joessportster Posted May 25, 2005 Share Posted May 25, 2005 is it common to have a pinging noise from the speakers after you turn off tube gear, i have a newly rebuilt st 70 by craig and a blueberry pre-amp from mark neither has much time on it since i bought them the sounds continue for a few minutesnot very loud sounds kind of like a car does after running hot and you shut it off the popping and pinging till it cools off (only way i know how to describe it) Joe Quote Link to comment Share on other sites More sharing options...
JJkizak Posted May 25, 2005 Share Posted May 25, 2005 Just like pinging in a car, it's not good. Almost sounds like there is no circuit to cut off the sound output after shutdown. Probably won't hurt anything except your pride. If it was a car the pinging could lead to detonation which is mucho baddo, puts holes in the pistons. JJK Quote Link to comment Share on other sites More sharing options...
3dzapper Posted May 25, 2005 Share Posted May 25, 2005 That is probably just what it is. When you shut your car off the metal of the cat shield cools and clinks. Both the Blueberry and anything Craig builds have a lot of capacitance to provide current for dynamics. These caps take a while to bleed off. What you are hearing is a tube clinking on cool down still being amplified. I would venture to guess that that tube would clink if you tapped it lightly with a pencil with the amps on and with no signal. If it has looser elements than the other tubes, you will hear it. You can go from there. Rick Quote Link to comment Share on other sites More sharing options...
joessportster Posted May 25, 2005 Author Share Posted May 25, 2005 is a loose element a problem i have to worry about i cant beleive craig wouldnt have checked for thisif it were a problem, cant afford to fry any of the gear right now Joe Quote Link to comment Share on other sites More sharing options...
3dzapper Posted May 25, 2005 Share Posted May 25, 2005 I wouldn't fault Craig, shipping is very rough on tubes new or old. Rick Quote Link to comment Share on other sites More sharing options...
lynnm Posted May 25, 2005 Share Posted May 25, 2005 Probably is not a problem. Transistors are essentially instant on/instant off devices.Thus when a transistor stops getting power the signal stops being amplified.Therefore you will rarely if ever hear the effects of the capacitors in the circuit as they discharge beyond a pop sound when the power stops being supplied. Tubes on the other hand are not instant instant/on instant/off devices and will continue to provide a signal after the power stops until such time as they cool to the point that the cathodes stop emitting electrons to the grid. During that brief interval you will sometimes hear various noises created by the various capacitors in the preamp and/or power amp sections as they discharge. Certainly! Do check with NOSValves and MDENEEN on this issue in case there is some underlying problem that they may be aware of but I suspect that what you describe is normal and not a cause for concern. Quote Link to comment Share on other sites More sharing options...
mike stehr Posted May 26, 2005 Share Posted May 26, 2005 I dunno...if the caps have a bleed-off then they would drain pretty quick I would guess. Once the filament/heaters go below a certain point they simply won't conduct. I notice the same thing, moreso with larger tubes. I think it's the glass envelope and the elements are expanded from the heat. And when you cut the power off to them, the elements and envelope contract. Hence the cling and ping. Listen to them through the speakers on turn-on, they may ping coming up as well. I wouldn't worry it if it was me.....who knows....If the amp motorboats a bit on turn-off, or does a little squirk, then I'd worry that. Quote Link to comment Share on other sites More sharing options...
joessportster Posted May 28, 2005 Author Share Posted May 28, 2005 Spoke with craig his advice was to rebalance the amp and to bias it again and set it a little lower. This helped a bit didnt get rid of the problem all togeather but did help, He seemed to think 1 of the tubes may be getting a little hotter than should, but that it wasnt a big deal, Nothing to get worried about. Also spoke with mark thru email i was able to isolate the problem as coming from the amp tubes. Gotta love this forum, A wealth of information Thanks Guys Lynn m Is this a better , more readable post Joe Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted May 28, 2005 Share Posted May 28, 2005 I had the same problem because I have a hybrid system (solid state and tubes) and I discovered that it is important that you turn off your components in a certain manner as well as powering them on. I have to turn on my pre-amp first let it sit for a few seconds then the amps, and then on powerdown I have to shut off the amps first and lastly the pre-amp otherwise I get that same noise you are describing. Best, George Quote Link to comment Share on other sites More sharing options...
Parrot Posted May 28, 2005 Share Posted May 28, 2005 Yes, I second what George said. For shutdown, turn off your power amp first, wait 10-30 seconds, then shut off your BlueBerry. Quote Link to comment Share on other sites More sharing options...
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