Members catphish Posted August 14, 2005 Members Posted August 14, 2005 Not much time to write this, in a hurry to get to rehearsal, but in a nutshell, my new amp (Eden VT-300B all tube) is making a sound that can best bedescribed as 'sleighbells', through the tweeter. Only through the tweeter. If I turn off the tweeter, the sound is gone. My first thought was that it was a bad tweeter, so I pulled out another cabinet, same thing, and then a third cab, same thing. So there are two issues for me. First of all, what could the problem be with the amp? Second, I've only had it for 20 days and should I just return it and not even bother worrying about it? The tone from this amp is far and away the best I've ever heard. It's basically my ideal tone, and it's fairly light for a 300W tube amp (45lb). But I dropped serious coin to buy it, and part of me says just return it, get your money and don't risk it. So what do you all think? Thanks.
Members Rowka Posted August 14, 2005 Members Posted August 14, 2005 It's not a defect. It's a feature.
Members baracuda2004 Posted August 14, 2005 Members Posted August 14, 2005 keep the amp and just play shows around Christmas and tell them it's part of your signature holiday sound.. maybe SANTA will bring you something special..
Members bassman1956 Posted August 14, 2005 Members Posted August 14, 2005 I'd say contact the company and see what they say, find out if they'd swap it out.
Members fretless Posted August 14, 2005 Members Posted August 14, 2005 noisy tube ? A tube can jingle , you can sometimes swap them around to find the source, as it will get quiet and or replace it , if of course it is a tube , you can gently ping the top with your finger nail 'gently" to find the noisier one . Just a guess .
Members Deville Posted August 14, 2005 Members Posted August 14, 2005 Yup, sounds like a microphonic tube. just buy a new preamp tube. If the problem doesn't go away after moving some preamp tubes around, it may be a power tube. Those should almost always be swapped in matched sets.
Members catphish Posted August 14, 2005 Author Members Posted August 14, 2005 Thing is guys, this is brand new. I feel like I shouldn't need to be jerking around with my brand new amplifier! Know what I mean?
Members fretless Posted August 14, 2005 Members Posted August 14, 2005 it is a hassle but , then again it is a tube amp , and a cheap preamp tube is like a $ 5 part ,if you determine that it is a tube , I bet they will send you a new one , at the same time I would have extra tubes on hand anyway I don't put to much trust in a $5 part, it's kinda like buying a brand new car with a bad tire , you would just replace the tire right ? If you can't diagnose it then take it in .
Members catphish Posted August 14, 2005 Author Members Posted August 14, 2005 Originally posted by fretless it's kinda like buying a brand new car with a bad tire , you would just replace the tire right ? If you can't diagnose it then take it in . I see you're point, but this differs in two ways. One, if it's a bad tire, you can see it's obviously a bad tire. the bad tube is just a guess. I don't have a clue how to diagnose it beyond trying what you guys tell me. The other difference is I have the option here of taking it back for a full refund, under 30 days. Car dealers won't give you teh same option if you had a flat tire.....or a faulty engine for that matter. They would fix it of course, but it's not the same. Not to mention I can change a tire with no problem. I understand tube amps are somewhat dangerous (even lethal) if you don't know what your doing.
Members catphish Posted August 14, 2005 Author Members Posted August 14, 2005 two other tid bits of info.... It doesn't do it when it's first turned on (suspect since the tubes aren't warmed fully) and two, it also makes the noise even if I'm not playing, but tap on the top of the amp.
Members fretless Posted August 14, 2005 Members Posted August 14, 2005 Originally posted by catphish I see you're point, but this differs in two ways. One, if it's a bad tire, you can see it's obviously a bad tire. the bad tube is just a guess. I don't have a clue how to diagnose it beyond trying what you guys tell me. The other difference is I have the option here of taking it back for a full refund, under 30 days. Car dealers won't give you teh same option if you had a flat tire.....or a faulty engine for that matter. They would fix it of course, but it's not the same. Not to mention I can change a tire with no problem. I understand tube amps are somewhat dangerous (even lethal) if you don't know what your doing. Tube amps are dangerous if they have stored electricity iin their caps and you touch it and ground it and then take the hit , can kill you , so you never want to mess around inside where all that stuff is usually exposed , but tubes are accessed from the top usually {check manual} , and slip in according to their pins . But if you have never done this then it is a good idea to have a tech show you . Yeah if have never changed preamp tubes before and the fact that you are worried that it could be other things , you should take it in , I feel comfortable enough myself to at least check out the preamp tubes and then say they where all the same ie. 12ax7 I would swap them around , but don't get me wrong , that is all I would do before it went back , the store should be able to swap tubes right there , but yeah you have a few options open so no worries Just a little hassle but the good news is you found "The tone from this amp is far and away the best I've ever heard" so I think it's worth sorting out before you give it up , especially because it could be just a cheap crappy tube that came stock .
Members fretless Posted August 14, 2005 Members Posted August 14, 2005 funny thing when I swap tubes in my Demeter pre , I DI out and monitor with headphones , if there is hiss , out it goes , but a tweeter hears all that stuff too .
Members catphish Posted August 14, 2005 Author Members Posted August 14, 2005 I have changed pre-amp tubes dozens of times on other various SS amps.....just never on a tube amp. Early on someone told me "don't ever mess around inside or you could kill yourself." So it was enough for me to keep out. If it's it's harmless to swap tubes if I don't dig around elsewhere I could try it.... I actually got a "Tube amp repair" book, but haven't read it yet.
Members catphish Posted August 14, 2005 Author Members Posted August 14, 2005 upon some research....I agree with the pre-amp tube diagnosis....off I go. If I'm not back in half an hour, call the paramedics, or the coroner.
Members fretless Posted August 14, 2005 Members Posted August 14, 2005 you know those wacky Audiophiles say that a preamp tube does not even blossom untill after on for 12 hrs. they also say the if a tube goes bad it's usually within the first 10 hrs . btw they also leave their amps on all the time to avoid waiting another 12 hrs for it to warm up & Welcome to the world of tube amps
Members L. Ron Hoover Posted August 14, 2005 Members Posted August 14, 2005 That's almost certainly a microphonic tube. I would assume you can access the tubes reasonably easily. If you can, pop the top off and power it up. Give each tube a light flick with your fingernail, the bad one will be obvious. Replace it. The power tubes will all ring a little when you flick them, but if it's a bad one it will ring much louder than the others. Or get a tech to do it if you aren't comfortable. You're actually a lot more likely to be injured or killed from the 120V AC line than any of the DC stuff in the amp, though I wouldn't characterize a 600V DC shock as pleasent or anything... AC is much more dangerous than DC in terms of shock potential.
Members catphish Posted August 14, 2005 Author Members Posted August 14, 2005 damn....thought I had some spare groove tubes around, but I can't find them for the life of me. looks like it'll have to wait.
Members The Insomniac Posted August 14, 2005 Members Posted August 14, 2005 Originally posted by L. Ron Hoover AC is much more dangerous than DC in terms of shock potential. I'm not an expert but I thought it was just the opposite. Direct current is the deadly one.
Members L. Ron Hoover Posted August 14, 2005 Members Posted August 14, 2005 Originally posted by The Insomniac I'm not an expert but I thought it was just the opposite. Direct current is the deadly one. Nope. AC's more dangerous. The oscillation causes muscle contraction which can cause you to grip on to the source instead of dropping it. A lot of serious injuries and deaths are caused by this. Someone touches a high voltage AC source and can't let go.... It also has more potential to interfere with the electrical signals in your body like the ones that control heart rythm. I can tell you from experience that AC shocks hurt a lot more. 120V AC is much more painful than 500V DC. Neither is all that fun...
Members catphish Posted August 14, 2005 Author Members Posted August 14, 2005 okay, since I'm the kind of guy that can't jsut sit around and wait when there's a problem.....I went to GC and got two new 12ax7 Elctro Harmonix tubes. Sadly, they didn't have the one 6N1P tube that is also in there, so I've got a 66.66% chance of getting it. So, you're saying I should turn teh amp on, with the chassis open and tap the tubes with something to see which one is bad?? Right?
Members L. Ron Hoover Posted August 14, 2005 Members Posted August 14, 2005 Originally posted by catphish okay, since I'm the kind of guy that can't jsut sit around and wait when there's a problem.....I went to GC and got two new 12ax7 Elctro Harmonix tubes. Sadly, they didn't have the one 6N1P tube that is also in there, so I've got a 66.66% chance of getting it. So, you're saying I should turn teh amp on, with the chassis open and tap the tubes with something to see which one is bad?? Right? Yep, if you're comfortable with doing that. It could also be a power tube so tap those too....
Members catphish Posted August 14, 2005 Author Members Posted August 14, 2005 Done. You guys were right. It was one of th pre-amp tubes (Luckily a 12ax7). I tapped on each one and the left one was jingle bells. Swapped it out and it's all good. I now have one official gripe about this amp. It's a MAJOR PIA to get the housing cover off to get to the tubes. 22 screws in all!!!!! Many were the tiny phillups head style and I ended up stripping on of the heads. Also they use PEM nuts on the sides and of the top and one fell out , and on the other side one of the screws snapped in two. FYI, I'm a mech engineer who designs with sheet metal so I know how to screw together peices of sheet metal, and that screw snapped with minimal force. Anyway....it's back together and in it's rack case. the two absent screws should not effect anything. However, I plan on getting a new top from Eden at some point. Also a point of interest is that Eden and Koch, from the Netherlands, make this amp together. Eden makes the pre-amp and Koch makes everything else, including the rediculous housing.
Members fretless Posted August 15, 2005 Members Posted August 15, 2005 the reason you try to swap around the tubes you have is because , sometimes one tube affects sound more or with a higher gain and in some amps doesn't affect the tone , so maybe the one in the 2nd spot may be less microphonic .
Members fretless Posted August 15, 2005 Members Posted August 15, 2005 Originally posted by catphish Done. You guys were right. It was one of th pre-amp tubes (Luckily a 12ax7). I tapped on each one and the left one was jingle bells. Swapped it out and it's all good. I now have one official gripe about this amp. It's a MAJOR PIA to get the housing cover off to get to the tubes. 22 screws in all!!!!! Many were the tiny phillups head style and I ended up stripping on of the heads. Also they use PEM nuts on the sides and of the top and one fell out , and on the other side one of the screws snapped in two. FYI, I'm a mech engineer who designs with sheet metal so I know how to screw together peices of sheet metal, and that screw snapped with minimal force. Anyway....it's back together and in it's rack case. the two absent screws should not effect anything. However, I plan on getting a new top from Eden at some point. Also a point of interest is that Eden and Koch, from the Netherlands, make this amp together. Eden makes the pre-amp and Koch makes everything else, including the rediculous housing. Wow , that's Great and sucks at the same time
Members fretless Posted August 15, 2005 Members Posted August 15, 2005 well at least you know how to get in there for future tube changes
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