Guitar Pickup straight to XLR

[Guitarist]

As an experiment I was thinking of sending a 5k or 8KΩ pickup to an XLR for going straight into my interface and into a Bias amp sim. The mic in impedance is >3kΩ Balanced. I'm only hoping to mainly use 80Hz to 7K Hz anyways.


Is this close enough for rock and roll?

ALSO saddened by the passing of Mr. Ahola, he was a legend since I started here;(

[Enzo]

You could have already tried it by now and reported back to us.

It won't hurt anything. I carry pairs of XLR to 1/4 adaptors in my adaptor set. I have them wired pin 2 hot and others pin 3 hot just to cover the bases. Wire hot to pin 2 or 3, then ground the remaining 2 or 3.

How well will it work? That is for you to decide.

[bbsailor]

As an experiment I was thinking of sending a 5k or 8KΩ pickup to an XLR for going straight into my interface and into a Bias amp sim. The mic in impedance is >3kΩ Balanced. I'm only hoping to mainly use 80Hz to 7K Hz anyways.


Is this close enough for rock and roll?

ALSO saddened by the passing of Mr. Ahola, he was a legend since I started here;(

To get the full range from your simulator make sure that you are not loading your high impedance pickup into too low of an amp input impedance. The best way is to use a low gain amplifier with a high input impedance of about 1 meg to 10 megs. This will look like a typical guitar amp but since it is active, it has a low output impedance that you can put into the XLR input without loading down the pickup. Normally, guitar pickups have volume control pot loads of 250K ohms for single coil pickups and 500K ohms for humbucker pickups. When the amp input impedance of 1 meg ohm is put across the volume control its effective value is 200K for single coil pickups and 333K ohms for a humbucker pickup.

Bottom line... don't alter your high impedance pickup sound by a low resistance load before you attempt to model the sound.

Joseph J. Rogowski

[Guitarist]

Thanks gents. I didn't think of trying an adapter!
I tend to favor high Z too as I started with 4.7Meg Ampeg VT-22 inputs.

I just found a calculator that gave me a loss of -10dB.

[rjb]

I just found a calculator that gave me a loss of -10dB.

You are using the pickup's DC resistance as the pickup's impedance. The pickup's impedance actually has a large inductive component which well exceeds the DCR at higher frequencies. I'll let someone who knows his stuff explain overdamped 2nd order lowpass filters, but bottom line is if you plug a typical high Z guitar pickup into a 3Kohm input, it will sound like a$$. Radio Shack used to sell inline barrel TS-XLR adaptors with an internal audio transformer; they sounded only slightly less like a$$. As bbsailor said, you'd be better off using an active buffer (low gain amplifier) with 1-10M input; then run an adaptor cable from the buffer's TS output to the XLR input. You probably already have a buffer on hand- I've used a (non-true bypasss) compressor stomp box turned "off" for similar applications.
-rb

[Helmholtz]

The problem is not signal loss. A low impedance input changes the PUs' frequency response as it kills (damps) the high frequency resonance peak. To get a natural PU sound you want to use a typical length guitar cable between guitar and buffer.