The Dynaco Tube Audio Forum

Dedicated to the restoration and preservation of all original Dynaco tube audio equipment - Customer support for Dynaco VTA tube amp kits, all Tubes4hifi.com products and all Dynakitparts.com products


    Order of priority

    Share
    avatar
    Dahlberg

    Posts : 107
    Join date : 2016-09-27
    Age : 56
    Location : Sweden

    Order of priority

    Post by Dahlberg on Fri Jan 13, 2017 7:35 pm

    I'm picking up things everyday now so..... Smile
    In wich order would you put the different tubes by "most important".

    Ficticious example:

    1:Output tubes   (It's the big ones)
    2:front tube        (first in line and decides what's to be)
    3:phase splitter   (everything important is already set)

    I dont have much of a clue yet so..... Cool
    avatar
    Kentley

    Posts : 436
    Join date : 2015-03-06
    Age : 65
    Location : Worcester, MA

    Re: Order of priority

    Post by Kentley on Fri Jan 13, 2017 7:50 pm

    I take it you mean "How do I prioritize my tube purchases to get the biggest bang per buck?"
    The consensus here is that your "front" driver - the volt-amp tube - is the single most important regarding tone quality. My humble advice is to purchase several different of these, as there's no way to predict absolutely what effect it might have in your system. Another recent thread here goes into detail about the various 12AU7 types. Also be aware that many really like a 12BH7 here.
    With output tubes, you might want to go for the most durable. SQ is less of an issue here - tho there are real differences.
    Splitters have not been known to have much effect on sound. Though some may argue otherwise, it seems that any functional QUIET tube will suffice.
    avatar
    Dahlberg

    Posts : 107
    Join date : 2016-09-27
    Age : 56
    Location : Sweden

    Re: Order of priority

    Post by Dahlberg on Fri Jan 13, 2017 8:06 pm

    Ok, so strangely enough the list wasn't way of then Shocked

    For those of you that would put a 12bh7 instead of a
    12au7 at the front position, why would you do that ?
    avatar
    Kentley

    Posts : 436
    Join date : 2015-03-06
    Age : 65
    Location : Worcester, MA

    Re: Order of priority

    Post by Kentley on Fri Jan 13, 2017 8:45 pm

    Because we can.
    Seriously, the 12BH7 is analogous to a slightly "bigger" 12AU7, and similar enough to be a useful sub. The plates tend to be larger, and while it draws a slightly higher filament current it will not stress the power section. Depending on your system synergy, you might find it gives a ballsier midrange. The tonal character is noticeably different. And best of all, there's truckloads of NOS 12BH7s available for quite cheap. My personal faves are the old New Jersey TungSols. But RCAs, GEs, Raytheons, etc. etc. are out there for a song.
    That's why.
    avatar
    vtshopdog

    Posts : 104
    Join date : 2015-07-11
    Location : UT, USA

    Re: Order of priority

    Post by vtshopdog on Fri Jan 13, 2017 10:58 pm

    Dahlberg wrote:Ok, so strangely enough the list wasn't way of then Shocked

    For those of you that would put a 12bh7 instead of a
    12au7 at the front position, why would you do that ?

    I just finished swapping out AU for BH type in my m125 over the weekend. To my ear bh7 seems a bit less bright and simply sounds better (more smooth and musical if you will) in my new speakers but in the old ones they were kind of dead. Power tranny does seem to run cooler with bh7

    If I'm correct you are running your amp with a digital X-over for a fairly narrow band in lower mid and bass frequency? (super cool looking rig you have built, very impressive and looks like you probably had a ton of fun building) I'm guessing your unique application is so different that generalizations from guys like me will not apply.
    avatar
    Dahlberg

    Posts : 107
    Join date : 2016-09-27
    Age : 56
    Location : Sweden

    Re: Order of priority

    Post by Dahlberg on Sat Jan 14, 2017 7:48 am

    So if we narrow down the list excluding the output tubes.

    1: Front tube
    2: Phase splitter

    I have a plan for my personal rig Cool but this was aimed at
    the basic guidelines.
    If the Phase splitter doesn't have that much impact on the
    final impression you might get away with simpler tubes in
    that position, right ?
    avatar
    arledgsc

    Posts : 466
    Join date : 2012-11-30
    Location : SF Bay CA

    Re: Order of priority

    Post by arledgsc on Sat Jan 14, 2017 1:05 pm

    Dahlberg wrote:So if we narrow down the list excluding the output tubes.

    1: Front tube
    2: Phase splitter

    I have a plan for my personal rig Cool but this was aimed at
    the basic guidelines.
    If the Phase splitter doesn't have that much impact on the
    final impression you might get away with simpler tubes in
    that position, right ?

    The phase splitters can influence sound so I try to keep them neutral. Recently the Mullard CV4003s were tried as splitters in the ST120. The CV4003 high frequency roll-off was very noticeable. The front tube though tends to give the ST120 its "voice".

    avatar
    Dahlberg

    Posts : 107
    Join date : 2016-09-27
    Age : 56
    Location : Sweden

    Re: Order of priority

    Post by Dahlberg on Sat Jan 14, 2017 1:44 pm

    arledgsc wrote:
    Dahlberg wrote:So if we narrow down the list excluding the output tubes.

    1: Front tube
    2: Phase splitter

    I have a plan for my personal rig Cool but this was aimed at
    the basic guidelines.
    If the Phase splitter doesn't have that much impact on the
    final impression you might get away with simpler tubes in
    that position, right ?

    The phase splitters can influence sound so I try to keep them neutral.   Recently the Mullard CV4003s were tried as splitters in the ST120.  The CV4003 high frequency roll-off was very noticeable.   The front tube though tends to give the ST120 its "voice".

     

    So you would say that they are equally important then ?
    avatar
    arledgsc

    Posts : 466
    Join date : 2012-11-30
    Location : SF Bay CA

    Re: Order of priority

    Post by arledgsc on Sun Jan 15, 2017 12:35 pm

    Dahlberg wrote:

    So you would say that they are equally important then ?

    They are all important in that they have to work together as well the other parts of your sound system.  My experience is it has been an iterative process selecting tubes.  Has been a fun, but expensive, experience.  I finally settled on KT120 power tubes and the other tubes that support the sound characteristics I like.  

    You have to discover what you like and dislike.  Some of the tubes recommended on this forum did not work for my tastes, system components, and room.  I think it is wonderful that the ST120 not a one-trick pony in that component changes are readily noticeable - good and bad.

    Anyway, I think you have the order correct on tube selection.  But you may have to reiterate the process fine tuning the sound you are seeking.  Have fun!
    avatar
    Dahlberg

    Posts : 107
    Join date : 2016-09-27
    Age : 56
    Location : Sweden

    Re: Order of priority

    Post by Dahlberg on Sun Jan 15, 2017 1:35 pm

    arledgsc wrote:
    Dahlberg wrote:

    So you would say that they are equally important then ?

    They are all important in that they have to work together as well the other parts of your sound system.  My experience is it has been an iterative process selecting tubes.  Has been a fun, but expensive, experience.  I finally settled on KT120 power tubes and the other tubes that support the sound characteristics I like.  

    You have to discover what you like and dislike.  Some of the tubes recommended on this forum did not work for my tastes, system components, and room.  I think it is wonderful that the ST120 not a one-trick pony in that component changes are readily noticeable - good and bad.

    Anyway, I think you have the order correct on tube selection.  But you may have to reiterate the process fine tuning the sound you are seeking.  Have fun!

    Thanks, of cource everything matters and since it's not ment to be "done" anyway there will be a
    journey this time as well. Bye the way, and OT, from your avatar we seem to share taste in caps Smile
    avatar
    arledgsc

    Posts : 466
    Join date : 2012-11-30
    Location : SF Bay CA

    Re: Order of priority

    Post by arledgsc on Sun Jan 15, 2017 7:39 pm

    Dahlberg wrote:

    Thanks, of cource everything matters and since it's not ment to be "done" anyway there will be a
    journey this time as well. Bye the way, and OT, from your avatar we seem to share taste in caps Smile

    Good luck and have fun. The results were nothing like I expected. What amp do you have?

    I no longer have the Dueland caps in my amp. They both leaked oil and were replaced with Mundorf Silver/ Oil.
    avatar
    Dahlberg

    Posts : 107
    Join date : 2016-09-27
    Age : 56
    Location : Sweden

    Re: Order of priority

    Post by Dahlberg on Sun Jan 15, 2017 8:02 pm

    I have a pair of newly built M-125's, there is a build thread in "photos".
    There is also a quick presentation of most of the rig.
    http://dynacotubeaudio.forumotion.com/t3163-my-kt120-m-125-s
    I have also had problems with leaking Duelunds, got new ones without
    any disscusion. The last pair has been solid for ~2years.

    I have the original K40's in the M-125 amps now, I will switch them to
    FT-3's. Will take some doing since they are quite big but it has been done before  Cool

    I went from Russian FT-3's to Mundorf silver/gold/oil in my KR 300b's.
    avatar
    pedrocols

    Posts : 100
    Join date : 2014-11-24
    Location : Western MA

    Re: Order of priority

    Post by pedrocols on Mon Jan 16, 2017 12:25 am

    I have tried the CV4003s and like stated before there is a hi freq roll off but the midrange is spectacular. I am currently using GEs clear top on front and RCAs on the back.
    avatar
    deepee99

    Posts : 1760
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Order of priority

    Post by deepee99 on Mon Jan 16, 2017 1:17 pm

    Kentley wrote:I take it you mean "How do I prioritize my tube purchases to get the biggest bang per buck?"
    The consensus here is that your "front" driver - the volt-amp tube - is the single most important regarding tone quality. My humble advice is to purchase several different of these, as there's no way to predict absolutely what effect it might have in your system. Another recent thread here goes into detail about the various 12AU7 types. Also be aware that many really like a 12BH7 here.
    With output tubes, you might want to go for the most durable. SQ is less of an issue here - tho there are real differences.
    Splitters have not been known to have much effect on sound. Though some may argue otherwise, it seems that any functional QUIET tube will suffice.
    Much as it pains me, I must concur with Kentley on this. The front driver tube(s) on the ST-120s and M-125s will have the greatest influence on sound qualities. Almost like tone controls, and they're a heck of a lot cheaper to experiment with than power tubes. I tried some very expensive NOS GE 6550As and IMHO they stunk compared with the Gold Lion KT-88s that Jim McShane sells. The better Shu Guang Chinese outputs (Black Treasures, Golden Voice) likewise will put a different audible spin on things.
    A caveat: judge no power tube until you've run it at least 100 hours. They all sound crappy straight out of the box.

    Dogstar

    Posts : 288
    Join date : 2014-06-23

    Re: Order of priority

    Post by Dogstar on Mon Jan 16, 2017 9:45 pm

    Kentley wrote:
    A caveat: judge no power tube until you've run it at least 100 hours. They all sound crappy straight out of the box.

    I was thinking the same thing about a break in period for tubes along with how long after power up does the amp sound really really good. My Gold Lions are still at the break in stage but I distinctly remember the Tung Sol KT-120's I had before seemed to become magical after about an hour of listening after they were broken in. The sound became more natural and more open and more three dimensional while listening. 30 years ago I would have attributed it to marijuana but I haven't consumed a mind altering substance in a long time so it must be the tubes.


    Last edited by Dogstar on Mon Jan 16, 2017 10:52 pm; edited 1 time in total
    avatar
    Kentley

    Posts : 436
    Join date : 2015-03-06
    Age : 65
    Location : Worcester, MA

    Re: Order of priority

    Post by Kentley on Mon Jan 16, 2017 10:40 pm

    It was deepee, not I, who said {and it doth pain me in turn to admit his rectitude} "A caveat: judge no power tube until you've run it at least 100 hours. They all sound crappy straight out of the box."
    As a semi-repentant tube-roller, I wholeheartedly concur with Dogstar and deepee. The art of judging the suitability of any given tube in any given position is a Fine Art with many red herrings and false positives. Add to this the fact that every tube is different, even those from the same manufacturer; even those from the same batch. That's what tube matchers are for. Some are better than others.
    Knowing when to roll and when to stop rolling (Keep them Tubies Rollin') is only learned through experience mixed with common sense. And Passion. But only so much of that....


    Last edited by Kentley on Mon Jan 16, 2017 11:25 pm; edited 1 time in total

    Dogstar

    Posts : 288
    Join date : 2014-06-23

    Re: Order of priority

    Post by Dogstar on Mon Jan 16, 2017 10:54 pm

    Sorry about the incorrect credit...it was the way I edited the text.

    Anyway....I figure maybe another 20 hours or so before my Gold Lions are broken in...
    avatar
    Kentley

    Posts : 436
    Join date : 2015-03-06
    Age : 65
    Location : Worcester, MA

    Re: Order of priority

    Post by Kentley on Mon Jan 16, 2017 11:39 pm

    Yer a gentleman an' a skawler, Dogstar. I just wish you'd stop being so Sirius. Wink

    Dogstar

    Posts : 288
    Join date : 2014-06-23

    Re: Order of priority

    Post by Dogstar on Tue Jan 17, 2017 11:36 pm

    Kentley wrote:Yer a gentleman an' a skawler, Dogstar. I just wish you'd stop being so Sirius. Wink

    Good one Kentley...and thanx for the compliment.

    Sponsored content

    Re: Order of priority

    Post by Sponsored content


      Current date/time is Thu Nov 23, 2017 5:00 am