SS rectifier & 6L6's in a 64 Deluxe

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by Seegs, Oct 18, 2004.


  1. Seegs

    Seegs Member

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    I just got a SS rectifier plug which can substitute for 5U4GB/5AR4/5Y3 rectifiers and want to experiment with it and 6L6's in my 64 Deluxe...the amp was been recapped about 5-6 years ago and is in good health...!!

    Any thing need to be done other than plug the rectifier/tubes in and rebias...??

    Whats a good bias range for 6L6's in my Deluxe with the SS Rec. plug??

    I am running a Weber Cali paper domed speaker and looking for more headroom!!

    Thanks in advance!!

    Chow,
    Seegs
     
  2. fullerplast

    fullerplast Senior Member

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    You should be good to go with just a re-bias. Optimum bias will depend on your plate voltage (and your ears) but generally you should be safe with 30-35mA. For more headroom, keep it on the low side. Try a 5751 or 12AY7 in V2. Coupling caps can be changed later if you want to go further to reduce bass fartiness.
     
  3. Seegs

    Seegs Member

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    FP...once again thanks a lot...now I get to see if I can squeeze just a hair more clean headroom out of this amp...or of she blows up on me...;)!!

    Chow,
    Seegs
     
  4. John Phillips

    John Phillips Member

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    Wait - be careful. The Deluxe has 'single', not 'stacked' filter caps. In normal Deluxes, the B+ is quite close to the cap voltage rating (450V usually). If you put a simple, no-resistor SS rectifier in, you could easily take it over the voltage rating.

    I would make sure 500V caps were used for the recap before doing that.

    If they're only 450s, power up the amp (with the SS rec in) via a Variac. Start at about 90V and bring it up to 120 slowly while metering the voltage on the filter caps too. If it goes to above 450, you'll need a Copper Cap or other SS rec with a resistor.
     
  5. Seegs

    Seegs Member

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    JP to the rescue...thanks a lot for the warning...I know only that the caps were replaced with Elcos...I don't know what voltage spec they have...

    Will it tell me anything if I monitor the B+ and it well within the 450VAC spec...???

    Plus the plug in rectifier says it replaces anyone of these rectifiers...5U4GB/5AR4/5Y3...??? Can it be that it already has the resistor in it...??


    BTW I'm in Germany and we run at 230VAC...!!

    Chow,
    Seegs
     
  6. fullerplast

    fullerplast Senior Member

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    John's warning is a good one, most people recap deluxes with 500V caps as standard procedure, but John's right-it's good to check.

    If you are well within the 450V you have nothing to worry about either way, over 450 make sure you have the 500V caps. The rating will be printed on the side. These caps are all under the doghouse on the bottom of the chassis.

    An additional warning, if you do use 6L6's, stick with an non-tube rectifier as the heater load is already bumped up from the 6L6's.
     
  7. Seegs

    Seegs Member

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    Thanks again FP...sure glad you guys are here...I'll check the ratings before I proceed...!!

    Chow,
    Seegs
     
  8. fullerplast

    fullerplast Senior Member

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    One more warning....:D You probably know this, but make sure the caps are discharged before you take off the doghouse! There's not much clearance between 400V and that cover!!
     
  9. Seegs

    Seegs Member

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    I am dully warned...thanks FP...if you don't see any more posts from me you'll know what happened:D !!

    Chow,
    Seegs
     
  10. Jon Silberman

    Jon Silberman 10Q Jerry & Dickey Gold Supporting Member

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  11. Seegs

    Seegs Member

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    Thanks jon...I am already part of the way there...I've already got a Weber Cali there in there and installed a mid-control on the first channel...the amp sounds great now until about 5 or 6 when it gets a bit fizzy and ratty when overdriven...I'm hoping the 6L6's and a SS rectifier will take care of that...

    Chow,
    Seegs
     
  12. Sir Ricardo

    Sir Ricardo Member

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    Hello Seegs:

    I've got a modded DR. Rather than go into lots of detail here, check out the links below. I asked the FDP and TDPRI forums for advice, and gots lots of it. The thing you may want to consider, and maybe ask some folks, is whether your power transformer is up to the task of powering 2 6L6s. And whether the output transformer can handle it, as well.

    Let us know what you find out.

    Cheers, and best to you -

    Richard

    http://www.fenderforum.com/forum.html?db=&topic_number=441054

    http://www.tdpri.com/viewtopic.php?p=218511#218511
     
  13. Seegs

    Seegs Member

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    Hi Richard,

    thanks for the info...it was good reading and gave me some more things to look out for...to the best of my knowledge all my trannies are stock and I will be on the lookout for how hot they get...!!

    Chow,
    Seegs
     
  14. fullerplast

    fullerplast Senior Member

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    Seegs, keep in mind that Ricardo's modded DR had four 5881 tubes-quite an extensive mod and very different from what you are doing. You should be fine with the stock PT. This is a very common DR practice. Just stay with a non-tube rectifier with the 6L6's.
     
  15. Seegs

    Seegs Member

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    FP thanks a lot for pointing that out...!!

    I think its always good to collect as much info. as possible before proceeding...!

    This thread has been most helpful in that regards...!!

    Chow,
    Seegs
     
  16. Sir Ricardo

    Sir Ricardo Member

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    Hello fullerplast:

    You are right to point out that my amp initially was running on 4 5881s. Now of course, to avoid burning down my house (!), I've just been running 2 6L6s.

    But my question is, and I don't know the answer, is....is the PT for a stock Deluxe Reverb capable of powering 2 6L6s and 6 12-type tubes?

    Modded DR:
    Here is the math, as it pertains to Seegs' (and mine) modded DR...each 6L6 draws .9a of current. each 12-type tube draws .3a current.

    So, 2x.9 + 6x.3 = 3.6a total.

    Stock DR:
    If you just kept the stock DR tube configuration, you would have

    2 6V6 x .45a +

    1 GZ34 x (I don't know how much it draws) +

    6 12-type x .3

    = total?


    Now, my Bassman PT is rated for 3a, so I'm just 20% over its rating.

    The question is, what is a stock Deluxe Reverb PT rated at? There has to be some net-based resource out there somewhere, where I could just find out that information. But I don't know where it is.

    Any thoughts?

    Cheers,

    Richard
     
  17. Seegs

    Seegs Member

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    Hi Richard,

    I have a 64 Deluxe...no reverb model....and off-hand I don't know how many 12xxx tubes there are but I think it's less than 6 plus if I take out the tube rectifier won't that less the current draw by whatever the GZ34 uses???

    Chow,
    Seegs
     
  18. fullerplast

    fullerplast Senior Member

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    Hi Richard,

    You're talking about heater current here, and I can't really add any more than what Mark Norwine said in your referenced thread. I agree with his analysis.

    I think your PT will run a little bit warmer and I would not use a tube rectifier, but I think you will be perfectly fine. People have been running Deluxes like this for years and years.
     
  19. Seegs

    Seegs Member

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    Well I finally got my amp up on the bench to look at it and the caps under the doghouse have different ratings...the closest to the op tranny is rated at 500V and physically bigger than the next 3 which are rated at 450V...


    I may still measure the B+ with and without the SS rectifier plug and give the SS rect. a shot if there is room to spare but right now I just swapped out a Weber paper domed Cali for a Weber 12F150 and am digging how the amp sounds...

    Chow,
    Seegs
     
  20. Seegs

    Seegs Member

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    The B+ is reading 430 V so I think I'll leave the 6V6's in as I'm afraid to toast something running 6L6's...

    Chow,
    Seegs
     

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