5U4 tube recommendations, SFSR

Discussion in 'Amps and Cabs' started by Carabinerx, Apr 21, 2015.

  1. Carabinerx

    Carabinerx Member

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    Im replacing some tubes in my SF super reverb, and I noticed the previous owner had a Ruby 5u4gc rectifier, so I figured while im already at it id get a 5u4 (the original rect. tube). But whats a good option, new production and NOS? I didnt realize it would be so much more than the preamp tubes (NOS, that is). Save me a little research time and throw some TGP approved rect. suggestions at me!
     
    Last edited: Apr 22, 2015
  2. big mike

    big mike Moderator - EL34 Emeritas Staff Member

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    Anything nos is worth it. It'll last forever.
     
  3. zenas

    zenas Member

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    An SFSR unless it's a very early one had the 5u4 originally. I wouldn't even mess with a current manufacturer 5u4. Get NOS or just go load up a few free organs till you score one.
     
  4. Buddy Boy

    Buddy Boy Member

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    Mullard...rebranded will be cheaper. I'd take a good used one over almost anything else.
     
  5. Carabinerx

    Carabinerx Member

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    Thats my understanding at this point, with limited experience. Im going the NOS route with the preamp tubes: any particularly good bang for buck rectifiers?

    thanks, corrected that. I was still looking at the BF specs (curiosity), my bad.
     
  6. DaveKS

    DaveKS Member

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  7. StompBoxBlues

    StompBoxBlues Member

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    I just bought one for my Budda SD-18, something called ANOS (I'd never heard of that until searching a little here) which is NOS but "used".

    I bought an RCA one, and it was a lot less expensive (still not cheap). Since this tube is pretty much utilitarian, in that it isn't directly in the signal path, it is used by the power supply as diode...it affects "sag" though.

    But mainly I asked the vendor if it really would most likely last long enough to make it worth the price and (I know...it's in his interest, but I actually got a feel for that it wasn't just to sell me one) he said yes.

    I'll find out. It is pretty cool to see one of the OLD time RCA boxes with the old tubes. It was an afterthought, I did also buy some ANOS preamp tubes. Again, I'm experimenting. But I do wonder, I have no problem using a decently made new 5U4, I don't think it will affect the sound BUT...how often does one of these tubes "go" on their own, and how often is it some resistor in the circuit that blows the tube? Because even a well made one, if there is some too high voltage, etc. will still go bad.
     
  8. Blue Strat

    Blue Strat Member

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    I don't think I've ever seen a Mullard 5U4.
     
  9. big mike

    big mike Moderator - EL34 Emeritas Staff Member

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    Any of the American rectos will be decently priced.
    Sylvania, ge etc. I'd probably just see what mike has in stock at KCA.
     
  10. Timbre Wolf

    Timbre Wolf GoldMember Supporter Gold Supporting Member

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    Since no one has yet specified their favorites, I'll jump in first...

    I particularly enjoy the feel of my cathode-bias 5U4 rectified amps when I use vintage Tung-Sol 5U4GB. I prefer them to RCA and Sylvania.

    My favorites are Ken-Rad 5U4G and GEC U52, but they're both expensive, and a bit more delicate.

    The Tung-Sol are robust, dynamic, and feasible to obtain.


    That's because Mullard never made a 5U4. At least it's not listed in their tube publications.

    - Thom
     
  11. swiveltung

    swiveltung Member

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    NOS US made 5U4GB's are cheap, plentiful and last forever. No reason to go import on those.
     
  12. Trout

    Trout Member

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    1st Choice Sylvania.

    Years ago when I was still using my old Seymour Duncan Convertible 100W it was the ONLY 5U4 that would survive.

    Those amps were very input cap heavy, way over the tube spec.
    Tung-Sol, RCA & GE would arc and fry in very short order. Some would start arcing withing 25 hours.

    YMMV

    Oh, I have a couple JJ 5U4's that have been in heavy rotation for nearly 3 years. The ONLY one I ever had fail was right out of the box, DOA due to no filament.
     
  13. Carabinerx

    Carabinerx Member

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    Missed all these responses before hitting the BUY button, but I wound up with a NOS RCA, pleasantly surprised that they are cheaper than I was expecting, even the often 'more desirable' imports were all under or around $30. Since I've RCAs elsewhere in the amp, good dealer score/return policy, NOS guarantee, and cheap -- this one seemed like a good choice. Thanks all the same
     
  14. The Dirty Tube

    The Dirty Tube Member

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    Durrr... since these tubes have your personal recommendation, then I sure hope you have experience with them. Please explain because I'm not aware, and it seems no one else is, of any Mullard 5U4 type.
     

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