Fender champ question?

Discussion in 'Amps and Cabs' started by cjp54, Mar 3, 2012.

  1. cjp54

    cjp54 Member

    Messages:
    501
    Joined:
    Apr 22, 2009
    Location:
    Az
    I just got an 80's (?) silverface Fender Vibro Champ from my brother-in-law and the amp does not have much volume at all.

    How loud should this amp be?
    Should I get any break up with the amp at full volume?

    I retubed it and it made no difference. It doesn't break up AT ALL and I can basically talk above the amp with everything dimed.

    Any thoughts?

    Thanks!
     
  2. '58Bassman

    '58Bassman Member

    Messages:
    4,913
    Joined:
    Jan 2, 2012
    It's 5 Watts but if the first tube is a 12AT/U/Y7, it won't be very loud. Also, the ECG equivalents can provide lower gain and if it has a 5751, it will never break up.

    Does it still have an Oxford speaker, or did some nimrod put an 8 Ohm replacement in it? That will definitely drop the output to a whisper.

    Vibro Champ, or just a Champ? I had a '65 Vibro Champ and after I recapped it and put a Weber Alnico Sig 8s in it, it was louder but no breakup at all. The EH rectifier that the previous owner had put in it increased the headroom to the point that it was always clean. Also, the recommendation that I change the bias resistor to 1K Ohm sucked all of the life out of it. The OEM resistor is 470 Ohm- every person who responded to my questions replied that the output tube would fail if I left it as it came, which I thought sounded like BS, but I did it anyway. I changed it to somewhere between the two and it sounded better but never broke up the way I expected it to. If you can, put an old rectifier in it- I had a newer one in mine until the night before I sold it and didn't realize it. I advertised it as having a 5Y3G (the big bottle type) and once I put that in, it sounded the way I thought it would. Oh, well. It never did much for me, so it was just taking up space.

    Does it hum, at all?
     
  3. keithb7

    keithb7 Supporting Member

    Messages:
    1,371
    Joined:
    Feb 16, 2007
    Location:
    Canada
    I have a 68 vibro champ. It's plenty loud for home use and there is no way I can talk over it at full volume. It should have a 3.2 or 4 ohm speaker in it. Mine breaks up plenty too. I run a nos 5Y3GT rectifier. I would suggest a cap can job may be necessary to fix your low volume issue.
     
  4. cugel

    cugel Member

    Messages:
    4,111
    Joined:
    Nov 2, 2006
    Location:
    eugene oregon
    a champ sf can scream if set up properly. replace the filter caps. there are a few other tips that you will find here if you search like the power tube resistor and cap. i did these simple changes and put a ceramic weber 8" with a huge magnet. use nos tubes no exceptions. my amp killed when dimed and took pedals well too. i miss it. plenty loud for home use. my amp was not far behind a swart in tone. and i paid 20$ for it
     
  5. LPVM

    LPVM Member

    Messages:
    2,072
    Joined:
    Jan 21, 2009
    Location:
    Dutchess County NY
    I've got a '78 and you are right, all controls on 10 yeilds almost no crunch at all. There are two things you can do that will get you were you want to be with that amp. One is boost it. I run an OD in front of mine with it's volume maxed and it's drive on zero. They sound great this way through an extension cab......have a listen.



    Sick huh? Hard to believe it's the same amp. They really sound completely different through a cab with bigger speakers.

    The second thing you can try is the Weber Tweedifying mod. This mod basically bypasses the tone controls. The tone controls really throttle that amp down and when you bypass them it turns the amp into a fire breathing monster. You get a huge volume boost and much more pronounced mids. It starts breaking up around 4-1/2 to 5 on the volume control, no pedals needed. I really liked this mod a lot but I was smoking 6V6 tubes like they were going out of style so I eventually returned mine to stock. I might have had better luck with it if I had done a recap before doing the mod. I think my filters were going bad and the strain from running that hot with weak filter caps contributed to my early power tube failures. If you are interseted in giving the mod a shot here is a link to it. http://www.lindseymontana.com/news/champtweedifyingmod.pdf It's a very simple mod with just a few resistor and cap changes.
     
    Last edited: Mar 4, 2012
  6. chervokas

    chervokas Member

    Messages:
    6,864
    Joined:
    Feb 16, 2008
    Maybe its a bad speaker or a mismatched impedance replacement speaker? Yeah, it's only a 5 watt amp, but a 5 watt amp with a 92 dB/m/w speaker, turned up even to half way and played hard should be about as loud as standing across the street from someone working with jackhammer if everything is working properly. Something's definitely wrong if you're having normal conversations over the thing dimmed

    And it'll break up too. A BF/SF champ doesn't deliever the most pleasant or intense crunch tone in the world IMO -- it's a bit shrill and bright, not marshally crunchy or tweed crunchy, though it does alright with some compression and mid boost like from a Tubescreamer. And of course everything's constrained by that single 8 inch speaker -- low frequency response, room filling spls, etc, just ain't gonna happen unless you're driving a bigger cab.

    But put it this way, when I'm at home practicing with my SF Vibro Champ (which is my practice/songwriting amp) -- my family complains they can't hear the TV one story up in another part of the house. My be time the amp made a trip to the tech.
     
  7. Davo17

    Davo17 Member

    Messages:
    2,173
    Joined:
    Jun 18, 2009
    I agree, thats a great tone. Hows it sound with a tele or strat?
     
  8. LPVM

    LPVM Member

    Messages:
    2,072
    Joined:
    Jan 21, 2009
    Location:
    Dutchess County NY
    It's great with my Strat too. I really don't have any clips of it with a Strat other than one I did just before I did the last one. It's just a test clip and a terrible example but it does show what it sounds like without any kind of boost cranked to 10 with a Strat. I had just replaced the filter caps and wanted to see how it sounded and wasn't really trying to play anything. The previous boosted clip was also an experiment to see how hard I could push it. Up until that point it was still running a little hot and hard on power tubes. I should put a fresh power tube in it and sit down and do a few proper clips to se what I can coax from it.



    The Tweed mod was particularly nice with a Strat. I highly recommend giving that a shot if you like Tweed champs.
     
    Last edited: Mar 5, 2012
  9. keithb7

    keithb7 Supporting Member

    Messages:
    1,371
    Joined:
    Feb 16, 2007
    Location:
    Canada
  10. LPVM

    LPVM Member

    Messages:
    2,072
    Joined:
    Jan 21, 2009
    Location:
    Dutchess County NY
    Very nice tone!!

    What is your compressor set like? I use my compressor all the time as a clean boost to get a less colored overdrive like that. My SFVC will break up a bit with that too with the pedal's volume around noon and the compression off. That's actually my favorite pedal and setting with my 1482. It gives the amp that nice controllable edge of break up touch sensitivity. Your clip makes me want to put down the paint brush and drag out my guitar. :aok
     
  11. keithb7

    keithb7 Supporting Member

    Messages:
    1,371
    Joined:
    Feb 16, 2007
    Location:
    Canada
    LPVM I run a MXR Super Comp. Usually I set all the dials at noon position. I don't use the compression for increased gain. I used it in the sound clip to get some feedback as heard at the very end of the clip. Without any compression, the amp won't feedback. I can't recall exactly but the compression may only be on lead guitar in the final section of the clip.
     
  12. '58Bassman

    '58Bassman Member

    Messages:
    4,913
    Joined:
    Jan 2, 2012
    Is there a chance that you can take yours to a local music store and play through another Champ, for comparison? If you're in Tucson, maybe Rainbow has one.
     
  13. cjp54

    cjp54 Member

    Messages:
    501
    Joined:
    Apr 22, 2009
    Location:
    Az
    Some nice sounding clips. Mine sounds like neither of them. I checked the speaker impedance. It's 3.1 ohms. Not sure if it's the original or not. No markings or sticker on the speaker. I'll try and get pics up later. I suspect it might be the caps or a bad speaker?? Thanks for the suggestions and the confirmation that something IS wrong with my amp.

    I'm in Chandler and a trip down to Tucson just isn't in the near future.

    Thanks
     
  14. chervokas

    chervokas Member

    Messages:
    6,864
    Joined:
    Feb 16, 2008

    Sounds like its time to get the amp to a tech's for a once over. Do you have another cab you can try in the mean time? At least you could narrow it down to a problem with the amp or a problem with the speaker.
     
  15. cjp54

    cjp54 Member

    Messages:
    501
    Joined:
    Apr 22, 2009
    Location:
    Az
    I have an 8 ohm 4x12 Mesa Recto cab and a 16ohm 1x12 Komet cab I could try it through. But, if the amp is meant to drive a 3.5 ohm speaker how loud would it be with either of my other cabinets? I'll try it tonight. As for the cap job, that something I can do myself. But your right, lets rule out the speaker first!

    Someone previously asked if it hummed at all. No, no hum what so ever.
     
  16. LPVM

    LPVM Member

    Messages:
    2,072
    Joined:
    Jan 21, 2009
    Location:
    Dutchess County NY
    The original speaker is a 8" 4 ohm (3.2 sounds right) Oxford. They aren't very good and flub out when you turn the amp up. It doesn't sound like the speaker is your problem but a speaker change is the best mod you can do on a Champ. Maybe the 6V6 is ready for retirement. Champs are cheap and easy to service so I would start with the filter caps and stick a new power tube in it to start and go from there.
     
  17. chervokas

    chervokas Member

    Messages:
    6,864
    Joined:
    Feb 16, 2008
    Well I wouldn't use the 16 ohm load but you can run it w/ the 8 ohm load and it should be fine. It won't be ideal in terms of power transfer and it will change the frequency balance somewhat, and you might not want to dime it for an extended period and risk protential damage from flyback voltages.....but really, it'll be ok with that 8 ohm load. Plug it into the 4X12, (you'll need a speaker cable with an RCA plug on one end and 1/4" on the other, or an 1/4" to RCA adaptor), and turn it up half way...should be loud enough that people in the next room will know you're playing electric guitar that's for sure.

    If not, and you said you've already swapped for new preamp, output and rectifier tubes, well, then, it could be anything including a bad OT. You'll need to bring it in to a tech for diagnostic work.

    Like I said BF and SF Champs and Vibro Champs to my ears aren't really great crunchy screamers -- a tweed Champ is a much better choice if you're looking for a vintage 5 watt Fender that can deliver grind -- but they can be nice low watt BF amps for practice, recording, certain kinds in formal jams. I have a 1980 Vibro Champ that I use for practice and some recording which I've taken out for informal jams at a buddy's barn with a tiny funky drum kit played quietly and it's plenty loud for the application with an updated speaker.
     
  18. chervokas

    chervokas Member

    Messages:
    6,864
    Joined:
    Feb 16, 2008
    What, btw, did you retube it with?
     
  19. cjp54

    cjp54 Member

    Messages:
    501
    Joined:
    Apr 22, 2009
    Location:
    Az
    The retubes were 2 NOS RCA 12AX7'S, A new MESA 5Y3G Rectifier and a NOS Ratheon 6V6GT. Absolutely no difference than the old RCA's that were in it.
     
  20. guitarcapo

    guitarcapo Senior Member

    Messages:
    2,337
    Joined:
    Mar 16, 2010
    Something's wrong. Dried up cathode bypass cap? Weak preamp tube? Check voltages everywhere. wrong speaker?
     

Share This Page