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Fender Bassman Head

Discussion in 'Amps and Cabs [BG]' started by Pre EB, Oct 22, 2002.


  1. Pre EB

    Pre EB

    Mar 15, 2002
    Denton, Tx
    My brother just gave me an old Bassman tube head that he had used for guitar, and I was hoping that some of you might be able to give me some info on how to date it. It sounds killer with both bass and guitar.:D
    Btw, it is the 50watt model and in great shape. I won't sell it, but I'm interested in how much it might be worth. Any info is appreciated.
    Thanks,
    Joe
     
  2. Man, I love those things. But I can't tell you exactly how old it is. If it is silver it is probobly from the 70's, late 60's, they go for like 300, 350 on ebay. If it has a black face it is probobly older and you you could probobly sell it for 400, if its in good condition. I'm definately not an expert, but I've learn a few things about them in the time I've spent admiring them, I love that rough, heavy sound, KILLER!!!
     
  3. Pre EB

    Pre EB

    Mar 15, 2002
    Denton, Tx
    It's now making some strange crackling and humming noises.:( Loud enough where I quickly turn it off out of fear of huting my speakers. Think it needs new tubes? It's been taken care of and kept clean and this is the first time I've heard them. I wonder if it was set up for guitar and my Music Man overloaded it or somefin".
     
  4. Take it to a tech. It needs new filter caps. If you keep running it like that, it will burn out the power transformer and that will cost you about $150 to replace. Don't use it anymore until it is fixed. It is dying a natural death due to its old age - your guitar didn't screw it up. A trip to a good tech and it will be ready for another 30 years of service. It may need new tubes, but probably not (although the tech will tell you it needs them even if it doesn't - he's trying to up the bill).

    If you are so inclined and know that electricity can kill you and how to be safe around it, you can learn how to fix it yourself. But if you screw up, it can kill you dead. So don't take it apart unless you truly know what you are in for and know how to be careful around electricity. Find someone you know to teach you if you decide to work on it yourself.

    Chris
     
  5. Chizzops

    Chizzops

    Oct 29, 2002
    You are a lucky man. I have a blackface bassman and use it whenever I'm not going for the hifi SWR MoBass love. I have a Benavente 219 4-string which sounds killer on the bassman, but the best is my old Ibanez Roadstar, which I had Benavente defret and put a composite wood-resin fretboard on, and while it sounds OK through the MoBass, the bassman brings it alive with that growly tube sound. i HIGHLY recommend, aside from the filter caps/capacitors, etc which should be serviced, getting a good set of power tubes and preamp tubes. I like groove tubes for the power tubes. You got this amp for free so might as well put some bucks into it! Also, it may say it is 50 watts, but we're talking tube power here! I can blow our my hartke transporter 4X10 with the bassman much easier than with my Mo'Bass!

    One last thing-if you get power tubes, think about the "hardness" you want to buy. They rate them from 1-10, 1 meaning it will distort very quickly on the gain pattern, 10 meaning it will be clean as a bell all the way cranked. For bass, I would recommend around a 7 or 8.

    AND ALWAYS REMEMBER to let those nice new tubes warmup with the standby switch on for five minutes before AND AFTER playing to ensure that your tubes get a nice wear and don't get stressed by the temp change of fully on to fully off. They will last a lot longer and will actually sound better over time as they are properly worn in.
    have fun!
     
  6. Pre EB

    Pre EB

    Mar 15, 2002
    Denton, Tx
    Cool! I will have it all fixed up when I get some $. Thanks for the great info- I did look at the preamp tubes and they are GTs. Not sure about the power tubes. Is there a way to check the hardness rating by looking at them or would it be on the packaging they come in? I'll take a look tonight.
    BTW, I know nothing about this stuff- I do know that tube lovers are quite the gourmands when it comes to different brands, etc.:D I used to have an old Ampeg V4B that sounded terrible. I should have fixed it instead of hocking it. I was young, dumb and poor:eek:
     
  7. Dude, that's going a little overboard on the Standby switch. 5 minutes in Standby is not necessary. 20 - 30 seconds is fine. You just want the heaters and cathodes to heat up to the point of emission before hitting them with High Voltage, that's all. And on power down, don't use any delay at all, just kill both switches or just the AC switch (just be sure to make sure the Standby switch is OFF before the next time you turn the AC ON.)

    Here's the reasons for this: You want the tubes to be hot before hitting them with High Voltage DC on the plates, or else you may get Cathode Stripping, which is where the High Voltage on the plate pulls electrons off the cathode before they are ready to be pulled off (before the cathode is hot enough to emit freely). It only takes 20 seconds or so for the tubes to heat up to emitting temperature. Just look at the cathode sleeve that holds the heater element. When the actual cathode sleeve is glowing (not just the heater wires inside that light up immediately), then it's ready to go.

    The reason you don't want to sit there in Standby for a long period of time is something called Cathode Poisoning. This is where the Cathode is all hot and emitting electrons, but the plate does not have any High Voltage on it to pull the electrons away from the Cathode, so they just sit there, cooking around the Cathode. Supposedly the Cathode oxide will slowly get crappier and crappier since it's just sitting there hot with not electrons being pulled off of it, and eventually it won't be a very good emitter of electrons, which is its job. I've never really experienced this, and before I became an electrical engineer, I would put my amps on Standby whenever we would take a break from playing, and I don't think it ever did anything noticeably bad, but still, now that I know that, I only use the Standby switch during the power up cycle or if I need to switch speaker cabinets or something quick like that (Don't ever disconnect the load from a tube amp while it's fully on, could fry the output transformer.)

    On power down, you can just kill AC and Standby at the same time. No need to wait any length of time at all. If you wanted to be completely proper, then you could kill Standby and wait 5 seconds and then kill AC to allow the High Voltage to drain away from the power tubes but still keep Bias voltage on their grids. On power down, it's not critical at all. I flick the Standby off, then flick the AC off. No big deal. See the bit on Cathode poisoning to see why there is no need to leave it on Standby for 5 minutes before killing AC power. Just ain't necessary. Seems like it would be annoying too.

    This ain't rocket science, and it'll work any way you wanna do it, but if you do it my way, your tubes will last 4 years instead of just 2 (maybe) :D. I've got tubes in amps that are still putting out full power after using them off and on for 10 years (they're old USA ones, of course). Good ones last for freaking ever.

    Definitely wait for them to cool down before moving the amp if possible. They are much more fragile when hot.

    Ranting's done. That's the shizznit on Standby switches. Word to your mother.

    Chris
     
  8. Pre EB

    Pre EB

    Mar 15, 2002
    Denton, Tx
    throbbin'nut,
    Thanks for the enlightenment! I too thought that you could use the standby switch as a mute and leave it on indefinately. This is only my second tube amp and so I haven't had a chance to really screw it up that way, but nice info to know.
    I took a look at the power tubes last night and they are Sovtek 6L6s. How can I tell if this thing has been set up for the geeter instead of bass? Are those good for the bass and does running an active bass have ANY adverse effect on the amp?
     
  9. Don't sweat the Standby thing. My rant above makes it sound like the world will end if you don't do it right, but I used to use it like a Mute too, and I don't think I ever really had any bad effects, but once I knew about all that crap, I had to start doing it the right way.

    Most importantly, make sure you always have a speaker (load) hooked up to it before turning it fully on. (And actually, Fender used a switching/shorting output jack to protect the transformer if you forgot to plug up a speaker, but still, rule of thumb, tube amps always need a load.)

    As for telling if it's been setup for bass or guitar, the only way to tell would be to take it apart and compare the parts to a stock one. My guess is that it probably has not been modified if it still looks orginal on the outside (knobs all still there, etc.). If it looks original, it can be used for either. Guitarists love them, most bass players don't like them because they have distortion, low power. I love that sound. Just play through it and see if you like it.

    An active bass won't do any damage, you just won't have to turn up the volume as loud as you would with a passive bass to get the same volume out of the speaker. Try both inputs, 1 and 2, because 2 is slightly lower gain and may sound better with Actives.

    Chris
     
  10. Pre EB

    Pre EB

    Mar 15, 2002
    Denton, Tx
    Cool! Thanks Chris:D