Receiver causing Surge Pop on Speaker driven by an external amplifier

[Verdinut]

I recently purchased a Marantz SR5010 receiver to replace a NAD T763 which let me down after 13 years.

In my system, I have been using a Furman PS-8R power sequencer to shut down my equipment as I have active crossovers and equalizers for the 3 front channels which are bi-amped. Without that sequencer, I was getting a loud popping noise from the front channel speakers.

Now, when I shut down the sequencer, the sequence #3 then becomes the first sequence for the SR5010 and the SONY 3200F power amp to shut down. Afterwards, I hear a slight popping noise from the bi-amped center channel speakers connected to the SONY amp. This noise is triggered by the crossovers and EQs shutting down in the last sequence.

With the NAD receiver, I did not have that problem. Could it be caused by the fact that the Marantz receiver is not powered by a 3 prong grounded power cord? Probably you remember that this SONY amp, which is about 50 years old and performs a lot better than recent Sony amps, is also powered by a 2 pin power cord.

Any hint someone?

 

[Speedskater]

Have you tried changing the shut-down sequence?

 

[slipperybidness]

I recently purchased a Marantz SR5010 receiver to replace a NAD T763 which let me down after 13 years.

In my system, I have been using a Furman PS-8R power sequencer to shut down my equipment as I have active crossovers and equalizers for the 3 front channels which are bi-amped. Without that sequencer, I was getting a loud popping noise from the front channel speakers.

Now, when I shut power down on the system, at the last sequence when the SR5010 and the SONY 3200F power amp are shut down, I hear a slight popping noise from the bi-amped center channel speakers connected to the SONY amp. With the NAD receiver, I did not have that problem. Could it be caused by the fact that the Marantz receiver is not powered by a 3 prong grounded power cord? Probably you remember that this SONY amp, which is about 50 years old and performs a lot better than recent Sony amps, is also powered by a 2 pin power cord.

Any hint someone?

Seems like classic capacitor discharge pop. Your AVR likely has circuitry to avoid that.

 

[WaynePflughaupt]

Now, when I shut power down on the system, at the last sequence when the SR5010 and the SONY 3200F power amp are shut down, I hear a slight popping noise…

And there’s the problem. All amplifiers should be powered down before the receiver. As speedskater suggested, you need to change the shut-down sequence.

Basically, amplifiers should be the last to turn on and the first to turn off.

Regards,
Wayne A. Pflughaupt

 

[Verdinut]

Have you tried changing the shut-down sequence?

The sequence being used is the best: The receiver and the Sony amp are turned on in sequence #3 and they are shut down first exactly to prevent noise from the crossovers and EQs.

 

[Verdinut]

And there’s the problem. All amplifiers should be powered down before the receiver. As speedskater suggested, you need to change the shut-down sequence.

Basically, amplifiers should be the last to turn on and the first to turn off.

Regards,
Wayne A. Pflughaupt

I don't see why amplifiers should be powered down before the receiver. That is the sequence I have always been using. Remember I mentioned that the problem did not happen with the NAD. The Marantz seems to be causing the problem and I suspect it is the non grounded chassis.
I tried your suggestion of turning on the Sony amp in sequence 2 and the SR5010 in sequence 3. With that arrangement, when I shut down the sequencer, the popping noise on the Sony amp driving the center channel was much louder, since its " off status" was closer in time to that of the crossovers and EQs, so I reverted to the original sequence.
I did not indicate clearly in the original thread that both the receiver and the external power amp were programmed in sequence 3 and therefore, they are always powered down first by the sequencer. I will edit the original text.
Regards,
Verdinut

 

[j_garcia]

The sequence being used is the best: The receiver and the Sony amp are turned on in sequence #3 and they are shut down first exactly to prevent noise from the crossovers and EQs.

You asked for advice. If you aren't willing to try it, don't ask.

That is the sequence I have always been using!

Problem #2. Since it now doesn't work, just because you have "always done it that way" does not mean it is correct for your new configuration.

 

[Verdinut]

You asked for advice. If you aren't willing to try it, don't ask.



Problem #2. Since it now doesn't work, just because you have "always done it that way" does not mean it is correct for your new configuration.

The only change is a replacement of receivers, don't you understand?

 

[j_garcia]

The only change is a replacement of receivers, don't you understand?

It isn't the same receiver, so the behavior may be different. DON'T YOU UNDERSTAND?

Looks like my next candidate for the ignore list.

 

[slipperybidness]

Well, to answer one question for the OP: I highly doubt that the "2 Prong Power Cord" on the Marantz is the source or your issue here.

 

[Verdinut]

Well, to answer one question for the OP: I highly doubt that the "2 Prong Power Cord" on the Marantz is the source or your issue here.

Thanks for your comments.
To avoid the problem in the meantime, before getting additional multi-channel amplifiers to bi-amp the 3 front speakers, I will just turn off the Sony amp before I shut down the sequencer.
Regards,

 

[WaynePflughaupt]

The sequence being used is the best: The receiver and the Sony amp are turned on in sequence #3 and they are shut down first exactly to prevent noise from the crossovers and EQs.

All line-level devices, including the receiver or pre-amp, should be turned on before and shut down after the amplifiers.

Regards,
Wayne A. Pflughaupt

 

[TLS Guy]

Well, to answer one question for the OP: I highly doubt that the "2 Prong Power Cord" on the Marantz is the source or your issue here.

The two prong cord is not the problem. There is no arguing that.

Power amps have large power supply caps and stay live longer after switch off than other units.

His Marantz has a capacitance discharge pop form the pre outs and the power amps are still live when he shuts them down. So yes, he needs to shut the power amps off first.

Now if the receiver was powering the speakers he would not hear the pop as receivers generally have a relay that disconnects the speakers on power off immediately. On power on there is a delay from timer circuits to delay speaker connection via the relays until the power on thumps have passed.

 

[mtrycrafts]

..., I will just turn off the Sony amp before I shut down the sequencer.
Regards,

Yes, try that. If that works, just cequence it's shut down first, then your other amps, etc.
You may also have to increase the elapsed time between shut downs?

By the way, which speaker/s did the popping?

 

[lovinthehd]

I'd try eliminating the Furman altogether and do things manually as a check....

 

[Verdinut]

All line-level devices, including the receiver or pre-amp, should be turned on before and shut down after the amplifiers.

Regards,
Wayne A. Pflughaupt

Well, I arranged for the receiver to turn on in the 2nd sequence with the Sony amp in the 3rd. Same noise problem!
But, there is no noise when I power down the Sony amp first before shutting down the sequencer after several seconds.

Regards,

 

[Verdinut]

Yes, try that. If that works, just cequence it's shut down first, then your other amps, etc.
You may also have to increase the elapsed time between shut downs?

By the way, which speaker/s did the popping?

By shutting down the external Sony power amp first, and powering off the sequencer several seconds later, there is no more popping noise.
The speaker which did the popping was the front center which is driven by the Sony amp.

Regards,

 

[Verdinut]

The two prong cord is not the problem. There is no arguing that.

Power amps have large power supply caps and stay live longer after switch off than other units.

His Marantz has a capacitance discharge pop form the pre outs and the power amps are still live when he shuts them down. So yes, he needs to shut the power amps off first.

Now if the receiver was powering the speakers he would not hear the pop as receivers generally have a relay that disconnects the speakers on power off immediately. On power on there is a delay from timer circuits to delay speaker connection via the relays until the power on thumps have passed.

But it's not the Marantz that pops into the speaker driven by the Sony amp when it power off, it's the crossovers and EQs which are powered off after the Sony which is powered down first and the Marantz which is powered down in the second sequence. Putting the Sony in the second sequences makes matters worse, because it powers off at a closer interval just before the crossovers and EQs.

Would it be possible that the noise might be caused by the Marantz not having delays in the pre-out circuit feeding the Sony amp?

Regards,

 

[mtrycrafts]

By shutting down the external Sony power amp first, and powering off the sequencer several seconds later, there is no more popping noise.
The speaker which did the popping was the front center which is driven by the Sony amp.

Regards,

Simple. If it works, use that sequence.

 

[herbu]

All amplifiers should be powered down before the receiver.

Uh oh. My Emotiva amp powers up via trigger from my Denon X4000 AVR. So power-on is OK. But when I press power-off on the remote, the AVR seems to turn off first. At least the front panel leds look that way.

You're saying I should get up out of my la-z-boy, walk to the components, bend over, open the cabinet door, turn off the amp, close the door, straighten back up with some effort, walk back to the remote, then turn off the AVR?

Really? It seems my amp may be in trouble.