Preset EQ vs. Sliders

[Gizzorge]

Is is possible to match the preset EQ with the sliders? I have never been able to, it seems like here is something different going on with the preset.

 

[screamingdaisy]

So far as I'm aware, no one has been able to nail it perfectly.

 

[diddlydan]

Nope,not from my experience anyway.The preset seems to bring up the highs pretty quick.I tend to change between them fair a bit though.Currently on the sliders at the min.I think it has to do with the eq curve.The sliders have control over each individual frequency but the preset reacts like knob on a console eq perhaps.Be interesting to compare them using a frequency analyzer.

 

[Chris19]

Recently I was groping about with the controls in extreme mode and I was able to get the preset and sliders practically indistinguishable. I don't remember exactly what the settings were, as I wasn't aware that people were having problems with getting them to sound similar, but one thing that I do recall is that the 2200 slider was almost maxed out. Not what my first guess would be but the tone was VERY close. I think 6600 was lower, maybe 1/3 up (or even less) between the middle and top lines. 750 was of course most of the way down. 80 and 240 were boosted but to what degree I can't recall. It's probably different for each mode but the key was definitely pushing that 2200 slider much higher than one might think. Hope that helps!

 

[LesPaul70]

ISTR, from an earlier post on this board, that the way the preset EQ pots worked was that they had a very steep V curve applied to them and what the pot did was basically just the mix ratio of EQ'd sound to pure un-EQ'd sound (and not the steepness of the V curve or anything such).

So it's an effect that is not easy reproduce with the GEQ sliders.

 

[MerlynMetal]

You can match sliders and presets exactly provided your Depth pot is at max. Presets are nothing more than a "fixed sliders" EQ section and the Depth controls influence only how much you'll hear the effect of that preset (which is the same for all channels) on the overall sound. There's nothing mysterious about that and it's clearly seen from the partial Mark V schematic available from the net. The whole EQ section is in the sound path at all times (even when it's OFF it still ON - the sound goes through the EQ, only inductors are lifted from ground) only the frequency control is switched from the regular sliders to the "fixed" ones.
The other thing is the presets are not exactly V-shape. 750Hz are not completely cut, 240Hz is completely out of the circuit and then you have some boost on 2k2 and 6k6. If you match sliders and presets you'll notice that 80, 2k2 and 6k6 are boosted approximately on the same level. Even if you never heard the amp you can also deduct that from the schematic as well.

 

[TamiYates]

As I wasn't aware that people were having problems with getting them to sound similar, but one thing that I do recall is that the 2200 slider was almost maxed out.
Not what my first guess would be but the tone was VERY close.
I think 6600 was lower, maybe 1/3 up (or even less) between the middle and top lines. 750 was of course most of the way down. 80 and 240 were boosted but to what degree I can't recall. It's probably different for each mode but the key was definitely pushing that 2200 slider much higher than one might think.

 

[OldTelecasterMan]

I had looked into this myself. I spent a bit of time but then I stopped and asked, why am I doing this? LOL

 

[Nicklotsaguitars]

Yep, the pre-set thing is a nice addition. Take it for what it is. Don't try and make it what it isn't. I think it's perfectly functional with clean to crunch sounds. Not so much with gain sounds where you need precision to get your preferred harmonic content.
FWIW I rarely get past 11 o'clock on the dial. But then again I find the tonestack on cleaner sounds makes more of an impression on the sound of the amp. Where the graphic is pretty essential to the driven sounds.
I don't scoop much, the centre slider just below the mid line and the 240hz slider about the same and the 2200 slider either a hair above of below depending. I'm finding those two sliders do a lot more when balanced to the centre slider, particularly for metal n punk. Getting decent sort of cut to the mids that the high gain really needs on this amp. Without completely losing the mid frequencies and keeping my sound a little more complex than the generic grind sound.

 

[MerlynMetal]

As I wasn't aware that people were having problems with getting them to sound similar, but one thing that I do recall is that the 2200 slider was almost maxed out.

Correct.

I think 6600 was lower, maybe 1/3 up (or even less) between the middle and top lines. 750 was of course most of the way down.

Also correct.

80 and 240 were boosted but to what degree I can't recall.

True for the 80Hz. As seen from the EQ partial schematic below 240Hz is out of the preset circuit.

It's probably different for each mode but the key was definitely pushing that 2200 slider much higher than one might think.

Not correct. As seen from the schematic it's the same preset circuit for all modes.

It's easy to figure out only from the schematic which frequency is boosted and which is cut and approximately by how much.
For example on the left you have R89 and R90 in parallel and "on top" of R83. They make a 41k to 1k voltage divider which means that you have the 80Hz 50 kOhm slider almost maxed (boosted). When you have bigger resistance "on top" that means the respective frequency is boosted and vice versa. Less "on top" means frequency is cut.

 

[diddlydan]

Interesting.I wonder why 240hz isnt in the preset circuit then?Funny thing is though,Im a sound engineer and 240hz is nearly always a good place to cut a guitar track as its slightly muddy there or around 250hz.Its not too low to take the body out of the guitar and actually makes the top end seem clearer and the bottom seem a tad fuller.I do find the 240hz slider makes things seem a bit muddy when raised slightly.

 

[MerlynMetal]

Personally I don't have any use for the 240Hz slider - I keep it at zero at all times but like most things in this field it's a matter of taste.