Do YOU know how a guitar amp EQ works?

Clecko

Inspired by the thread on whether modelling amps have a ‘sound’, but not wanting to hijack it, there was a comment that got me a-thinkin':

[on traditional amps] a lot of guitarists don’t know how EQ works and so find it hard to get the best out of them. 

I'm really intrigued as to what other forumites think about 'how EQ works'. My approach is pretty ham-fisted: sounds a bit toppy = turn the treble down / bit flubby = mess around with the mids a bit etc.

Nikc

Pretty much start at 12 that should be level and then take away rather than add has always been my approach - run the master high and control volume with the volume

Snags

I've seen various approaches over the years, but mostly boil down to "listen to it" and "think about the context", rather than absolute systems.

Of course, it also depends on whether you have an amp that has active/inter-related EQ (e.g. some of the Mesa ones) were tweaking one knob has an impact on all the others.

prlgmnr

http://www.duncanamps.com/tsc/ is the answer to many knob questions

guitarfishbay

It’s mostly straight forward unless it’s something like a Mesa Mark (knobs EQ is Pre distortion, graphic is post). Or a Dual Rec, where the treble knob effectively voices the amp (eg high treble reduces bass). 

Hmmm no wonder people find Mesa’s a bit awkward... I swear it’s fine if you read the manual!

skunkwerx

Left one makes me sound good so turn it up. 

Middle one.... off. 

End one, makes cat hurt above 1 o clock. 

John_P

Work through the tone controls one at a time turning each one until you find the point where it is having the most impact.   

Set them all and only then make adjustments if you need more bass, mid, top to suit the band, songs and room.   

Sassafras

All amps are different so there's no magic formula.

ICBM

prlgmnr said:

http://www.duncanamps.com/tsc/ is the answer to many knob questions

Be careful how you use this. All it tells you is the frequency response *of the tone stack*. It does not tell you anything about the rest of the amp - which may have quite drastic bass cuts, treble boosts or treble cuts which can be done with single capacitor values at many points in the circuit - or even more importantly, the speakers and cabinet.

The reason the classic Fender tone stack has a huge mid cut with all the knobs at 12 o'clock is because that's necessary to get something like a reasonably flat response from an open-back combo with single-cone speakers that essentially only give midrange... it does *not* mean that the amp has a flat response if you turn the mid up full and the bass and treble right down.

thegummy

Clecko said:

Inspired by the thread on whether modelling amps have a ‘sound’, but not wanting to hijack it, there was a comment that got me a-thinkin':

[on traditional amps] a lot of guitarists don’t know how EQ works and so find it hard to get the best out of them. 

I'm really intrigued as to what other forumites think about 'how EQ works'. My approach is pretty ham-fisted: sounds a bit toppy = turn the treble down / bit flubby = mess around with the mids a bit etc.

This approach is infinitely better than anything based on theory and knowledge of how the circuits actually work.

Anyone who knows me might be surprised I'd say that after many years of learning the geeky depths of audio gear but genuinely, without doubt, just getting used to how a knob, switch or slider changes the sound in practice then using that experience to save time with trial and error is the most effective approach.

E.g. Knowing how the presence control works differently to the treble and bass controls might make someone come up with a theory on how they might be best used but really the only thing that matters is how the sound changes when the knobs are turned.

Doodlegame

On tube amps, I go with everything at 12, turn each EQ till you hear it kick in, and adjust for my sound from there

On my boss katana (which doesn't sound at all like the stereotypical Solid state amp), I find it quite hard to dial in so I tend to download presets and tweak over the course of weeks when I notice something I don't like.  Part of this I could put down to everything sounding pretty good on it, part of it is me being picky with all the options.

Lestratcaster

Everything at 12 for me as well, then playing the middle two or G and B strings with my right hand I fiddle the knobs with the left til I like.

terada

I hate amps that you need to fiddle with to get the best from. The amps I’ve ended up keeping are pretty set and forget. Just with slight changes based on different guitars used/mood etc

francer

ICBM said:

prlgmnr said:

http://www.duncanamps.com/tsc/ is the answer to many knob questions

Be careful how you use this. All it tells you is the frequency response *of the tone stack*. It does not tell you anything about the rest of the amp - which may have quite drastic bass cuts, treble boosts or treble cuts which can be done with single capacitor values at many points in the circuit - or even more importantly, the speakers and cabinet.

The reason the classic Fender tone stack has a huge mid cut with all the knobs at 12 o'clock is because that's necessary to get something like a reasonably flat response from an open-back combo with single-cone speakers that essentially only give midrange... it does *not* mean that the amp has a flat response if you turn the mid up full and the bass and treble right down.

Apologies for the dumb question, what does all eqs at 12 o’clock mean on a Fender amp? The knobs on my twin go from 1 to 10.

francer

ICBM said:

prlgmnr said:

http://www.duncanamps.com/tsc/ is the answer to many knob questions

Be careful how you use this. All it tells you is the frequency response *of the tone stack*. It does not tell you anything about the rest of the amp - which may have quite drastic bass cuts, treble boosts or treble cuts which can be done with single capacitor values at many points in the circuit - or even more importantly, the speakers and cabinet.

The reason the classic Fender tone stack has a huge mid cut with all the knobs at 12 o'clock is because that's necessary to get something like a reasonably flat response from an open-back combo with single-cone speakers that essentially only give midrange... it does *not* mean that the amp has a flat response if you turn the mid up full and the bass and treble right down.

Apologies for the dumb question, what does all eqs at 12 o’clock mean on a Fender amp? The knobs on my twin go from 1 to 10.

Paul7926

12 o'clock as in the pointer straight up. Think of a clock face.  

ICBM

5 if they go from 1 to 10.

Kebabkid

I once read or watched Matt Schofield's take on it. He basically turns down each EQ knob and slowly turns them up, one at a time until he notices a pronounced difference and stops. That's how he sets them.

It sounds basic but it might be a good starting point.

My experience of Fender's (Twin, DRRI or Super Reverb) is all straight up works or is also a good starting point. Boogies are much harder and Mesa suggest turning the bass down as you increase the gain.

enjo

francer said:

ICBM said:

prlgmnr said:

http://www.duncanamps.com/tsc/ is the answer to many knob questions

Be careful how you use this. All it tells you is the frequency response *of the tone stack*. It does not tell you anything about the rest of the amp - which may have quite drastic bass cuts, treble boosts or treble cuts which can be done with single capacitor values at many points in the circuit - or even more importantly, the speakers and cabinet.

The reason the classic Fender tone stack has a huge mid cut with all the knobs at 12 o'clock is because that's necessary to get something like a reasonably flat response from an open-back combo with single-cone speakers that essentially only give midrange... it does *not* mean that the amp has a flat response if you turn the mid up full and the bass and treble right down.

Apologies for the dumb question, what does all eqs at 12 o’clock mean on a Fender amp? The knobs on my twin go from 1 to 10.

Typically it means in the middle as in 12 O'clock on a clock face.

Fuengi

Or 4.5 on a Tone King. 

thegummy

Something worth noting is that, regardless how the pot works, starting off where it affects the sound the least is arbitrary - i.e. the only end goal is that it sounds good, there's no desire to have it as close to the sound of the pure guitar pickup as possible.

So any starting point is essentially arbitrary; 12 o clock makes sense because it allows you to turn it both up and down an equal amount. But it doesn't really matter.

A concept I have for a software audio processor, like an EQ, would be that when it's inserted, the values of each band's setting is randomly chosen and hidden. The user can turn the value up or down but is never shown what the value is. That would mean they would just have to listen and turn it up if it needs more or down if it needs less but wouldn't be influenced at all by where they think the knob should be.

For example, someone might turn a band on an EQ up 15db and think it sounds good but when they see that they've turned it up so much decide something must be wrong because it should never be turned up so high. In my concept, they wouldn't know that they'd turned it up so much, just that it sounds right. In fact, the +15db might have been the value that was randomly chosen and they found that turning it down made it worse.