Members Karma1 Posted June 20, 2007 Members Share Posted June 20, 2007 I recently bought a mid 70's silverface Fender Vibro Champ. It's a cool little amp, but I'm trying to get more clean headroom out of it. It starts seriously breaking up around 5. I know a lot of people like them because of that, but I'd be happy if it was clean all the way to 10, since I use a Mesa Boogie V-Twin pedal with it and have all the crunch and distortion I need. I ordered a Weber alnico Sig 8S because it is said to have later break up. I installed it yesterday and found that it didn't make much difference as far as offering any more clean headroom. I tried swapping the 12AX7 preamp tube for a 12AT7 and that didn't make much difference either. I'm thinking of trying a 12AU7 to see if that helps. Any other suggestions about what I might do to get a cleaner tone at higher volume? I've heard that replacing the caps might help, but don't want to spend the money doing this unless I know that there is a good chance it will make a difference. Any advice would be appreciated. Link to comment Share on other sites More sharing options...
Members angus_old Posted June 20, 2007 Members Share Posted June 20, 2007 get a bigger amp. champs aren't known for their clean headroom Link to comment Share on other sites More sharing options...
Members geddins81 Posted June 20, 2007 Members Share Posted June 20, 2007 What kind of power tube is in there? Groove Tubes makes some pretty nice tubes that are "rated" in terms of when they start to break up. Get one with a higher value and see if that'll help....you should be able to have some decent cleans Link to comment Share on other sites More sharing options...
Members mdintx Posted June 20, 2007 Members Share Posted June 20, 2007 The silverface champs seem to vary alot. I can hardly get my Champ to break up unless I'm using my Les Paul. Maybe it needs a service... Link to comment Share on other sites More sharing options...
Members angus_old Posted June 20, 2007 Members Share Posted June 20, 2007 The silverface champs seem to vary alot. I can hardly get my Champ to break up unless I'm using my Les Paul. Maybe it needs a service... my old one was like that - it wouldn't break up but it wasn't really clean either Link to comment Share on other sites More sharing options...
Members valentsgrif Posted June 20, 2007 Members Share Posted June 20, 2007 My new(old) VC is the same. Previous posts all point to a "cap job". Pardon my noobness, but what does this mean in terms of money and do it yourself capability? Link to comment Share on other sites More sharing options...
Members mdintx Posted June 20, 2007 Members Share Posted June 20, 2007 People tend to enthusiastically recommend switching out all the caps every 10-15 years. The guy I took my amp to, David of Dabeck Custom Amps, check mine over and only replaced 3 of the caps. This was under $50. If he had done the whole thing, I think it would have run ~$90-85 if I remember correctly. Doing it yourself will be a lot cheaper but you've got to have some knowledge/do some research/practice. Apparently, caps that haven't been drained of their charge can kill you. Link to comment Share on other sites More sharing options...
Members Karma1 Posted June 20, 2007 Author Members Share Posted June 20, 2007 get a bigger amp. champs aren't known for their clean headroom I've already got a Mesa Boogie and a Marshall, so I don't need a bigger amp - just trying to clean this little guy up a bit. I realize Champs aren't known for their clean headroom, but from what I've heard from other Champ owners, some of them are much cleaner at higher volumes - so I know it's possible. Link to comment Share on other sites More sharing options...
Members geddins81 Posted June 20, 2007 Members Share Posted June 20, 2007 I've already got a Mesa Boogie and a Marshall, so I don't need a bigger amp - just trying to clean this little guy up a bit. I realize Champs aren't known for their clean headroom, but from what I've heard from other Champ owners, some of them are much cleaner at higher volumes - so I know it's possible. You are right. I don't think you'll ever get "Deluxe Reverb" clean tones (at volume) with a VC or Champ, but you can get into some very nice shimmery clean tones with 'em. Link to comment Share on other sites More sharing options...
Members jerry_picker Posted June 20, 2007 Members Share Posted June 20, 2007 You are right. I don't think you'll ever get "Deluxe Reverb" clean tones (at volume) with a VC or Champ, but you can get into some very nice shimmery clean tones with 'em. The 12au7 will give more clean at higher volume settings (at the expense of output volume). A well-oiled Champ will give clean to volume settings 4-5, progressive grit though 8 or so, and gutsy gravel at 9-10. The "harder" (ribbed) Weber ceremic speaker is my favorite Champ speaker. What a filter cap job will get you is less wall-current hum. Filter caps have little to do with overdrive. However, coupling caps can drift over time. These are the "chiclets" that are in the tone-stack or that connect the output of the preamp section into the grid (input) of the 6V6 output tube.http://www.ampwares.com/ffg/schem/champ_aa764_schem.gif Replacing these with high quality replacements ("orange drops") can help, sometimes. Link to comment Share on other sites More sharing options...
Members Jim_Soloway Posted June 20, 2007 Members Share Posted June 20, 2007 Vibro Champs are very reactive to input level. If you boost your level with the V-Twin, it's going to break up pretty quickly regardless of which tubes you use. A hot humbucker will also cause it to breakup pretty quickly. Link to comment Share on other sites More sharing options...
Members Wyatt Posted June 20, 2007 Members Share Posted June 20, 2007 You need a bigger amp. Plain and simple. You are maxing up the clean headroom you can get out of that poweramp design. Any tweaks are just going to change the volume curve; by that I mean you can tweak the amp to be clean at 10, but it won't be any louder than it is now at 5. That distortion and breakup you are hearing is the power tube saturating, which means it's tapped out, no more power, and driving it more only causes distortion. "She's giving all she gots, Cap'n!" People have this habit of trying to ask impossible volume levels out of small amps. They want their Champs to be as loud as Deluxe Reverbs, their Deluxe Reverbs as loud as Pro Reverbs, etc. The amp may need a cap job, but it won't really give more volume, just tighter bass and more punch. You can plug the amp into a 2x12 or 4x12 and see if the extra speaker surface gets it loud enough. If that doesn't work, then nothing will. Someone might suggest the option of switching out the power tube to a 6L6, but the small output transformer can't take advantage of it and you don't get a noticeable volume boost. *Any* extra headroom you might be able to coax out of the amp is going to be a 3 to 4% boost, at most. It's not enough extra to be usable, if audible at all. People like to believe that they just need a little bit more, but it's never enough. The Champ is a small amp, that is optimum for overdriving tubes at comfortable volume levels, but if you need a clean palate for pedals, you going to need a minimum of ~20 watts. It takes that much energy to simply double the clean headroom of the Champ, which isn't much to start with. you need enough clean headroom to play with a drummer, then you need more like 35 to 40 watts. Link to comment Share on other sites More sharing options...
Members jerry_picker Posted June 20, 2007 Members Share Posted June 20, 2007 Vibro Champs are very reactive to input level. If you boost your level with the V-Twin, it's going to break up pretty quickly regardless of which tubes you use. A hot humbucker will also cause it to breakup pretty quickly. That is so true, and one reason an overdrive pedal can sound great at low volumes through a V-Champ. (I realize that doesn't help with the clean question.) Link to comment Share on other sites More sharing options...
Members geddins81 Posted June 20, 2007 Members Share Posted June 20, 2007 The 12au7 will give more clean at higher volume settings (at the expense of output volume). A well-oiled Champ will give clean to volume settings 4-5, progressive grit though 8 or so, and gutsy gravel at 9-10. The "harder" (ribbed) Weber ceremic speaker is my favorite Champ speaker.What a filter cap job will get you is less wall-current hum. Filter caps have little to do with overdrive. However, coupling caps can drift over time. These are the "chiclets" that are in the tone-stack or that connect the output of the preamp section into the grid (input) of the 6V6 output tube.http://www.ampwares.com/ffg/schem/champ_aa764_schem.gifReplacing these with high quality replacements ("orange drops") can help, sometimes. Whatever JP says I'll defer to when it comes to Champs / VChamps...he knows 'em.... JP, did you see my thread from yesterday? I picked up a '75 VC. Link to comment Share on other sites More sharing options...
Members mdintx Posted June 20, 2007 Members Share Posted June 20, 2007 One last addition from me, try a JJ/Tesla 6V6S tube. That's what I use. I've read that it is considered to be 6L6 like though I don't know how true that may be. When I put it in, I noticed a big change and it sounds loud, clean and full. Link to comment Share on other sites More sharing options...
Members Karma1 Posted June 20, 2007 Author Members Share Posted June 20, 2007 The 12au7 will give more clean at higher volume settings (at the expense of output volume). A well-oiled Champ will give clean to volume settings 4-5, progressive grit though 8 or so, and gutsy gravel at 9-10. The "harder" (ribbed) Weber ceremic speaker is my favorite Champ speaker. I'm going to try a 12au7 tomorrow. I don't mind sacrificing a bit of volume for later break up. Also, just wondering what it is you like about that particular Weber ceramic speaker for the Champ? I checked out a lot of Weber speakers, but when eventually I talked to Ted Weber on the phone about which speaker would provide the cleanest tone with less or later break up he recommended the Alnico Sig8S. I just put it in yesterday and haven't had too much time to check it out. But I'd be interested to read your impressions of the Weber ceramic. Link to comment Share on other sites More sharing options...
Members Karma1 Posted June 20, 2007 Author Members Share Posted June 20, 2007 Vibro Champs are very reactive to input level. If you boost your level with the V-Twin, it's going to break up pretty quickly regardless of which tubes you use. A hot humbucker will also cause it to breakup pretty quickly. Yes, definitely true, on all counts. My humbucker guitars push it more than my single coils. As far as boosting the level with the V-Twin, it can make a difference as you say. Although, even without it - plugging straight into the amp, it still breaks up earlier than I would like, or earlier than I've heard on other Champs or Vibro Champs. Link to comment Share on other sites More sharing options...
Members jerry_picker Posted June 21, 2007 Members Share Posted June 21, 2007 But I'd be interested to read your impressions of the Weber ceramic. IMHO, it (Sig8S) is a very efficient (decibels out per watt in), fairly balanced speaker that lets a Champ kick up its heels a bit. 5 watts can be surprisingly loud. At about $25, it is a good buy. Again, my biased views...YMMV! Link to comment Share on other sites More sharing options...
Members orzklegbok Posted June 21, 2007 Members Share Posted June 21, 2007 Cool, another great Vibro-Champ thread! Link to comment Share on other sites More sharing options...
Members DaleH Posted June 21, 2007 Members Share Posted June 21, 2007 Hi Jerry what speaker would you suggest for a Blues Jr. For cleans Link to comment Share on other sites More sharing options...
Members BootRoots Posted June 21, 2007 Members Share Posted June 21, 2007 man vibrochamp threads only remind me about the '71 that was sold out from under me at the store a few weeks back. I walked into the store to pick up one thing and one thing only. when I get there there are two other guys in the store.....one is playing the vibrochamp. I wander around the store waiting for this guy to move on to something else to wank on, and then......he does. But he takes the amp with him, and walks up to the counter. {censored}!BASTARD! Link to comment Share on other sites More sharing options...
Members dcindc Posted June 21, 2007 Members Share Posted June 21, 2007 ya need a bigger amp. Link to comment Share on other sites More sharing options...
Members jerry_picker Posted June 21, 2007 Members Share Posted June 21, 2007 Hi Jerry what speaker would you suggest for a Blues Jr. For cleansI surely do not know. Link to comment Share on other sites More sharing options...
Members mc5nrg Posted June 21, 2007 Members Share Posted June 21, 2007 Use the padded input-#2. Link to comment Share on other sites More sharing options...
Members Karma1 Posted June 22, 2007 Author Members Share Posted June 22, 2007 Many thanks for all the responses and advice - much appreciated. I tried a 12 AU7 preamp tube in it today and it did keep it clean all the way to 10, however, as Jerry_Picker said it did cut the volume quite a bit. I got a number of responses about getting a bigger amp or expecting too much volume out of the Vibro Champ. I already have two much larger amps I can use for gigging (Mesa Boogie and Marshall). I want this amp more for studio recording, so volume isn't as important to me as clean headroom. But I can definitely appreciate what you are saying. Link to comment Share on other sites More sharing options...
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