Prior to embarking on an unplugged tour, Cardinal Black guitarist Chris Buck decided he needed a really good acoustic guitar. He chose a lovely used Atkin OM37, but there was one slight hitch: it needed a pickup system. After doing some research, Chris decided on LR Baggs HiFi Duet and asked me to fit it for him.
Although some of the procedures are specific to LR Baggs, much of the work required applies to acoustic pickup systems in general. The HiFi Duet comprises two pickups and a small electret microphone, all of which attach to the bridge plate. There’s also a control unit with an internal preamp and an output socket that doubles as a strap button.
Holey Moley
The scariest procedure in most acoustic pickup system installations is making and/or widening holes in the body.
The first hole I’m referring to is the one that often needs to be drilled through one end of the saddle slot to install an under-saddle piezo pickup. Thankfully, there’s no need to do so with this system, but some under-saddle pickups require an angled hole and care must be taken not to drill through the X-brace.
Most pickup systems have the output socket mounted through the tailblock and that usually means widening the strap button hole to around 12.5mm or ½ inch. Loading a ½-inch bit into your drill and just going at it is dangerous because the bit will most likely bounce around before it gets a grip and chip the finish.
Granted, the Atkin is reliced and that takes some pressure off, but I’m sure all but the most ardent anti-relicers can agree there’s a difference between tasteful ageing and damage
Granted, the Atkin is reliced and that takes some pressure off, but I’m sure all but the most ardent anti-relicers can agree there’s a difference between tasteful ageing and damage.
To avoid the latter, my advice is to use a step cutter because they’re easy to get hold of, inexpensive and ideal for the job. I bought my first set from the ‘middle of Lidl’ several years ago and they’re still going strong.
The existing strap-button hole will help to guide the step cutter and the hole should get incrementally wider while retaining a crisp edge.
Once the step cutter has opened up the outer part of the hole to the required diameter, I swap over to a regular drill bit of the same diameter to continue through the tail block. If you can get your arm inside, try pressing a scrap chunk of wood up against the tailblock to minimise tear out and don’t forget to vacuum out any debris.
LR Baggs suggests fitting the output socket assembly after installing the pickups and before the microphone. Given all the messing around inside the body needed to install the socket, I decided to fit it first, rather than risk knocking the pickups off the bridge plate.
The entire socket assembly is threaded and a cover screws onto the inside end to protect the solder joints. A nut fixes it in place, and both can be adjusted to match the depth of any tail block so that about a millimetre of the wider threaded section protrudes outside the body.
It may take a few attempts to get it just right, but you can make things simpler by placing a long screwdriver or a piece of dowel through the hole that’s thin enough to enter the socket.
You can use this to guide the socket assembly through the tailblock hole and slip over the first washer with the wider aperture followed by the second one, which goes over the narrower threaded section.
The small nut goes on next and, once it’s finger tight, you can push an Allen wrench through the holes in the narrow threaded section to prevent the assembly from turning as you fully tighten the nut. Lastly, the outer collar/strap button is screwed on to cover the small nut and washers.
Fixing The Bug
LR Baggs specifies a minimum ¾-inch of bridge plate in front of the bridge pins for mounting the sensors. I used my phone camera to look inside the Atkin’s body and found there was just enough space to mount the pickups. After ensuring the surface was smooth and free from glue, I gave it a wipe down with isopropyl alcohol as instructed.
Speaking of instructions, none are included with the product, but you can scan a printed QR code and follow the link to a video demo explaining the installation procedure. Like other LR Baggs pickup systems, the HiFi Duet comes with a jig for aligning and installing the pickups.
This comprises a clear Perspex plate and two pairs of rods. Each pair of rods has a different diameter and you should choose the pair that is closest in diameter to your guitar’s pin holes. The rods mount onto the plate and can be adjusted to align with the outer pin holes before you tighten them up.
The short end of the rods are placed through the outer pin holes, and the pickup positions should be aligned with the saddle with the leadout wires running between the top E and B pins and the low E and A pins. They are then temporarily fixed to the Perspex plate using small sticky pads that are stuck over the LR Baggs logo.
If you’re feeling confident, you can peel off the adhesive pad coverings and go ahead with the installation. I chose to perform a dry run before exposing the adhesive to assess the difficulty of getting the rods to go through the pin holes. It turned out to be fairly easy and I just went ahead with the installation.
After pressing the pickups firmly against the bridge plate, the alignment jig can be pulled clear leaving the pickups in situ.
Power Stations
It’s suggested that this is a good juncture to test that everything is working before installing the microphone. In order to do that, the pickups must be connected to the control unit and the battery pouch must be installed so the system can be powered up.
To make battery changes easier, the pouch is secured by Velcro so it can be taken in and out. The conventional location is up against the neck block, but you should ensure that the pouch doesn’t obstruct truss rod access. For this guitar, I decided to put the pouch in sideways, rather than upright.
The control unit has a moulded notch to clear any braces placed in the vicinity of the soundhole. If the braces are unusually thick, it may prevent the control unit from attaching firmly, so you need to find out if it will fit and identify the best position. I had no problems finding a workable location and I used low-tack masking tape for a visual reference.
After connecting the battery, pickup and output wires, I peeled off the adhesive pad coverings and stuck the control unit under the soundboard. I put the strings back on the guitar, tested it through an amplifier and everything worked as it should with an even string-to-string balance and a strong output level. The strings were then removed once again to install the microphone.
Final Hook Up
Installing the microphone is done by feel, rather than jig. It’s positioned between the two pickups, and the leadout wire passes between the D and G bridge pins. When positioning it, try to leave sufficient space for the ball-ends of the strings. The microphone cable must also be connected to the control unit by feel, but again it’s not tricky at all.
The final part of the installation involves tidying up all the cables that are loose inside the body. Pliable metal hooks with adhesive pads are provided and LR Baggs is very generous with both the hooks and spare adhesive pads.
In fact, if you store all the spares in the box, you’ll be able to transplant the entire pickup system to another guitar if you ever decide to. I have also seen identical metal hooks at B&Q if you need more.
I prefer to partially pre-bend the hooks prior to installation because it makes it easier to gauge when the wires are in position. After all, this is yet another part of the installation that is done by feel. I placed the first hook just behind the bridge plate and used it to secure the pickup and microphone wires.
Although some fix the hooks to the soundboard itself, I prefer to keep that to a minimum. Instead, I attach the remaining hooks to the side just under the kerfing, with the second hook placed as far inside the body as I could reach to retain the output wire.
The third hook was positioned on the bridge side of the waist to grab the pickup, microphone and output wires, with a fourth on the other side of the waist. The object of the exercise is to ensure that there are no loose cables inside the body that can rattle about and create unwanted noises.
Plug & Play
When testing the sensors without the microphone installed, I had noticed that I was still getting signal when the mixer control was fully set to ‘Mic’.
That’s because the mixer also acts like a crossover to attenuate the pickup’s highs while retaining some of the low-frequency content to beef up the tone in microphone mode.
The mic level control provides additional tone shaping and, overall, the system delivers a dynamic and natural acoustic tone that’s pleasingly devoid of piezo quack.
- This article first appeared in Guitarist. Subscribe and save.
