Orange Micro Terror tube swap

RVA

RVA

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This is fun to do since there is only one tube to swap!

Anyway, this amp came with a JJ EC83-S. It was too dark for me. I tried the following, in order of preference:

Mullard 12AX7 - good but not all that much different. I bit mellower with lower output. The gain suffers

Sovtek 12AX7 - bright and loud. This gave the amp more of a "modern" sound

Tung-Sol 12AT7 - Yes!!! Strong mids, clear highs that were not too bright and balanced low end - and loud! This tube had at least as much as the Sovtek, and maybe even a bit more.
 
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A while back, I had half a dozen tubes which I tried in two behringer OD pedals - they all sounded crap in both...

But, the micro terror seems like a perfect swap out platform.

Don't forgot the sound clips...:D
 
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Mr Grumpy said:
A while back, I had half a dozen tubes which I tried in two behringer OD pedals - they all sounded crap in both...

But, the micro terror seems like a perfect swap out platform.

Don't forgot the sound clips...:D
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I was too lazy. I started this project at 10:30 pm, which is why you got my insightful descriptions.
 
Tony M. said:
Hmmm...
Maybe I should play swapsies with
the first tube in my Supro Comet.
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Do it! It is fun and cheap. Do a little reseach about what tubes provide the most color to your amp. I think V1 and the phase inverter are important, but I ambasing this info on my Marshall
 
V1 is more than likely the key.
If you put a JJ in a Princeton it's like
removing the blanket it was under.

The comet sounds different, bigger than it is..
It's 6/14 watts but instead of the usual pair of
EL-84s, the guys at Supro put in a single 6L6.
 
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RVA said:
Tung-Sol 12AT7 -
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12AT7's are a very interesting tube. They have a gain factor of 60, compared to the 12AX7's gain factor of 100. But an 12AT7 produces 10x the current of a 12AX7. This is one of the reasons why the AT's are consistently used as a Reverb driver tube. Depending on the style of the phase inverter circuit in certain amps, a 12AT7 swap will induce a bit more headroom with plenty of signal to push the power tubes.

Personally, I don't have any 12AT7's as a Phase Inverter tube. This is all info that I've read up on thru the years.

While you're at it, you should try a 5751 tube. Those are just like 12AX7's but a gain factor of 70.
 
syscokid said:
12AT7's are a very interesting tube. They have a gain factor of 60, compared to the 12AX7's gain factor of 100. But an 12AT7 produces 10x the current of a 12AX7. This is one of the reasons why the AT's are consistently used as a Reverb driver tube. Depending on the style of the phase inverter circuit in certain amps, a 12AT7 swap will induce a bit more headroom with plenty of signal to push the power tubes.

Personally, I don't have any 12AT7's as a Phase Inverter tube. This is all info that I've read up on thru the years.

While you're at it, you should try a 5751 tube. Those are just like 12AX7's but a gain factor of 70.
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Is the fact that 12AT7 produces more current safe for an amp with 1 preamp spot, like the Orange MT?
 
RVA said:
Is the fact that 12AT7 produces more current safe for an amp with 1 preamp spot, like the Orange MT?
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That's a good question, and it's beyond my knowledge to say that it is safe. But... I'm guessing that the greater current translates to a stronger signal level. It's not like it's introducing crazy voltages down the line. I think it's safe... :hide:
 
RVA said:
I listened to my track again. No more singing for me!!
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Don't be too harsh on yourself; you did a much better job of it than I'd do. Plus, you're making music - that's always good. Plus, singing is just another skill, like guitar playing, to practice and improve.
 
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Mr Grumpy said:
Don't be too harsh on yourself; you did a much better job of it than I'd do. Plus, you're making music - that's always good. Plus, singing is just another skill, like guitar playing, to practice and improve.
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Thanks Mr. G!
 
FRom what I understand a 12AT7 there is more likely to not be a good idea.
I dont know that circuit.
Agree with above,
I do know that the 12AT7 is more suited as a driver type tube and commonly used in reverb stages and pulls a lot more current.
I do know that the 12ax7 compatible / ok to swap includes the 5751 and 12ay7.
Personally, I wouldn't do it without more analysis and understanding of that circuit and the available current specs of the PT.
 
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jtcnj said:
FRom what I understand a 12AT7 there is more likely to not be a good idea.
I dont know that circuit.
Agree with above,
I do know that the 12AT7 is more suited as a driver type tube and commonly used in reverb stages and pulls a lot more current.
I do know that the 12ax7 compatible / ok to swap includes the 5751 and 12ay7.
Personally, I wouldn't do it without more analysis and understanding of that circuit and the available current specs of the PT.
Click to expand...
I have read that they are swappable, but maybe I will switch to second best. Thanks.
 
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