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    6SL7 for Dynaco amp?

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    snav

    Posts : 18
    Join date : 2011-05-18

    6SL7 for Dynaco amp?

    Post by snav on Mon Jun 09, 2014 11:12 pm

    Found a bunch of these. Any use for dynaco? Seems like a higher gain 6sn7? I thought I read somewhere they were used in some Dynaco tube designs.

    MontanaWay

    Posts : 767
    Join date : 2014-02-06
    Age : 58
    Location : Cameron, Montana

    Re: 6SL7 for Dynaco amp?

    Post by MontanaWay on Mon Jun 09, 2014 11:18 pm

    snav wrote:Found a bunch of these. Any use for dynaco? Seems like a higher gain 6sn7? I thought I read somewhere they were used in some Dynaco tube designs.

    there is an optional octal 6SN7 VTA driver board for the ST70 or ST120 available through the Tubes4Hifi we page.
    People have different opinions about the 6SN7, some say they are no different to say using the 12AU7 VTA, some say they prefer the 6SN7.
    A very important thing to keep in mind is that the 6SN7 does draw more current, having said that, the ST70 & ST120 power supplies can handle that, although for the ST70, the copper top WZ38 rectifier is better suited to handle that extra current draw.
    I am running a ST120 with the 6SN7 VTA board and so far I it sounds great. Is it better than the 12AU7's on my ST70?, so far I cannot really tell any difference.
    The Tubes4Hifi SP14 preamp also uses the 6SN7's.

    snav

    Posts : 18
    Join date : 2011-05-18

    Re: 6SL7 for Dynaco amp?

    Post by snav on Mon Jun 09, 2014 11:48 pm

    But nothing Dynaco designed to use the 6SL7? I will put them in my sell bin.

    sKiZo

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

    Re: 6SL7 for Dynaco amp?

    Post by sKiZo on Tue Jun 10, 2014 12:07 am

    I seem to remember someone tried it with good results. You can get adapters to plug an 8 pin tube into a 9 pin socket, but I expect there was also some pin swapping inside the adapter involved as they're made for an ECC40 application.


    stewdan

    Posts : 160
    Join date : 2010-03-07
    Age : 78
    Location : Houston Texas

    Re: 6SL7 for Dynaco amp?

    Post by stewdan on Tue Jun 10, 2014 7:54 am

    Hi Snav --- there was a commercial venture about 6+ years back (I don't remember the Brand Name) which marketed an all octal replacement board for the Dynaco ST70 and used 6SN7 - 6SL7 - 6SN7 tubes. At that time, octal 6Sxx tubes were plentiful and very cheap on the e-site which might have explained the board's existence.

    Then I saw someone on another Forum used the 6SN7 - 6SL7 combo and built a hard wired (no PCB) homebrew board for his Mk IIIs. (There is someone on this forum who uses Octal front-end tubes on his Mk IIIs ... don't remember his name though.)

    For what it is worth. I quess the answer to your question is Yes, they are useable on Dynacos, but not as standard fare. As a side note, the 6SN7 type tubes were used by Heathkit in several of their amps and actually sounded pretty good.
    Stew

    zx

    Posts : 194
    Join date : 2011-08-05

    Re: 6SL7 for Dynaco amp?

    Post by zx on Tue Jun 10, 2014 10:10 am

    Dynacos, but not as standard fare............stock input tubes 7199,6AN8 are the only tube i would say are standard fair......right?
    6SN7s have big tone.....sound great as input tubes....An as preamp tubes....i got in to the 6SN7 in the with my frist Atma-Sphere OTL tube amps thats all Ralph uses to drive his amps an preamps.................
    The 6SL7 have more gain...it sounds nothing like the 6SN7 to me.....
    Cary used just one 6SL7 as a driver in some older amps....


    Thanks for the site Bob.................

    arledgsc

    Posts : 330
    Join date : 2012-11-30
    Location : SF Bay CA

    Re: 6SL7 for Dynaco amp?

    Post by arledgsc on Tue Jun 10, 2014 10:18 am

    sKiZo wrote:I seem to remember someone tried it with good results. You can get adapters to plug an 8 pin tube into a 9 pin socket, but I expect there was also some pin swapping inside the adapter involved as they're made for an ECC40 application.

    Been using the 12AU7/6SN7 adapter for over a year in the center position of the ST120.  Works great and love the sound if you have the vertical clearance.  Just search Ebay "6SN7 12AU7 adapter".  Be sure to get the right flavor - 8 pin on top/ 9 pin on the bottom and 6.3V version.  The same adapter will work for 12AX7/6SL7 needs as well.  I can highly recommend the experience.

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    MontanaWay

    Posts : 767
    Join date : 2014-02-06
    Age : 58
    Location : Cameron, Montana

    Re: 6SL7 for Dynaco amp?

    Post by MontanaWay on Tue Jun 10, 2014 11:03 am

    so apart from higher gain, is the 6SL7 and direct drop in for the 6SN7?, if yes, might do some tube rolling on my ST120 with the octal VTA.

    tubes4hifi
    Admin

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    Re: 6SL7 for Dynaco amp?

    Post by tubes4hifi on Tue Jun 10, 2014 11:36 am

    same pin out, but the higher gain, and the tube characteristics are different enough that you would need to make a lot of resistor changes for it to work correctly

    zx

    Posts : 194
    Join date : 2011-08-05

    Re: 6SL7 for Dynaco amp?

    Post by zx on Tue Jun 10, 2014 5:07 pm

    Cary has a old amp.......Sweet 807 that uses one 6SL7 for ea ch.....
    Vary cool setup with a pot to bal any make 6SL7 that you may have......old are new....
    For years on most my tube amps i have been useing this stand by setup.... works great to get the tube hot befor you hit them with the B+......

    Ck this out the manual.....page 10 gives you a look.....at B+V an Rs used.....

    http://caryaudio.com/pdfs/manuals_archive/sweet807.pdf


    Thanks for the site Bob...........................

    snav

    Posts : 18
    Join date : 2011-05-18

    Re: 6SL7 for Dynaco amp?

    Post by snav on Fri Jun 13, 2014 3:00 pm

    zx wrote:Cary has a old amp.......Sweet 807 that uses one 6SL7 for ea ch.....
    Vary cool setup with a pot to bal any make 6SL7 that you may have......old are new....
    For years on most my tube amps i have been useing this stand by setup.... works great to get the tube hot befor you hit them with the B+......

    Ck this out the manual.....page 10 gives you a look.....at B+V an Rs used.....

    http://caryaudio.com/pdfs/manuals_archive/sweet807.pdf


    Thanks for the site Bob...........................

    Interesting circuit, Are two rectifiers in parallel a low cost version of a more powerful rectifier or to get lower loss?

    zx

    Posts : 194
    Join date : 2011-08-05

    Re: 6SL7 for Dynaco amp?

    Post by zx on Fri Jun 13, 2014 3:36 pm

    The 807 is a vary cool tube.....in the 80s less than $2.pr tube....I just retube a VTL 807 amp for a guy.....807 has a sweet tone...to day new tubes are only $7.ea.....not minny 807 amps around...
    this Cary setup is nice ....less is more.....you see theres NO choke...i have pulled the chokes out of my MK3s ....best sound i have ever got out of the MK3s...chokes can sound good but i have not found any that sound as good as no choke......for less than $80-100ea.....an need to be 5-10h...an not room on the old Dynacos for this....an your right on a two ch amp two rectifiers would work better.....Some of my Eico tube amps have no chokes....an thay have great tone...gofig


    Thanks for the site Bob.......................

    sKiZo

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

    Re: 6SL7 for Dynaco amp?

    Post by sKiZo on Fri Jun 13, 2014 7:21 pm

    arledgsc wrote:
    Been using the 12AU7/6SN7 adapter for over a year in the center position of the ST120.  Works great and love the sound if you have the vertical clearance.  

    Is that a Mullard ECC32 you're running? Neet bottle ... be a nice match for my GZ37 rectifier.

    Was looking into a Full Music 6SN7 a bit back ... few hundred bucks cheaper anyway ...

    arledgsc

    Posts : 330
    Join date : 2012-11-30
    Location : SF Bay CA

    Re: 6SL7 for Dynaco amp?

    Post by arledgsc on Sat Jun 14, 2014 12:12 pm

    sKiZo wrote:
    arledgsc wrote:
    Been using the 12AU7/6SN7 adapter for over a year in the center position of the ST120.  Works great and love the sound if you have the vertical clearance.  

    Is that a Mullard ECC32 you're running? Neet bottle ... be a nice match for my GZ37 rectifier.

    Was looking into a Full Music 6SN7 a bit back ... few hundred bucks cheaper anyway ...
    It is a Sophia Electric 6SN7 which looks exactly like the TJ Full Music 6SN7.  I have both and they sound OK after 50-100 hours of burn in time.  My favorite new stock of the 6SN7 types is the Black Treasure CV181Z.  I could go on and on about the BT virtues in the ST-120 but it has bested any other tube tried in the center position including NOS of all types.  The BT CV181Z is an even larger bottle and takes a LONG time to burn in but well worth the wait.  PM me if you want more detail on each type.

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