2. amps-preamps
  3. 1224022381

Random pop sounds in my system are scaring me

Hi, I need some help and expertise on this potentially expensive situation! The last few times I've powered up my 18wpc SET amp it has been plagued by some startling "pop" sounds at random intervals. The amp switch is in the mute position, with no source selected and yet at random intervals I hear an alarming pop sound coming from the speakers. The volume of the popping isn't SUPER loud, but it does startle me and has me worried. The weird thing is, sometimes it happens, sometimes it does not. I'll have to do some more testing, but I haven't noticed this happenig when a source is actually playing through the speakers. When I bias the tubes immediately after hearing a pop, I don't see any weird numbers or behavior on the bias meter. The amp is only about 3 months old and it took so long to get, I'd hate to lose it! I know it could probably be a million different things, but does anyone have an idea of what might be happening here? Help!
Thanks!
mbleming

Showing 7 responses by mbleming

mbleming OP
33 posts
 
If it is indeed a capacitor breaking down, is this something that has the risk of destroying the whole system if I keep listening?
thanks!
mbleming OP
33 posts
 
Yes, the unit is definitely still under warranty, but I'd need to ship it back to Japan! I'd like to avoid that if at all possible for cost reasons, as well as wear and tear from shipping. Thanks, for the suggestion, I'll give it a shot.
mbleming OP
33 posts
 
First, thanks to everyone who has offered their help and expertise on this, I'm new to tubes and need all the help I can get. I played around a little bit last night and I could reproduce the pop when I plugged and unplugged my phono stage. The weird thing is, it didn't happen every time! I have no idea what it could be, does the problem lie with the amp itself or my wall outlets, or both? Again, this is a new problem, only within the last week. It's strange because I was hearing it on its own, withough plugging or unplugging components...only today it happened when I plugged/unplugged my phono stage.
mbleming OP
33 posts
 
No, no, I'm not unplugging the ICs, just the power unit to my phono stage and I haven't done the plug/unplug thing with a source selected...the times I've heard the sound, the amp's source select switch has been in mute! I've tried tapping the tubes lightly, but nothing. Its a strange problem as it seems very random, other than today when I plugged in my phono stage.
mbleming OP
33 posts
 
I think it's both channels, but I'm not 100% sure yet, as the last two times I've heard it I've been next to the left speaker. I haven't tried to swap tubes as money is a little tight at the moment...I'll definitely have to bite the bullet soon though, as a bad tube seems to be the most likely culprit. Its tough to figure out because the instances are so random. Also I've noticed that the pops seem to happen more or less within the first 20 mins after power up, after that point I haven't heard much. So many variables! I'd love to just move the whole thing to another room/power outlet, but this is impossible in my apartment at the moment.
mbleming OP
33 posts
 
The amp is an Almarro 318B, about 4 months old. I will try the tube swap, but I'm pretty sure its coming from both speakers. I could be wrong though as its tough to tell as I'm never ready for it when it happens!
Thanks
mbleming OP
33 posts
 
Well, I finally tracked down the culprit responsible for the random popping in my speakers...a bad 6C33C power tube. Thanks for all the assistance and suggestions, I should have just checked these first by swapping them to see if the popping sound switched speakers (which it did)...got a new one and everything is now fine.
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