Pickup for Bass Strings of a Harp Guitar

[paulsmusic]

I've recently acquired a 20-string harp guitar, which comes fitted with a single pickup. The 6 bass strings are not being amplified very well, and I would like to fit an extra pickup / contact mic just for the bass. Any recommendations would be much appreciated! (budget around £100)

[Sam Spoons]

Nylon or steel strings, piezo (what type, UST, SBT or WHY) or mag pickup? And a pic of the instrument so we can see how it is laid out?

[paulsmusic]

It’s a steel-string with under-saddle piezzo (photo at link)
https://drive.google.com/file/d/1j4INi5 ... p=drivesdk

[paulsmusic]

I’m thinking something like this could work well:

https://www.andertons.co.uk/xvive-xu8-a ... avel-case/

[Drew Stephenson]

Is there a separate piezo under each bridge and do they all come out of the same output?

[paulsmusic]

It looks like just a single piezzo under the central bridge

[Sam Spoons]

Is there a separate piezo under each bridge and do they all come out of the same output?

It looks like just a single piezzo under the central bridge

If that is the case I'd be looking to add piezo elements under the other two bridge saddles with either a combined output (easiest) or three separate outputs (needs a multi channel preamp or a small mixer). For the single output system I'd also invest in a Tone Dexter preamp. The only real problem I can see is getting the three piezo's to balance.

The mic system you linked to would also mean you need to be going into a mixer, then what about the harp/sympathetic strings?

[Wonks]

Have you got any details of the preamp used? Some preamps have inputs for another pickup. It may have unused inputs (though there is normally an obvious volume control for any second pickup).

If it is a single pickup unit, you might be able to find one of a matching size shape that has multiple inputs or maybe one with an internal microphone that will help to bring out the bass strings.

[paulsmusic]

Thanks for your suggestions. The preamp is called an EQ-7545, and only has a single output. Having now got the super-trebles tuned up (there was no tuning key supplied, so I have temporarily used a spanner!), there is no output coming from the super-trebles either. So I will definitely need either a piezzo or clip-on mic for bass strings and super-trebles.

My current setup is guitar DI output to a Radial PZ Deluxe, to pedalboard FX (including an Eventide H90 Max, which I'd like to be able to use with all the strings amplified), which then goes to a Zoom L12 mixer and out to my PA.

I'm thinking if I fitted 2 piezzos with a single output they could go into a Radial PZ-Pro (dual-channel version of Radial PZ Deluxe), along with the on-board preamp from the harp-guitar.

Any recommendations for a dual piezzo system with a single output? Or is there a similar system that uses clip-on mics instead? I like the idea of using a clip-on mic as it would also capture some of the acoustic ambience of the guitar.

[paulsmusic]

Currently looking at these transducers from K&K. Do you think the Twin Spot would work well enough with a single transducer for the bass, and super-trebles? The Pure Classic would give me 4 transducers...

https://www.andertons.co.uk/k-k-sound-t ... CeEALw_wcB

https://www.andertons.co.uk/k-k-sound-p ... ic-pickup/

[Dave Rowles]

I'd be very tempted to go for an under saddle pickup on each bridge. small hole drilled at the edge of the saddle and then sand down the saddle to account for the extra height. After that I'd look into ways of combining the saddles. You'd either need to solder them all together and hope one of the internal pre-amps has enough drive to split the load, or wire them into a single output jack and get an external preamp to drive it.

Of course, if you really wanted to go all out, under saddle pickups, separate output for each, then you can blend with a mixer to taste.

[Drew Stephenson]

Another thing to consider might be a Zepplin Labs Cortado. I find they give a pretty nice representation of an acoustic guitar if you play around with the positioning enough to get the balance you want. You do have be careful of handling / cable noise though.
The guitar in the left channel of this track is a Cortado recording https://drewstephenson.bandcamp.com/track/the-norwegian

[Wonks]

Currently looking at these transducers from K&K. Do you think the Twin Spot would work well enough with a single transducer for the bass, and super-trebles? The Pure Classic would give me 4 transducers...

https://www.andertons.co.uk/k-k-sound-t ... CeEALw_wcB

https://www.andertons.co.uk/k-k-sound-p ... ic-pickup/

Whilst K&Ks are very good, I think they'd be very difficult to fit on that guitar. They come with a little jig to help position the dots in the right place, but it's very much a hands in the soundhole job. As the soundhole looks relatively small and the bass and sympathetic string bridges are a long way from the soundhole (and at a comparative angle), it would not be an easy task and you'd definitely have to make your own elongated jig up. As the K&Ks can sound poor if not positioned correctly, and you really need to use superglue to mount them, it;s a big risk if you're inexperienced.

A standard under-saddle piezo strip or a body-mounted pickup is the safest and surest way, unless you take the whole top or back off and then fit the K&Ks. But that is rather extreme.

[paulsmusic]

It sounds like under-saddle pickups for the bass strings and super-trebles is the way to go. Is it possible to buy a dual pickup system with a single output, or would I need to make that myself?

[paulsmusic]

Whilst K&Ks are very good, I think they'd be very difficult to fit on that guitar. They come with a little jig to help position the dots in the right place, but it's very much a hands in the soundhole job. As the soundhole looks relatively small and the bass and sympathetic string bridges are a long way from the soundhole (and at a comparative angle), it would not be an easy task and you'd definitely have to make your own elongated jig up. As the K&Ks can sound poor if not positioned correctly, and you really need to use superglue to mount them, it;s a big risk if you're inexperienced.

A standard under-saddle piezo strip or a body-mounted pickup is the safest and surest way, unless you take the whole top or back off and then fit the K&Ks. But that is rather extreme.

Re: the K&Ks, could you position a dot inside the guitar, around the position of the saddle for the bass strings and super-trebles? That way, both dots would reach to the output jack if it was fitted where the guitar-strap button is.

[Wonks]

I don’t think so. The dots don’t have a wide pickup area, so it’s normally one dot between 2 strings. You’d end up with a very unbalanced sound.

A contact mic would be a better choice than trying a single dot IMO.

[paulsmusic]

Cool, thanks!

[Sam Spoons]

You may well be able to add piezo elements under the bass and super-treble bridges and simply connect all three elements in parallel. The place you might encounter problems is with balance but if you source elements from the same manufacturer as the original one (or buy three identical elements from Fishman or somebody else and replace the current one while fitting the new) you may well find the results are good.

As simple as they are piezo UST elements rely on even pressure, if the bottom of the saddle and it's slot are not dead flat you can get one string sticking out or sounding dead. It is possible to DIY but unless you have a bit of experience it might be worth considering getting a luthier to fit them?

[Wonks]

The bass saddle looks to be a standard length (or standard enough) but the super-treble saddle is much longer (especially if you plan to use all 8 possible strings.

A lot of piezo saddles these days are six separate piezo elements, one for each string, connected in parallel. You’d really want a super-treble pickup element that’s one long piezo strip, and long enough for all eight saddles. You’d certainly have to look around and read the specs carefully.

[Sam Spoons]

True but I have several Fishman style braided piezo transducers which have plenty of length to the active section, more than enough to span the 8 super trebles.

[Folderol]

Piezo devices are essentially capacitors and as such behave best when fed either into the highest impedance you can get or into a virtual S/C.
I've experimented with both options, and a few years ago made a battery powered test module (that I still have) that could be switched to either feeding a 10M input or a capacitor feedback virtual earth. Each had their own volume control so you could get a reasonable balance between them.
I loaned this to a member of this parish to try out, and he was unable to decide which was which, or which he preferred.
One advantage of the virtual S/C is much better interference rejection.

For those interested in such details I used a separate (quite expensive) Op/Amp for each path, feeding both from a pair of PP3 batteries.

[Drew Stephenson]

I loaned this to a member of this parish to try out, and he was unable to decide which was which, or which he preferred.

It is worth pointing out that it was plugged into a cheap piezo set, self-installed, on a double bass.
A set of K&K's, properly fitted, to a guitar might give a much more audible set of differences.

[Folderol]

I loaned this to a member of this parish to try out, and he was unable to decide which was which, or which he preferred.

It is worth pointing out that it was plugged into a cheap piezo set, self-installed, on a double bass.
A set of K&K's, properly fitted, to a guitar might give a much more audible set of differences.

NOW he tells me!

[Drew Stephenson]

I told you at the time!
It's actually pretty rare now to get a guitar with a piezo pick-up but no pre-amp built in. Certainly none of mine had one.

[Wonks]

And my K&K sounds best fed into a 10k input. Too bassy into 10Meg. But your standard under-saddle piezo strip is normally best into 10 Meg.

I've used the Fishman style braids before, especially on two 12-strings where the saddle length is about 1cm longer than a normal 6 string saddle. You might just do it with one of those, but you need to be aware that the piezo section doesn't run the whole length of the braid.

I normally drill a small hole at the other end of the saddle channel to bend the tip of the braid into (as the piezo element stops slightly short of the tip), which gives you the maximum length of piezo under the saddle, but even so, I had to juggle the position a bit to get an even sound from all the strings.

I haven't cut one open (though I really should) but hitting the braid with a screwdriver whilst it's plugged in to a preamp and amp, gives you a reasonable idea of the length of the sensitive section.

Whilst it would generally cover a 7-string saddle, whether it covers 8 strings probably comes down to the make of the piezo braid element. The manufacturers don't want too long a pickup area, as the bits not squashed under the saddle are then free to vibrate/knock against the hole in the bridge and make spurious noises.

One option would be to use two piezo strips, fed from opposite ends of the saddle slot, so one strip does four strings and the other strip does the other four strings. Wire them in parallel and feed into a preamp.

The wiring is still a bit of an issue though, primarily down to the awkward access as the bridges are further away from the soundhole than normal.