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Premium Tubes for ART Pro MPA - KRAAAZY!

Discussion in 'Recording' started by Hawkeye, Sep 20, 2005.

  1. Hawkeye

    Hawkeye Active Member

    Has anybody tried the new JJ Tesla ECC83S tubes yet as a replacement to stock OEM ones?

    I want to replace the tubes in my recently-acquired ART Pro MPA mic preamp. The only experience I've had in "tube rolling" (as the audiophiles refer to it) is replacing the stock tubes in my VTL TL2.5 stereo preamp with NOS Mullard 12AT7's and 12AU7's. BIG difference! Tighter, punchier bass, lowered noise floor, more detail in the treble, overall it was a terrific cost-effective upgrade for my audio system.

    I also replaced the motley collection of tubes in my Ampeg SVT 3 Pro Bass head with new Electro Harmonix tubes and enjoyed a quieter amplifer, with less crispy overdrive and cleaner output.

    I was thinking of trying the new JJ Tesla's as they are supposed to be a modern copy of the revered Telefunken 12AX7's. I was wondering if anybody had an opinion on these tubes or perhaps on another brand that you tried and liked in your ART Pro MPA.

  2. RAIN0707

    RAIN0707 Guest

    I liked Raytheon or Westinghouse 12AT7's in mine.
  3. CoyoteTrax

    CoyoteTrax Well-Known Member

    I like the Tesla/JJ's alot in my Pro VLA. I liked the stock tubes the the Tesla's are a little smoother with more dimension. Very quiet, and the highs are better represented I think.

    If you like the Mullards I may have to give them a try just for the heck of it. I've been a fan of the Tesla ECC83S for a lot of gear though and they do very well in my Pro VLA.
  4. jonyoung

    jonyoung Well-Known Member

    Raytheon 12DF7's, Westinghouse 12AX7's and Mullard 12AT7's. I need one more Pro MPA, too many tubes and not enough channels!
  5. CoyoteTrax

    CoyoteTrax Well-Known Member

    Looks like I'm going to have to try the Raytheon's and the Westinghouse tubes. Thanks guys.

    Anyone try the GT Gold series tubes in their ART Pro series stuff yet? Cucco says they're great tubes but I haven't heard of anyone using them in a Pro VLA or MPA yet.
  6. Hawkeye

    Hawkeye Active Member

    I knew this would happen, more choices! Hmm jonyoung has it right, must get more channels, Try them All! BWaHaHahaha.
  7. jonyoung

    jonyoung Well-Known Member

    Ooops, got my Raytheons and W'houses mixed up. The W'houses are the 12DF7's........but good luck finding any, I think I got the last 2 in existance.
  8. Hawkeye

    Hawkeye Active Member

    I see some 12AU7's and 12AT7's suggested here. Using my limited understanding of these things, don't the AU's and AT tubes have a lot less gain than a 12AX7?

    If so, is there sufficient overall gain in the preamplifier to make them useful without a corresponding increase in noise?

    As it is, I've ordered a couple of the JJ Tesla ECC83S but am interested in understanding what the effects of these different specification tubes would be.

    While I'm thinking about it the ART Pro MPA is specified with 12AX7A tubes. I'm substituting 12AX7's (without the "A" suffix).

  9. CoyoteTrax

    CoyoteTrax Well-Known Member

    Right. AT7's put out around 70% of the gain as AX's; and AU's around 50% I think. That's what helps change the tone so dramatically but at the same time reduces noise.

    The Tesla/JJ's are 12AX7's, they're just called ECC83S's. So you're getting the same gain levels with them a 12AX7 gives you, but smoother and more balanced (IMO). More of an audiophile-type performance.
  10. Hawkeye

    Hawkeye Active Member

    Thankx, that seems to echo what I've heard before.

    Here's a good table on the differences between the aX7 type tubes.


    ECC83 is the European nomenclature for the 12AX7. 12AX7A can be used in parallel or series circuits, the 12AX7 in parallel filament series circuits only. Ohhh.
  11. jonyoung

    jonyoung Well-Known Member


    I haven't had any trouble using 12AX7's instead of 12AX7A's. Any AX7 category tube has a gain factor of 100, the DF7's and AT7's are 70. They're much easier to use on vocals due to the lower gain. It's almost impossible to drive one into distortion, as well as being warmer sounding.
  12. Hawkeye

    Hawkeye Active Member

    Good info JY. I can see what you're saying about the 12AT7. To back up your story from the bass world, players who use Traynor's new YBA-200 all tube bass head are saying that replacing the 12AX7 with a 12AT7 gives them the opportunity to play cleaner and louder before the circuit distorts because of the lower gain.

    With the ART Pro, I plan to experiment tracking Elec Bass Guitar and don't mind if I can get some overdrive on the sound, so for now I'll stay with 12AX7's. My Focusrite Trakmaster give me a pretty clean DI bass sound. I'll see if the ART can give me something different. I think it will.
  13. jonyoung

    jonyoung Well-Known Member

    Hmmmmmm.....I'm a bassplayer myself, got a "94 Trace Elliot combo rig with 2 10's, and a tube preamp. Gonna have to pop an AT7 in there! That's what I've been using for tracking, it has an XLR pre out on it.
  14. CoyoteTrax

    CoyoteTrax Well-Known Member

    Hawkeye, if you're talking about the ART Pro VLA then expect good results. It does a great job limiting bass.

    Try cascading channel 1 into channel 2 for some even cooler effects; i.e., limit one channel and compress the next or whatever.
  15. Hawkeye

    Hawkeye Active Member

    Hi Coyote Trax, I'm actually talking about the Pro MPA but I've got my eyes open to pick up a VLA also. It just seems like a natural pairing with the Pro MPA. That would give me two different flavours of mic pre and two different flavours of compressor.

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