Tube Question – Replacing a 12AX7 with a 12AT7

[treyhaislip]

Re: Tube Question – Replacing a 12AX7 with a 12AT7

Re: Tube Question – Replacing a 12AX7 with a 12AT7

Update, the 12AT7 came in and I swapped it in for the first position 12AX7. Used it live on Sunday and was super happy with the results! My clean channel is able to be turned up to around 5. Really happy with the tones at the volume levels. The regular drive ("More Drive" turned off) sounds more bluesy with my Eastman E8D and Bill Lawrence A300 than it did before.

Question though, when on the drive channel with "More Drive" its like super hot...like volume at 2 and almost too loud. I was able to have it around 3 before the switch and it wasn't this loud on the drive channel (using the same guitar, Fender Strat with Fat 50s.) My Hot Rod Deluxe is a '95, which I believe is the first year it came out, and has been used and abused. I had it worked over by a local amp company that modded the drive channel to get more of a Mesa type drive...so maybe something is going on there or maybe its just a worn amp that needs some more work or something.

Any ideas on the super loud "more drive"?

 

[dystrust]

Re: Tube Question – Replacing a 12AX7 with a 12AT7

Re: Tube Question – Replacing a 12AX7 with a 12AT7

My guess is a loss of compression from the lower gain preamp tube. It's possible that your 'mesa mod' influences this as well, but I don't know the HRDx well enough to comment further.

 

[treyhaislip]

Re: Tube Question – Replacing a 12AX7 with a 12AT7

Re: Tube Question – Replacing a 12AX7 with a 12AT7

My guess is a loss of compression from the lower gain preamp tube. It's possible that your 'mesa mod' influences this as well, but I don't know the HRDx well enough to comment further.

I appreciate the feedback! The handle is broken on the amp so I need to take it back to the shop to get a beefier fix on it–I will inquire about the volume issue then...oh and the Reverb quit working on the amp (not a big problem due to a Holy Grail from forum bro Nostalgic Distortion) but would like to get it looked at as well. The response I am getting on the clean and regular drive are just too good to switch back for normal volume with the More Drive section.

Thanks again!

 

[GuitarDoc]

Re: Tube Question – Replacing a 12AX7 with a 12AT7

Re: Tube Question – Replacing a 12AX7 with a 12AT7

I'm not familiar with the circuitry of your amp, but it could be that the "more drive" doesn't even use the V1 tube and therefore hasn't changed at all. But since your clean is now quieter, the "more drive" sounds louder by comparison.

The 12AT7 makes a great PI tube, by the way.