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Got a NOS GE 12AX7 for my Dem 201s

Discussion in 'Amps and Cabs [BG]' started by lo-freq, Aug 21, 2003.

  1. lo-freq

    lo-freq aka UFO

    Jan 19, 2003
    DFW, Texas
    It's a bit of a long and convoluted story, so I won't go into the details, but my cousin found out I was interested in preamp tubes and sent me one in the mail that he got for free through some line of friends of friends.

    It is a GE 12AX7 that has some redish-orange printing on it with the number 6681 and "Made In USA". I think it's from the 1960s, but I'm not certain.

    It seems to be working fine.

    The tube it replaced was a Mesa-Branded Electro-Harmonix 12AX7EH.

    Compared to the previous tube, it sounds a tad bit cleaner especially in the lower frequencies, speed and punch between the two are very close to the same, midrange is a tad bit more polite (with my bass (SR5), I think that's a good thing), and treble seems to be smoother than the EH. Overall, the GE is more clean & polite sounding with just a bit of a rounder tone. The EH has kind of a in-your-face grindy-wooly-ness to its sound from the lower midrange down that is better for most Rock and Blues. The GE has a better sound in general for just about any other type of music.

    I haven't played live with it yet, so these impressions are just based on listening to it in my house.

    I think it's a keeper though and the price was definitely sweet.
  2. Cool Lo
    I just put some Telefunken NOS Smooth Plates in my Dem last week. I thought I would go for the real thing. They were expensive...but sound very nice and balanced, similar to what you described. NOS tubes are definatley better sounding and supposed to last forever so to speak. I like my EH tubes too, and also liked the JJ set I tired. Both are not as even and "polite" to all the tones as the famed Telefunkens. I recommend them so far as I have not gigged out with them yet either. I can honestly say so far there is not a VAST HUGE difference from current production tubes to my ears at least for bass gear. I do not regret spending the amount I did for the Tele's and I look forward to trying different settings etc. with different speakers. I will receive the Berg NV610 next week and do some playing around. Keep you posted.
  3. lo-freq

    lo-freq aka UFO

    Jan 19, 2003
    DFW, Texas

    Yeah, I'm amazed at how good the EH's sound for Rockier stuff now that I have my tone tweaked out between my SR5 and the 201s. I was tempted to put it back in after listening to the GE.

    I'm about to move back to the Dallas-Ft. Worth metroplex area from where I've been in the sticks of NE TX. Depending on the type of band(s) I land in, I may switch it back yet.

    I bet that NV610 will sound awesome run off your 400+. I'd sure like to hear it.
  4. Maybe you should have those GE tubes tested to see if they are up to snuff...might be worth it.

    I'm sure the 400+ would sound good in just about any cab, but I don't think it has enought nuts to push any of the Bergs except maybe a single 112.
    I'm hoping my Dem/PLX rig will sound superb with this cab.
  5. Something I didn't catch in your original post.
    Although, to my knowledge, there is nothing wrong with mixing 12ax7 pre tubes I didn't realize you had only one NOS tube. You may not be getting the full benefit depending.....
    Also, did you put the NOS in the gain side or the tone side? I'm not that sure if they affect one another. From the front gain is on the left near the volumne know and tone on the right. I should do more experimenting. I know ChuckM does just that. I believe he has a GE or Sylvainia in the gain and a Telefunken in the tone side but both are NOS. Just a thought.
  6. lo-freq

    lo-freq aka UFO

    Jan 19, 2003
    DFW, Texas
    I wasn't sure what the right tube was used for (someone told me it is for the effects loop).

    I just emailed Demeter to find out for sure and here's their reply:

    According to this, the gain and tone are from the left tube.
    I'm not sure what the 'output' above designates; guess I'll email them back. Would that have anything to do with the output to the power amp?

    I had a GT in the right socket and replaced it with the EH that had been in the left socket.
  7. lo-freq

    lo-freq aka UFO

    Jan 19, 2003
    DFW, Texas
    OK, I just got a reply back from my second query (which was concerning the function of the right tube) and here it is.

    I don't know how much tone contribution there is to the second tube (the tube on the right).

    But I know that multiple sources have said that these type of preamps aren't benefited by matched pairs.

    The Dems in particular, I've heard that the tube on the left is the main source of the pre's tone.

    I will experiment with different combinations (I have about five 12AX7's to play with so far and a few old 12AT7's and 12AU7's).
  8. Actually I can get both of my feet in my mouth at once. I was just going by what another had stated on the site. Learn something new everyday!!! let me know the rest.