Silenced Fred Posted December 18, 2010 Share Posted December 18, 2010 My amp starts acting up. Intermidently (I don;t know how to spell it, just sound it out) it will start a super high pitch squeal that goes on until I shut it off. No rhyme or reason to it, just happens. Any ideas as to what this could be? Probably going to find an amp tech to take it into on Monday Link to comment Share on other sites More sharing options...
S t e v e Posted December 18, 2010 Share Posted December 18, 2010 feedback? Link to comment Share on other sites More sharing options...
MrNylon Posted December 18, 2010 Share Posted December 18, 2010 What kind of amp Fred? Link to comment Share on other sites More sharing options...
Silenced Fred Posted December 18, 2010 Author Share Posted December 18, 2010 Steve- I don't think its feedback. its a Sunn T50C, and just normal playing, then all of a sudden it sounds like a pteradactyl is planning to swoop down and murder me. I know feedback, and I highly doubt thats it. I just swapped out the preamp tubes, hoping that helps Link to comment Share on other sites More sharing options...
MrNylon Posted December 18, 2010 Share Posted December 18, 2010 Does it do it with all your guitars? Link to comment Share on other sites More sharing options...
ChanMan Posted December 18, 2010 Share Posted December 18, 2010 yeah, good thinking. I was thinking tubes, but I'm clueless.... Link to comment Share on other sites More sharing options...
Silenced Fred Posted December 18, 2010 Author Share Posted December 18, 2010 Does it do it with all your guitars? Yup. I don;t get it at all. I'm really hoping djroge checks this out, I believe he knows amps Link to comment Share on other sites More sharing options...
MrNylon Posted December 18, 2010 Share Posted December 18, 2010 I never saw a Sunn do that. Using the same guitar cord? Just for the hell of it, try another cord. Link to comment Share on other sites More sharing options...
Silenced Fred Posted December 18, 2010 Author Share Posted December 18, 2010 Changing everythign out, still happens. It seems to be all happening at around the same decibel range, when the amp volume hits about 2... I'm lost guys, not sure what to do, its a terrible piercing screech, and once it starts, it won't stop until the amp is off Link to comment Share on other sites More sharing options...
Andy R Posted December 18, 2010 Share Posted December 18, 2010 Changing everythign out, still happens. It seems to be all happening at around the same decibel range, when the amp volume hits about 2... I'm lost guys, not sure what to do, its a terrible piercing screech, and once it starts, it won't stop until the amp is off Does it do it without the guitar plugged in? Does it have an effects loop if so plug your guitar directly into the return. If it still does it it's an issue with the power amp section if not then you know it's in the pre-amp section. If it does it when plugged into the effects return then switch out your power tubes if you can as they become microphonic a well. If you determine it is in the pre-amp section try swapping around tubes with your phase inverter tube( if it is a class A amp it won't have one) as well not just pre-amp. If it is not a tube then it has to be a component or possibly a pre-amp tube wire that has vibrated too low to the heater lines. If your comfortable with opening up the amp ( make sure it is unplugged and don't touch anything with fingers as the caps store a ton of volts/amperage.) Take a dowel rod or something non conductive. Avoid pencils and get the feedback happening. Now poke around and tap on components and see if it goes away. Look for burnt resistors or popped caps. Also lift the wires around the pre-amp tubes to make sure they are spread out and away from each other. Does any guitar level come through? Wish I could do more to help ya. Good luck. Please be careful if you take any of my advice!!!!! Andy Link to comment Share on other sites More sharing options...
Silenced Fred Posted December 18, 2010 Author Share Posted December 18, 2010 Thanks guys! I swapped out pre amp tubes, and nothing changed. I don't have any power tubes, and don't want to spend 50 bucks on those because I'm not sure if that's the issue or not. My dad's friend works on amps and I'm gonna take it to him early next week, he said he can probably fix it within an hour or so depending on what it is. i described it to him and he said he should be able to handle it. Link to comment Share on other sites More sharing options...
Andy R Posted December 18, 2010 Share Posted December 18, 2010 I can understand that don't want to waste 50 bones for nothing. Does it have effects loop? Like I said a quick check is to plug directly into the return this completely bypasses the pre-amp section. Then you know if it is power amp section/power tubes.... If not then not much other way to check... Link to comment Share on other sites More sharing options...
Silenced Fred Posted December 18, 2010 Author Share Posted December 18, 2010 I can understand that don't want to waste 50 bones for nothing. Does it have effects loop? Like I said a quick check is to plug directly into the return this completely bypasses the pre-amp section. Then you know if it is power amp section/power tubes.... If not then not much other way to check... yeah it does. Right now, I don't feel like messing with it, just gonna take it into my dad's friend and let him mess around with it Link to comment Share on other sites More sharing options...
surfpup Posted December 18, 2010 Share Posted December 18, 2010 Tube amp rule #1... Always keep spare tubes on hand! Spend the money - especially now that you have a gig coming up. Does the amp have reverb? I've had my Deluxe Reverb squeal like a pig when the reverb tube was bad or loose. However, I guess if you have swapped out all the preamp tubes it can't be that. I assume also that you are plugging straight in and not going through pedals (which can create that kind of noise when their batteries are dying). Have you tried pulling the power tubes in and out a few times (amp off obviously) to ensure good connection there? Link to comment Share on other sites More sharing options...
Andy R Posted December 18, 2010 Share Posted December 18, 2010 yeah it does. Right now, I don't feel like messing with it, just gonna take it into my dad's friend and let him mess around with it If you're not comfortable doing it I completely understand. It took me about 25 years before I felt brave enough to get the courage to dig into my own amps. They are dangerous but common sense and precaution prevents injury. Honestly if you have powered it on and it didn't blow any fuses or produce any smoke or burnt smell you are pretty safe to experiment with tubes and trying the things we have mentioned. (that doesn't involve opening the amp!) You might learn something simple that saves issues, time and money at a gig in the future. Not trying to push you into doing anything you are uncomfortable with and will leave it at that. Let us know what you find out! Link to comment Share on other sites More sharing options...
ChanMan Posted December 18, 2010 Share Posted December 18, 2010 You could try ApostleTone at the other place. He builds amps.... Link to comment Share on other sites More sharing options...
Andre S Posted December 18, 2010 Share Posted December 18, 2010 You could try ApostleTone at the other place. He builds amps.... I thought that was djroge1? Link to comment Share on other sites More sharing options...
surfpup Posted December 18, 2010 Share Posted December 18, 2010 It is. And he is around here some still. Maybe he can chime in on the squealing Sunn. Link to comment Share on other sites More sharing options...
ChanMan Posted December 18, 2010 Share Posted December 18, 2010 I thought that was djroge1? Is it??? Crap, I need a program.... Link to comment Share on other sites More sharing options...
Andy R Posted December 22, 2010 Share Posted December 22, 2010 So what Happened with your amp man???? Link to comment Share on other sites More sharing options...
Silenced Fred Posted December 22, 2010 Author Share Posted December 22, 2010 I'm gonna take it to the guy after the holidays, he's booked as all hell Link to comment Share on other sites More sharing options...
Andy R Posted December 22, 2010 Share Posted December 22, 2010 Bummer! Don't forget to let us know. I'm an amp freak and like to know what fixed issues! Link to comment Share on other sites More sharing options...
tazzboy Posted December 22, 2010 Share Posted December 22, 2010 Time to get your amp retube Link to comment Share on other sites More sharing options...
LarryUK Posted December 22, 2010 Share Posted December 22, 2010 Sounds like a tube to me. Is it called 'harmonic' when a tube starts to ring? This rings a bell to me. When a tube is failing it vibrates and the ringing builds up. Link to comment Share on other sites More sharing options...
LarryUK Posted December 22, 2010 Share Posted December 22, 2010 This has got me thinking. Am I right that you can lightly tap each tube and the duff one gives a rattle sound? Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.