I thought I'd share a few ideas about setting up tube amps, and share a few things I experiment with to discover how to get 'my sound' out of a new amp.
Most players I talk with start by setting everything at noon, tweak from there, and for that reason never get close to discovering what their shiny new amp can really do. Here's why:
Most (not all) tube amps have passive tone controls. That means all their tone controls do is cut frequencies.
It also means that with the amplifie's tone controls set to noon, it's actually cutting bass, midrange and treble. Amps with passive volume controls have a flat frequency response with the tone controls all the way up.
When we read about legendary Marshall or Black Panel Fender players "cranking" everything to ten on the tone controls, well, they're not. They're simply not cutting any frequencies.
Oh yes, the amp has more gain when it doesn't cut frequencies. Makes sense, right? You're letting more signal reach the power amp.
[There are amps that really are flat with the controls at noon, that boost when the tone control is increased, and cut when it's decreased. If memory serves, some Tweed amps do that, as well as others, but offhand I can't remember which ones have those active tone controls. My amps all have passive tone controls.]
On a passive tone control amp, all tone controls on 10 bypasses the tone controls' effect. Bypass the tone controls, and give the amp a little volume and that's what your amp sounds like at heart. Experiment from there.
This doesn't mean you should always (or regularly) put all the controls on ten.
It's simply interesting to see what the amp really sounds like before you cut frequencies. THEN start cutting and shaping the sound.
If you start with no frequency cuts, and experiment with each control, you'll get a feel for what it does. By the same token, if you turn all the tone controls down to zero - you won't get a sound - and go through the entire range of each control seeing what it does, what its turnover frequencies are, etc, you'll get another perspective.
You can't really understand your tone controls if you don't actually have a feel for what each one does.
The same principle can be applied to the volume, gain, master, and other options. Find out the range of each one, and see how the other controls affect it.
Ah, then there's the presence control. Who the heck knows what that thing does. Well, I kinda do, though I can't explain the technical details of how it's done. I'm not Dr. Science. I'm just some guy. You want science? Ask Em7.
What I do know is that the presence control is not part of the preamp section like the tone controls. It's part of the power amp section. It comes after the preamp does its thing, and before the power amp's output does its thing. It usually does something to the phase, which of course cancels out or affects certain frequencies in a different way (phase cancellation is a frequency whose signal is out of phase. When one signal is out of phase, and the same frequency is in phase, the frequency is cancelled. Humbuckers and balanced audio lines use this principle to eliminate hum. A lot of players work on their tone, go into a different room with the amp, and don't want to mess up their carefully set tone controls. So a presence control can help.
Then there's the room.
A substantial part of what you think you hear coming from an amp isn't the amp. It's the reflections off the ceiling, walls, and floor of the room. And every room has different modes that exaggerate or null out certain frequencies, different reflection points, and blah blah blah I could go on, but let's just say that your amp sounds different in a different room. Your amp sounds different raised off the floor than on the floor. It sounds different at different volume levels, not only because of its gain increasing, but because it interacts with the room differently at different volumes.
You'll often hear people say they can't get a recording to sound like the amp sounds in a room. They blame the mic. They blame the engineer.
Well, you don't listen to an amp when you're playing with your ear an inch from the grille cloth; you hear it after all those reflections start bouncing around a room.
It isn't the mic. It isn't the engineer. It's the placement. Put a mic in the room instead of up against the grille, you'll hear something a lot closer to what you hear in the room. Move it closer to the amp to hear less of the room Farther back to hear more of the room.
There are reasons people have cut records since the '70s with a 57 against the grille - to prevent bleed, or isolate the tone, or for a million other reasons. It may be standard practice, but it's not the only way.
Yes, the miracle of microphone placement! But I digress. The point is, respect the room. It matters.
Put an amp on the floor, you've got half space reinforcement of the bass; Bass is omnidirectional and bounces to your ears louder when it hits the floor. Put it against a wall on the floor, and you've reinforced the bass even more, because now you have quarter space reinforcement, both a wall and the floor reflecting the bass. In a corner, there's still more bass - eighth space reinforcement.
"My amp sounds muddy."
Maybe it's not the amp. Maybe it's where you put the amp.
"My amp is too harsh/bright." Maybe you should consider playing it in a space with carpeting and furniture, instead of an unfinished basement, and see what it sounds like there.
"I'm just not bonding with it."
Have you tried it with a different type of cab or speaker? Have you experimented with the tone controls, and by that I mean, really learned what they do?
"It's fizzy."
If all you're doing is cranking the preamp, and the power amp is hardly putting out any volume, no wonder. Preamp tubes create a fizzier kind of distortion.
This isn't to say you shouldn't ditch your amp and go with the Next Shiny Object! That's fun, too. But it's a shame to abandon an amp that might be perfectly great with a different placement in the room.
And - this is a whole universe unto itself - try setting it up with some good NOS tubes, instead of the current junk masquerading as the revered brand names of yesteryear. Some enterprising dudes bought old brand names like Mullard and Tung-Sol, and are now importing junk in boxes that look like the old boxes, and with labels that look like the old labels, to make folks think, "Wow, I just retubed my Marshall with Mullards [insert name of great tube of yesteryear that's been renamed, not cloned, here]."
Well no, you retubed your Marshall with Russian (I think they're New Sensor) tubes that someone stuck the old label on. Actual, sought-after, Mullards were made in England and Europe, depending on the factory that built them (some were made by Philips; the old tube companies often made tubes for each other), and production of those tubes stopped by 1980. The new ones ain't the same. The real ones were made better, and sound different. [End of tube rant]
"Is there a point to this post, Les?"
"Yes. See what your amp can do, and you just might like it more."
Most players I talk with start by setting everything at noon, tweak from there, and for that reason never get close to discovering what their shiny new amp can really do. Here's why:
Most (not all) tube amps have passive tone controls. That means all their tone controls do is cut frequencies.
It also means that with the amplifie's tone controls set to noon, it's actually cutting bass, midrange and treble. Amps with passive volume controls have a flat frequency response with the tone controls all the way up.
When we read about legendary Marshall or Black Panel Fender players "cranking" everything to ten on the tone controls, well, they're not. They're simply not cutting any frequencies.
Oh yes, the amp has more gain when it doesn't cut frequencies. Makes sense, right? You're letting more signal reach the power amp.
[There are amps that really are flat with the controls at noon, that boost when the tone control is increased, and cut when it's decreased. If memory serves, some Tweed amps do that, as well as others, but offhand I can't remember which ones have those active tone controls. My amps all have passive tone controls.]
On a passive tone control amp, all tone controls on 10 bypasses the tone controls' effect. Bypass the tone controls, and give the amp a little volume and that's what your amp sounds like at heart. Experiment from there.
This doesn't mean you should always (or regularly) put all the controls on ten.
It's simply interesting to see what the amp really sounds like before you cut frequencies. THEN start cutting and shaping the sound.
If you start with no frequency cuts, and experiment with each control, you'll get a feel for what it does. By the same token, if you turn all the tone controls down to zero - you won't get a sound - and go through the entire range of each control seeing what it does, what its turnover frequencies are, etc, you'll get another perspective.
You can't really understand your tone controls if you don't actually have a feel for what each one does.
The same principle can be applied to the volume, gain, master, and other options. Find out the range of each one, and see how the other controls affect it.
Ah, then there's the presence control. Who the heck knows what that thing does. Well, I kinda do, though I can't explain the technical details of how it's done. I'm not Dr. Science. I'm just some guy. You want science? Ask Em7.
What I do know is that the presence control is not part of the preamp section like the tone controls. It's part of the power amp section. It comes after the preamp does its thing, and before the power amp's output does its thing. It usually does something to the phase, which of course cancels out or affects certain frequencies in a different way (phase cancellation is a frequency whose signal is out of phase. When one signal is out of phase, and the same frequency is in phase, the frequency is cancelled. Humbuckers and balanced audio lines use this principle to eliminate hum. A lot of players work on their tone, go into a different room with the amp, and don't want to mess up their carefully set tone controls. So a presence control can help.
Then there's the room.
A substantial part of what you think you hear coming from an amp isn't the amp. It's the reflections off the ceiling, walls, and floor of the room. And every room has different modes that exaggerate or null out certain frequencies, different reflection points, and blah blah blah I could go on, but let's just say that your amp sounds different in a different room. Your amp sounds different raised off the floor than on the floor. It sounds different at different volume levels, not only because of its gain increasing, but because it interacts with the room differently at different volumes.
You'll often hear people say they can't get a recording to sound like the amp sounds in a room. They blame the mic. They blame the engineer.
Well, you don't listen to an amp when you're playing with your ear an inch from the grille cloth; you hear it after all those reflections start bouncing around a room.
It isn't the mic. It isn't the engineer. It's the placement. Put a mic in the room instead of up against the grille, you'll hear something a lot closer to what you hear in the room. Move it closer to the amp to hear less of the room Farther back to hear more of the room.
There are reasons people have cut records since the '70s with a 57 against the grille - to prevent bleed, or isolate the tone, or for a million other reasons. It may be standard practice, but it's not the only way.
Yes, the miracle of microphone placement! But I digress. The point is, respect the room. It matters.
Put an amp on the floor, you've got half space reinforcement of the bass; Bass is omnidirectional and bounces to your ears louder when it hits the floor. Put it against a wall on the floor, and you've reinforced the bass even more, because now you have quarter space reinforcement, both a wall and the floor reflecting the bass. In a corner, there's still more bass - eighth space reinforcement.
"My amp sounds muddy."
Maybe it's not the amp. Maybe it's where you put the amp.
"My amp is too harsh/bright." Maybe you should consider playing it in a space with carpeting and furniture, instead of an unfinished basement, and see what it sounds like there.
"I'm just not bonding with it."
Have you tried it with a different type of cab or speaker? Have you experimented with the tone controls, and by that I mean, really learned what they do?
"It's fizzy."
If all you're doing is cranking the preamp, and the power amp is hardly putting out any volume, no wonder. Preamp tubes create a fizzier kind of distortion.
This isn't to say you shouldn't ditch your amp and go with the Next Shiny Object! That's fun, too. But it's a shame to abandon an amp that might be perfectly great with a different placement in the room.
And - this is a whole universe unto itself - try setting it up with some good NOS tubes, instead of the current junk masquerading as the revered brand names of yesteryear. Some enterprising dudes bought old brand names like Mullard and Tung-Sol, and are now importing junk in boxes that look like the old boxes, and with labels that look like the old labels, to make folks think, "Wow, I just retubed my Marshall with Mullards [insert name of great tube of yesteryear that's been renamed, not cloned, here]."
Well no, you retubed your Marshall with Russian (I think they're New Sensor) tubes that someone stuck the old label on. Actual, sought-after, Mullards were made in England and Europe, depending on the factory that built them (some were made by Philips; the old tube companies often made tubes for each other), and production of those tubes stopped by 1980. The new ones ain't the same. The real ones were made better, and sound different. [End of tube rant]
"Is there a point to this post, Les?"
"Yes. See what your amp can do, and you just might like it more."
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