Preamp tube that gives most clean headroom.

[Dr. Jimmy]

I'm using a Delta Blues 1x15 clean channel only. I use a Blues Driver to obtain my gain tones, and switch that off for cleans. Obviously I'd like the amp to be as clean as possible as a foundation for the pedal as well as for it's own clean (think clean funk rhythm) sound.

One of the things I've noticed with the amp is that once I turn up past 2 it starts to get loud (and this is at gigs or rehearsal with a full band). 2 is too quiet, 3 is too loud kinda thing. So for laughs I dropped a 5963 in V1 to drop the gain a little. This seems to work in the sense that I have more control over the volume, I can run the amp around 4 or 5 and still have room either way before being too loud or too quiet. However I think the cleans are not as clean as I'd like them.

Am I approaching this the right way? Should I go with a tube with a little more gain, like say a 5751? Am I asking the impossible?

What say you knowledgeable folk?

Thanks!

 

[J M Fahey]

Preamp tubes do not give you more or less headroom, only more or less gain.
So if with one tube amp distorts "on 3" and with other " on 6" , it only means the second one has less gain, you can achieve the same by lowering the volume pot setting.
The actual power output, sound pressure, presence in the band mix, etc. will be exactly the same.

 

[Steppin' Wolfe]

Dr Jimmy, ime, you are going about things properly. Ime,a 12AY7 in V1 works wonders in that amp. The sweep can be extended on up the dial....anywhere you want it. As Mr. Fahey noted...when we use a lower gain tube, what we are doing is simply reducing the ultimate gain. The sweep of that volume pot with a 12AY7 allows one all of the gain that is needed there--imho, great cleans, and a much more precise usage of the volume pot. Also, the reduced gain in the first stage affects the sound of the overdrive functions...makes them more usable, imho..because these are single channel amps that stack gain for the overdrive. FWiw, the circuit is somewhat like the 5F6A BAssman....and that 12AY7 is what Fender put in those amps.

 

[Blue Strat]

Another vote for a 12AY7. A 5963 ( 12AU7) typically has too little gain in guitar amps...though if it's working for you it might be "the one". A 5751 probably has too much gain to help you. A 12AY7 could be just right.

 

[billyguitar]

I think every amp sounds better with a 12AY7 in the first position!

 

[Guinness Lad]

Part of the problem is with the taper of pots. Seems like almost any amp is like this, 1 nothing, 2 loud, 3 to 6 louder than 2 slightly, beyond 7 amp gives out.

I wish they could make the taper between 1 to 4, more like 1 to 7. My Rivera is less hyper sensitive than just about any other amp I can think of, not sure why.

 

[DaveKS]

Well to me, don't judge all the 12au7 family by a 5963, their about the worst sounding of them all. If you wanna stay in that gain range try a RCA 5814a, much brighter, clearer and more articulate and often a hint more gain than most of the 12au7.

But yea try a 12ay7. It's one step up on gain factor over 12au7, good old GE won't set you back much.

Another affordable option to try would be to go to Eurotubes and get a JJ ecc823, it's a reverse wired 12dw7, v1a is a 12ax7 half, your guitars input stage, v2b is a 12au7, it's what drives your tone stack. Your guitar will see a 12ax7 just as it always has but then you have a warmer, lower gain triode driving the tone stack.

 

[Dr. Jimmy]

Good info guys!!! Looks like I'm going tube shopping. Any preferred ay7 (along with the aforementioned GE)?

 

[DaveKS]

Sylvania are my favs, but getting hard to find.

These are best ever, but their like hunting unicorns these days.

 

[Sean French]

I think every amp sounds better with a 12AY7 in the first position!

A Marshall doesn't.

 

[Aaron Mayo]

To m

Preamp tubes do not give you more or less headroom, only more or less gain.
So if with one tube amp distorts "on 3" and with other " on 6" , it only means the second one has less gain, you can achieve the same by lowering the volume pot setting.
The actual power output, sound pressure, presence in the band mix, etc. will be exactly the same.

Yup. Clean headroom=power. Doesn't matter what the knobs say. More efficient speaker would help.

 

[Dr. Jimmy]

Looking into an ay7 now. Any difference between those and the 6072? Blackplate vs. grey???

 

[IM4Tone]

My preference is for a 5751 in V1. I don't want absolute, pristine clean. If I did, I'd get a solid state amp for a pedal platform. Edge of breakup in a tube amp is a good basis for OD pedals IMO.

 

[logdrum]

Linear pots, get audio taper pots

 

[michael.e]

I like the lower gain factor of at's and ay's, but they typically don't sound as "full" as an ax7. Can somebody point me to one that does?

 

[IM4Tone]

I like the lower gain factor of at's and ay's, but they typically don't sound as "full" as an ax7. Can somebody point me to one that does?

5751

 

[DaveKS]

Looking into an ay7 now. Any difference between those and the 6072? Blackplate vs. grey???

6072 just military 12ay7, sometimes extra support rods etc to rugidize them.

All makers did that transition from black to grey as they tried to improve their formula, better cleaner audio reproduction was the goal along with better life. So usually black plate will be early 50's (or earlier) to 1960'ish models. To my ears as far as guitar use, they usually seem a little more "ragged around the edges" for lack of better way to describe it, slightly less smooth and neutral.

 

[soundchaser59]

I think every amp sounds better with a 12AY7 in the first position!

That's just the extra straw I needed to push me into trying it. searching now for 12AY7's for sale.....

 

[jlinde]

Another vote. Ge makes a great cheap 12ay7.

 

[Guinness Lad]

12ay7 tubes are only good if you want cleans, if you don't however they are not the best choice. To make a blanket statement like this is a huge stretch.