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  • Less bass mod question

    In changing the .1 caps, do I only switch out the 3 coupling caps??
    2 on the 12AY7 & just one on the 12AX7 as there is already a .022 on pin 1.
    What about the .1 cap on pin 8?? Do I leave it as is??
    (What happens if I lower this one as well?)

    Thanks
    Sean
    Last edited by Ringwraith; 08-22-2008, 09:08 AM.

  • #2
    Dude, you've got to be more specific. I assume you're talking about a 5E3 because I see a thread above this one where you're asking about OD caps in a 5E3. You can't just ask questions without some kind of background info as if everyone knows what you're talking about.

    On a 5E3 there are 4 coupling caps, one from each input stage to the volume controls, pins 1 & 6 on the 12AY7. And two from the PI to the 6V6's, pins 6 & 8 on the 12AX7. If you're going to change the coupling caps to the 6V6's you need to change them both. If you're going to change the preamp coupling caps you can change just one if you like, as you're only using one channel at a time anyway. Which ever one you change will have reduced bass. Or go ahead and change them both out, your choice.

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    • #3
      Originally posted by hasserl View Post
      Dude...
      On a 5E3 there are 4 coupling caps, one from each input stage to the volume controls, pins 1 & 6 on the 12AY7. And two from the PI to the 6V6's, pins 6 & 8 on the 12AX7. ...
      And I think he means four .1uF caps, not four total coupling caps as there are actually 5 coupling caps.
      Bruce

      Mission Amps
      Denver, CO. 80022
      www.missionamps.com
      303-955-2412

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      • #4
        Sorry, I figured because it was a 5E3 forum I didn't need to specify which amp unless it was something different. ;-)

        Some more background...
        My clone is built from an original 5E3 schem/layout other than adding a 3 prong & stand by.

        Regarding the caps...
        I was a bit confused because I wasn't sure if the cap on pin 8 of V2 was considered a coupling cap. I was thinking just the caps on the plates were coupling caps. (I need to re-read my books!)

        So I think I'm clear now.
        I can change both or just one of the .1 caps on V1.
        If changing the .1 caps on V2 I need to change both.
        I don't change the .02 cap on V2

        Cheers
        Sean

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        • #5
          Sorry, I figured because it was a 5E3 forum I didn't need to specify which amp unless it was something different. ;-)
          My bad, I was just looking at the new posts at the Ampage discussion board, where it lists new posts from all the Ampage forumes. I didn't notice your's was from the 5E3 forum. Sorry about that.

          Thanks for the clarification Bruce, yes four .1uf coupling caps (and one .022uf).

          Pin 8 (cathode) of V2 is one half of the phase inverter, a cathodyne or split load type that uses both the anode and the cathode to drive the power tubes. The cap at that pin is coupling the signal from that half of the PI.

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          • #6
            Originally posted by hasserl View Post
            My bad, I was just looking at the new posts at the Ampage discussion board, where it lists new posts from all the Ampage forumes. I didn't notice your's was from the 5E3 forum. Sorry about that.
            Still a good idea to give all the info so people don't waste time answering questions based on wrong assumptions. Also, it's not unheard of for people to post in the wrong forum.
            In the future I invented time travel.

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