12AX7 vs 12AT7 vs 12AU7

[goodguy]

Re: 12AX7 vs 12AT7 vs 12AU7

My experience:

Bassman 59' RI (Circa 1992)

Swapped 12AY7 (GT) tube into V1 (in place of the stock 12AX7).

With the 12AY7, the amp had more clean headroom (breakup was not as early as the 12AX7).
Basically, you could turn the volume knob to 3.5 - 4 with the 12AX7's and then start to breakup nicely.
With the 12AY7 you were at 4.5 before any breakup started to occur (so higher volume before breakup).

In theory (please correct me if I am wrong), the advantage of the 12AY7 is: you could gain more clean headroom on the amp -and- if volume wasn't an issue, more of the breakup would come while you were into power tube territory (rather than just preamp tube breakup). So I guess if you were wanting to get to the dirt in a lower volume situation (home, small gigs) then use the standard 12AX7 -but- if you are playing where higher volume is acceptable before you breakup, then the 12AY7 would work well. OR - if you want to get dirt from pedals, then the 12AY7 might be the better way to go. If that makes any sense?

Hope this helps anyone thinking about the swap.

[Bob@Montreal]

Re: 12AX7 vs 12AT7 vs 12AU7

Just did this morning on my Bugera 5w. Amazing difference!! I'm not a big gain user, so the clean given by the AU7 is perfect for what I want. I aim for clean and would rather use pedals for the crunch, reverb ect, (although this little amp has great reverb). I think it all depends on what amp you're using. Worth a try if you get too much gain in your lower setting, though you will lose a bit of output Volume.. Not much to spend..20$. I may pick up a12AY7 just to see the difference.
BTW, for you cash strapped folks..this amp is worth looking into(200$US from Amazonia).
It's a bit of a crap shoot from what I read, in that some are defective right outta the box and have to be returned for a replacement . I found mine 2nd hand so no worries there. Really sweet tone.

Standard American Tele / Ibanez roadstar (1985 model w/ coil-tapped bridge p/u).

[GilmourD]

Re: 12AX7 vs 12AT7 vs 12AU7

[Mr. B]

Re: 12AX7 vs 12AT7 vs 12AU7

It is not a dead topic if people are currently discussing it again... Why do people get their panties in such a wad if people want to revisit an old discussion?

[saxmo]

Re: 12AX7 vs 12AT7 vs 12AU7

The best answer-right below including Gain Factors. For a clear explanation go to thetubestore.com.