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    Check it out - new 5AR4s

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    PeterCapo

    Posts : 386
    Join date : 2008-12-05

    Check it out - new 5AR4s

    Post by PeterCapo on Thu Oct 24, 2013 10:38 pm

    http://www.thetubestore.com/5AR4-GZ34-Tube-Types

    DynakitParts
    Admin

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    Join date : 2008-11-30

    New 5AR4's

    Post by DynakitParts on Fri Oct 25, 2013 8:02 am

    Hi,
    Looking at the construction of these three (3) new rectifier tubes...you have to wonder if these are
    all the same tubes with just different branding and base variations?

    Maybe Jim McShane can shed some light on this?

    Kevin @ Dynakit






    Zimmer64

    Posts : 113
    Join date : 2013-01-29
    Age : 52
    Location : Switzerland

    Re: Check it out - new 5AR4s

    Post by Zimmer64 on Fri Oct 25, 2013 10:47 am

    I use the inexpensive Sovtek im my ST 70 since march without any problems.

    Michael

    Analog Man

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    Join date : 2013-09-01
    Age : 54
    Location : St. Louis, MO - On The Hill

    Re: Check it out - new 5AR4s

    Post by Analog Man on Fri Oct 25, 2013 8:18 pm

    Zimmer64 wrote:I use the inexpensive Sovtek im my ST 70 since march without any problems.

    Michael
    Same here Wink 

    skriefal

    Posts : 118
    Join date : 2011-09-20
    Location : Utah, USA

    Re: Check it out - new 5AR4s

    Post by skriefal on Fri Oct 25, 2013 8:21 pm

    They certainly do look like the same tube with different branding, higher prices (than the Sovtek), and a shorter plastic base on the "Mullard". But looks don't always tell the whole story. Maybe they've actually improved things. That'd be nice. But I'll let others prove or disprove that. Smile

    fedoragent

    Posts : 35
    Join date : 2013-09-14

    Re: Check it out - new 5AR4s

    Post by fedoragent on Sat Nov 30, 2013 1:05 am

    Alright gang, I decided to go ahead and bite the bullet and get the Mullard GZ34 Reissue. And I have gone ahead and purchased the Mullard EL34 Reissue. Might as well see what they all sound like together. No fear. Smile I will let you guys know. Because I have saved and stored my vintage Mullards GZ34, EL34 and such. I know how they sound with the original PC3 and I'll see how they sound with the 'reissues'.

    skriefal

    Posts : 118
    Join date : 2011-09-20
    Location : Utah, USA

    Re: Check it out - new 5AR4s

    Post by skriefal on Sat Nov 30, 2013 1:58 am

    There is some feedback on the Genalex-branded tube towards the end of the following Audiogon thread:
    http://forum.audiogon.com/cgi-bin/fr.pl?fcabl&1341498195&&&/5AR4-GZ34-Rectifier-Tubes

    zx

    Posts : 194
    Join date : 2011-08-05

    Re: Check it out - new 5AR4s

    Post by zx on Sat Nov 30, 2013 4:17 pm

    I have a pr of Eico hf60s.......setup to run 6550s......for year i have been told that it was the better output tranfourmers......that gave the Eico better, sweeter, diff sound than my Dynaco MK3s... all stock .....new caps ........
    But i got to looking at the hf60s an saw thay use No choke off there GZ34 for the b+..............
     
    So all i did is move the MK3s Red output trans B+ feed from in front of my choke...to the back..to right on pin 8 on the GZ34.
     
    WOW...funny thing all $50-100 ONS GZ34s an 5u4s...still sound great but even my $12 Rudy an sovtek 5ar4 that i would not even use befor..  also sound much better ....an i think the new tube sound better.......the so called better,older GZ34s can sound a littel dark..
    .Has any one done this??.....an what do you think of the sound??
    You well lose some output....but the MK3s never sounded better...well to me...
     
     
    All i am saying.......is we all put some much $$ into caps an tube..an tranfourmers.........you may give this set a try...an hear what these rectifier tubes..........Can sound like!
    An as for a $13-5. Choke that were sending all the GZ34 B+ in to....we may wount to get better chokes.......
    I am NOT puting down the chokes that are sold in these Kits.....i know that there much better than the 60 year old stock chokes in my MK3s.........
    how about a 5H 300ma..........to big?what other down sides
     
    It just may be money well spent on the geting better B+ to our output an front end tubes............
     
    Thanks..........an thanks for this site Bob.....

    sKiZo

    Posts : 1313
    Join date : 2013-04-01
    Location : Michigan USA

    Re: Check it out - new 5AR4s

    Post by sKiZo on Sat Nov 30, 2013 5:02 pm

    So maybe I DID make an improvement when I went with the larger C17x chokes in my ST120 ...



    Truth be told, only reason I did the substitution was I had the room with a custom case. They wouldn't fit in the standard dynaco type chassis.



    One thing I just realized ... The chokes are mounted to the wood sides, and I never did get around to running ground straps to the chassis plate. Guess I didn't have to after all ... next time in though, I might add them just ... well ... uh ... because ... tongue

    fedoragent

    Posts : 35
    Join date : 2013-09-14

    Re: Check it out - new 5AR4s

    Post by fedoragent on Sat Nov 30, 2013 7:16 pm

    skriefal wrote:There is some feedback on the Genalex-branded tube towards the end of the following Audiogon thread:
    http://forum.audiogon.com/cgi-bin/fr.pl?fcabl&1341498195&&&/5AR4-GZ34-Rectifier-Tubes
    Thanks sir. I am actually going to check those out too. Smile And Bob gave me the idea of trying that with KT66 Gold Lion's. I'm so excited about all of this.

    FG.

    zx

    Posts : 194
    Join date : 2011-08-05

    Re: Check it out - new 5AR4s

    Post by zx on Sun Dec 01, 2013 9:48 am

    sKIZo.......yes i saw your upgread choke...Vary cool.....But what about two chokes in you Amp....why just one for bouth ch??
    As if you dont know....you amps looks killer...thanks for all the info you have posted...an pic..

    .....till i move the output tran  B+ to pin 8...i also thought that my MK3 sounded better with EH KT88- EI KT90s............but now the 50 years old GE6550  an my new EH6550 sound so much better than any other tube i have ever tryed in the MK3s....the choke seems to add a dealy to the sound that just is not there...........but that what it dose is ....choke..the sound!
    I also used this setup with ea. 1N4007 having 1A / 1,000 ....an no GZ34....as dose other tube amp  Quicksilver ....No choke on the output....just the frount end.......
     
    Even if you dont keep this setup in............an move back to the choke....you well have a much better insite on how these tube rely sound............
    i have found that  haveing 60mf an a .1mf pp caps right at pin 8 of the 5ar4....is all thats needed to keep the noise down.....
    All this is just one mans o-pine..........have fun...
     
    Thanks for the site Bob....

    sKiZo

    Posts : 1313
    Join date : 2013-04-01
    Location : Michigan USA

    Re: Check it out - new 5AR4s

    Post by sKiZo on Sun Dec 01, 2013 3:37 pm

    Derail! Derail I say!! What a Face 

    But what about two chokes in you Amp....why just one for bouth ch??

    Keeping in mind the ST120 is a stereo amp ... The original chokes were good for around 400mA current flow total - ONE C17a tops out at 300mA. Multiple chokes prevent coupling and improve isolation ... Besides that, I wasn't looking to redesign an effective circuit. My main goal was to improve heat dissipation by adding iron - not necessarily a problem with the original chokes, but as long as I had the room ...

    End derail!

    Bob Latino
    Admin

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    Location : Massachusetts

    Re: Check it out - new 5AR4s

    Post by Bob Latino on Sun Dec 01, 2013 5:53 pm

    The ORIGINAL DYNACO C-354 choke was a 200 milliamp rated choke but was probably rated a little on the low side because they rarely go bad. The original C-354 chokes do, however, get very hot even in a stock Dynaco ST-70. Most of the original C-354 chokes would melt out from the heat a "brown waxy substance" that would stick to the bottom cover below. The two Triad C-24X chokes, as found in the newer VTA ST-120 amps, can (together) handle a current flow of 480 milliamps and do fit inside the original chassis. They are a much better made choke than the original Dynaco C-354 and don't contain any waxy substance inside. The C-17X is good for 300 milliamps, as sKiZo has said, but is too large to fit inside a stock ST-70/ST-120 chassis which has an interior height of about 1 11/16 inch. The C-24X choke has a depth of 1 5/8 inches so it almost touches the bottom cover when you put the bottom cover back on the chassis.

    If you want to replace your original Dynaco C-354 choke, either get a single Triad C-24X choke OR get one of the newer C-354 chokes from Dynakitparts. The newer C-354 chokes from Dynakitparts are much better than the original Dynaco C-354.

    Bob

    fedoragent

    Posts : 35
    Join date : 2013-09-14

    Re: Check it out - new 5AR4s

    Post by fedoragent on Sun Dec 01, 2013 8:01 pm

    Bob, I recently noticed that there is a build up of waxy stuff that is as you described to the bottom of my cover. in fact I'm looking at it right now and it is at the bottom of the choke. Does the choke indeed need to be replaced or can I run it like this?

    Jon

    Bob Latino
    Admin

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    Re: Check it out - new 5AR4s

    Post by Bob Latino on Sun Dec 01, 2013 8:27 pm

    Hi Jon,

    The choke will probably continue to work - BUT - personally if I saw the wax leaking out > I would replace the choke. Those original C-354 chokes always ran hot. The Dynakitparts C-354 choke is much better made.

    Bob

    fedoragent

    Posts : 35
    Join date : 2013-09-14

    Re: Check it out - new 5AR4s

    Post by fedoragent on Mon Dec 02, 2013 2:21 am

    I ordered a new one. I figure that the choke was being killed by the bad quad cap. So I'll just go ahead and replace both and be good.

    Jon

    Jim McShane

    Posts : 154
    Join date : 2011-10-19
    Location : South Suburban Chicago

    Re: Check it out - new 5AR4s

    Post by Jim McShane on Mon Dec 02, 2013 2:04 pm

    Someone earlier mentioned my name...

    I have the new brown base Tung-Sol 5AR4 in stock, so far so good, but there are just a few out there. I can't get the Genalex until mid-month or a bit later, they are on back order all the way to Russia. But I will carry them, no doubt.

    The Tung-Sol reissue stuff has been excellent, I suspect the 5AR4 will be as well. And I agree with Bob, the JJ 5AR4 is not a very reliable tube.

    corndog71

    Posts : 454
    Join date : 2013-03-19
    Location : It can get windy here

    Re: Check it out - new 5AR4s

    Post by corndog71 on Mon Dec 02, 2013 3:09 pm

    I've had much better luck with Ruby 5AR4's than with Sovtek or JJ.

    http://www.amplifiedparts.com/products/T-5AR4-C

    Jim McShane

    Posts : 154
    Join date : 2011-10-19
    Location : South Suburban Chicago

    Re: Check it out - new 5AR4s

    Post by Jim McShane on Mon Dec 02, 2013 3:45 pm

    corndog71 wrote:I've had much better luck with Ruby 5AR4's than with Sovtek or JJ.

    http://www.amplifiedparts.com/products/T-5AR4-C
    Ruby is not a tube maker, they are a relabeler. You've likely been using Sovtek or Chinese tubes, the 5AR4C is Chinese. Ruby does do a nice job of screening though, that helps.

    sKiZo

    Posts : 1313
    Join date : 2013-04-01
    Location : Michigan USA

    Re: Check it out - new 5AR4s

    Post by sKiZo on Mon Dec 02, 2013 4:28 pm

    Yup ... same could be said of Psvane, TAD, or any one of a number of tube suppliers. I remember seeing some ridiculous number on rejects quoted by Grant. Best I can say is their KT88's work real fine here ...

    Not to go completely off track here on a rectifier thread, but the same seems to be happening with KT120's ... makes me wonder if the relabels aren't really the way to go if they're getting additional screening before relabeling?



    zx

    Posts : 194
    Join date : 2011-08-05

    Re: Check it out - new 5AR4s

    Post by zx on Mon Dec 02, 2013 5:55 pm

    Well the JJ tube vary unrelabel............an thay dont sound any better than any of the Chinese tubes....EL34 ...5AR4...
    So the Rudy must be the sovtek 5AR4........ i can see that.......with the choke bypass...the sovtek-Rudy...sound vary close....But the Rudy  5AR4s wins... sweeter,fuller sounding.....Vary good
     
    An can anyone say if any other tube makers.... that make the KT120-KT150..... Are Tung-Sol the only one??
    So any other brand.......relabeler..........an thay well be better??

    I think Jim McShane is the only one on this site... that dose a lot of tube testing an matching...i know the jim thinks highy of the Tung-Sol 6550s....so i well get some of there 5AR4s...
    Thanks jim for your input an info on All tubes......
     
    Thanks for the site Bob.........

    fedoragent

    Posts : 35
    Join date : 2013-09-14

    Results so far

    Post by fedoragent on Sat Dec 07, 2013 6:48 pm

    Gents,

    So far, I have obtained the JJ GZ34 and the Mullard Reissue GZ34. I also in my kit have two GE 5AR4 NoS tubes. I wanted to do an experiment as you know to see if these different rectifiers would make a difference in my ST70 sound-wise. Now after the reading that I have done, I know that these are rectifier tubes (From Quad Cap 2 to pin 8 on the Rectifier) and shouldn't affect sound. Pardon me being new, but I figure if the rectifier is in line with the power tubes (My EH EL34s) that they play an integral part in the grid voltage of the power tubes. And of course, there is the 7199s/6GH8A (depending on what I'm using...) that DO affect sound due to how they are all being driven. I have done some listening on the JJ, Mullard and vintage GE. Hands down, what drives this system better is the vintage GE 5AR4, but the Mullard and the JJ both have their uses. I personally found the Mullard GZ34 reissue (Russian made, not British Blackburn) to have a great affect on the tone of the tubes. The mids were clear, the bass was light for my tastes, but the highs were great. The JJ was the flattest sounding of them all. I find it to be utilitarian and somewhat weak. I'll be doing more studying with my meters to see if there is an actual difference when it comes down to the numbers of all three. But, nothing beats these NoS GE 5AR4s out of what I have tested.

    For Christmas, my brother in law is going to be getting me the GL GZ34 as I hear that it is the closest to the Blackburn Mullards as possible. I'm curious what the thoughts are of you folks. I just thought that I would share what I have observed. And of course, what is good to my ear would be totally different from yours. Therefore I submit this as my .02 cents with the understanding that all things are subjective.

    -Jon

    sKiZo

    Posts : 1313
    Join date : 2013-04-01
    Location : Michigan USA

    Re: Check it out - new 5AR4s

    Post by sKiZo on Sat Dec 07, 2013 8:11 pm

    Here's an interesting one ... Peavey Euro GZ34/5AR4.
    Unusual structure, unless it's just a bad pic ... I expect the "euro" part means it's Russian?


    skriefal

    Posts : 118
    Join date : 2011-09-20
    Location : Utah, USA

    Re: Check it out - new 5AR4s

    Post by skriefal on Sat Dec 07, 2013 8:15 pm

    Looks like a 5U4GB.

    zx

    Posts : 194
    Join date : 2011-08-05

    Re: Check it out - new 5AR4s

    Post by zx on Sun Dec 08, 2013 10:24 am

    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

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