elferoony Posted February 1, 2004 Share Posted February 1, 2004 This has never happened to me before. I have two different cables which I have used for this 'test.' My Fender Champion 30 (Solid State) has two channels, passive input and active input. When I plug my AM Strat into passive input, there is massive feedback/radio signals (AM Radio?) received. Then I twist how the guitar cord is plugged into the amp a bit so that it is straighter, and there is no problem. (But I must hold it down in this way. )There is also no problem when I plug into active, mysteriously. I have no idea what the problem is or why it is occuring. Help! Link to comment Share on other sites More sharing options...
Dak Lander Posted February 1, 2004 Share Posted February 1, 2004 They're calling you. Face it. You can run but you can't hide. You'll never get away. Just think. It's been happening more since the rovers landed on Mars, hasn't it? Yes, you know it has. There's nothing you can do. The time warp continuem has been severed and it's too late... BWWWWAAAAAHAHAHAHAHA!!!! Our Joint "When you come slam bang up against trouble, it never looks half as bad if you face up to it." The Duke... Link to comment Share on other sites More sharing options...
elferoony Posted February 1, 2004 Author Share Posted February 1, 2004 It's the Tube Amp Nazis! They are trying to destroy solid state once and for all! Link to comment Share on other sites More sharing options...
Blue Strat Posted February 1, 2004 Share Posted February 1, 2004 The higher impedance of the passive channel, in addition to the un-shielded pickups in your guitar are acting as a radio antenna. If your cable is in a coil, it could be working like a air-core choke (a wire coil with an open air center), a device used in many radio reciever tuners. BlueStrat a.k.a. "El Guapo" ...Better fuzz through science... http://geocities.com/teleman28056/index.html Link to comment Share on other sites More sharing options...
Caevan O’Shite Posted February 1, 2004 Share Posted February 1, 2004 O.K., are you saying that this happens with either cable? If the cables are fine, then the twisting part makes me think that there's a bad connection like loose hardware, a broken/bad solder-joint, or the like on the "passive" input jack. Approach this as a process of elimination: rule out what isn't causing the problem, and you'll uncover what is. Ask yourself- What Would Ren and Stimpy Do? ~ Caevan James-Michael Miller-O'Shite ~ _ ___ _ Leprechaun, Esquire _ ___ _ Link to comment Share on other sites More sharing options...
Dak Lander Posted February 1, 2004 Share Posted February 1, 2004 Actually, I think Blue and Kev are on the right track. The higher impedence Bluestrat talks about could likely be caused from a bad solder joint or other connection problem as Caevan suggests. There is no doubt that a coiled cord of any kind, passing, or not passing, electrical signal of any kind, can become an antenna for radio signals. It may be too, that your amp's electronics, with the inherrent variations from spec, could be turning your amp into an am band radio at certain frequencies. There is no way to cure that short of rebuilding the amp but you can help attenuate (Bluestrat, you like that?) the issue by making sure your connecting cords are straight. Also make sure your power cord is not in proximity to, nor in line with, the instrument cable. Our Joint "When you come slam bang up against trouble, it never looks half as bad if you face up to it." The Duke... Link to comment Share on other sites More sharing options...
Prague Posted February 1, 2004 Share Posted February 1, 2004 I think Caevan is on track, here. It sounds like a poor connection on the passive jack. These jacks are a friction fit. Look at how they operate when the plug is inserted. Try bending the contacts a bit so they are tighter. It may just be dirty, too. Find some kind of contact cleaner and see if that helps, too. Of course, look to see that the circuit board or wiring connections are okay. Link to comment Share on other sites More sharing options...
elferoony Posted February 2, 2004 Author Share Posted February 2, 2004 Thanks guys. My cable isn't in a coil. (Actually, I can't find coiled cables sold anywhere these days.) I tested my cables with another amplifier and they work fine. So it does seem like it is the passive input. But it isn't loose or anything. The connection only works when I hold the cable very straight and very tight to the amplifier. I can't make it stay the way after I let my hand go. The warranty on my amplifier (which I got from Sam Ash) is still good. Should I try to open it up and repair it myself, or should I bring it in? Your advice is very trusted! Link to comment Share on other sites More sharing options...
Dak Lander Posted February 2, 2004 Share Posted February 2, 2004 Originally posted by elferoony: Thanks guys. My cable isn't in a coil. (Actually, I can't find coiled cables sold anywhere these days.) I tested my cables with another amplifier and they work fine. So it does seem like it is the passive input. But it isn't loose or anything. The connection only works when I hold the cable very straight and very tight to the amplifier. I can't make it stay the way after I let my hand go. The warranty on my amplifier (which I got from Sam Ash) is still good. Should I try to open it up and repair it myself, or should I bring it in? Your advice is very trusted! The cable coil won't be that tightly coiled stretch cable, it'll be more like a loop or two of cable. If the amp is still under warranty, TAKE IT IN! Don't try to fix it yourself. You will likely void the warranty if you mess with it. Our Joint "When you come slam bang up against trouble, it never looks half as bad if you face up to it." The Duke... Link to comment Share on other sites More sharing options...
elferoony Posted February 2, 2004 Author Share Posted February 2, 2004 I just called Sam Ash Cerritos, and the guy working there said that the reason I am picking up signals is the electricity coming into the amp. He suggested using a ground lift or plugging into different power connections. So I will, as soon as I get home from the library. Link to comment Share on other sites More sharing options...
Caevan O’Shite Posted February 2, 2004 Share Posted February 2, 2004 I could be wrong, but that sounds like a cop-out to me. Try different outlets, and even a power conditioner (if you can get your hands on one, don't go buying one unless you really need it). use one of those "three-to-two" plug-adapters, do not remove the ground-prong from the plug (that could be considered grounds to void your warranty!). I'd think that you'd get the RFI with either input, if it's due to dirty AC. I'd insist that they make absolutely dead-certain for sure that it isn't the jack on the amp, before the warranty runs out; it's their job to do so. Part of the reason for spending the money for new gear at a real live store is the WARRANTY and CUSTOMER SERVICE and SUPPORT!! Too often store employees will find a way to give a customer the brush-off, instead of actually helping them. Best of luck to ya, elferoony! Definitely keep us posted on things! Ask yourself- What Would Ren and Stimpy Do? ~ Caevan James-Michael Miller-O'Shite ~ _ ___ _ Leprechaun, Esquire _ ___ _ Link to comment Share on other sites More sharing options...
Blue Strat Posted February 2, 2004 Share Posted February 2, 2004 Ok, I think that the "dirty AC" stuff is a myth, and here's why. A power supply takes AC and converts it to DC. To do that, the AC signal (from your wall socket, 60 cycles in the US, 50 cycles if you're in europe) is fed into some diodes, either vacuum tube or solid state, then into filter capacitors. Capacitors are seen as an AC short circuit, or a DC open circuit. The way that the capacitors in a power supply are arranged is as an AC short to ground. All of the radio frequency crap that comes in on the power cord is sent to ground, and essentially pure DC comes off of the other end of the filter cap. There's a little low voltage ripple, but that's heard as a low volume buzz, if it's heard at all. Poor grounding could be a problem. Bad solder connections of components could be a problem. If the wiring in your wall checks out, the problem is in your amp and should be covered by the service plan from Sam Ash. BlueStrat a.k.a. "El Guapo" ...Better fuzz through science... http://geocities.com/teleman28056/index.html Link to comment Share on other sites More sharing options...
Adamixoye Posted February 2, 2004 Share Posted February 2, 2004 Originally posted by elferoony: My cable isn't in a coil. (Actually, I can't find coiled cables sold anywhere these days.)I believe Musician's Friend is selling them (my brother bought me one earlier this year). It is in fact a tightly-coiled stretch cable. I liked it at first, but recently it seems to be pretty noisy. I dunno. Just my two cents on this part of the topic... I believe that is the greatest reply I\'ve ever read! I\'m not even joking. -- justinruins Link to comment Share on other sites More sharing options...
elferoony Posted February 2, 2004 Author Share Posted February 2, 2004 Ok. I thought about it after reading your posts, and really tightened the input jacks. The sound is gone. What fuss about nothing, sorry. Now nothing goes between me and my tone! Except a distinct lack of technique and vacuum tubes. Thanks! Link to comment Share on other sites More sharing options...
Caevan O’Shite Posted February 2, 2004 Share Posted February 2, 2004 No prob, elf'! A good time and a 'learning experience' was had by all! Ask yourself- What Would Ren and Stimpy Do? ~ Caevan James-Michael Miller-O'Shite ~ _ ___ _ Leprechaun, Esquire _ ___ _ Link to comment Share on other sites More sharing options...
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