Preamp tubes

[gritstogroats]

Anyone find they prefer 12at7 ecc832 or 12au7 instead of 12ax7 in preamp? Or why someone might want to try something else?

Pretend i am as dumb as I look.

standard boilerplate response seems to be reduce gain or gain clarity.
- if there is less gain factor. Doesn't that mean it will max out gain easier and get dirtier?
-or like the ecc832 is medium/high gain with its weird setup so more clarity and gain or wildcard?
-is this PI position the only one worth replacing or any worth in replacing all12ax7s?
-is this benefit more for amps that do the marshall cathode thing vs the fender other thing? Or in general a clean amp? Is this just mysticism and if a tube besides 12ax7 was best a company would already have it in use?

I had some grievances with fender blues and marshall 2203. At least on the 2203. Replacing the PI with 12at7 sounds better to my ears. Its almost singing. Boost and mr scary much better too!

For all I know its not even the tube change. The fx loop was fucked up when i unboxed this new amp. Maybe something was loose and I fixed it by accident. Or moving the amp 0.5 inches removed a buttloat of EM/WIFI interference.

Fender blues deluxe tube made no difference. Medium Alnico ii bridge pickup and scumback speaker did what I wanted.

For fun: dual rec. Other tubes nothing good. Mr scary was ok it was good or bad depending on what you were wanting. It cut some presence altered eq. Low gain good. Unit might be microphonic it made noises noisegates wouldn't stop when gain cranked (does not happen otherwise)

Headfirst has been interesting. Took ecc832, 12au7 12at7 and/or mr scary mod like a champ (except high gain in plexi mode when the stock boost and bright cap engaged. it also made that weird sound....). I like stock. Just interested in what these things can do and push it.

Its been cool to get sounds I cannot get from eq pedal or cannot exactly get from pedals. That marshall singing got me all hot and bothered with just the 12at7. Are my ears deceiving me or is there something to this rabbit hole? And is there any guide to the questions I asked way above?

 

[S̷͖͑m̵͎͂á̵̺s̸͚̈́h̴̬̑]

I would recommend not doing that and just buying silver dragons. They have a lot of clarity, low microphonics and are still high gain

 

[Alpha Stryke]

Nope. Gain factor 100 Mr. Zulu.

 

[dstroud]

I like 12at7 in some instances. My understanding is they are about 60-70% the gain of a 12ax7 - won’t harm the amp in any way. To my ears they can be less fizzy, better mids and a “cleaner” distortion if that makes sense.

 

[gritstogroats]

I would recommend not doing that and just buying silver dragons. They have a lot of clarity, low microphonics and are still high gain

Whats a silver dragon?
And why not recommend? Is it not worth it or something else in your opinion?

Im fairly sure i have no issues with microphonics. When i say im getting feedback ive done cranked everything to 11.

 

[gritstogroats]

Nope. Gain factor 100 Mr. Zulu.

ok so 100 nemoys is the max.

Or are you saying for real the 100 gain factor is sort of the pinnacle and my initial paragraph was wrong

 

[gritstogroats]

I like 12at7 in some instances. My understanding is they are about 60-70% the gain of a 12ax7 - won’t harm the amp in any way. To my ears they can be less fizzy, better mids and a “cleaner” distortion if that makes sense.

It does. It seems to make my marshall sing and headfirst it does some stuff.

I just dont understand what amps it is helpful for though. So far 2203/2204 circuits, the PI mostly.

My take away so far is its nothing to obsess about and its probably really complicated what works and what doesnt for a person's taste.

 

[Alpha Stryke]

ok so 100 nemoys is the max.

Or are you saying for real the 100 gain factor is sort of the pinnacle and my initial paragraph was wrong

 

[gritstogroats]

Thanks.
Is there any general rule of thumb how to best use these bad boys?

I would have thought clean fender, id notice a lot more than the marshall using a 12at7 instead of 12ax7. Chat gpt is sort of helping me navigate. The other tubes may add bounce. Stiffness. Reduce fizz. Add other eq. Add clean headroom. It depends on the spot and the circuit.

And my 12dw7 is a freak.

maybe a better question for you and others. Generally are these drop in replacement for 12ax7 or do I need to worry/adjust anything?

 

[fek]

I have used JanGE 5751's in random preamp spots over the years. Worked well in some spots with some amps, and not so well in others. In general regardless of whether they are in V1 or the PI for example, they can cut some fizz, gain, increase clarity, etc... Depending on what you want more or less of out of an amp, it is worth it to do some testing with what you have.

Examples: a 5751 in the PI of a Randall RM100 added some clarity and allowed the module gain to run higher without falling apart. I also tried a 5751 in a few different positions of a 5150III 50W El 34 and a Stealth. Just sounded and reacted slightly different and worked at the time for what that did.

IMHO, fairly cheap mod to try out and see what that gives you.

 

[Dave L]

as far as I know, all the gain factor tells you is how much it amplifies, that is how hot the signal coming out of it is for any given circumstance, bias and such. Want a little less somewhere in the circuit, stick in something else than a 12AX7. In the PI spot you end up slamming the power tubes less, and it basically boils down to where the amp saturates by design.

 

[gritstogroats]

I have used JanGE 5751's in random preamp spots over the years. Worked well in some spots with some amps, and not so well in others. In general regardless of whether they are in V1 or the PI for example, they can cut some fizz, gain, increase clarity, etc... Depending on what you want more or less of out of an amp, it is worth it to do some testing with what you have.

Examples: a 5751 in the PI of a Randall RM100 added some clarity and allowed the module gain to run higher without falling apart. I also tried a 5751 in a few different positions of a 5150III 50W El 34 and a Stealth. Just sounded and reacted slightly different and worked at the time for what that did.

IMHO, fairly cheap mod to try out and see what that gives you.

Appreciate it. Yeah my big concern is something bad will happen to the tube socket or something else important. Outside of that it seems just fine and is an accessible mod.

Im now more comfortable and am having a blast. V1 v2 v3 v4. Many choices. Its cheaper than a new amp.

I learned yesterday for some reason my 2203x is like, pretending I put a nois3 gate in its effects loop. I thought something happened making it sound shitty that was ..like real. This was just super weird. And I also learned 12au7 is good on v1 of my headrfirst amp. ECC832 IS great v1 for marshall. And I can't wait to open up some of my other amps. I decided I want to find the best clank for metal music and tweak that high end sound.

 

[Alpha Stryke]

Thanks.
Is there any general rule of thumb how to best use these bad boys?

I would have thought clean fender, id notice a lot more than the marshall using a 12at7 instead of 12ax7. Chat gpt is sort of helping me navigate. The other tubes may add bounce. Stiffness. Reduce fizz. Add other eq. Add clean headroom. It depends on the spot and the circuit.

And my 12dw7 is a freak.

maybe a better question for you and others. Generally are these drop in replacement for 12ax7 or do I need to worry/adjust anything?

Same pinout direct replacement just lower gain. No worries.

 

[311boogieman]

I have used JanGE 5751's in random preamp spots over the years. Worked well in some spots with some amps, and not so well in others. In general regardless of whether they are in V1 or the PI for example, they can cut some fizz, gain, increase clarity, etc... Depending on what you want more or less of out of an amp, it is worth it to do some testing with what you have.

Examples: a 5751 in the PI of a Randall RM100 added some clarity and allowed the module gain to run higher without falling apart. I also tried a 5751 in a few different positions of a 5150III 50W El 34 and a Stealth. Just sounded and reacted slightly different and worked at the time for what that did.

IMHO, fairly cheap mod to try out and see what that gives you.

This is what I came to say...very low noise/high clarity ratio.

 

[Beyond Black]

12AT7/AU7 work great in amps that are overly compressed/gained.
I’ve used them in a JSX, XXX, and EVH amps for that reason with excellent results.
I usually have a Tung Sol in V1 and used those in V2,V3 or both.