Micro Terror Tube Swap

Discussion in 'The Squawk Box' started by moses, Apr 16, 2013.

  1. moses

    moses Member

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    I play a lot of micro venues, mostly with acoustic guitar and banjo run through LR Bagg Para DIs into a board. However I have been really getting into electric stuff recently, bought an Epi LP Standard and rewired the whole thing with SD SH-55s. Totally pleased with the result.

    now to the amp bit

    For the money the Micro Terror seemed to solve all of my problems perfectly. Super small so it fits in all the venues I play, still has some tubeness, etc. etc. and when I first got it I was pretty pleased. However i'm a blues guy, and I found that i couldn't really turn the gain knob past 12 o'clock without getting into some not so bluesy territory.

    Quick swap of the preamp tube 12ax7 to the 12at7 and i couldn't be happier. The gain knob now gives me usable amounts of crunch and cleans throughout the whole sweep and it seems to have warmed up the tone quite a bit.

    Anybody else play around with the tube in these things?
     
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  2. nutsauce

    nutsauce Senior Member

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    That's something I've been meaning to try but just haven't gotten around to it. Thanks for your input!! That little amp gets loud doesn't it?
     
  3. moses

    moses Member

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    No kidding! I'm getting another ppc108 so that it has a touch more low end and is pushing at 4 ohms. And I just can't imagine I will need something bigger for the clubs I play. I'm really happy with how the tube swap turned out.
     
  4. romsquiz

    romsquiz Senior Member

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  5. moses

    moses Member

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    That was a bunch of great info. But I still don't quiet understand it. So the 12at7 has less gain which is what I want, but has way more TC and is running 10 times the milliamperes.

    What does that mean for signal and tone? The paper said that it means you need more front end signal to get the same output. Does that mean I would need less volume to achieve the same result with a 12ay7 versus a 12at7

    Thanks for helping a nube:) this is totally blowing my mind.
     
  6. Neemo

    Neemo Senior Member

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    you can try upgrading the speakers too

    I switched to a tungsol 12ax7 and it resulted in a little bit more headroom and a bit smoother gain, i didnt try at7's or ay7's

    2 ppc108s makes a huge difference imo over one...i swapped for 2 jensen mod8-20's ($27 ea @ guitar center) brought out more low end, not so shrill
     
  7. romsquiz

    romsquiz Senior Member

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    Well the ol 12AT7 is a popular topic at the mo, I know from trying it myself in V1 it didn't impress me. The 12AT7 is rarely used in a tone-generating stage, but rather in function stages......could be the TC factor. It all depends on what you want to achieve...if you want to knock off the gain a little bit, something like a 5751 or a NOS 12AX7 would do it, or if you want a more definite reduction then a 12AY7 will do it. It's not an exact science unfortunately....tube amps are kinda organic, that's why we luv em!!
     
  8. moses

    moses Member

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    This info is great.

    I have ordered a 5751 and will report back.

    The next purchase after that will be another ppc108. The speaker upgrade suggestion has been noted and appreciated.

    For all of the naysayers I have really been impressed by this little amp. Especially with how easy the upgrades have been to make it even better.
     
  9. TWANG

    TWANG Senior Member

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    12AY7 would work, too.
     
  10. Rhust

    Rhust Senior Member

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    or 12au7.. I put a 12au7 in my HT5 to cut the gain and give the gain a more classic crunch instead of a fizzy gain
     
  11. moses

    moses Member

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    I tried the 5751 and I must say while there were parts of it that were nice, I prefer the 12at7

    First off, it did cut the gain, and had a nice warm tone. However, for whatever reason (i'm sure someone could chime in here) I had to turn the gain up really far (past 12 o'clock) to get even the tiniest amount of break up. At the same point the volume would have to be rather low as this tube made the amp real loud.

    I play mostly micro and small venues, so this wasn't really what i was going for. And I must say that I really like what the 12at7 did for the sound.

    I'll definitely keep it around for shows that require more volume before breakup, but as of right now I really like the sound of the 12at7, even with its higher TC and all of that.

    anybody else done any tube swapping on this amp?
     
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