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    New to the Forum & new owner of a ST-120; Tube questions

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    DavidR

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    New to the Forum & new owner of a ST-120; Tube questions

    Post by DavidR on Wed Aug 16, 2017 11:06 pm

    Hi may name is David and a happy new owner of a VTA ST-120.

    I was wondering if there's a thread on Tubes 101.

    What's good (brands) - what's not, what's a waste of money, burn-in, etc.
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    peterh

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    Re: New to the Forum & new owner of a ST-120; Tube questions

    Post by peterh on Thu Aug 17, 2017 3:06 am

    Always buy tubes from someone with good reputation and that has a good warranty policy.
    Don't buy from 'bay or markets, this will keep your amp troublefree.
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    Peter W.

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    Re: New to the Forum & new owner of a ST-120; Tube questions

    Post by Peter W. on Thu Aug 17, 2017 9:01 am

    Peter H. has given you the best short answer possible. And the best for a newbie of any nature.

    There are much longer answers that will be meaningful if you get much deeper into the hobby and start to DIY past the most basic levels. Otherwise, stick with sourcing from a reputable dealer and follow the advice you get from that source. A reputable dealer will *NOT* try to up-sell you or push you in a direction you do not want to go. And he will stand behind his goods. After all, he wants you back.

    wildiowa

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    Re: New to the Forum & new owner of a ST-120; Tube questions

    Post by wildiowa on Thu Aug 17, 2017 9:14 am

    I can only tell you what I have found works best for me. I try to buy the best brand I can afford, and today's popular opinion is that the Gold Lion brand seems to fill that bill. You can chase old stock but the price varies wildly and you don't know what you've got....I have bought matched quads from Jim McShane in Chicago, a well known and trusted tube guru, and I have bought a matched quad from another seller with good reviews and a bit cheaper price. Jim sells premium stuff, and you get a lot of support if you need it, but Jim knows he's the best and charges accordingly...a bit more, in other words. You can save a few bucks on the internet if you want to look around.

    I have a Citation II and have lost a couple of KT88's for various reasons. Not sure if it was a tube failure or something internally started it, hard to tell when the fireworks begin. It goes with the territory.

    I don't know much about the Sovteks, other stuff on the market. I have some old original Gold Lions from the 60's and those seem to be highly regarded...working with Don Sachs and other rebuilders those seem to be what they prefer, even though they are Russian now, I believe.

    Have fun!
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    Dave_in_Va

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    Re: New to the Forum & new owner of a ST-120; Tube questions

    Post by Dave_in_Va on Thu Aug 17, 2017 9:27 am

    If the VTA is new and came with tubes, I wouldn't do anything. Let the amp settle in for a couple of months.
    It's tempting to start trying different tubes but you run into potential problems with the tube sockets if you don't retention at every swap.
    Just enjoy it as is for a while.

    If you didn't buy it with tubes, probably getting a quad from Mr. McShane would be a safe bet. Asking for opinions about new production tubes on the internet is kind of like asking people what their favorite color is. Also, I believe there are only a handful of factories worldwide making all of these different brands.
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    slate1

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    Re: New to the Forum & new owner of a ST-120; Tube questions

    Post by slate1 on Thu Aug 17, 2017 9:36 am

    Dave_in_Va wrote:If the VTA is new and came with tubes, I wouldn't do anything. Let the amp settle in for a couple of months.
    It's tempting to start trying different tubes but you run into potential problems with the tube sockets if you don't retention at every swap.
    Just enjoy it as is for a while.

    If you didn't buy it with tubes, probably getting a quad from Mr. McShane would be a safe bet. Asking for opinions about new production tubes on the internet is kind of like asking people what their favorite color is. Also, I believe there are only a handful of factories worldwide making all of these different brands.

    ^^^ What Dave said....

    I recently received my ST-120 as well and have prior experience with KT88/6550 tube amps - this is by far the finest sounding amp I believe I have ever owned. I'm thoroughly enjoying it! Astoundingly, it's also the first tube amp that I don't feel compelled to start rolling tubes through.

    If you got the "stock" tubes, keep them for a while, they are very very good. You may find something in the future that you like better, but my bet is the rate of return you get for the investment would be minimal.

    Dogstar

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    Re: New to the Forum & new owner of a ST-120; Tube questions

    Post by Dogstar on Thu Aug 17, 2017 11:34 am

    Greetings. I bought my VTA ST-120 built by Bob Latino a few years ago. Included were Sovtek KT-88's which I used for 3 or 4 months while the amp was 'settling in'. They worked fine and I still have them but I did switch to TungSol KT-120's. I also have a quad of Genelex Gold Lion KT-88's.

    Despite what was said about buying from a reputable dealer and avoiding eBay many here have purchased NOS tubes from eBay. Personally, even though I do possess a few NOS tubes I too would still to reputable dealers.
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    DavidR

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    Re: New to the Forum & new owner of a ST-120; Tube questions

    Post by DavidR on Thu Aug 17, 2017 12:11 pm

    Thanks for all the answers. My amp is used but just trying to get an understanding about Brands and Sellers. It came with new Sovtek 6550 output tubes.

    Tube Depot has been suggested as a good source and VacuumTubes.net. I bought a pair of NOS Sylvania 6SN7 tubes for a tube buffer off of eBay and they are very good tubes. No issues with them but will stay away from here on out based on your input.

    What are some good NOS Brands for driver tubes?
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    peterh

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    Re: New to the Forum & new owner of a ST-120; Tube questions

    Post by peterh on Thu Aug 17, 2017 12:29 pm

    DavidR wrote:Thanks for all the answers. My amp is used but just trying to get an understanding about Brands and Sellers. It came with new Sovtek 6550 output tubes.

    Tube Depot has been suggested as a good source and VacuumTubes.net. I bought a pair of NOS Sylvania 6SN7 tubes for a tube buffer off of eBay and they are very good tubes. No issues with them but will stay away from here on out based on your input.

    What are some good NOS Brands for driver tubes?
    For your VTA-120 ; use the driver tubes bob recommends ( and sells). I assume you got
    3 with the kit and are using them now. Good choice !
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    deepee99

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    Re: New to the Forum & new owner of a ST-120; Tube questions

    Post by deepee99 on Thu Aug 17, 2017 1:11 pm

    DavidR wrote:Thanks for all the answers. My amp is used but just trying to get an understanding about Brands and Sellers. It came with new Sovtek 6550 output tubes.

    Tube Depot has been suggested as a good source and VacuumTubes.net. I bought a pair of NOS Sylvania 6SN7 tubes for a tube buffer off of eBay and they are very good tubes. No issues with them but will stay away from here on out based on your input.

    What are some good NOS Brands for driver tubes?
    Hi, David, and welcome.
    As others have said, I would suggest listening to what you've got for a month or two before even considering doing any tube-rolling. Bear in mind that a new tube, whether NOS or brand-new, needs about 50- 100 hours on it before it's fully blossomed. And it takes about that long to get used to its sound and decide whether you like it or not. Don't expect conclusive results in five hours, or even 10, whether the tube was built in 1950 or 2017. Then, if you're not happy, a few suggestions:
    Firstly, NOS tubes, unless you really know what you're doing, can be hugely over-priced as you're competing with collectors who will out-bid you on FleaBay. Reputable and honourable dealers in new stock are limited; Jim McShane (jimmcshane@mcshanedesign.com) is your best bet. Straight shooter.
    For NOS, there are only two I know of worth of an email or phone call:
    First is Andy Bowman : http://vintagetubeservices.com/
    Do not email him, he won't answer, just go to his website and phone him up. He doesn't do email.
    Second would be Koray Kural: sales@nostubestore.com
    Koray is in Turkey so shipping is a bit slow, but he's an honourable guy with a huge post-War inventory at decent prices.
    Enjoy! Tubes are our "tone controls" and you'll find something just right for you.
    Dave




    Jim McShane

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    Re: New to the Forum & new owner of a ST-120; Tube questions

    Post by Jim McShane on Thu Aug 17, 2017 1:44 pm

    wildiowa wrote:I can only tell you what I have found works best for me. I try to buy the best brand I can afford, and today's popular opinion is that the Gold Lion brand seems to fill that bill. You can chase old stock but the price varies wildly and you don't know what you've got....I have bought matched quads from Jim McShane in Chicago, a well known and trusted tube guru, and I have bought a matched quad from another seller with good reviews and a bit cheaper price. Jim sells premium stuff, and you get a lot of support if you need it, but Jim knows he's the best and charges accordingly...a bit more, in other words. You can save a few bucks on the internet if you want to look around.

    Well, thank you for the vote of confidence, but I regularly shop my competition and price accordingly.

    There is one tube vendor (excluding eBay; for a variety of reasons I don't compete with them) in particular that has very competitive prices on the new production tubes. But when you read closer you see that there is an extra charge of $6.00 per quad for 24 hour burn in of the tubes. I do not charge extra for burn in . So I would just like to mention that when shopping for tubes be sure to compare "apples to apples".

    I'd be interested in what tubes you find my prices are out of line on - thanks.

    wildiowa wrote:I have a Citation II and have lost a couple of KT88's for various reasons. Not sure if it was a tube failure or something internally started it, hard to tell when the fireworks begin. It goes with the territory.

    FYI - there is an issue with some Citation II amps where intermittent failure of the bias supply occurs. It may only fail briefly then resume working; or it may fail for a longer time. The cause is a solder joint inside the transformer that is part of the bias winding (see picture below). This solder joint work hardens over time and goes intermittent. If the tubes in the amp are exposed to the loss of bias they are often damaged and more prone to failure in the future even if they seemed to be okay after the incident. We have a little kit that addresses this without having to have the power trafo rewound. I discovered this a few years ago and found that once the bias is working reliably and the tubes in the amp haven't been stressed by intermittent bias failures the Genalex KT-88 reliability is really good. The failure rate is just a tiny fraction of a percent.


    And of course poor socket to tube pin contact can always be an issue.

    wildiowa wrote:I don't know much about the Sovteks, other stuff on the market. I have some old original Gold Lions from the 60's and those seem to be highly regarded...working with Don Sachs and other rebuilders those seem to be what they prefer, even though they are Russian now, I believe.

    The consensus seems to be that the current production Genalex are every bit as good - and some say better - as compared to the original 1950s - 1960s Genalex/Gold Lion or Gold Monarch tubes. If you want KT-88s for your VTA or other amp this is my #1 recommendation.

    A small aside - you may not know that Don Sachs got his start as my bench tech. I had a waiting list for my bench that was likely 3-5 years long - that's TERRIBLE customer service! So when I was able to hook up with Don in about 2008 it made possible a great improvement in customer service with top quality workmanship. Don still does my Citation bench work and he's now branched out into other areas as well. He is a huge fan of the KT-88 Genalex as well.

    I hope Bob doesn't mind this reply on the forum even though it isn't 100% VTA related.
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    DavidR

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    Re: New to the Forum & new owner of a ST-120; Tube questions

    Post by DavidR on Thu Aug 17, 2017 2:57 pm

    @Jim McShane: I have your website in my Bookmarks Wink

    wildiowa

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    Re: New to the Forum & new owner of a ST-120; Tube questions

    Post by wildiowa on Fri Aug 18, 2017 12:46 am

    Jim...Easy man! I first got in touch with you I believe back in 1997, pre Don, when you were doing stuff out of your place in Chicago. Actually talked to you a couple of times as you were THE Citation II man...but then you got very very busy....I even offered to drop my Cit II by personally when I drove thru Chicago but you were overwhelmed. Literally, years passed..then you told me to call Don. He rebuilt my Cit II, I sent him another core I found, we've kept in touch and he is also The Man. Since then I have purchased ALL my tubes from you but admit, strayed one time to check out a guy who had a Gold Lion quad online. My point was, if you want service, matching, confidence etc etc, buy from you. Or you can maybe save a buck or two if you want to take a chance. I frankly don't know how you compare price-wise, I am not down in the weeds that far...but for what little $$ difference there is I buy from you, and I recommend others do as well...there!

    Working with Don, I installed the mod you refer to which I think involved adding a separate toroidal transformer to power the bias circuit...I just did what you guys told me and it worked well. Since then, a stable and dependable amp, no tube meltdowns.

    Just trying to contribute what i can for the cause.
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    arledgsc

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    Re: New to the Forum & new owner of a ST-120; Tube questions

    Post by arledgsc on Fri Aug 18, 2017 9:33 am

    Gold Lion KT-88s are my favorite of that model of tube.  But I prefer KT-120s in my ST-120 amp.  Either case Jim McShane is my man for power tubes.  Jim knows Bob's amps and matches the tubes accordingly.  His prices are extreme competitive and takes care of warranty issues straight away.

    Had pretty good luck buying preamp tubes from different sources.  But I've also had to eat tubes purchased on Ebay as you usually get no warranty.

    But let the amp run in with the Sovteks while you figure out what to try next.  You will be confused on true amp sound until it breaks in.
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    DavidR

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    Re: New to the Forum & new owner of a ST-120; Tube questions

    Post by DavidR on Fri Aug 18, 2017 10:30 am

    Thanks for the responses.
    Just to reiterate: My query was not for info to be doing tube rolling. I just want to know the ins and outs of tubes before I need them. At some point I will need to replace them and I don't want to be scrambling to understand tubes then. I've received some good info. Smile

    I like the Sovtek 6550. Nice ballsy sound in the bass and lower mid, clear and fluid.

    Biggest interest is in replacement of driver tubes. GE, RCA, Sylvania, Gold Lion, etc NOS brands? Seems like so many to choose from; even types/styles within each brand. The seller of my unit recommends using the 12AU7A on the two outside tubes and a 12BH7A for the center.

    Remember, I don't know much about these.
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    Dave_in_Va

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    Re: New to the Forum & new owner of a ST-120; Tube questions

    Post by Dave_in_Va on Fri Aug 18, 2017 11:05 am

    The reason you're getting all kinds of comments and answers is that there is NO answer. You just have to try different tubes and see what you like.

    The good news is that 12AU7's and 12BH7's are really, really inexpensive tubes even new in box NOS stuff. Usually around $5.00 more each than new production. (unless, of course, you're looking for some kind of exotic tube only produced for one year for French submarine telecommunications gear).

    As a vague generalization, most people like RCA clear top 12AU7's. They're about $20-$25 each.
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    arledgsc

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    Re: New to the Forum & new owner of a ST-120; Tube questions

    Post by arledgsc on Fri Aug 18, 2017 11:21 am

    You have to discover what works best for you and yes there are many, many choices.  Some suggested tubes did not work in my setup and for my tastes.  But for starters the center tube has the most affect on sound so you can start there.  But I can tell differences in the outside and power tubes as well.  I found combos of new production tubes that absolutely beats any NOS in my stock.

    So is your ST-120 used and already broken in?    

    But it is daunting and I had to try many tubes to settle on what I like.  And if you ask each member of the forum they are going to all list different tubes and types they prefer.  That was the initial confusing part for me.  There is no definitive "golden" set of tubes that works for everyone.  And we are here for help.. just ask!
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    deepee99

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    Or . . .

    Post by deepee99 on Fri Aug 18, 2017 11:46 am

    You could go bug-nutty and install an octal driver board, which uses 6SN7/CV-181/6H8C type tubes. The drop-in is fairly simple. There are a number of guys on the forum here who can build the board for you, or you can do it yourself. Roy Mottram has a stock of them, and I think so does Don Sachs.
    I personally prefer the sound of the octals over the novals you've got, but it's a Ford-Chevy thing. No other circuit changes are needed; filament volts and draws are the same, so are the other values.

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    DavidR

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    Re: New to the Forum & new owner of a ST-120; Tube questions

    Post by DavidR on Fri Aug 18, 2017 11:59 am

    arledgsc wrote:You have to discover what works best for you and yes there are many, many choices.  .................................... 

    But it is daunting and I had to try many tubes to settle on what I like.  And if you ask each member of the forum they are going to all list different tubes and types they prefer.  That was the initial confusing part for me.  There is no definitive "golden" set of tubes that works for everyone.  And we are here for help.. just ask!

    You are correct. We all have ears but they are all different. I hope I didn't open up a can of worms.
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    arledgsc

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    Re: New to the Forum & new owner of a ST-120; Tube questions

    Post by arledgsc on Fri Aug 18, 2017 12:21 pm

    DavidR wrote:You are correct. We all have ears but they are all different. I hope I didn't open up a can of worms.

    No, we are an open forum but full of knuckleheads and break out into electronic fist fights occasionally. About every six months this question comes up and everyone is eager to help. Welcome to the forum BTW!
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    deepee99

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    Re: New to the Forum & new owner of a ST-120; Tube questions

    Post by deepee99 on Fri Aug 18, 2017 12:24 pm

    arledgsc wrote:
    DavidR wrote:You are correct. We all have ears but they are all different. I hope I didn't open up a can of worms.

    No, we are an open forum but full of knuckleheads and break out into electronic fist fights occasionally.  About every six months this question comes up and everyone is eager to help.  Welcome to the forum BTW!  

    Consider this the FaceBook for geeks.
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    DavidR

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    Re: New to the Forum & new owner of a ST-120; Tube questions

    Post by DavidR on Sun Aug 20, 2017 2:44 pm

    Electro-Harmonix Gold or Genalex Gold Lion for 12BH7A tube ?
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    deepee99

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    Re: New to the Forum & new owner of a ST-120; Tube questions

    Post by deepee99 on Sun Aug 20, 2017 2:58 pm

    DavidR wrote:Electro-Harmonix Gold or Genalex Gold Lion for 12BH7A tube ?
    David, ask Bob L. or Jim McShane on this one. I'll take the Gold Lions from Jim McShane any old day, but Bob may have some NOS that are just as good or better.
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    DavidR

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    Re: New to the Forum & new owner of a ST-120; Tube questions

    Post by DavidR on Sun Aug 20, 2017 3:07 pm

    Thanks for the reply. I think I goofed when searching the web early this a.m.
    I don't think Genalex makes a 12BH7 now that I re-look.
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    Dave_in_Va

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    Re: New to the Forum & new owner of a ST-120; Tube questions

    Post by Dave_in_Va on Sun Aug 20, 2017 4:38 pm

    Aren't Genelex tubes the same Russian tubes from the same factory that makes several brands?

    As far as I know these brands (Mullard, Tung-Sol, Genelex) have absolutely nothing to do with the the original companies.

    Correct me if I'm wrong but aren't there only three tube factories? One in China, one in Russia and one in the Czech Republic (or somewhere in eastern Europe)?

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    Re: New to the Forum & new owner of a ST-120; Tube questions

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