| Author | Message | ||
| moongerm
Junior Username: moongerm Post Number: 33 Registered: 8-2013 |
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
Junior Username: moongerm Post Number: 34 Registered: 8-2013 |
I removed the entire metal tube sleeve very carefully.  | ||
| moongerm
Junior Username: moongerm Post Number: 35 Registered: 8-2013 |
Grabbed the new Electro Harmonix 12AX7EH tube (with clean gloves)  | ||
| moongerm
Junior Username: moongerm Post Number: 36 Registered: 8-2013 |
Slid the top of the tube into the bottom of the metal sleeve. It had no problems fitting in.  | ||
| moongerm
Junior Username: moongerm Post Number: 37 Registered: 8-2013 |
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
Senior Member Username: sonicus Post Number: 3751 Registered: 5-2009 |
I prefer the sound from a a smooth plate Telefunken ECC83/12ax7 . Thank you very much . | ||
| moongerm
Junior Username: moongerm Post Number: 39 Registered: 8-2013 |
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
Senior Member Username: sonicus Post Number: 3753 Registered: 5-2009 |
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
Junior Username: moongerm Post Number: 40 Registered: 8-2013 |
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
Senior Member Username: jazzyvee Post Number: 4314 Registered: 6-2002 |
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
Senior Member Username: sonicus Post Number: 3755 Registered: 5-2009 |
Brain , I think that you did a great job in this thread showing your well thought out technique. | ||
| sonicus
Senior Member Username: sonicus Post Number: 3756 Registered: 5-2009 |
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
Senior Member Username: sonicus Post Number: 3757 Registered: 5-2009 |
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
Senior Member Username: gtrguy Post Number: 810 Registered: 9-2004 |
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
Senior Member Username: pauldo Post Number: 1346 Registered: 6-2006 |
I agree with Wolf. Brain, That was very thoughtful to put together a nice tutorial with decent pictures. Thanks! | ||
| keith_h
Senior Member Username: keith_h Post Number: 2116 Registered: 2-2005 |
To the best of my knowledge all 12AX7 tubes are built to the 7025 specification and have been for many years. However if you are buying new old stock from the 60's this is something to take into account when looking at 12AX7 tubes. There can be quite a bit of variance in tube quality even with the older stuff from the heyday of tubes. Even tubes within the same manufacturing run can vary quite a bit not to mention between manufacturers. This means if you are depending upon a tubes characteristics as part of your sound you should be prepared to try out several tubes. A lot also depends upon the design of the amp. Some amps like those from Eden aren't really affected by the 12AX7 itself as it serves as nothing more than a buffer. For others such as those based on Fender designs the tube can have a dramatic affect since it is part of the gain stage. This variance is one of the reasons sound equipment design using tubes is as much a holistic exercise as an engineering one. Keith (Message edited by keith_h on November 29, 2014) | ||
| sonicus
Senior Member Username: sonicus Post Number: 3759 Registered: 5-2009 |
Here is a must read as part of the terminology such as "MU " differences in currently manufactured 12ax7/7025 ( tubes /valves ). https://www.amplifiedparts.com/tech_corner/12ax7_comparison_of_current_made_tubes | ||
| moongerm
Junior Username: moongerm Post Number: 41 Registered: 8-2013 |
Interesting read Wolf, very informative. I learn so much from all of you the past year or so I have been a member. The F1X is brilliant. I have been playing through a 600 watt class d amp (acoustic image focus 2) for many years because of its flat sound and light weight. But ever since I learned and finally tried out Alembic gear, just over a year ago (Distillate, miss that bass) then a 2nd hand f1x, it warmed up and brought to life what would otherwise be a flat amp that is sterile, in a good way, but sterile nonetheless. I can't play without an f1x now without missing a big part of my tone. Addicted  | ||
| sonicus
Senior Member Username: sonicus Post Number: 3760 Registered: 5-2009 |
Brian , I am pleased if we can all help each other here . Yes , the F1-X is a fine piece of gear. The DI's are also very useful and quiet enough for recording . | ||
| edwin
Senior Member Username: edwin Post Number: 1872 Registered: 5-2002 |
When I had an F1-X, I tried a lot of different tubes. I didn't notice a huge variation in sound, certainly not as much as the F2-B. |
