Blonde Bassman overdrive issues

Discussion in 'Amps and Cabs' started by monkeyodeath, Jun 1, 2008.

  1. monkeyodeath

    monkeyodeath Member

    Messages:
    201
    Joined:
    Jan 20, 2007
    Location:
    Los Angeles, CA
    Hi guys, just thought I'd tap into your collective knowledge for some ideas....

    I recently got a '64 blonde fender bassman head (6G6-B) and I'm really digging its sounds, such a nice, balanced clean.

    I have noticed, however, that getting the thing to overdrive with anything besides a humbucker-equipped guitar is a difficult task. My Yamaha SG-2000 with hot pickups starts to break up at about 4 or so, but with both my strat and tele, I need the volume at about 8 or so to really get it to break up at all.

    The amp tech I bought it from did the simple mod described elsewhere on this forum to the bass channel - but if anything, that channel's a little harder to break up.

    I'm running it through a Fender ToneMaster cab with V30's. Tubes are Sovtek 6l6WXT's with a Sovtek 12AX7 in the V1 position and EH in the rest.

    I don't know if a speaker or tube change is in order...or if I just need to boost my single-coil guitars when I want to get dirty.

    Any thoughts would be really appreciated!
     
  2. waxnsteel

    waxnsteel Member

    Messages:
    3,131
    Joined:
    May 14, 2005
    Sounds about like I remember. If you want more dirt, mods or pedals.
     
  3. khromo231

    khromo231 Guest

    Messages:
    457
    Joined:
    Jun 14, 2007
    That doesn't sound right to me. The bass channel on mine overdrives almost immediately with humbuckers, even medium output versions. It goes from mild overdrive to a pretty heavy crunch pretty naturally and is cooking like mad by 4 or 5 on the volume control. The clean/normal channel has somewhat stiff Fender cleans up through the point it is way too loud for my purposes. When I switch to single coils, I get a little more headroom in the bass channel, but not much.

    My bass channel and normal channel sound completely different, with the bass channel offering little that is clean, and the normal channel offering only clean tones. The caps were pregnant when I bought mine, so they have been replaced, and the rectifier diode(s) were also replaced. The tech who did the work told me it sounded typical for that circuit when he was done. I get very useful tones out of both channels, and with an A/B box in front it is very versatile.

    I'm not sure what mod to the bass channel you are talking about, but it sounds like it got castrated!
     
  4. GuitarsFromMars

    GuitarsFromMars Member

    Messages:
    11,516
    Joined:
    Jun 7, 2004
    Location:
    playing in traffic...
    get a Zendrive,and leave the amp alone...
     
  5. monkeyodeath

    monkeyodeath Member

    Messages:
    201
    Joined:
    Jan 20, 2007
    Location:
    Los Angeles, CA
    The mod was to remove a couple caps from the bass channel...I've seen it a couple of times on this board as a means to make the channel more "marshally" and guitar suitable that it is normally.

    I'm really not trying to make the amp something it's not, and if this is the way it is I still really like its tones. I had just heard comments from people like khromo231 that had led me to wonder if my head was normal or if there was possibly something wrong with it.
     
  6. GuitarsFromMars

    GuitarsFromMars Member

    Messages:
    11,516
    Joined:
    Jun 7, 2004
    Location:
    playing in traffic...
    if you think there's 'something' wrong with the amp,take it to a pro who knows those amps.Find out if it meets the schematic spec,then,only then,look at the available mods...make sure they're reversible.Any other methodology,is an approach to crime,on an amp that old.
     
  7. Leonc

    Leonc Wild Gear Hearder Gold Supporting Member

    Messages:
    17,183
    Joined:
    Jan 4, 2002
    Location:
    Upstairs, L.A.
    From what I recall of my old one, a properly functioning blonde Bassman should be overdriving by 6 or 7 and will sound very much like an old Marshall if you play it through a nice 4x12 with G12Ms or Hs. It'll be louder than hell too. Sounds to me like maybe your cab/speakers are not happening with that amp or there is something "off" with the amp.

    I'd be inclined to crack it open, review what's in there and take some readings. If you're not comfortable doing that, definitely take a different tech who you trust.
     
  8. mrbungel

    mrbungel Member

    Messages:
    2,189
    Joined:
    Feb 1, 2006
    Location:
    Armpit of California
    Agree, could be a problem with the amp, and/or, the speakers. I'm lucky to have a 64 blonde Bassman (orig amp and cab), they sound pretty dang good. Actually, they sound real dang good. If you want crunch and mucho distortion, look elsewhere, if you want rockabilly and 50's tone, get yersef a pre-BS Bassman :BEER
     
  9. v-verb

    v-verb Supporting Member

    Messages:
    5,886
    Joined:
    Jan 4, 2002
    Location:
    Toronto
    make sure you're running all 12AX7's in the pre's
     
  10. dougk

    dougk Silver Supporting Member

    Messages:
    5,686
    Joined:
    Jan 22, 2008
    Location:
    Sacramento, CA
    Thats what Im thinking for mine. Same issues when I play strats through mine. Sounds awesome cranked but to loud for in the house.
     
  11. monkeyodeath

    monkeyodeath Member

    Messages:
    201
    Joined:
    Jan 20, 2007
    Location:
    Los Angeles, CA
    Thanks for all the tips, guys.

    I'm not super knowledgeable about amp innards, but I spent some time with a layout and it looks like everything is there and accounted for - just about everything looks original, too, resistors and caps (cept for the filter caps).

    Just on a whim, I tried swapping the Sovtek 12ax7wxt in the V1 position with the EH 12ax7 in V4. Big difference! With the volume at noon, the bass channel sounds nice and overdriven with single coils and has a different character than the normal channel - more biting and middy like a Marshall.

    Is this an indicator of a bad tube - do I want to replace the Sovtek, even if I put it in the PI position? Or is this maybe just a lower gain tube?

    Thanks again for all the help guys!
     
  12. meterman

    meterman Member

    Messages:
    7,412
    Joined:
    Jun 24, 2002
    Location:
    ATL
    Sovtek sucks!! Put another EH or maybe a JJ in there...
     
  13. ROKY

    ROKY Member

    Messages:
    7,029
    Joined:
    Mar 2, 2004
    Get some RCAs or GEs in there ,, that amp deserves it !
     
  14. sickboy79

    sickboy79 Member

    Messages:
    10,420
    Joined:
    Aug 17, 2006
    Location:
    Chicago
    I'll echo the above comments. I've got 4 Bassman heads in my collection - 62 and 63 Blondes, and 65 and 66 BFs. The Bass channel on all of them are absolute animals, with very little clean headroom. With low to medium output humbuckers, P-90s, or a nice Tele bridge pup - I'm at classic rock levels or crunch by about 11 oclock. From there - it's full on rock overdrive that only get's thicker and nastier. The Normal channel has a bit more headroom - but, not a whole lot more.

    FWIW - V1 affects the Bass channel only. So, you'll hear the most differences in that slot on the Bass channel. You can also try something different in V2 as well for the Bass channel. Your Sovtek tube may not be bad - just lower in gain than the EH you tried. My advice would be to try a bunch of different brands of 12AX7s see what your ears like. (V3 for the Normal channel). Some tubes of the same brand, and sometimes production run, are higher gain than others.
     
  15. I'm Incinerator

    I'm Incinerator Supporting Member

    Messages:
    2,151
    Joined:
    Apr 27, 2005
    Location:
    Omaha, NE
    I've heard that running higher gain pre amp tubes, power tubes that will knock down the power about 5 watts per tube and biasing on the hotter side turn the 6g6-b into a twang and bang powerhouse (I'd love to find this out for myself someday...just need to find a good 6G6-B and have the money on hand...). If your looking for any recommendations for running your Blondie to get more crunch. I'd seek the advice of Tavo, his SN on here is "wiredturtle". He's fairly knowledgable about these, and is a hoot to talk with.
     
  16. Griz

    Griz Member

    Messages:
    2,837
    Joined:
    Sep 23, 2006
    Location:
    Toronto, Canada
    When was the last time the amp thoroughly serviced? I agree with khromo231; my '62 has more trouble giving up the clean than the dirty tones at any but the lowest volume settings (1-3). Get a good tech to give it the once over; with luck it'll be a cheap fix.

    Cheers :drink
     
  17. DocRock

    DocRock Supporting Member

    Messages:
    1,845
    Joined:
    Feb 15, 2006
    Location:
    The Caves of Altamira
    I'd start by ditching those V30 speakers. Less efficient, lower-wattage speakers will facilitate better and earlier breakup.
     
  18. DGG

    DGG Member

    Messages:
    202
    Joined:
    Feb 9, 2006
    I would try making all your minaitures are 12AX7's and use the new RI TUNG-SOL 5881's. With that set-up and a stock 6G6-B it should sound like the twang and bang Incinerator mentioned.
     
  19. monkeyodeath

    monkeyodeath Member

    Messages:
    201
    Joined:
    Jan 20, 2007
    Location:
    Los Angeles, CA
    Thanks so much for the suggestions, guys! Awesome stuff.

    Changing the preamp tubes around made a really nice difference, and I think I'll try replacing the Sovtek's with something better, definitely. The amp's definitely breaking up a lot more, starts screaming (bass channel) with buckers and p90's at around 3!

    And I have been looking to replace at least a couple of the V30's with something like a greenback, so I can imagine that it might make a good change.

    I'm thinking that part of the problem might also have been the fact that I've been playing mostly through a Fargen Olde 800 lately...I almost forgot what low-gain sounds like! Switching to a NMV amp after spending a lot of time with a high-gain amp with a great MV can take some time to get used to :p.

    Thanks again for all the help guys!
     
  20. khromo231

    khromo231 Guest

    Messages:
    457
    Joined:
    Jun 14, 2007
    That sounds about like mine. How could anyone use that channel for electric bass?
     

Share This Page