Unidentifiable popping sound

Not 100% sure it goes in this forum — apologies if there is a better place.

For 6 months now, something in my system is making a clicking/popping sound. It usually happens 15 minutes after I power things up, or about 10 minutes after I power them down. It can also happen spontaneously when everything is technically on standby. I actually have a recording of it, but not sure how to upload here. Any ideas?

Preamp — Nagra Jazz (possible) (it happened with both old and brand new tubes)
Amp — Nagra Classic Amp (possible)
DAC/Source — PS Audio Directstream (possible)
Phono stage — Pure Audio LV-1 (probably not)
TT — Clearaudio Concept (definitely not that)
Cables — Luna Orange (also, definitely not that)


You should power cycle each piece individually to isolate the defective component


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Have you isolated all of the tube equipment to determine if anything else that has tubes in it might be the culprit? I had a very similar experience with some NOS tubes in my preamp years ago. Yes, they were the correct values and exact same type for this preamp. After I turned on the equipment and a short while later, I would hear a pop. I thought something was going to blow up the system. I started with the preamp and replaced the NOS tubes with more modern tubes, PSVayne, and voila, no more pops. Luckily,, this was the first step in my investigation which isolated the issue. I examined the NOS tubes, RFT Germany, and noticed that perhaps a filament was more than likely the cause. It was hanging on barely by a thread, probably arcing or something. Not sure, but when I replaced them, everything was back in order and never had the problem since. Popping noise is never good when it comes to Electonics. Also, make sure that when you are switching between components, that all connections are properly installed. If you have WBT or similar connectors which require an extra turn or two to lock the connector, you may also experience some type of weird anomalies such as popping or hum…I have experienced this as well. 

@fuzztone good call. will try that.
@audioquest4life Nagra is very, very good at QC and it happened with both the tubes that came with the Jazz (picked it up pre-owned), and with new ones I got directly from Nagra. If it is the preamp, I'm not sure it's the tubes (but anything is possible at this point!).

So, you hear popping 10 minutes AFTER you power the system down? Is this popping through the speakers? Not likely.

Pretty easy to rule out the DAC. Turn it off, disconnect the interconnect cables at the pre-amp input end and listen to vinyl only for a few days, or until you hear the popping noise. If you hear the popping noise with the DAC turned off and disconnected front the pre-amp, you've ruled out the DAC as a potential cause.

Question: Do you hear the popping noise through the speaker(s) or do you hear it emanating from the electronic equipment? If speakers, from one or both?

Start with all components off. Power them up one at a time starting with the power amp, then preamp. Once a component is powered, leave it on and work your way upstream until the popping starts.

party poopers

Model A driving by? Maybe a model T.. Retard the amps timing that will stop the popping. :-)

I had this problem with my PS Audio Directstream dac when using the bridge.  PS Audio was very helpful and sent me special firmware updates and a new bridge to try but the popping continued.  Finally, they took back the bridge.  Things sound very good even without it.

Popping sounds when there are tubes in the signal chain can be caused when the tube loses contact with the circuit -- bad tube, loose socket, or socket to wire or socket to board solder joint. Usually happens when heating up and cooling down as the bad solder joint  shifts with change in temperature. 

Substitute another preamp to rule this out.

I'm not sure if this will help, but I experienced a similar crackling sound and it was a cable shield that wasn't earthed. Once it reached a certain level it discharged across the inner insulation.

It was a quality brand subwoofer cable with terrific shielding. Problem was it wasn't earthed. After slicing back a slither of the outer protection I gently soldered a wire to the shielding and connected it back to a central earthing point. Fixed.

Thanks so much for the replies everybody. Lots of good thoughts and suggestions for me to experiment with here (and some solid jokes). @wolverine1 I'm really curious to see if this is the same sound you heard with the bridge. Is there any way I could fling this recording I made over to you to see if its a match?

@reubent it's definitely coming from something electronic, it's not from or through the speakers.

I don't know if there's a way for you to send me the recording.  Maybe someone else knows about this.  

I do have two suggestions.  If you're using the bridge, try removing it and see if the ticks go away.  Also, try calling PS Audio customer service.  I dealt with TJ a couple of years ago and he was very helpful.  As I mentioned previously, he sent me a replacement bridge to try as well as some beta software.  Unfortunately, none of those things fixed the tick problem so I returned the bridge for a refund.  We never did figure out the cause but I'm very happy with the sound absent the bridge and there are no ticks..


it's definitely coming from something electronic, it's not from or through the speakers.

I would think that would make it easier to find as you may only need to have one component powered up to hear the sound. So, sometime when you can be in the room, but not listening to music, simply power up only one component for a reasonable period of time to determine if you hear the sound. If not, power it off, wait an appropriate period of time to determine if you hear it after power-off, then repeat with the next component. Worse case, it should take you less than 2-3 hours based on your description in the original post.

Good luck. Hope you solve this soon.