Thanks for all the feedback here, it convinces me that the piezo picks are the right way to go, in this instance. It’s good to know others are using this pick up and amplifier. I will now get hold of a set and it seems from the comments here and some other advice I have had that I should give it a go without a preamp and add a small inline preamp depending on the result. I am waiting for a reply from k&k at the moment as the standard cables seem a little short and I have made an enquiry for some custom longer leads. I will keep you posted once I have put some on the harp.
Thanks again

Hello, just an update, I have installed the microphones and tested a couple of mobile amplifiers and I am really pleased. The pick ups from K and K were super simple to install, I used the internal jack and drilled the harp back for this, I glued a plywood disk to reinforce the jack hole on the inside and the internal cables actually run without touching any internals. I ordered custom cable lengths from k+k 29 inch and 12 inch so I have placed the pick ups at 1/3 and 2/3 rds along the string run on the back of the soundboard.
I have tried Roland and Yamaha mobile amplifiers and was so impressed by the Yamaha thr5a especially the nylon microphone setting that I purchased one, it’s almost like having a new harp, playing around with the settings I can make the sound both big and rich, turning the small harp into something which sounds much bigger. I don’t need any preamp it works just fine plugging straight in.
So I am still experimenting but it has been a good addition to this harp..

Hello evolene, it’s a bit expensive, but good value, as I can use the amplifier with other instruments. I think the pick ups were a good price especially as I ordered custom cable lengths $110. The. shipping and us customs fees 60 usd. But then I had the pick ups stopped by the Douane,customs in France, who charged 50 euros for the pleasure. So the main profit here was made by the US and French governments. Normally if you order overseas from France and the total cost is less than 140 euros then the douanier don’t stop the package, this time it was slightly over the limit hence the customs cost…
The amplifier cost just under 200 euros in Cultura, I think you are in France so you may know them as a hobby supermarket. I could find it cheaper online, but the shop let me experiment with several different amplifiers, in fact it turned into a bit of a performance for their customers. The ability to try before you buy is a very good reason in my mind to not buy online. If the shops allow it they deserve a bit extra..
i haven’t explored all the possibilities with the amp yet, but it has several microphone emulations together with compression, chorus, delay, reverb, I haven’t found any loop function yet, but you can plug it into the laptop which gives a lot more options, which I haven’t explored yet. The main thing for me is that it runs off mains or batteries and is small enough to take to the practices and beat those cornemuses and vielle à roue :), which is why I am pleasantly surprised I didn’t expect it to enhance the different sound possibilities with the harp which it has done…

Hello Nancy
The adhesive seems to work well, it’s very sticky. Its only been on for a few weeks, so I can’t say how temperature, humidity and time affect it. There’s plenty spare tape provided so if they do need to be restuck there’s enough to do it again. It took me only a few seconds to stick them to the back of the soundboard.
The reason I drilled the harp was to place the jack connector. The internal jack connector is mounted flush into the back of the harp so you need to drill a hole and push the connector through it.
The external jack connector is easier to mount as it just clips to the side of the sound holes in the back, but I wanted a more permanent look, so chose the internal connector. I have a bit of a personal phobia about wires not being hidden and connectors which seem to be added afterwards.
That being said, I am thinking about adding the same pick ups to my Camac Korrigan, this time with the external jack connector I don’t want to drill the Camac, also you can move the pick ups from one harp to another easier with the external, so I can also move these pick ups to my pedal harp if I want to.
Just to be very clear, I only drilled and reinforced the back of the harp soundbox, for the internal jack connector, NOT the soundboard.
Hope this helps
Talfryn