K&K XLR preamp or Beringer

[Wooly]

I have a few guitars equipped with K&K pure mini pickups in them. I run them into a K&K XLR preamp and then into a Fishman Loudbox Mini.

To me they sound OK but not great. I'm just wondering if it would be an advantage to use a Behringer V-Tone Acoustic Amp Modeler instead of the XLR. I'm thinking I should be able to tweak my sound a little better with the Behringer?? Any thoughts?

[buzzardwhiskey]

At $30 it may well be worth the experiment. I've paid twice that for a darn cable.

[6L6]

When you're playing into an acoustic amp like your Mini, no preamp is required. Or for that matter, desired!

The Mini already has the needed preamp inside. Adding another outboard preamp will hurt your tone.

[chitz]

Originally Posted by 6L6

When you're playing into an acoustic amp like your Mini, no preamp is required. Or for that matter, desired!

The Mini already has the needed preamp inside. Adding another outboard preamp will hurt your tone.

^^^This^^^ X2

[Wooly]

Originally Posted by 6L6

When you're playing into an acoustic amp like your Mini, no preamp is required. Or for that matter, desired!

The Mini already has the needed preamp inside. Adding another outboard preamp will hurt your tone.

But then where does the impedance mismatch come into play? I read on several threads on this board that the K&K has a 1 ohm output and the amp has 10 ohm input. Therefore you need the 1 ohm input on the preamp to tame the mids and bass?

I know this subject has been thrashed over and over but I'm just not sure what to believe anymore

[guitarmac62]

The K&K has an output impedance of 500k to 1 Meg ohms. Channel 1 on the Loudbox has an impedance input of 10 Meg ohms, high impedance. Plug straight into channel 1. Using a preamp on channel 1 will cause a mismatch and probably not sound good. Is your sound muddy when using your preamp on channel 1?Channel 2, XLR input, is low impedance of 2k ohms. The output of the preamp is also low impedance. Is this clear as mud?

[ljguitar]

Originally Posted by 6L6

When you're playing into an acoustic amp like your Mini, no preamp is required. Or for that matter, desired!

The Mini already has the needed preamp inside. Adding another outboard preamp will hurt your tone.

Hi 6L6

I don't find that to be true at all - particularly then part about hurting tone.

I've got K&K pickups (with internal mics as well) in 4 acoustics, and my gigging partner has them in 2 of his acoustics, and we mix sound for, or play with, half dozen others regularly with K&K Pure mini pickups running through preamps before stage-amps/PA.

We have an array of decent acoustic amps and PA systems, and all of the guitars sound better running through an external preamp before the acoustic amp/PA.

The external preamp expands tone adjustment, and improves the tone, despite the fact there are preamps in PA boards, and acoustic amps.

In the case of dual source rigs using internal powered mics, there is no option for not using external preamps.

[sdelsolray]

Originally Posted by Wooly

But then where does the impedance mismatch come into play? I read on several threads on this board that the K&K has a 1 ohm output and the amp has 10 ohm input. Therefore you need the 1 ohm input on the preamp to tame the mids and bass?

I know this subject has been thrashed over and over but I'm just not sure what to believe anymore

Originally Posted by guitarmac62

The K&K has an output impedance of 500k to 1 Meg ohms.
...

The K&K output impedance varies depending on frequency. None of those impedances are anywhere near 500k or 1 MegOhm.

The output impedance of a device is usually much lower than the input impedance of the next device in the signal chain.

K&K recommends a preamp with an input impedance of 1 MegOhm. Several tests presented on this forum strongly suggest that any input impedance of 880k or higher (e.g., 10 MegOhm) all act, behave and sound identically with the K&K pickup.

[guitarmac62]

[QUOTE=sdelsolray;5323246]The K&K output impedance varies depending on frequency. None of those impedances are anywhere near 500k or 1 MegOhm.

Thanks for correcting me. I should have said the Pure sounds best with input impedence of 500k-1Meg per their spec sheet.

[fotofantom]

So there you have it - all good advice, and differing opinions on impedance match/mismatch. That's not surprising since there are always other variables involved. When I play my Yamaha guitar with K&K Mini PU, I don't hear a lot of difference if I add a preamp. Here's something you can try: Plug the lead from your preamp into the Aux input in the back of the Loudbox Mini. That bypasses the built-in preamp.

Experiment!

[Wooly]

Originally Posted by fotofantom

So there you have it - all good advice, and differing opinions on impedance match/mismatch. That's not surprising since there are always other variables involved. When I play my Yamaha guitar with K&K Mini PU, I don't hear a lot of difference if I add a preamp. Here's something you can try: Plug the lead from your preamp into the Aux input in the back of the Loudbox Mini. That bypasses the built-in preamp.

Experiment!

Learn something new every day. Didn't know that. I'll give it a try for experimental purposes. Thanks