Lowest gain best sounding preamp tube?

[talltxguy]

I understand that certain preamp tubes have more gain than others:
(tube) (gain)
12AX7 100
5751 70
12AT7 60
12AY7 45
12AV7 41
12AU7 19

Bill M, the guy who does the Fender mods, said that only the 12AX7, the 5751, and the 12AT7 are worth putting in the preamp slots. The other preamp tubes, he said, just don't sound that good.

I'm looking for a preamp tube with the lowest gain but one that still sounds respectable. According to Bill M, my best bet is the 12AT7.

I've got an HT Distortion pedal that I want to use not for distortion so much as a way to warm up a Digitech GSP 1101. I already tried a 5751 in the pedal, which worked great for my distorted tones but made playing clean tones absolutely impossible - even with the gain barely activated on the pedal, I still couldn't cop a convincing clean tone.

Anybody know if Bill M is right about the 12AT7?

Thanks for any ideas,
Scott

 

[thunda1216]

the 5751 is not going to sound very different from the 12ax7, maybe slightly less gain. The 12at7 will probably have noticeably less gain, but the tube flows a lot more current than the 12ax7 and the 5751. In the end, only your ears will tell if it is what you are looking for.

 

[94Tremoverb]

I would have to say I think he's wrong on two counts (maybe three).

First, I don't think the 12AT7 sounds very good as a 'gain stage' tube, especially not early on. It's great as a phase inverter, and can work well later in the amp, but to me it sounds cold and sterile as a V1 tube.

Second, not only does the 12AY7 not sound bad, it's the *best* sounding of the whole lot, to me - unless you want maximum gain and harmonic distortion. It was the tube Fender used as V1 in most of their 50s Tweed amps and still sounds great today if you want a cleaner, clearer sound.

And the 12AU7 is a very good-sounding tube too - true, it has so little gain that it's not enough for many amps, but it has great tone - very clear and clean - and can be useful in amps which have far too much gain as stock... a good example is the Peavey Classic 20.

I also personally tend to find 5751s quite shrill and harsh-sounding, but it may be just the particular ones I've tried (which is not many).

The only 12AV7 I tried sounded good but was very microphonic, so I don't have a real opinion on those.

 

[talltxguy]

Thanks for the replies. With respect to Bill M, I reread the article he wrote and he said the following:
"12AT7s are almost indistinguishable from the stock 12AX7s. You can go a notch or so higher in clean volume, but they sound just like the 12AX7s in breakup. The 12AV7s and 12AY7s are much more noticeable in terms of availability of clean headroom, but the 12AY7 is the better choice because its higher internal impedance doesn't dull the tone as much as the 12AV7."

"The 12AU7 is so quiet that it's not worth bothering with--unless you want a low-volume practice amp that only plays clean."

So yeah, I misquoted him in my initial post. Sorry about that - wasn't trying to stir up anything.

Tremoverb, between what you said and what Bill M said, I'm thinking the 12AY7 is the best option for me.