Changing Resonant Frequency instead of Changing Pickups

Kamil Kisiel said:
Yeah could make a single board with switchable caps and a trim pot quite easily
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I guess if the form factor is small enough you could even make something attached to its own pot, where it's basically a wide ranging resonant frequency adjustable volume pot. That would be a very cool thing. Now add it to a dual concentric (volume lower knob / tone upper knob) and you're really cooking! I wonder how many people would go for that. I guess if you demonstrated the power of a device like that in a YouTube video you could really do it.

But still keeping the PCB floating would be convenient if you wanted to dangle the thing from a pickguard while adjusting. But if you have a back control cavity, you just adjust the pot with attached PCB directly. So many ways to go with something like that.
 
JasonE said:
This is a cool mod. I think this is basically what PRS is doing with the TCI process. They are setting the resistance to specific levels. I am not sure how they are measuring that or what they are looking for but I believe they are basically doing this same thing. I am also not sure if they are using any sort of adjustable resistance or if they measure things and then solder in static value components. I don't own any of the newer TCI tuned PRS guitars to look in the control cavity fo find out.
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No resistors on the PRS TCI. There are a couple of small caps on the switches. I haven’t tried to decipher it. Works really well on the neck pickup.
 
skolacki said:
No resistors on the PRS TCI. There are a couple of small caps on the switches. I haven’t tried to decipher it. Works really well on the neck pickup.
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Okay, so that would make the neck brighter I think, which is what a neck humbucker often calls for. Very cool. I gotta remember to look for one when I'm out and about.
 
State of Epicicity said:
Okay, so that would make the neck brighter I think, which is what a neck humbucker often calls for. Very cool. I gotta remember to look for one when I'm out and about.
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I can hear that small cap glassiness on the split. The thing with the TCI is there is very little volume drop with the split. I’ve seen some drawings but they don’t show the switch schematic and whether or not there’s a coil tap. I could puzzle it out but the guitar is listed right now. I regard the neck pickup as the best one I’ve had because the split is so good. But the guitar didn’t really grab me. You guys know how it is. But I will say PRS is onto something with the TCI thing.
 
skolacki said:
I can hear that small cap glassiness on the split. The thing with the TCI is there is very little volume drop with the split. I’ve seen some drawings but they don’t show the switch schematic and whether or not there’s a coil tap. I could puzzle it out but the guitar is listed right now. I regard the neck pickup as the best one I’ve had because the split is so good. But the guitar didn’t really grab me. You guys know how it is. But I will say PRS is onto something with the TCI thing.
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Funny, I didn't know they were doing this with splits too. Dean Zelinsky Guitars has a split that's supposed to be almost the same volume as the humbucker, and I wonder what they're doing to achieve that.
 
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skolacki said:
I can hear that small cap glassiness on the split. The thing with the TCI is there is very little volume drop with the split. I’ve seen some drawings but they don’t show the switch schematic and whether or not there’s a coil tap. I could puzzle it out but the guitar is listed right now. I regard the neck pickup as the best one I’ve had because the split is so good. But the guitar didn’t really grab me. You guys know how it is. But I will say PRS is onto something with the TCI thing.
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PRS has been doing well with the splits for a good while. They have been doing that by putting resistors on the switch where the split wires go. I have a few PRS core guitars where they have done that.

The TCI process is to get all of the components in the system to have values with much tighter tolerances than a standard component. I don't have a guitar where this has been done to open it up to look at it. They may be doing this by selecting components by their exact value when putting the circuit together or adding other components to get them there. It is definitely a process that they are doing. There have been some posts about it on the PRS forum.
 
Rex said:
And they’re still too bloody big to fit inside a guitar. :)
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Not big like that picture. There are miniature trimmer-caps of 6mm diameter, like the trim-pots that @State of Epicicity has used. You could fit an array of them, but even then you may have to adjust them all individually with a small screwdriver to make a significant change. :D

The most practical thing would be a rotary switch with different RC combinations. Like the King Tone switch.

I find that it is overpriced for what it is, though. And it has nasty poop at the knob😂 . I vote for using the Axe-FX Filter block. That can simulate any RC filter, so I don't see why it should be different than doing it inside the guitar. With the advantage that you can use any range of non-standard component values, and change it as you wish on your presets and scenes.
I am experimenting with that this weekend
 
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Piing said:
Not big like that picture. There are miniature trimmer-caps of 6mm diameter, like the trim-pots that @State of Epicicity has used. You could fit an array of them, but even then you may have to adjust them all individually with a small screwdriver to make a significant change. :D
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Okay, a few of those would fit. :)

Piing said:
The most practical thing would be a rotary switch with different RC combinations. Like the King Tone switch.
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Or a rotary switch with caps, along with a pot.

Piing said:
I vote for using the Axe-FX Filter block. That can simulate any RC filter, so I don't see why it should be different than doing it inside the guitar.
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That would help, but it's not the same. Sure, it can add a filter. But it can't change the resonant frequency of your pickup. So that resonance will still be there.

If you have an Axe-Fx, the selectable input impedance will, however.
 
Today I decided to install the trimpots to keep them accessible. Since I have six drill holes for mini-switches in my pickguard, I just hot-glued a trimpot each into two of those holes. This way I can keep it loose. If I feel like retuning the resonant frequency at any time, I don't have to take anything apart.

Tonight I played a ton with the York Audio Friedman pack, which I had bought some time ago. Tonight, for the first time, I felt like everything was sounding and acting just right. Again, I was finding tonight that I was getting great tones without altering the IRs at all; no smoothing, no trimming, whereas before I was really having to smooth and trim everything. This opens such a world of possibility, like I'm reentering the world of dudes who get great easy tone. I even brought up the new Leon Todd Fryette D60 Less video and found myself copping his tone easily. I had way less output from my pickups, but a little boost from the Input Block took care of that, and it was just so easy. That's what I'd been missing.

I'm still trying to decide which pick I'm going to go with, but I'm leaning toward keeping my trusty standard .60mm orange Dunlop Standards. They just have so much personality. I have a bunch of the modern shred picks, including all of the Petrucci picks, but I just can't jive with them tonally. The Dunlop Jazz III 1.14 mm is my favorite of the little picks, but still, I'm not feeling a ton of personality from it, relatively speaking. It's between these Dunlop Standards and the Fender 351 Heavy right now. The Fender is an interesting and powerful tone, but again, I'm not sure it has as much personality with my style. Anyway, I'll feel my way through that part. And I'm reacquainting myself with the low output of the Saturday Night Specials. I do feel like these things just speak, even in a bright superstrat.

I got things heading in the right direction tonight, getting great tones out of the Archon as well as the JVM410HJS, and amp I had never before liked. I just have to figure out exactly what I want to set as a baseline for a neutral tone to which to "tune" the pickups. I think the next time I can play I'll do what I did last time: use the 5150 block letter, 1959 SLP Treble, and Dumble ODS Clean. Tonight was just for fun, but next time I'll be more serious about setting it up.

Thanks to everyone's input so far. This is, like I said, damn near life changing for me. It's bizarre to have so very much control over your pick attack like this. The resonant frequency is so important to have right; this just hammer that home for me.

@Piing, it's great if you can get the Filter Block to do what you want. I did get cool results from it before, but I did have to set it differently for each pickup. Plus, it still was not the same as actually changing the resonant peak. But, as always, if it sounds right and inspires you, that's all that matters. I'm just blindly groping as I go along in tone world, as I always have. This is just the way that feels right to me.
 
Piing said:
Not big like that picture. There are miniature trimmer-caps of 6mm diameter, like the trim-pots that @State of Epicicity has used. You could fit an array of them, but even then you may have to adjust them all individually with a small screwdriver to make a significant change. :D

The most practical thing would be a rotary switch with different RC combinations. Like the King Tone switch.

I find that it is overpriced for what it is, though. And it has nasty poop at the knob😂 . I vote for using the Axe-FX Filter block. That can simulate any RC filter, so I don't see why it should be different than doing it inside the guitar. With the advantage that you can use any range of non-standard component values, and change it as you wish on your presets and scenes.
I am experimenting with that this weekend
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Like a VariTone.
 
I misremembered what I read, and caps are necessary to lower the resonant frequency. Apparently you are altering the Q with resistors. With the trimpots I've been using, it's a massive change even though it's only the Q that's changing!

I've ordered recommended caps plus 1m trimpots for better experiments tomorrow. The details again are here:

https://guitarnuts2.proboards.com/thread/7782/basic-resonant-peak-factor-manipulation

There is also a great spreadsheet file by him called Guitar Freak where you can plan all sorts of wiring changes and see their effects on frequency response, including with treble bleed networks.

So the deal is, if you run the RC in series you raise your resonant frequency, and in parallel you lower it.
 
State of Epicicity said:
I misremembered what I read, and caps are necessary to lower the resonant frequency. Apparently you are altering the Q with resistors. With the trimpots I've been using, it's a massive change even though it's only the Q that's changing!

I've ordered recommended caps plus 1m trimpots for better experiments tomorrow. The details again are here:

https://guitarnuts2.proboards.com/thread/7782/basic-resonant-peak-factor-manipulation

There is also a great spreadsheet file by him called Guitar Freak where you can plan all sorts of wiring changes and see their effects on frequency response, including with treble bleed networks.

So the deal is, if you run the RC in series you raise your resonant frequency, and in parallel you lower it.
Click to expand...

Once you have the RC combination that you like, you can load it on LT Spice (it is free) and plot a similar curve at the Filter block. Or let me know the values and I can do it, I have LT Spice installed at my PC
 
Piing said:
Once you have the RC combination that you like, you can load it on LT Spice (it is free) and plot a similar curve at the Filter block. Or let me know the values and I can do it, I have LT Spice installed at my PC
Click to expand...

Dude, thank you so much for that. I just installed it. I am horrible with this stuff, and it's a goal of mine to read and understand schematics properly to be able to translate them to wiring diagram, and vice versa.
 
Hey @State of Epicicity , can you clarify what you mean by lug 1 on the volume pot, is that the input to the left on the pot? Middle lug is output and third lug is ground? Now on the trimpot, which one is lug 2 and lug 3? I haven’t found a schematic that explains that online… BTW very interesting idea!
 
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