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    Check it out - new 5AR4s

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    fedoragent

    Posts : 35
    Join date : 2013-09-14

    Re: Check it out - new 5AR4s

    Post by fedoragent on Sun Dec 08, 2013 12:01 pm

    zx wrote:All the Nos GZ34  GE, RCA, Mullard... i have with the choke in the power supplie sound best......An the new 5AR4 Sovtek , Rudy, JJ............ an others sound brite...with less bass.........
    Choke out...........just on the output tubes.....the sovtek,Rudys sound just right,highs mids an lows
    All Nos have fat bottem ends,rolled off top, mids ok............but the new 5AR4s win........
    An in the No choke setup the 6550......sound much better than the KT88s....any brand Nos are new..
    go fig...........have fun
     
    Thanks for the site Bob.......happy Hoho.
    zx
    Just out of curiosity, what are the ramifications of not running a choke?

    Happy Holidays Folks!

    Jon

    zx

    Posts : 194
    Join date : 2011-08-05

    Re: Check it out - new 5AR4s

    Post by zx on Sun Dec 08, 2013 6:34 pm

    Well till i moved the output tranfourmers B+ feed to pin 8 on the tube.rectifier.... on a pr of MK3s.... i had moved on to all SS rectifiers  for my tube amps....Less stress on the power tranfourmers...better bass...mids....an one less tube to Spend $$ on.......
    Then i was looking at older tube amp  setups....  Eico,Qucksilver,an others did not use choke at all or just for the frontend......So i thought i would see what happen if did this setup on my Dynacos.......
     
    All i can say is i never heard how sweet the sound of a tube rectifiers could be on the MK3s....
    An the new 5AR4s sounded great.... ....with the choke in.....not so much....for my ear!
     
     
     
    Over 40years of minny MK3s .....never sounded so good an this  is with a all stock 6AN8  front end...new caps all aound.....lot fun
     
    Thanks for the site Bob....

    sKiZo

    Posts : 1287
    Join date : 2013-04-01
    Location : Michigan USA

    Re: Check it out - new 5AR4s

    Post by sKiZo on Sun Dec 08, 2013 8:31 pm

    Interesting ... normally you'd expect to have increased hum/noise and/or decreased headroom if you eliminate a choke ...


    Maintarget

    Posts : 208
    Join date : 2013-02-10

    JJs

    Post by Maintarget on Mon Dec 09, 2013 12:17 am

    My personal experience with the JJ GZ-34 in the VTA ST-120 has not been good one in 125 hours and the other didn't even survive the initial start up, using the Latino recommended Sovtek GZ 34 I will keep you posted.

    zx

    Posts : 194
    Join date : 2011-08-05

    Re: Check it out - new 5AR4s

    Post by zx on Mon Dec 09, 2013 11:02 am

    sKiZo wrote:Interesting ... normally you'd expect to have increased hum/noise and/or decreased headroom if you eliminate a choke ...

     
    Yes you lose about 10 watts..........noise .....i have 60mf right at pin 8 an a 1.mf poly cap......mike at Quicksilver has over a 100mf at pin 8 for his 5AR4s..................But the sound......
    This sound better than in the  triode mode ...an you have more power............well too me!
    It a real shock to hear how great the GZ34/5AR4s CAN sound.... it would vary hard for me to go back to get choket!............
    As wall as the EL34s6550s an KT88.........Nos an New
     
    .....I think we look at these Chokes  ...well there good a neff... an the a $15-20 part is fine.. thay well fit in the amp......but i have V caps that are $80ea...an big $$ in these tubes.........An great Dynaco amps New like Bob offers.......an over 50years old  amp like i have.....an the sound being lowerd by this one part..... it is the one an only B+ it make all the sound......feeds all the tubes....an output trans......cant be hard to see......hear...hehe
     
    Look it all about the best sound.........have fun
     
     
    My preamp is a re-worket hhscott 355...60old all tube  
    My speakers are Apogees Stages....Acoustats ESL...an Older Maggys..the two ways on one sheet of mylar....i say there as close to a oneway fullrang driver....0ne can find for vary littel cash...
     
    thanks for the site Bob............

    Bob Latino
    Admin

    Posts : 2378
    Join date : 2008-11-26
    Location : Massachusetts

    Re: Check it out - new 5AR4s

    Post by Bob Latino on Mon Dec 09, 2013 1:50 pm

    zx wrote:Well till i moved the output tranfourmers B+ feed to pin 8 on the tube.rectifier.... on a pr of MK3s.... i had moved on to all SS rectifiers  for my tube amps....Less stress on the power tranfourmers...better bass...mids....an one less tube to Spend $$ on.......
    Then i was looking at older tube amp  setups....  Eico,Qucksilver,an others did not use choke at all or just for the frontend......So i thought i would see what happen if did this setup on my Dynacos.......
     
    All i can say is i never heard how sweet the sound of a tube rectifiers could be on the MK3s....
    An the new 5AR4s sounded great.... ....with the choke in.....not so much....for my ear!
     
     
     
    Over 40years of minny MK3s .....never sounded so good an this  is with a all stock 6AN8  front end...new caps all aound.....lot fun
     
    Thanks for the site Bob....

    If you do this - yes - you are now bypassing the choke but the choke is there to pull off any ripple AC current that may be riding on the DC. Evidently there is little audible AC getting through. Personally, I do not recommend doing this but I recognize they are your amps to with what you want ... The "better bass...mids..." etc. that you experience may be the result of two things. (1) the use of a solid state rectifier which has virtually no voltage "sag" and (2) a somewhat higher B+ voltage because of the DC not going through a choke. A choke does have resistance and will knock the B+ down a little.

    Again, I would feel safer with a choke in there to strip any remaining AC ripple off the DC produced by the rectifier .. That said .. The Dynaco ST-35, Mark II and the SCA-35 do not use a choke and a lot of them are still out there playing fine ..

    Bob

    turbotoy

    Posts : 47
    Join date : 2012-04-15

    Re: Check it out - new 5AR4s

    Post by turbotoy on Mon Dec 09, 2013 5:07 pm

    +1 - Try correlating B+, preferably transiently, to listening observations.

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