UST Query

I am investigating under saddle pickups as I've been asked to fix a couple of instruments which don't amplify well. I suspect the UST as they look a bit battered. They're not equipped with high end electronics so I don't want to spend a great deal. Besides, my payment is usually a bottle of wine rather than parts and labour. I'm trying to find something that's relatively inexpensive but does an adequate job. This item looks promising (remove the space after https)
https ://www.aliexpress.com/item/4000270022108.html?spm=a2g0o.productlist.0.0.77774199TJH4Lg&algo_pvid=f3b4dee9-1c68-476c-ba36-ddc51ecc51dc&algo_expid=f3b4dee9-1c68-476c-ba36-ddc51ecc51dc-50&btsid=0ab6f81e15867554655684502e53e3&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_

My question has 2 parts:
1. Does anybody have experience with this type of pickup? If so, do you recommend them?
2. The red piezo rod is too long for the ukulele's saddle slot. Will it still work OK if you cut off the last 15mm or so?

All feedback appreciated. TIA
Miguel

I've used an Artec pickup that looks similar. I drilled an angled hole through the saddle to allow me to tuck the excess away. Having said that at that price i'd be tempted to cut off the 15mm and see.

lauburu said:

My question has 2 parts:
1. Does anybody have experience with this type of pickup? If so, do you recommend them?
2. The red piezo rod is too long for the ukulele's saddle slot. Will it still work OK if you cut off the last 15mm or so?

All feedback appreciated. TIA
Miguel

Click to expand...

1) I've had experience with installing piezo pick-ups in ukes, but not with that particular brand. The piezo technology is rather simple (people have used parts from a smoke detector to make them) so even this cheapy should work fine. It is the stuff down the line that needs quality like the pre-amp, pots, etc.

2) I think you could safely cut off the end and if not, like Brian says, at that price ($3.95 USD), what the hell.

Thanks for your responses. You're right, at that price I should just buy a couple and experiment. I shall report back my findings.

Next question:

Some preamp systems are 9v and others are 6v (2 * CR2032 batteries). Do the two systems require different USTs or will any UST work and it's the "down-the-line stuff" that needs the different voltages?
Miguel

The Cigarbox nation people are always cutting piezos. https://www.cigarboxguitar.com/knowledge-base/how-to-cut-a-rod-piezo/
Unfortunately it looks like the rods they cut are different so I think the illustrated pickup might not cut well. If it turns dead when you cut it you have probably shorted the end. You might be able to fix that by sanding the end. You may have to wait a while as mail is painfully slow at the moment. A little more searching should find you similar uke length pickups which would be less issue prone

lauburu said:

Some preamp systems are 9v and others are 6v (2 * CR2032 batteries). Do the two systems require different USTs or will any UST work and it's the "down-the-line stuff" that needs the different voltages?
Miguel

Click to expand...

That is correct, Miguel. The piezo element creates a variable output signal (millivolts) that is independent of the amplifier power source.

lauburu said:

Next question:

Some preamp systems are 9v and others are 6v (2 * CR2032 batteries). Do the two systems require different USTs or will any UST work and it's the "down-the-line stuff" that needs the different voltages?
Miguel

Click to expand...

I believe that the piezo pick-up itself is not dependent on energy from a battery. A small electrical current from the crystalline substance it is made of is produced when it is vibrated (like from a vibrating saddle) and this tiny current is then amplified by the "down the line stuff" which are dependent on voltage. So to answer your question: the pick-up is independent of voltage.

My pick-up pre-amps use the 6v CR2032.

Excellent feedback. Thanks
Miguel

After waiting about 3 months for these items to arrive (due to COVID lockdowns all over), they finally arrived. They were well packaged and looked just like the pictures (not always the case). I decided to try one on an unamped uke.
Because it was too long and was a hard piezo rather than a soft one, I had to nip about 10mm off the end with a pair of sidecutters to get it to fit into the saddle slot. The UST was 1.5mm thick so I sanded 1.5mm off the bottom of the saddle. All fairly regulation stuff.
I connected it to a Joyo JE63 preamp and fired it up. Quite pleased with the result. Good volume across all 4 strings though it has a noticeable the piezo "quack" if you pluck hard. Nice and cheap to buy, nice and easy to install. I'm pretty happy with the result.
Miguel