Other Amps

Do my amp controls cut or boost?

1

I have a Music Man 210 RP. It has a gain control, master volume and bass, middle treble controls, I'm curious to know the mechanics behind the tone controls.

Do they work like passive tone knobs on a guitar, i.e. cutting, or are they more like an active circuit whereby they boost?

2

I don't know about Music Man amps, but in most classic, vintage type guitar amps, the tone controls cut.

What happens when you turn everything down to zero? (except the volume knob of course..)

4

I haven't seen that amp's schematic but most amps function by cutting tone.

What an amp will typically do is boost the signal immediately upon entering the amp....typically with half a 12AX7 tube. Then the signal will be modified by a "tone stack" which is an array of caps, resistors and pots which shape the tone by shunting some frequencies to ground and bypassing others to the next stage of amplification ..... which is typically the second half of an 12AX7.

Then it might be on to a tremolo or reverb circuit and then on to the phase inverter and power tubes.....but a lot of what we define as an amp's "tone" comes from that tone stack.

Some famous tone stacks are the Fender Blackface tone stack, the Baxandall tone stack, the Marshall tone stack and the Vox tone stack. There are dozens of variations, but most are designed to passively remove frequencies and then boost the resulting signal in its entirety...not adding boosted frequencies to the signal

6

"Tone stack" = "tone suck".

Get a Champ.

7

Thanks for all y'all's inputs chaps, most helpful. Although now I'm a little embarrassed...

I started playing guitar around 40 years ago and got my first amp probably around '80/'81. Up until then my only experience of amps and tone controls were in hi-fis, most of which had centre detents on the bass/treble controls. Following a similar (although apparently WRONG) logic I assumed the '5' position was neutral and either side was cut or boost - like the parametric controls on a mixing desk. Tonight, and just for fun you understand, I dimed the 3 tone controls just to see what happened.

Whatdya think happened? MY AMP CAME ALIVE!!!

Has it really taken me almost 40 years to find out how to work an amp? Jeez, Louise...

For the record, Music Mans (Men?) were Leo Fender products, so it's no surprise they follow the Fender paradigm.

8

"Tone stack" = "tone suck".

Get a Champ.

– Powdog

Only if you want that sound

The word 'Tone' I find, is subjective, it really means totally different things to different people.

Many champs I've seen have a built in tone shaping circuit, it sounds good , It's still a tone control, you just can't adjust it.

9

Thanks for all y'all's inputs chaps, most helpful. Although now I'm a little embarrassed...

I started playing guitar around 40 years ago and got my first amp probably around '80/'81. Up until then my only experience of amps and tone controls were in hi-fis, most of which had centre detents on the bass/treble controls. Following a similar (although apparently WRONG) logic I assumed the '5' position was neutral and either side was cut or boost - like the parametric controls on a mixing desk. Tonight, and just for fun you understand, I dimed the 3 tone controls just to see what happened.

Whatdya think happened? MY AMP CAME ALIVE!!!

Has it really taken me almost 40 years to find out how to work an amp? Jeez, Louise...

For the record, Music Mans (Men?) were Leo Fender products, so it's no surprise they follow the Fender paradigm.

– Deke Martin

Usually, turning up all your tone controls equally is like turning up your volume control.

10

download this tone stack calculator(if you have a pc) It will show you what the tone controls dohttp://www.duncanamps.com/tsc/

11

Wow, that looks like a cool piece of software. Maybe the first time in 7 years I wish I was still Wintel...

12

My music computer is a pc . I drag stuff from y internet mac to the PC if I need to. It;'s neat for seeing what they do and also if you're building an amp it helps to make informed decisions, and you can tweak the components.

13

I recently saw an online tone stack calc...let me sift through my forums to see where it might've been.

14

Only if you want that sound

The word 'Tone' I find, is subjective, it really means totally different things to different people.

Many champs I've seen have a built in tone shaping circuit, it sounds good , It's still a tone control, you just can't adjust it.

– Toxophilite

Of course it's subjective. You're absolutely right. "Tone suck" is just my ridiculous way of explaining how tone controls work by removing signal and redirecting it to ground.

I'm a sarcastic wisenheimer, and in respect for Baxter's new guidelines I apple-o-gise to anyone I've upset.

15

Interesting topic. The human nervous system acts much in the same way: without the controls of different systems acting on neurological activity, we would be “wide open,” or a hot mess. A walking screaming sack of spastic tissue.
I never knew that this is how a guitar amp is designed, but it makes sense.

16

Of course it's subjective. You're absolutely right. "Tone suck" is just my ridiculous way of explaining how tone controls work by removing signal and redirecting it to ground.

I'm a sarcastic wisenheimer, and in respect for Baxter's new guidelines I apple-o-gise to anyone I've upset.

– Powdog

I'm not offended. It just sounded like you were saying tone controls were bad. When almost every amp has them to some extent..even a NFB circuit could be considered a type of tone control. I like sarcasm

17

Pretty much the same circuit as blackface Fender, but solid state so resistances are smaller and caps are bigger. Turning all tone controls down cuts all the sound. Turning up Bass or Treble gives you back those frequencies. The Mid control changes the slope of the Bass control, from a bump at 100hz to a gradual slope from 100hz up to around 800hz.


Register Sign in to join the conversation