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12AX7 vs 12AU7

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I prefered the AX7B (first one). I just thought it sounded more smooth and I preferred the less gritty sound. I think that valve also suites your playing style better in terms of the sounds it yields are excellent for blues

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I prefered the AX7B (first one). I just thought it sounded more smooth and I preferred the less gritty sound. I think that valve also suites your playing style better in terms of the sounds it yields are excellent for blues

Thanks krock for your input. Did the 12AU7 sound louder, more gain as well? I'm experimenting with different valves with this Persuader Pedal.

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Thanks krock for your input. Did the 12AU7 sound louder, more gain as well? I'm experimenting with different valves with this Persuader Pedal.

 

Yeah I definitely thought the AU7 had more gain and way louder, it made your mic clip. Experimentation is always good, that's how you learn what best suits you. Were you playing a les paul? Oh and I forgot to mention, great chops

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Yeah I definitely thought the AU7 had more gain and way louder, it made your mic clip. Experimentation is always good, that's how you learn what best suits you. Were you playing a les paul? Oh and I forgot to mention, great chops

Thanks mate. I was playing through a Fender Strat with a set of custom shop 69 pickups.

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The AX7 seemed to have a better tone in my opinion, as mentioned previously it was has less grit.

 

However, the AU7 seemed to be at a louder volume, without switching any settings. Could this be why it seemed to have more bite? If the volume was rolled off a bit on the unit, would it sound nice and smooth too?

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Hard for me to tell without the same volume. Of course the 12AU7 was louder and the 12AX7 was a Chinese tube.

 

They make some different tubes for the 12AX7, but I saw none for the 12AU7, as of now.

 

http://www.sweetwater.com/store/search.php?s=12AX7+tubes

 

Chinese tubes usually be rated the worse, and of course there was a Russian tube also somewhere, but then I just did a quick search at Sweetwater.

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I liked the 12au7 tube .more of a overdrive sound, thanks for showing that , I'm not big on pedals , the only one I have is a vox satchurator distortion pedal , but after seeing the persuader , its a must have for me , [thumbup]

Glad my video was helpful. Yes, the Persuader is a great pedal indeed. I'm trying to get a 6189 preamp tube and see how that one would fair.

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The AX7 seemed to have a better tone in my opinion, as mentioned previously it was has less grit.

 

However, the AU7 seemed to be at a louder volume, without switching any settings. Could this be why it seemed to have more bite? If the volume was rolled off a bit on the unit, would it sound nice and smooth too?

I didn't want adjust the controls as I wanted to show how the tone of the pedal can be greatly effected by simply swapping out the tubes instead of modifying the pedal internally. Just swap out the tube on the fly, then instant tone and dynamic response change.

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Pedal sounds great! I find it very odd though that the 12AU7 is louder since they have about 20% of the gain of a 12AX7. [confused] Either something is wrong with the 12AX7 or the pedal's circuit is compensating somehow. To me the first tube was what I would expect from a 12AU7 and the second a 12AX7. Strange. Sounds great either way though!

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Pedal sounds great! I find it very odd though that the 12AU7 is louder since they have about 20% of the gain of a 12AX7. [confused] Either something is wrong with the 12AX7 or the pedal's circuit is compensating somehow. To me the first tube was what I would expect from a 12AU7 and the second a 12AX7. Strange. Sounds great either way though!

Hmmm......now you go me thinking if my pedal is working properly. I will shoot another demo.

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Pedal sounds great! I find it very odd though that the 12AU7 is louder since they have about 20% of the gain of a 12AX7. [confused] Either something is wrong with the 12AX7 or the pedal's circuit is compensating somehow. To me the first tube was what I would expect from a 12AU7 and the second a 12AX7. Strange. Sounds great either way though!

 

 

What's probably happening is that the kit is designed for the AX7, a high gain, low current tube. When you drop an AU7 in it, which is low gain and high current, it's probably way over biased.

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What's probably happening is that the kit is designed for the AX7, a high gain, low current tube. When you drop an AU7 in it, which is low gain and high current, it's probably way over biased.

I agree-

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Ok, I did another video, This time, I swapped in a different RCA 12AU7. The pedal seems to break up like an old Marshall plexi when it is cranked to full volume and at the verge of failure....something what Hendrix would appreciate.

 

http://www.youtube.com/watch?v=Ijl7hhqiTL4

DUDE!! That was COOL!!

 

Now, I wonder what a 12at7 would do. And a 5751. Heck, I wonder what a GOOD (RCA?) 12ax7 might do.

 

There are limits, right? I mean, could you slam it with a high gain signal (compressor set loud?) and not fry something?

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Ok, I did another video, This time, I swapped in a different RCA 12AU7. The pedal seems to break up like an old Marshall plexi when it is cranked to full volume and at the verge of failure....something what Hendrix would appreciate.

 

http://www.youtube.com/watch?v=Ijl7hhqiTL4

 

[thumbup]

 

That's the stuff right there. Awesome.

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DUDE!! That was COOL!!

 

Now, I wonder what a 12at7 would do. And a 5751. Heck, I wonder what a GOOD (RCA?) 12ax7 might do.

 

There are limits, right? I mean, could you slam it with a high gain signal (compressor set loud?) and not fry something?

I haven't tried it with the 5751, but I find that tube, I will certainly plug it in. Yes, there are no limits with this pedal IMHO.

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just to add to the confusion ,this is out of a old training manual-

 

There are several different tube numbering systems that you may see on tubes, which generally are a result of where they were built. Most commonly the numbers contain digits only (e.g. 5751), or are some combination of numbers and letters (12AX7, ECC83, CV4004). These different numbering systems may be from the American or British military, or from American or European industrial or consumer use, and then of course there are many strange exceptions. But to use the notation commonly seen in the United States, here is the meaning of "12AX7":

12 - the filament voltage

AX - an arbitrary model number

7 - the number of internal elements, including the filament

To make things more complicated, many tubes have letters after the name, such as 6L6WGB, 6L6GC. Sometimes these letters mean functionally nothing (design revisions) and sometimes they refer to different voltage capabilities of a given type.

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