View Full Version : K&K pickup question

03-04-2017, 05:13 AM
I just installed a K&K big island spot in my Islander AC4. Today I plugged in my Boss TU2 tuner pedal and right away I noticed that the sound became much better from my Loudbox mini amp.
Could have something to do with "impedance", that I've read about in a "piezo" thread?
The loudbox has two inputs:
Ch1: 10 MOhm (instrument)
ch2: 2 kOhm (mic XLR)

(Not that I know what this means.) I use the instrument channel now, should I use the Mic channel instead with an XLR cable?

Brad Bordessa
03-04-2017, 08:44 AM
Yes, it has something to do with impedance. Your tuner is acting as a buffer (which alters impedance). I'm not super hip on the ins and outs of it, but here is some info from a highly-regarded pedal builder: https://www.mrblackpedals.com/blogs/straight-jive/6629774-buffers-impedance-and-other-internet-lore. You want a high-impedance input, but 10MOhm seems stupid high. Our own Booli is the guy to ask, but he's been busy lately.

The only reason I'd use the XLR is if I had a preamp/DI to convert the signal.

03-04-2017, 09:52 AM
Thanks, but a little hard for me to really understand.
Seems like there are some guys at the Martin forum that had the same observation with the Boss TU2:

03-13-2017, 11:09 PM
I have 2 x Kala Travel Ukes with K&K external pickups, with no preamp - from memory, they recommended the purchase of their preamp at the time, for better performance!

Like you, I get confused by all the terms ..... but I hope this may help ....

Both my ukes work fine with my small portable amp connected directly to it by one cable. But they don't always play well with BIG Sound Systems as the signal from the K&K pickup isn't strong enough to get thru 'on it's own'.

When you fitted your Big Spot - did it have one circular bit (ie the pickup) that was 'stuck' on the inside the uke with a thin cable going to the 'output jack'?

Taking a bit of info from Buddhuu's post here (well worth a read, even if a little bit confusing): http://forum.ukuleleunderground.com/showthread.php?18970-Amplification-Basics-for-Uke-Pickups-Mics-Preamps-Amps-Feedback

The bits below in (brackets) is MY input, not Buddhuu's!

If a pickup element is wired directly to an output jack (like your K&K with the circular/pickup bit stuck on the inside of the uke - the cable from the uke goes straight to the portable speaker with just the one cable), then it is a passive pickup. Passive pickups generally produce a fairly weak and thin signal which will benefit from boosting before going to an amplifier.

Boosting, and sometimes tone modification, are done by a preamp, which is a kind of mini amplifier designed to add gain and sometimes some EQ modification. You may have seen electro-acoustic instruments which feature a little control panel with volume and tone controls and a battery compartment - that is usually a preamp. (2 cables needed - one to the battery operated, foot controlled preamp & one from the preamp to the speaker - and it SHOULD PLAY LOUD. You can turn it on or off, by stamping on it with your foot - it is like an accelerator pedal.)

An active pickup is a pickup system which includes some kind of preamp (like BBand, Misi, LR Baggs. (They can be plugged directly into the Sound System and be well amplified, ie LOUD! The Misi system doesn't even need a battery - it is recharged in seconds & lasts for hours of playing time!)

I've just bought 2 ukes with Preamps already installed in them. You just need to check the batteries now & then, as they do drain even if not used ...... but it eliminates the need for a 'separate preamp' between your uke & the sound system - so just one less thing to worry about when playing.

Reno Dave
03-16-2017, 03:38 AM
I have two tenor ukuleles both with passive K & K pick ups installed. I am not tech savvy with amps or electronics either. For a long time I just plugged into a amp and played, but the sound was not to my liking. I called K & K and they strongly suggested using their belt mounted clip on pre amp to make better adjustments to sound. Magically, my sound and tone problems disappeared and it was a simple fix.
Reno Dave

03-16-2017, 05:30 AM
Interesting, I have a Larrivee guitar with a Passive K&K pickup, and also have a Boss TU-2 tuner. I'll try the guitar straight into my PA, then add the TU-2 into the signal chain, and see if there is any difference. It would be cool if the pedal provided a more pleasing sounding boost.

Dave West
03-16-2017, 05:32 AM
I have a Big Spot in my Mainland tenor and I find it will work without a pre-amp but it is improved when I run through my L.R. Baggs para DI. I prefer passive pickups in my instruments and external pre-amps just for flexibility and no batteries to mess with in the instrument. But that's just me.