Tube for an F1-X

[ajdover]

What tube should I buy for an F1-X?  I tried Groove tubes but they're way too wide for the sleeve.  Suggestions?
 
Alan

[elwoodblue]

I remember a post explaining this predicament about a year ago...I'll see if I can find it.

[elwoodblue]

here
 
and here

[hieronymous]

Great detective work elwoodblue! I took a look in the FAQ section - these should definitely go in there!

[elwoodblue]

thanks...using google's advanced search with alembic.com as the domain is a nice a quick way to find these nuggets...(now if I could find some of those other nuggets that easy)
 
kris(the sober one)

[ajdover]

Guys,
 
    Thanks for the help.  I've ordered several tubes (new production Mullard, JJ/Tesla, and a Sovtek) from Tube Depot.  I know the Sovtek should fit, so I'll see if the others do.  Maybe we should do a listing at some time of the tubes that fit the F1-X/F2-B so folks know what to buy when the time comes?  Might come in handy.
 
More to follow,
 
Alan

[elwoodblue]

that'd be good...I have yet to open mine up, I'd like to see how the different ones color the sound as I'm used to the tight pristine sound of how they are now...I always see it as a dark starry night, with fireballs of sound as I play.
 Maybe the mullards would be like a breezy day??...um, I'm a strange one, I'll admit that.
cheers

[wayne]

I'm using 5751 and 12AT tubes.  Both fit much easier than the 12AX7, but have lower gain.  Although, I've had no complaints on the level I can produce with them.
 
I run the neck through the 5751 and the bridge through the 12AT.  Both are more open than the 12AX7 with the 5751 having a bit more bottom than the 12AT (but less than the 12AX7).
 
When I got my F2B I went through an a-b-c trial and found that the 12AX7 sounded loose to me.  So, I have an F1X with a 5751, an F1X with a 12AT, and an F2B with one of each.
 
My 12ATs are NOS Phillips and the 5751 is a new Phillips (I think).
 
FWIW.....
 
C-Ya.........wayne

[elwoodblue]

great info...thanks wayne
I'll have to open both of mine up and try some A/B-ing .
 
I'll post what I find.One I bought used so it might have something different than stock in it.

[mica]

In the How to Change a Tube post in the FAQ, I mention the problem of tube diameter. You can find tubes from every manufacturer that fit, and you can also find ones that don't fit. The ratio of too big to okay size changes over time.
 
I'll ask my dad to reveal the sizing specs so that you can ask your tube supplier to send you something that will certainly fit. Once I get the details, I'll add it to the FAQ for both preamps.

[elwoodblue]

Thanks Mica.
 
it's a treat to have things made easy,

[ajdover]

Got the new Mullard, JJ, and Sovtek from Tube Depot today.
 
Mullard: didn't fit.
Sovtek: didn't fit.
JJ: fit.  Is in the pre as we speak.
 
Alan

[jazzyvee]

I am trying to get the tube out of my F1-x but can't even get the sleeve off. it is well and truly solid and i dont want to just pull and risk breaking the board or a solder joint. any suggestions? can i spray it with Wd40 to loosen it up or will that stuff damage any of the other components.?

[jazzyvee]

Ok done it, the sleeve is in two parts with the top half needing to be slid down to expose the top of the tube. Pulled out easy. phew.

[edwardofhuncote]

Good hint!