Author Topic: Changing the tube in the F1X (Read 526 times)

moongerm · « **on:** November 28, 2014, 07:16:17 PM »

I have been having some noise issues in both of my F1Xs which are indispensable. One tube wound up being microphonic (Sovtek) which I learned later was the case but at first I thought I blew my tweeters or something else was rattling loose somewhere inside the cabinet. A high pitched rattle was occurring when the volume was slightly pushed. The other tube in my 2nd F1X was simply too noisy for recording so I replaced the stock (Ruby) tube as well. I came across a thread that stated the Electro Harmonix 12AX7EH didn't fit inside the metal tube sleeve after I had already bought the tube. To my suprise it did indeed fit after giving it a whirl. The EH tube is quiet and sounds fat. Digging it over the JJ I replaced in my other F1X. I'd thought I'd share this in case anyone has run into both of these issues.

moongerm · « **Reply #1 on:** November 28, 2014, 07:44:45 PM »

I removed the entire metal tube sleeve very carefully.

moongerm · « **Reply #2 on:** November 28, 2014, 07:49:19 PM »

Grabbed the new Electro Harmonix 12AX7EH tube (with clean gloves)

moongerm · « **Reply #3 on:** November 28, 2014, 07:53:45 PM »

Slid the top of the tube into the bottom of the metal sleeve. It had no problems fitting in.

moongerm · « **Reply #4 on:** November 28, 2014, 08:00:29 PM »

Attached the tube to the base carefully first while the sleeve was over the tube then carefully wiggled the sleeve onto the base. Then I extended the sleeve all the way out once it was attached to the base firmly. The base of the sleeve is wider then the top of the sleeve which is also the case with the tube.

sonicus · « **Reply #5 on:** November 28, 2014, 08:26:58 PM »

I prefer the sound from a a smooth plate Telefunken ECC83/12ax7 .

Thank you very much .

moongerm · « **Reply #6 on:** November 28, 2014, 09:00:15 PM »

Would love to try a Telefunken. I just grabbed the eh in a pinch and was pleasantly suprised for $13.00.

(Message edited by moongerm on November 28, 2014)

sonicus · « **Reply #7 on:** November 28, 2014, 10:08:29 PM »

I suppose the $13.00 is nice if the tube makes you happy and has settled the noise issue . We all like different stuff .

moongerm · « **Reply #8 on:** November 29, 2014, 06:13:31 AM »

No doubt Wolf. I brought this up because in another forum when folks were mentioning what tubes they like, the EH came up with positive feedback but that they don't fit. I went to a local store to pick up any decent tube and the EH was all they had in stock. I got home to install it and it wouldn't fit in the sleeve. Determined to see if it would fit before I took it back I was able to remove the sleeve entirely and install it as mentioned above. I guess the point is if anyone wants to try a slightly larger tube perhaps try installing it this way.

jazzyvee · « **Reply #9 on:** November 29, 2014, 06:18:14 AM »

Well timed I've been thinking of changing the tubes in my F1-x's so will see about trying the telefunken and the EH valves.

sonicus · « **Reply #10 on:** November 29, 2014, 07:25:13 AM »

Brain , I think that you did a great job in this thread showing your well thought out technique.

sonicus · « **Reply #11 on:** November 29, 2014, 07:43:42 AM »

A good aspect of the EH valve is that it is a Russian valve. According to a friend of mine who builds valve amplifiers as as business ;___Russian preamplifier valves of this description have a higher envelope vacuum then their Chinese counterparts. The higher envelope vacuum results in a lower distortion rating . That would be good for Bass players wanting a clear sound. The Chinese tubes with a lower envelope vacuum seem to be overdriven easier according to him as well . That might appeal to a guitar player with a desire for that effect.

sonicus · « **Reply #12 on:** November 29, 2014, 07:55:23 AM »

This one , looks interesting to me as well ; a reissue 7025 type .
http://www.thetubestore.com/Preferred-Series-7025-12AX7
I might try this one .

gtrguy · « **Reply #13 on:** November 29, 2014, 10:54:15 AM »

It is hard to go wrong with JJ's! Price, sound, quality, and they fit. I also like trying old tubes to see how they sound, but a new JJ is a safe bet.

pauldo · « **Reply #14 on:** November 29, 2014, 02:17:23 PM »

I agree with Wolf.

Brain,
That was very thoughtful to put together a nice tutorial with decent pictures.

Thanks!