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Topic: Amp EQ adjustment |
Al Evans
From:
Austin, Texas, USA
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Posted 14 Jul 2021 6:37 am |
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I was told some years ago by a top sound engineer that if a guitar amp has passive EQ, the way to start adjusting is with all tone controls all the way up. Then start cutting the one (or two) that are too high.
If you end up cutting all three (bass, mids, treble) on an amp with a passive tone stack (e.g., Fender or Fender-like), then you're only attenuating the overall level (i.e., "throwing away signal") and should bump up the knobs until one of them is at its maximum.
This made good sense to me, so I immediately started doing it that way, and have been happy with the results. But my EQ knobs get funny looks now and again from people who comment, "wow, you've got that one all the way up". It doesn't seem to help much to explain that actually, it/they are just not turned down -- if they're at TEN, they must be all the way up.
And I see other peoples' amps. or pictures of their adjustments, with all three knobs turned down on a passive EQ (or one that's set to passive on an amp with a choice). If they're getting a sound they like, it doesn't matter.
But what do you folks with lots more experience think?
--Al Evans
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2018 MSA Legend, 2018 ZumSteel Encore, 2015 Mullen G2, G&L S-500, G&L ASAT, G&L LB-100, Godin A4 Fretless, Kinscherff High Noon |
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Fred Treece
From:
California, USA
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Posted 14 Jul 2021 7:42 am
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If its working for you, great!
I’m not an engineer, so I can’t explain the why and how of the interaction between EQ, Gain, and Volume, but the correlation does exist, and that’s why amps are built with adjustments for them. Even if the point is to “cut signalâ€, as if that is always a bad thing.
My starting point with EQ on any amp is 12 o’clock, adjusting all the way up and down one at a time to see how the mid reacts to bass and treble, bass to mid and treble, etc.
The flip side of “EQ up all the way†can yield some interesting results, too. Try turning your EQ knobs down all the way and turn the volume to 11. Then set the EQ’s between 1-4. |
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Ian Rae
From:
Redditch, England
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Posted 14 Jul 2021 8:03 am
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Al, you may have been having your leg pulled. It's misleading to imagine that just because the circuitry is passive, then "all up" is flat. On a guitar amplifier there may not be a flat setting at all. A hi-fi needs to be able to run flat but a guitar amp just needs to sound interesting.
Tone is changed by fooling the ear with phase shifts. Any control that cuts and boosts will have the least effect at some intermediate position. So the nearest you'll get to flat will be with the knobs somewhere around the middle - ish 
_________________
Make sleeping dogs tell the truth!
Homebuilt keyless U12 7x5, Excel keyless U12 8x8, Williams keyless U12 7x8, Telonics rack and 15" cabs |
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Georg Sørtun
From:
Mandal, Agder, Norway
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Posted 14 Jul 2021 8:31 am
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Real (old type) passive tone controls work, and are best adjusted, as described by OP: start with all control-knobs turned all the way up, and reduce only the freq-ranges that sound too loud.
Active tone controls are (usually) flat at normal gain when all are centered (knob marker straight up 12 oclock), and designed to be turned up or down as needed for desired overall sound. But, if all are way up or all are way down then linearity are lost and overall gain is either too high or too low.
Other than that: passive tone controls may be designed to be linear around the 12 oclock setting, and act more or less as if they were active. The difference between passive and active controls is otherwise simply that passive controls have their amp-stages before and after all controls, while active controls are built around/into independent amp-stages for each control knob / freq range. There are also various hybrids, where for instance only the mid-freq is designed around an independent amp-stage, while low and high freqs act as passive tone controls.
There are so many ways to build tone controls that there are not enough distinct "names" for all variants. Most of today's variants fall into the "active" class though. |
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Donny Hinson
From:
Glen Burnie, Md. U.S.A.
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Posted 14 Jul 2021 3:43 pm
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With all due respect, audio engineers generally have zippo knowledge about how you or I want our pedal steel to sound, unless they are players of the instrument. And even if the do play the instrument, they may like something completely different. Therefore, I don't generally listen to anyone where my sound is concerned. I have my own sound in my head that I want to hear when I play, so asking someone else tell me how to set my amp is rather useless. Of course, this attitude all goes out the window if you actually want to sound like some particular player. In that event, he may be able to help you...somewhat. But even then, a lot of a player's sound comes from their head and their technique. And no, that stuff's not transferable.  |
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Roy Carroll
From:
North of a Round Rock
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Posted 15 Jul 2021 5:27 am
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I remember Paul Franklin telling us in a session in Dallas. The proper way to set the amp is to start wide open on everything except the Gain, the slowly back off each knob until you have the sound that YOU like to hear.
His tone is pretty good I think. I remember that on a NV112,
the bass was at 1oclock for him.
He would be a pretty good example to follow.
_________________
Just north of the Weird place, south of Georgetown |
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Al Evans
From:
Austin, Texas, USA
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Posted 15 Jul 2021 6:54 am
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It's great to see the different perspectives and opinions!
Honestly, I have no interest in even suggesting how anybody should adjust their amp. This is only a suggestion as to a procedure to use for doing so.
What I am saying is that a classic passive tone stack on an amp (Fender, Vox, Marshall, Dumble, others), or an accurate emulation of one, cannot increase the the level of a frequency band.
Here is a diagram of such a tone stack:
As you can see, there is no component capable of amplification in the circuit. This circuit itself uses about 3-10 dB of level.
So what I am suggesting (and it's certainly not an original suggestion) is that the optimum way to adjust it is to start with all the pots all the way up, and cut only the frequencies that need cutting. I've used this approach in different contexts, and it seems to me the best way to arrive at a quick and consistent result.
The two sound injunctions I've absorbed from the masters are: (1) begin by establishing unity gain through the sound path, as nearly as possible. And (2) everything is a tone control. Keeping to those simple injunctions has kept me from yonking lots of control knobs around uselessly!
--Al Evans
_________________
2018 MSA Legend, 2018 ZumSteel Encore, 2015 Mullen G2, G&L S-500, G&L ASAT, G&L LB-100, Godin A4 Fretless, Kinscherff High Noon |
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Fred
From:
Amesbury, MA
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Posted 15 Jul 2021 1:31 pm
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With a Fender style eq circuit the closest to flat is mid all the way up, bass and treble all the way down. It’s down around 20db but pretty much flat.
With everything up all the way there’s a big mid cut centered around 400hz, more or less. There’s a lot variations that tune the circuit a bit. For example the tweed Bassman and Marshall’s(they copied the Bassman) have a shallower mid cut with a higher frequency and a little more bass roll off.
There’s usually enough gain to compensate for the lossy passive circuit so I don’t see any reason to take it into account when adjusting tone.
Fred |
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Donny Hinson
From:
Glen Burnie, Md. U.S.A.
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Posted 15 Jul 2021 4:46 pm
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| Al Evans wrote: |
It's great to see the different perspectives and opinions!
Honestly, I have no interest in even suggesting how anybody should adjust their amp. This is only a suggestion as to a procedure to use for doing so.
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You're right Al, most have their own procedure. I always start with the Bass all the way up, and the Mid all the way down. I do that for two reasons:
1.) The bass response of pedal steels is pretty crappy, and that's because we only have a bridge pickup.
2.) Also, for the same reason (only a bridge pickup) steels have TONS of Mids and highs, and with the Mids set high, the response is very "flat" (no depth or body). In addition, all that heavy metal in the changer and bridge just adds to the highs.
Therefore, my usual starting point is Bass-10, Mid-0, and treble or highs at 3 or 4 (about the ten o'clock position). Sometimes I back the Bass down to 6 or 7 to clean up the bottom end, but that's not typical. There's no point whatsoever in me starting with everything at the mid-point because I NEVER use a mid-point setting on anything.
Different strokes, etc., etc. I don't recommend that anyone do what I do. That's because (unlike most of you), I'm not trying to sound like someone else.
(No offense intended.)
By far, the biggest complaint I hear from the audience and singers about the steel heard on the radio and modern recordings is "Everyone sounds the same".  |
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Fred Treece
From:
California, USA
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Posted 15 Jul 2021 8:00 pm
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I agree with Al, it has been interesting seeing the different points of view on tone-tweaking starting points, whether the amp’s system is active or passive. I have no idea what side of that fence my amps are on, and I don’t really care. The same process on all of them always results in a workable sound, and I rarely end up with any of the controls all the way up, down, or straight up middle.
The reason I start straight up noon with Treble/Mid/Bass is that if the amp doesn’t sound halfway decent there, I figure I am in trouble. If I ever get another amp, I will experiment with these other starting points, although I’m sure I must have tried the “all the way up†thing at least once.
The first gig with a new amp (or new anything) is always exciting, even if I’ve spent hours “yonking†on it the day before in rehearsal. Usually it works out just fine. |
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John Limbach
From:
Billings, Montana, USA
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Posted 17 Jul 2021 5:16 am
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Regarding tone adjustments for lap steels, I have videos of both Herb Remington and Jerry Byrd saying that it's very easy. Turn the bass all the way up and the treble all the way down. Adjust the mid as required. Jerry Byrd then adds "the last thing a lap steel needs is more treble."
I've tried it for years, and it works for me. Doubt that it would be that simple with a pedal steel because of it's range, particularly the lows on the C6th neck. |
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