What are mods you can do to ANY valve amps?

[Pott]

And that won't mess up the whole circuit...? Just curious as to what can be universally changed everywhere in a valve amp.

Right now I can think of the preamp tubes' cathode resistors perhaps? Lower value for a bit more gain (where a foostwitchable one may become a simple gain boost), bigger for more headroom and dynamics?

[Buffaloamps]

What kind of amp are you working with?
What exactly is it that you want your amp to do or not do?
How much electronic knowledge/experience do you have?

I don't want this to sound like this is a members only club to work on the inside of an amp, but if you don't know what you're doing, you can potentially injure or even kill yourself by poking inside. But if you're confident enough to work on one, then I would suggest picking up one of Gerald Weber's books for starters. He has some great tips and tricks for amp electronics. "The Ultimate Tone" book by Kevin O'Conner is an excellent source for mods and tricks to hot rod your amp.

When you ask for "universal" mods that can be done to an amp, that pretty much sums up to different tube swaps. But going inside will take much more thought and planning depending on the circuit type and what you want to accomplish.

I hope this helps.

Good luck,

Rob

[Blue Strat]

Generalizations are dangerous in virtually all aspects of life.

Do you have a specific amp or intentions in mind?

[Pott]

Nope. This is just curiosity. I have built one amp that works fine, I want to do more but I'm without an income so it's not for now... I just enjoy reading theory about things and other things basically. This is not for immediate practice work, though I have worked with high voltages. I rebiased my first valve amp on my own without having anyone showing me, I got hooked since.

[John Phillips]

Old-production tubes :).

There is nothing else I can think of which will universally improve tone.

If you want bigger headroom and better dynamics, start with military-spec old-production power tubes, and high-quality preamp tubes, possibly lower-gain types such as 5751s, 12AT7s or 12AY7s in specific places.

[Pott]

I didn't necessarily mean improve the tone... that's very much subjective to a big extent. I meant mostly change.

[Blue Strat]

I didn't necessarily mean improve the tone... that's very much subjective to a big extent. I meant mostly change.

So you'd rather make the tone worse?


Just kidding:)

[TubeBy12]

Other than tubes/speakers/cabinets, how about upgrading output transformers and clipping bright caps? I am not an amp tech, by the way, but I did stay at a Holiday Inn Express last night.:)

[Blue Strat]

Other than tubes/speakers/cabinets, how about upgrading output transformers and clipping bright caps? I am not an amp tech, by the way, but I did stay at a Holiday Inn Express last night.:)


These are actually excellent answers to the original question. Wish I had thought of them. Then there are speaker and tube changes (mentioned earlier in the thread).

[TheAmpNerd]

For me,

I'm a power supply guy. Upgrade the power supply for the amp
on which you are working. It is not glorius, but it IS very affective.

Thanks to Todd and John for their excellent post I'm definitely going
to be milspecing all they modern Fender amps for their voltage drop
resistors feeding the channel switching zeeners.

Finally once the amp is electrically and functionally sound, I upgrade certain components including caps and resistors in the signal chain that
have a over all affect on tone, sensitivity, and responsiveness.

[TheAmpNerd]

For me,

The Foundation First
I'm a power supply guy. Upgrade the power supply for the amp
on which you are working. It is not glorius, but it IS very affective.

The Function Second
Thanks to Todd and John for their excellent post I'm definitely going
to be milspecing all they modern Fender amps for their voltage drop
resistors feeding the channel switching zeeners.

The Final Third
Finally once the amp is electrically and functionally sound, I upgrade
certain components including caps and resistors in the signal chain that
have a over all affect on tone, sensitivity, and responsiveness.