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kentforbes
New Username: kentforbes
Post Number: 1 Registered: 1-2008
| Posted on Sunday, January 20, 2008 - 10:11 pm: | |
Has anyone added a tube to the F-1X? My idea is to simply connect another 12AX7 pin-to-pin using a stand-up tube socket. Any advice is greatly appreciated. Thank You |
davehouck
Moderator Username: davehouck
Post Number: 6056 Registered: 5-2002
| Posted on Monday, January 21, 2008 - 6:44 am: | |
Hi Kent, welcome to the board. As far as I can recall, no one has posted anything like that to the board before; so my guess is that none of the members here have done it. I'm not an electronics person, so I have to ask what such a modification would do, and what effect it would have on the existing circuits. Since you own both an F-1X and an F-2B, I'm guessing you know what these are worth on the used market. And my guess would be that such a modification would significantly reduce the market value. I'm guessing that the reason you are wanting to do this is that you prefer the sound of your F-2B, but like the added features of the F-1X, such as the effects loop, direct out, and crossover. In my own rig, I run my effects between the preamp and the power amp; I've added a direct out before the power amp; and I've added a crossover (ELF) before the power amp as well. Since the circuits in an F-1X and an F-2B are not the same, my guess is that adding a second tube pin-to-pin is not going to give you an F-2B tone. But again, I'm not an electronics person, and I have no idea what this modification would do to the tone or the circuits. The F-1X page at the main Alembic site says that the preamp's input is "buffered by a cathode follower tube circuit, which is a unity-gain impedance matching amplifier to feed the guitar level effects loop" and that this circuit "gives minimum loading on the output signal from the guitar while driving the effects loop gear with the same signal voltage level as the guitar but at a lower impedance, to isolate cable and other loading effects from the guitar pickups". The other half of the tube provides the preamp's gain; and then "a solid state circuit restores the signal level after the volume control and provides impedance matching to drive the full range output jack on the rear panel". So, not being an electronics person, I have no idea how a second pin-to-pin tube would affect those circuits. There are some other members here who are knowledgable about electronics; hopefully one of them may see this thread an offer some helpful advice. |
gtrguy
Intermediate Member Username: gtrguy
Post Number: 123 Registered: 9-2004
| Posted on Monday, January 21, 2008 - 11:35 am: | |
I have both also. My F2B has been modded to cascade one tube into another if I so desire using the other input jack. It looks like an easy mod. All it does is allow the tubes to overdrive more. It really doesn't do that much as far as I am concerned for the sound of a guitar (not like a Mesa!). Both these are really designed right off an older Fender tube pre amp design (with a printed board) and as such should not be too hard to change around. However, they do what they are supposed to do quite well. Dave |
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