Popping sound

It is most likely a tube, but ut can also be a bad capacitor.   But before you take the covers off look around the house to see if anything like a plug in air freshener or anything that cycles on and off like that.  Pull them out while troubleshooting this type of problem.  

If you suspect the pre, swap the right and left channel tubes.  I believe with earlier cj preamps the channels each had their own tubes, not sharing a twin triode for both channels like more recent ones. 

Before switching tubes, try switching the speaker wires.

After that you can switch the interconnects from pre to amp

Good point about speaker wirr interference .   I had a ethernet cable running alongside a speaker wire and it caused a weird intermittent crackle noise.  

Although the sound probably originates with a tube in your preamp, often there is nothing wrong with the tube, just the contacts with the pins and socket, and the problem can go away by just wiggling the tube or taking it out and reinserting it. Reversing the tubes can also solve or identify the problem (if it's a bad tube).  

Ask Chat GPT. No, really. They have an audiophile network that has been incredibly helpful in trouble shooting problems like this. I was shocked how good the response was.

Thanks for all the responses.

@gdaddy1

That was a great idea. So, I had to do it. It asks at the end for a component list. 

Possible Causes:

1. Loose or Oxidized Connections:

   • Speaker cable connection at the amp or speaker might be loose or dirty.

   • Interconnect cable (RCA/XLR) between the source and the amp (or preamp) could be partially failing.

2. Faulty Component in the Signal Chain:

   • The left output stage of a preamp, DAC, or source device could be unstable.

   • If it's a tube amp or preamp, a tube in the left channel might be going noisy with heat cycling.

3. Dirty or Aging Potentiometer or Switches:

   • Balance knobs, input selectors, or volume controls (especially analog ones) sometimes arc or pop intermittently when oxidized.

4. Interference or Ground Loop (less likely if infrequent and only in one channel):

   • A nearby device or power fluctuation could be inducing noise—but these usually affect both channels or are more frequent.

5. Amplifier Issue (Left Channel Only):

   • The left power amp channel might have a capacitor or solder joint failing, causing momentary instability as things warm up.

🧪 Diagnostic Steps:

1. Swap the Left and Right Speaker Wires at the amp:

   • If the popping moves to the right speaker, the problem is upstream from the amp.

   • If it stays in the left speaker, the issue is likely in the speaker or amplifier.

2. Swap Interconnects (Left ↔ Right) from your source (DAC, CD player, etc.) to the amp or preamp.

   • Does the popping follow the cable?

   • This can isolate the problem to a particular input device or cable.

3. Try a Different Source or Bypass Components:

   • If you're using a preamp + power amp, try running a DAC directly to the amp if possible.

   • Or vice versa: bypass the DAC if using digital gear.

4. Monitor for Changes with Heat:

   • If it always happens after ~20 minutes, it could be a heat-related issue with a solder joint, tube, or aging component.

🛠 What to Do Next:

• Clean all connections (interconnects, speaker terminals) with contact cleaner like DeoxIT.

• Inspect tubes if you're using a tube system—try swapping left/right tubes to see if the issue follows.

• Check your cables—they can go intermittent internally without being visibly damaged.

• If it only occurs at long intervals, consider setting up a recorder or monitoring app to capture the pop and correlate it with system use or temperature.

Let me know the type of gear you're using (amp, preamp, DAC, etc.), and I can give you more targeted advice.

@gdaddy1 ...and +10 for the Chat GPT tip....
Can't think of a less biased info source for now... 👍😎

It could be a tube. In this case the problem would most likely manifest itself even if the music is not playing. Other problems could be as mentioned above capacitors. 
It might also be power or digital connection related. You have powered speakers - is the popping sound in the bass region or in higher frequencies?

I would rule lout tubes first. Swap tubes left to right and see if the problem moves with the tube to another channel and go from there. 

The way my system is set up and my physical condition it’s just about impossible to access things such as speaker leads.  I can  swap tubes out though.  If that doesn’t work I’ll live with it.

@ghdprentice Giving the list of equipment is really important. The more information you give the better the result. I have used it several times with excellent results.

I stream from a laptop using Audirvana and one day, out of the clear blue, the music would just stop playing in the middle of a song for no reason. I could not figure it out for several days.

I gave GPT a list of all equiptment and it came back and asked me what make, model of the laptop and what operating system. It came back with a specific list to follow and was dead on accurate. I would NEVER have figured it out on my own. It did it in about 6 seconds and worked perfectly.

I used it also for a bilge pump problem on my son-in-laws boat. Again it required all associated equiptment but it did give an accurate assessment for correction even including part numbers.

Welcome to the new age! 

Welcome to the new age indeed. Enjoy the music

@gdaddy1 

Yes, it looks that way. I just used the OPs question as posted. 

It’s good to know it that level of detail works. I must admit I am using AI more and more, and it is becoming so much more useful. 

Thanks for the tips.

I use it all the time to find out how to do things on my computer, usually just google. And the step by step instructions are so much better that a list of possible sites and posts that talk about it. 

I use it the most for history and philosophy. Great for summaries. 

Yes, GPT was extremely helpful to me in many ways. Plus it referred to my setup thusly: 

“Strengths: Reference-level neutrality, detail, and low jitter.”

Good for the ego!