EMG Mark Knopfler mod

[CarlosG]

Hi!
I'd like to try Mark Knopfler's mod.
The idea was that with the HSS circuit with EMG in position number 2 (bridge + middle) it was supposed to sound like a Stratocaster with a single coil on bridge.
And yes, I know there is a model 89 or 81tw that allows coil splitting, but EMG itself doesn't provide an autosplit wiring. I'd like to try this simple mod with a regular EMG 85 (maybe x).
Is it a simple filter (resistor and capacitor) that should be connected to the hot wire in series?
I found a photo online that shows it's a series connection of a resistor and a capacitor. I'm just not entirely sure if connecting it to the hot wire is correct for active pickups.
For now I want to test it , if I like it I guess I'll need a superswitch?

 

[freefrog]

My archives mention this "Suhr mod" as involving a 22k in series with a 33nF cap, the whole being in series with the EMG85. It's basically a hi-pass filter.

The second row of poles on a regular 5 ways switch should allow to wire that. Will dig the question and share about it if time permits (am busy right now, thx for your understanding).

 

[freefrog]

The second row of poles on a regular 5 ways switch should allow to wire that. Will dig the question and share about it if time permits (am busy right now, thx for your understanding).

Well, business made me post BS or, at least, leaves me too tired to see how to wire an ACTIVE pickup for series cap with a regular 5 ways switch (even if with a passive one, it should be doable). So, yes, a superswitch seems to be needed finally.

 

[Artie]

Freefrog is correct. A standard 5-way won't work. The good news is, you only need the single-wafer, (2-quadrant), version of the Superswitch.

Fender 5-way

 

[GilmourD]

My archives mention this "Suhr mod" as involving a 22k in series with a 33nF cap, the whole being in series with the EMG85. It's basically a hi-pass filter.

The second row of poles on a regular 5 ways switch should allow to wire that. Will dig the question and share about it if time permits (am busy right now, thx for your understanding).

So it's kind of the Fender Jaguar "strangle switch".

 

[Chistopher]

Yeah, but a lot more aggressive

 

[GilmourD]

Yeah, but a lot more aggressive

Ah, with a 33nF cap versus a 3.3nF cap (which I had to look up because I didn't remember off the top of my head) the knee frequency is way different.

 

[idsnowdog]

A 22K resistor with a 33nf cap would give a cutoff at 220hz, which is pretty bright.

 

[freefrog]

FWIW, a series capacitor doesn't work with an EMG like with a passive humbucker.

Reason: the preamp of an EMG HB already includes a hi-pass filter...

Revealing comparison there:

https://www.cycfi.com/wp-content/uploads/2021/06/all-freq-response.jpg

More tests and explanations there:

https://guitarnuts2.proboards.com/thread/8989/emg-response-curves

ElectroSmash - EMG81 Pickup Analysis.

EMG81 Schematic, Voltage Gain, Frequency Response, Electronic Humbucker Unbalance, Bajaman Active Pickup.

www.electrosmash.com

HTH.

 

[freefrog]

Ah, with a 33nF cap versus a 3.3nF cap (which I had to look up because I didn't remember off the top of my head) the knee frequency is way different.

For the record, it also depends on the resistive load.

With a passive pickup + a cap in series, a similar hi-pass effect could practically be obtained from a 2,2nF cap alone or from a 22nF + a 100k resistor to ground. The difference being how the 100k load would also flatten the resonant peak, behaving like a lowered tone pot and adding a subtle low-pass filter to the circuit.

It's interesting to see that EMG humbuckers are voiced exactly like that by their inner preamps: no bass, no visible resonant peaks. Just a wide mid bump...