Ultratonic K&K Conversion - review and recommendations

[fazool]

Preface:

This is an un-endorsed and unrequested product review. I am a customer who bought this and have no connection or arrangement of any sort relating to this.

I didn't take pictures to show my installation (there really is nothing to show from my pics so I pasted some of the manufacturer's at the end).

Background:

I have a lousy sense of smell. My wife, on the other hand, is gifted with bloodhound-level scent detection.

She can smell a moldy cracker from three rooms away and it's so strong the "stink" seems to cause her actual physical pain. Meanwhile, I'm sitting outside blissfully unaware of the propane grill leaking next me and a skunk sleeping under my chair. That level of sensitivity difference is how I feel about piezo quack: I see people listening to amplified acoustic guitars and blissfully enjoying the music, while I am almost in physical pain from the air-raid-siren of piezo quack pummeling my ears.

I remove any UST's that come on my guitars and have installed K&K Pure Mini's in three of my acoustics.

A soundboard transducer is a piezo disc attached directly to the soundboard. This produces a more authentic acoustic tone, and eliminates the quack phenomenon.

The tradeoff is that SBT's are very sensitive to feedback and can tend to be a little "muddy" sounding.

Overall, I am very happy with my three K&K pure mini's (two six-string and one twelve-string). I use an external LR Baggs GigPro preamp to shape the tone and the result is excellent.

Using the external amp is cumbersome and I dislike using a soundhole-cover for feedback.

Introduction:

I read a thread here on AGF (but can't find it again to link it) where the OP was singing the praises of the James May Ultratonic upgrade for K&K Pure Mini's.

I had never heard of these so did some reading to learn more.

James May Engineering invented an improved version of the K&K Pure Mini style SBT called the Ultratonic (currently at version 3.)

http://jamesmayengineering.com/

In addition, he has added a "conversion kit" with which you can modify your existing K&K Pure Mini to be just like an UltraTonic - this is what I am discussing.


This conversion:
-Adds a fourth piezo disc to double the pickup power of the higher frequencies
-Adds a large feedback eliminating piezo disc that focuses on configurable lower frequencies
-Adds a soundhole volume control, with cable compensation

The claimed advantages of this conversion are:
-Improved high end response
-Improved low end clarity
-Reduced feedback even at high volumes

The conversion basically works in the following way:

The K&K Pure Mini has one disc that focuses on the low (E & A) strings, one on the mid (D & G) strings and one on the high (B & E) strings.

The conversion kit adds an additional piezo disc on the treble side of the bridge, basically doubling the output with the K&K disc already there. This adds more treble response and clears up some low-end tones.

The feedback eliminator is a large piezo disc, just like the existing four discs but a bit larger. This is mounted on the bass side of the bridge plate and it is mounted with a reversed polarity. The way this works is that it will create a negative electrical signal that will cancel out some of the positive signal created by the other discs. By selecting location and size of this reverse-polarity crystal you can have the negative signal focus on a general part of the tone - in this case the lower frequencies.

There is a printed circuit board where the five different piezo discs and the volume control are all connected together and then feeds out to the output jack. Also, part of this interface board is a bank of switches which as explained by James "the dip switch ... is a 12 step attenuator (with roughly 2dB per step) that determines how much of the feedback cancellation sensor gets passively mixed in with the main sensors. The resultant effect is that when set within a certain range, the system will cancel certain frequencies that are specific to your guitar resonances."


The two added Ultratonic piezo discs, and the volume control, come already attached to this interface board.


To upgrade your existing K&K Pure Mini, you will cut all three of the K&K lead wires and then attach them to this interface board.

Installation

The installation instructions are easy to follow.

http://jamesmayengineering.com/wp-co...tions-V1.1.pdf

If you have installed the K&K Pure Mini, this uses the same process. A few things to add to help that process:

One strong recommendation is to reverse the process and solder the wires before gluing the discs to the soundboard. This may give you a little more length to move around when soldering.

Similarly, this is a special process so you will be using a soldering iron over your soundboard. A solder splatter or drip can ruin your finish - so cover everything with something very protective like a thin sheet of wood.

Soldering is the only hurdle for a DIY installation. You need to strip the wires very carefully and following the instructions. You are then soldering very small lengths of wire and soldering several leads to one common pad on the PCB. This is a tricky process and you have to be adept at soldering technique to do this properly. So, make sure you know how to solder small leads and can join multiple wires without loosening an already soldered wire.

Finally, gluing the discs last will give you a little more control over wire routing so you don't have a "birds nest" with all the wires going every which way inside.

The kit does NOT include the recommended putty - K&K includes some putty with their kits. You need the same type of thing - I used extra putty from my K&K installations. The recommended magnets worked perfectly for this installation.

Performance Review & recommendations

My K&K Pure Mini was installed very carefully and, I think, perfectly. It had just the perfect amount of glue and exactly correct location. The sound of mine was quite good - I wasn't sure if I even needed the tone improvements from the Ultratonic but I wanted to try it. I suspect that the claimed lack of treble response comes from a sub-par K&K installation. Similarly the claimed "muddiness" of a K&K is likely largely attributed to a less-than-perfect installation. Mine may have had some of that but I sure didn't ever notice it.

I wasn’t sure I needed the added treble disc but found that the Ultratonic treble was outstanding – it was so crisp and clear. Similarly, my low end sound was beautifully opened up and sounded much better. I didn’t even know my original K&K sounded “muddy” until I heard it as an Ultratonic conversion. It really was a nice tone improvement at both ends.

I did still need to use an external preamp. It improved the tone and it sounded nicer without the preamp but I will still use a preamp. I think it’s good enough that I could get by in a pinch but I still prefer the preamp sound.

The volume control works nicely – it is very conveniently located and easy to operate. It does a great job of setting volume without losing tone from the added resistance. One thing to note is that the board is mounted facing down on the soundboard (obviously) so the knob feels like it goes the opposite rotation to what you might be used to on a volume pot for an electric guitar. There is a cable length compensation switch on the volume controller.


After a few tries you can figure out the feel to switch it at will. I tried it on and off with a 2’ cable, 15’ cable and 0’ cable (wireless directly plugged in). I did notice a little better treble tone and it made a little difference but nothing hugely noticeable.

The feedback elimination really does work! This was the most important feature for me. Now, it’s not possible to eliminate it 100% of the time and all volumes but my originally K&K Pure Mini was very prone to feedback. I set my switch where I liked it best, finished my installation and spent a lot of time test-driving this. I used a really loud Line6 amp and sat next to it. This was not quite full-band-practice volumes but it was a significant improvement. Based upon this I am confident that I will go to my next full band practice without using a soundhole cover.

So my recommendations are these:

If you do not yet have a SBT pickup system and need one with feedback control, go straight to the James May Ultratonic.

If you do not yet have a SBT pickup system and don’t have feedback concerns, simply go with the K&K Pure Mini as-is.

If you already have a K&K Pure Mini installed and need better feedback control, definitely go with the Ultratonic conversion kit.

If you already have a K&K Pure Mini installed and need better tone (from a sub-optimal installation), definitely go with the Ultratonic conversion kit.

I reached out to James a few times and found him to be exceedingly responsive and supportive so very easy to deal with.

[SpruceTop]

Great detailed installation review and I'm glad everything worked out well with significant amplified tone improvement for you!

[alohachris]

Aloha,

After all the recent discussions about the inexact science of placing Dazzo pickups into the optimal position, this thread is interesting.

First, if true, the upgrades will help improve the K&K Mini with a few of its shortcomings. But, if your guitar has the bridgeplate space, having four K&K pods makes it potentially very simple to place them in the optimal spot. Because... there really IS no room for error, literally.

You just superglue the three pods in a line, spaced as usual per the regular K&K installation, & add the new bass pod right next to the original bass pod, & be done with it. Simple installation.

Comparing it to the Dazzo installation, where you apparently have to move the two glued, triangular pods around to "find" the sweetspot, the new K&K installation is a piece of cake, Ha!

I hope these K&K mini upgrades work for many guitarists interested in a decent live acoustic pickup sound & a simpler installation. I would also recommend adding an internal mic & a dual-source preamp to the mix to really complete your LIVE acoustic sound & control.

alohachris

[gfirob]

Very informative post, thanks very much.

[SpruceTop]

Originally Posted by alohachris

Aloha,

After all the recent discussions about the inexact science of placing Dazzo pickups into the optimal position, this thread is interesting.

First, if true, the upgrades will help improve the K&K Mini with a few of its shortcomings. But, if your guitar has the bridgeplate space, having four K&K pods makes it potentially very simple to place them in the optimal spot. Because... there really IS no room for error, literally.

You just superglue the three pods in a line, spaced as usual per the regular K&K installation, & add the new bass pod right next to the original bass pod, & be done with it. Simple installation.

Comparing it to the Dazzo installation, where you apparently have to move the two glued, triangular pods around to "find" the sweetspot, the new K&K installation is a piece of cake, Ha!

I hope these K&K mini upgrades work for many guitarists interested in a decent live acoustic pickup sound & a simpler installation. I would also recommend adding an internal mic & a dual-source preamp to the mix to really complete your LIVE acoustic sound & control.

alohachris

Hi Chris,

Did you see my follow-up to your comment on the other thread? https://www.acousticguitarforum.com/...3&postcount=72

Regarding my recent first and only Dazzo installation, and as dumb as some will think I may sound, frankly, I hate having to even try all the dipsy-doodling around that some makers indicate is necessary to optimize the installation of their pickup systems--I find it tedious and clumsy! I just placed the Dazzos similarly to what is in Teddy's installation video and the system worked pretty well with good balance, clarity, and tone. I used the same line of thinking with my several Trance installations by placing the Amulets in the recommended locations and got good consistent tonal results by using the original Trance method of applying the overall-pressure of soundhole c-clamps to the Amulets without bothering to even try applying the newer suggested rigamarole of selected-area clamping using the included turnbuckle pickup clamp. A bonus for both these systems is that the Dazzo and Trance systems are quite feedback resistant.

I've never used an UltraTonic system or heard one live, but based on what those who have used the system report, I'm sure it delivers a great amplified tone with good feedback resistance. *The only criticism I have of the original and conversion versions of the UltraTonic system is that it seems like a lot of stuff to apply to the bridge plate to arrive at a good tone that is achievable with a simpler Dazzo or Trance system. It could be that the amplified tone and feedback resistance of an UltraTonic system surpasses those qualities in a Dazzo or Trance system when played live under the same venue conditions? If that's the case, then applying the five disks and setting the DIP switches on the module would be worth the effort for many players.

I now remember seeing on James' website the new rendition of the UltraTonic before it was available but I forgot about it. Having only two transducers to apply to the bridge plate certainly keeps the installation of the latest UltraTonic version simpler.

[loco gringo]

The UltraTonic doesn't have 5 discs. The V1 did. It now has one long transducer plus the bass disc, so just 2 things to stick on the bridge plate. Now the 5 discs would only apply if you are upgrading a K & K.

http://jamesmayengineering.com/

[SpruceTop]

Originally Posted by loco gringo

The UltraTonic doesn't have 5 discs. The V1 did. It now has one long transducer plus the bass disc, so just 2 things to stick on the bridge plate. Now the 5 discs would only apply if you are upgrading a K & K.

http://jamesmayengineering.com/

Thanks for that clarification, I now remember seeing on James's website the new rendition of the UltraTonic before it was available but I forgot about it. Having only two transducers to apply to the bridge plate certainly keeps things simpler.

[RogerPease]

I'm very satisfied with the Ultra Tonic conversion kit that I installed in my Martin CEO 7.

When I first installed the K&K Mini pick up it came away sounding very muddy with EQs
set flat. I had to do a really big cut at around 180 Hz just to get it to sound ok. Yeah, I
could work with it but it took some pretty extreme EQ adjustment.

Installing the Ultra Tonic conversion solved this problem and improved feedback
resistance, too. Now it sounds good with EQs flat. I used to turn on the guitar Tone
Match setting on the Bose S1 Pro. Now I leave it off and it sounds better. I don't
need to use the Platinum Stage anymore. I can go through the Red Eye.

Yeah, I'm happy.

Cheers, _Roger

[tadol]

I’m glad the Ultratonic is getting the recognition it deserves - I remember the NCAL meeting when James demonstrated the installation into Bruce Sexauers guitar, and how it did an amazing job of amplifying it while keeping the amazing tone and quality of Bruces build. I had a braz rw 0 of Bruces with a Barbera soloist pickup on it, and until hearing the Ultratonic, I thought the Barbera was the cleanest and sweetest pickup I’d heard. But the Ultratonic changed that immediately. I had always wanted a pickup for my baritone, but acoustic baritones, especially very resonant and responsive ones like my Santa Cruz, are incredibly susceptible to feedback (in my experience) - but the Ultratonic seemed to be the answer. So I installed one of the new V2s, and it was so simple, and the results so great - I could play it directly facing my amp at high volume, and no feedback! - I knew I needed to add it to my regular gigging guitars. I was hesitant at first, thinking maybe I’d be better off removing the K&K I really liked, but finally decided to order the retrofit kit - and am very glad I did!

I have to agree - if you need a pickup, get the Ultratonic V2. If you have a K&K, get the Ultratonic retrofit. If you feel like you can’t afford the Ultratonic but need a pickup, install a K&K, and start saving for the retrofit. And once you have the Ultratonic, start saving for the Tonedexter - it’ll work with all your guitars with pickups, and beyond that - just start saving for the best acoustic amp you can!

[martingitdave]

I concur with this review and the conclusions as they are consistent with my experience with the UT pickup. Well done.

[fazool]

Having sold my GS8 with the ultratonic conversion kit in it, I picked up a small body GC3 that has a K&K installed.

I wasn't sure how the low end effects would interact with this small body since it isn't very "boomy" to begin with.

For this installation, I chose to not use the soundhole volume control. I found the installation even easier on a small-body since I could reach around inside better. I also used my probe camera to watch what I was doing.

I also knew better about the wire routing so I more carefully packaged the wires so it was very neat.

Also getting the depth of the endpin jack just right for my acousti-lok was easier to reach.

After the installation, I did the normal test sequence where I sequentially tried a different dip-switch setting to balance bass-output versus feedback resistance.

The results, frankly, shocked me. So I sat in front of my amp and simply flipped a switch from #12 to #11 and instantly i got a big feedback - I changed switches and it stopped. I switched again and it fed back again.

The point is that the attenuation switches *REALLY* made a big difference and totally worked.

Now on my big body guitar I didn't notice much bass "sacrificed" but on the little guitar it was more sensitive to the feedback system. I did notice a difference in string-to-string balance as I adjusted my switches. When I got it nicely balanced I think there was a tiny reduction in bass but a *MASSIVE* (!) immunity to feedback. It was completely eliminated. I was totally shocked and impressed.

I was thinking a smaller body guitar might not be as responsive or affected by the feedback system but it was even MORE so.

Again - a great system that I highly recommend.

[jonfields45]

The Ultratonic and the conversion kit are a ground breaking innovation, on the same level of innovation as Baggs' mic plus UST using a crossover network.

I in particular like the single main element version of the Ultratonic. That pickup is not made out of stuff off some electronic distributor's standard catalog.

James May has recently automated the switch setting (you need equipment that is cheap by factory standards but not home brew price friendly). Hopefully a major guitar manufacturer will get this pickup the exposure it needs to take off.

[jricc]

Nice review and explanation of installation fazool, thnx!

[tadol]

I completely agree, and will be upgrading any K&K guitar I get with this kit. And if I need to put a pickup into a guitar, the UltraTonic is the only option for me. If you want to take it one step further, try plugging into the Tonedexter and training it up -

[varmonter]

I've pretty much given up on piezo pickups for live performance.
I've about 20 yrs or so of tweaking
And de-quacking all sorts of vibration
Sensing pickups. None of which satisfied me when played at volume.
That said I'm certainly glad you
like what you've installed and I hope
you get many years of service from it.
I think james is a brilliant designer .
I remember his first rendition of this required a single use vibration generator that helped
determine the feedback frequency. This turnedme off to the purchase . At the time it was
an 80 dollar item that you only used once.
Hopefully this is no longer the case.