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Fender Tube Head!

Discussion in 'Amps and Cabs [BG]' started by GrooveWarrior, Jan 25, 2006.

  1. One of my colleagues gave me a Fender PA 100 tube head (Free is GOOD!) in near mint condition. He used it for a couple of years in the early 80's to DJ. He is still DJing, and hasn't used this thing in 20 years. It is in great shape. From the mid 70's. It has 4 Sylvania 6L6 tubes in the power section, 3 12AT7's in the pre-amp, and 3 12AT7's for the reverb. It has a great clean tone, and I will probably use it primarily for noodling on my Peavey strat copy (sounds real good clean), although, I could see some situations where I may use it with my bass. It's definitely a departure from my Euphonic Rig.

    My question is this: I have read reviews on this and guys are using it as a guitar head (they call it the poor man's twin reverb), but they are talking about chaining the 4 channels together. I'm not sure how that would work. Any ideas?

    Also, what will the "Hum Balance" do?

    Here are some pictures:
  2. Passinwind

    Passinwind I Know Nothing Supporting Member

    Not much, typically. It's there to balance the two sides of the filament supply. Just turn it until you hear the least noise with the amp at idle.

    As far as chaining channels: just plug in the second input on Channel 1 into one of the inputs on Channel 2. You get a little more juice, and you can play with setting the tone and volume controls differently on the two channels. This trick is generally a lot hipper on Fenders where the channels are out of phase with each other though. A good tech could do some fun mods along those lines for you. It's an easy amp to work on, and the extra channels offer up some nice possibilities. PM me if you want some ideas on this. As always, just want to say that I'm not fishing for work on Talkbass. ;)

    BTW, nice score! That thing is nicer than a Twin Reverb or Showman, potentially. Especially for bass.
  3. Thanks for the reply. I can see where that would sound cool if you had different settings on the channels.

    I was also thinking it would be cool to have a looper made that would split one guitar into 4 different inputs. You could use one channel for chorus, one for delay, etc. and could adjust the tone on each. I see a lot of possibilities that could come out of this.

    And, the price was right.
  4. Passinwind

    Passinwind I Know Nothing Supporting Member

    You could also wire up a couple of the channels as an all tube EFX loop, or wire cascading gain stages, or a bunch of other possibilities. That's a real nice piece if you're into modding tube gear, as I said. And the price was right. :bassist:
  5. You have just exceeded my capacity to understand what you are talking about. Sounds great though. If you weren't so far away, I may send it to you and let you tinker with it. This thing is heavy as a mother.

    I am going to look at all of the tubes and see if they are the same. Is there a different kind of tube I could put in the preamp (it has 12AT7's no w I think) to get it to break up a little more. I was running the input gain on 10 and the master on 2 to get a little grit, but it stayed remarkably clean even when I was running my 18 volt Warrior through it. Doing that gave it a little "hair". I would maybe be into modding this thing, but I would have to know more than I do now.

    Do you think the Sylvania 6L6's are good for it? I've never had an amp with a tube power amp section, so this is new water for me.
  6. Passinwind

    Passinwind I Know Nothing Supporting Member

    Here's a site with a nice overview on the sort of stuff I'm talking about: .
    Also, check out Ampage: . You could spend a few months there and still be learning about tube amp mods. :cool: So don't expect to comprehend it all today.

    You could try subbing in 12AX7 anywhere there's a 12AT7 now, that'll increase gain and may create more breakup. Whether you like the sound is another issue of course. Bigger Fender amps are usually valued for their very clean nature, and they're kinda tricky to get nice breakup from.

    Those Sylvanias look like they might well be the original tubes! They're probably worn out by now, but maybe not. They're great tubes if they're still in proper working order.
  7. Yeah, I do love the clean tone. Amazing really, I guess getting it to break up would have been a plus. Not to mention, I don't think I'll ever be able to push the power tubes to break up. It would be way too loud before that ever happened.

    The power sounds fine. I guess I don't know how to tell if the power tubes are worn out or not. When it was used before, it was not used much at all, and it practically brand new. He told me that he used it for less than 6 months before he bought something lighter. The guy he bought it off of used it 5 times and then stopped DJing, so this thing has very little wear on it.
  8. Passinwind

    Passinwind I Know Nothing Supporting Member

    You could always do what all my friends with Twins do, use a pedal in front of the amp if you want distortion.

    If it sounds fine, it is fine. Have fun, that's a cool amp!