2004 DRRI needs a new rectifier 5V4GA or wait for a 5AR4 ???

Discussion in 'Glowing Bottle Tube Amp Forum' started by blues bondsman, Apr 27, 2020.

  1. blues bondsman

    blues bondsman Tele-Afflicted

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    I just picked up a used 2004 Deluxe Reverb Reissue and it has a poorly performing Russian 5AR4 in it, the center pin was snapped off and I cant get more than 29 ma per tube fully cranked on the bias pot.

    Yes 29 is enough but..... at full tilt that's boarder line low.

    I swapped out the tragically weak Groove Tube 6V6GT's for some sweet Sylvanias and put a Weber 12A150 alnico 50 watt 8 ohm speaker in there that I've had for several years.

    Sound Great !

    However how long can I trust the sov-tech GZ34 ??? not long I'm guessing.

    Any way I see a bunch of 5V4GC out there and their pretty cheap ! and just as durable as the famous older versions of the 5AR4 right ?

    Without getting too technical and without talking about that other tube (5U4GB)

    Has anyone found happiness with a 5V4GA in a DRRI ???

    Or did it lose too much bass response, Get flabby ???
     
  2. Jerry J

    Jerry J Tele-Afflicted

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    The Sovtec GZ34 works fine in my Allen Sweet Spot. It's been reliable. Not sure if the 5V4GA will work in a DRRI but at one time you could get a NOS tube for a very decent price, especially compared to the GZ34, which has been and continues to be ridiculously priced.
     
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  3. blues bondsman

    blues bondsman Tele-Afflicted

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    The 5V4GA will work for sure, it will affect the tightness and headroom, to what degree ??? I'm not sure.
    I used one in a 1969/70 Super Reverb I had and it was great, but that is the 6L6GC side of things, not sure if the 6V6GT's in my Deluxe will be too loose ???
     
  4. MickM

    MickM Friend of Leo's Platinum Supporter

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  5. blues bondsman

    blues bondsman Tele-Afflicted

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  6. Andy B

    Andy B Friend of Leo's Silver Supporter

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    Try it. You just might like it. I am currently running 5R4’s in both of my big Fender amps. I like the sound the lower B+ gives me.
     
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  7. schmee

    schmee Doctor of Teleocity Silver Supporter

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    I've used 5V4's in a vintage DR and other amps. They are usually pretty much the same as 5AR4's sound. May have one in there now, cant remember.

    But why dont you just adjust the resistor value on the bias pot? Or do you really think the tubes are weird?

    I'd far rather use a 5V4 than a modern GZ34. Not had good luck with them.
     
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  8. blues bondsman

    blues bondsman Tele-Afflicted

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    My 5AR4 is what's messed up.
    I found a sweet Nos 5v4ga sylvania green lable.
    And 25 bucks shipped.

    I'm looking forward to checking it out.
     
  9. Dacious

    Dacious Poster Extraordinaire

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    If you can't adjust bias up past 29ma that's likely to be the range adjustment of your bias pot. Nothing to do with the rectifier. They tend to work, or not. If they go bad you'll know it.

    The tubes you installed are possibly just a low-draw pair. That's possibly why they're 'NOS' - that can also mean 'consigned to a spares draw, out of spec'. What's your B+? Does it drop as you wind bias up?

    The 5V4 will drop power overall but won't harm the amp. B+ and power at the plates will be lower. I ran one in my VR - slightly earlier breakup was all I noticed.
     
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  10. pjd3

    pjd3 TDPRI Member

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    I am going through this exact thing right now with a 6V6 plexi I just built. After a bunch of searches about using the 5V4GA I felt pretty confident that it would work for my amp seeing as that it was a pair of 6V6's and not a quad of 6L6's that I would be blasting everynight. Most people reported good things about using the 5V4GA with 2 6V6's as long as you don't mind a 5-10 volt plate drop. Some even like it. I just ordered a NOS 5V4GA from KCA NOS tubes as they were only 26 bucks and deemed very stout and long term reliable as opposed to new production GZ34/5AR4's. The data sheet for these tubes does tote 10uF as the maximum first in line filter cap but many said this as more of a safe and even typical value that is contingent on many other things. Since my amp will be seeing around 420 volts on the plate of new NOS sylvania 6V6's, I was feeling pretty good about it. And the fact that 6V6's call for much less HV current. At least I was led to believe that is a factor. Good luck with that! Let me know how it goes, I'm in the same boat as you with this one, more or less!
    Phil
     
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  11. blues bondsman

    blues bondsman Tele-Afflicted

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    My 5v4GA has left Texas and should be here early next week.

    I have a sweet pair of RCA 6V6GT'S in case the sylvania dont pan out.

    Its great to be back in the tube amp game !

    P.S.
    I've already clipped c-10 (bright cap).
    Still need to pull the cover off of the filter capacitors and check them out.
    The tested date was August 2004 on the board and so those caps are probably 16 years old.
     
  12. pjd3

    pjd3 TDPRI Member

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    Awesome bluesbondsman. Although this may not be critical, I've heard that if for any reason you would worry about a filter cap shorting, we can protect the power transformer HV windings by adding in IN4007 diodes to each HV line, forward biased of course to allow positive going pulses to the rectifier tube. Seems like good cheap insurance for any amp period, really. I guess if the filter cap shorts, that shorts the rectifier tube, and that in turn takes out the HV coil on the PT. So, for a few cents we can save a $100 power transformer. I'm game. Keep us updated! Wishing for good perfomance. Again, I"ve found most people have good experience with a 5V4 and a pair of 6V6's. Thats what they tell me!
     
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  13. blues bondsman

    blues bondsman Tele-Afflicted

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    Most of the people who have tried them haven't had any issues, I 've found several people online that have successfully used the 5V4GA so...
    The Professor here ran his DRRI on one without issue.
     
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  14. pjd3

    pjd3 TDPRI Member

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    Well that's darn good news!
    Best,
    Phil D.
     
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  15. theprofessor

    theprofessor Poster Extraordinaire

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    I'm late to the party, but what @schmee said. A 5V4 will just drop your voltages but won't yield much noticeable sonic difference from a GZ34, if any at all. Other tubes, like a 5R4, will change the sound and feel of the amp more.
     
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  16. blues bondsman

    blues bondsman Tele-Afflicted

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    It is certainly a more viable option financially for an NOS rectifier and if the performance is that close then... Why not !
     
  17. Sea Devil

    Sea Devil Tele-Afflicted

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    I've tried it and it sounded fine. A little "softer," if that makes any sense. And I liked the fact that most components in the circuit were under less stress with marginally lower voltages. I did it mostly because I scored a half-dozen or so at a yard sale, and they looked cool. I went back to the regular recto tube, but not for any particular reason.

    Bias voltages and everything else tend to "travel with" the voltage of the rectifier, so no adjustments were needed.
     
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  18. blues bondsman

    blues bondsman Tele-Afflicted

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    I still have a few days wait for my sylvania 5v4ga, if it works to my liking I'll get a few extras.

    I've read that it potentially warms the preamp by changing the bias there too.

    I hope I dont lose too much punch in the low end aka headroom.

    I will check and adjust the bias as necessary.
     
  19. blues bondsman

    blues bondsman Tele-Afflicted

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    Another tube swap I did as soon as I got the amp was a GE five star 5751 in V2
    Something I've done with every fender tube amp I've ever owned.
    I was able to buy a big bunch of them years ago and they just seem to do the trick at least for me.
    There is a "USA" 12AX7 in V4 , it will probably get a sweet old RCA in there.
    I also have a handful of new in the box Motorola 12AT7 for the PI and reverb driver.

    This is becoming my #1 amp due to its tone and relative light weight and so its getting all of my best tubes !

    That weber 12A150 made a dramatic difference in the amp ! the 16 year old "Jensen" didn't sound bad and had obviously had plenty of break in ! but the weber pushed it over the top !
     
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  20. blues bondsman

    blues bondsman Tele-Afflicted

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    Well long story but new R62 and R63 (kinda crispy) and the new 5V4GA and my Sylvania 6V6Gt's were cooking along at 26.9 to 28 ma and sounded BIG and Strong.
    A few minutes in and I got distortion and lost a bit of volume, took a peak and the 6V6 furthest from the rectifier was cherry red ! so...
     
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