off my cr-620 their is a loud 'pop' from the speakers. What might be causing this? thanks...
 
When I turn off my cr-620 their is a loud 'pop' from the speakers. What might be causing this? thanks...

Burnt out lamps - believe it or not. If the lamps are burnt. Contact AK'r Dgwojo for the correct replacements.
 
In the CR-600 and CR-800, the lamps are powered by a DC voltage and they are important to open the relay a short time after turn-off. But not in the CR-620 and CR-820, where they are powered directly from the transformer.

I think that you have a large DC offset in your receiver and this is that offset which is the cause of this "pop" noise.
 
In the CR-600 and CR-800, the lamps are powered by a DC voltage and they are important to open the relay a short time after turn-off. But not in the CR-620 and CR-820, where they are powered directly from the transformer.

I think that you have a large DC offset in your receiver and this is that offset which is the cause of this "pop" noise.

If this is indeed the case, how can it be repaired and is it an expensive proposition?

Thanks...
 
Before jumping to conclusions you can easily check the DC offset.
Without any speakers hooked up. Select, on the front panel, and input that has no source connected such as TAPE1/2 or AUX. With a multimeter .Measure the DC voltage at the speaker spring clips for both the left and right channel of SPK A or B (whichever you use make sure the front panel speaker select switch corresponds to whichever your using ie. A or B.) Ideally your looking for 0.000 vdc. Realistically you will have some voltage there. Report how much you measure. More than 50mv (.050 volts) you might have and issue.
Just hook your meters red probe to the red post and black probe to the black post.


You can check it this way provided the receiver is not in protect mode. ie. "clicks" shortly after power on.
 
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I don't have a multimeter so I'm going to replace the bulbs and go from there.

Thanks for the help... it is always appreciared....
 
You should invest in a multimeter. You can find good digital multimeters for less than 20$

I know the CR-620 so well to affirm that new lamps ( you need 4 lamps of 12V, 60mA by the way), or burned lamps, will change nothing to the "pop" noise that you have at turn-off.
 
Does it "pop" on both channels ? If yes. I could also be a power supply issue.
 
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I've ordered a multimeter and will check the speaker connections when it arrives on the 18th of April.

Will keep you all posted as to the outcome.
 
OK. Got a multimeter. Here are the readings.
Speaker A: L = -7.3 mV; R = -4.7 mV. Speaker B: L = -8.0 mV; R = -10.1 mV.
All the readings are NEGATIVE and continued to increase slowly in a negative direction.

Is the unit junk?

Thanks,
 
Something else... there is a GND connector on the back of the receiver. Do I need to actually ground the unit? If so, how can I accomplish that? The wall plug for the receiver is 2 pronged.
Thanks...
 
Before jumping to conclusions you can easily check the DC offset.
Without any speakers hooked up. Select, on the front panel, and input that has no source connected such as TAPE1/2 or AUX. With a multimeter .Measure the DC voltage at the speaker spring clips for both the left and right channel of SPK A or B (whichever you use make sure the front panel speaker select switch corresponds to whichever your using ie. A or B.) Ideally your looking for 0.000 vdc. Realistically you will have some voltage there. Report how much you measure. More than 50mv (.050 volts) you might have and issue.
Just hook your meters red probe to the red post and black probe to the black post.


You can check it this way provided the receiver is not in protect mode. ie. "clicks" shortly after power on.

OK. Got a multimeter. Here are the readings.
Speaker A: L = -7.3 mV; R = -4.7 mV. Speaker B: L = -8.0 mV; R = -10.1 mV.
All the readings are NEGATIVE and continued to increase slowly in a negative direction.

Is the unit junk?

Also, there is a GND connector on the back of the unit. Do I need to actually physically ground the unit? If so, how can this be accomplished. The power cord has a 2 prong plug
Thanks,
 
Something else... there is a GND connector on the back of the receiver. Do I need to actually ground the unit? If so, how can I accomplish that? The wall plug for the receiver is 2 pronged.
Thanks...

No, that ground is for a turntable.
 
I just noticed that when I turn on the receiver there is a quiet pop about 2 seconds after turning it on. I haven't heard it before as my stereo equipment envirnoment is a wee bit noisy.

Is this a sign of anything?
 
Yes.... loudly even with the volume knob turned all the way down...

If it is power supply would that be an expensive fix? ... I'm not very good at fixing (soldering, etc) stuff, so would have to take it to a shop for repair.
 
I just noticed that when I turn on the receiver there is a quiet pop about 2 seconds after turning it on. I haven't heard it before as my stereo equipment envirnoment is a wee bit noisy.

Is this a sign of anything?

This quiet pop could be the sound of the relay which is closing, but 2 seconds is a short delay.

If you do a test with speakers or headphone, do you have a delay between the time you turn on the receiver, and the time you have sound from the receiver. This delay is typically 4 to 5 seconds, and is controled mainly by capacitor C816.
 
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