OK- my surmise was correct- you have a lot of gain with that amp. If you want the Modwight to work you will have to hand-pick the 6SN7s for low noise. This should not be that challenging- we use 6SN7s in all of our line stages and can get them to be nice and quiet on speakers that are much more efficient than yours!
I would also listen to the character of each preamp and see which you prefer. Generally speaking I find that I like 6SN7-based circuits better as they are usually smoother without lacking detail. But that is not always the case so you will want to play them and see which you like other than the noise.
If the Modwright comes out on top then you might want to consider some boutique tubes for it- hand picked by Andy at Vintage Tube Services or maybe Sophia or TJ Music tubes; Kevin at Upscale is a good source too. However you do it the tubes should be returnable if there is a problem.
Have fun! but don't drive yourself nuts- different tubes sound different and some people go right down the rabbit hole with this and trust me on this one, its not worth it! You want to solve the problem you have and spend the money left over that you didn't spend on 50 other types of tubes just getting more tunes to play :)
I would also listen to the character of each preamp and see which you prefer. Generally speaking I find that I like 6SN7-based circuits better as they are usually smoother without lacking detail. But that is not always the case so you will want to play them and see which you like other than the noise.
If the Modwright comes out on top then you might want to consider some boutique tubes for it- hand picked by Andy at Vintage Tube Services or maybe Sophia or TJ Music tubes; Kevin at Upscale is a good source too. However you do it the tubes should be returnable if there is a problem.
Have fun! but don't drive yourself nuts- different tubes sound different and some people go right down the rabbit hole with this and trust me on this one, its not worth it! You want to solve the problem you have and spend the money left over that you didn't spend on 50 other types of tubes just getting more tunes to play :)