Piezo tweeter help

[ivorcally]

Hi,

I have been using a pair of piezo tweeters in my system since the 1970s and one has recently gone open-circuit after the chip amp that was driving it went DC. I have attemped a repair but it doesn't sound so good now.

I am looking for a replacement, but these seem to be hard to find. The tweeter is a direct-radiating piezo with a metal chassis instead of the usual plastic one, and I think they were used in some early Celef and ProAc speakers. They are about 3.25 inches in diameter.

When I bought them, they were marketed by Bandridge but I suspect that they were made by Motorola.

If anyone knows where I can get one of these, or any other info about them please let me know.

I hope I have successfully attached an image...

Keith

[applehorn]

Keith,

Motorola sold their Piezo division some time ago. It has been through a number of different hands. It is now owned by Piezo Source.

Iain

[norman bates]

martinsoundpro.com is selling piezos (not the cheap junk sold at partsexpress).

http://www.martinsoundpro.com/item.asp

here is another source.
http://www.adelcom.net/MotorolaTweeters1.htm

The 1016a is nice but can't be run passively without a transformer network.
I've had great luck running a piezo with an active crossover (the ones that ring at 4.5khz, I run 60 ohm in series and active cross it at 5khz LR so it is 6db down at 5khz).

Norman

[ivorcally]

Thanks Iain and Norman,

I have checked all three websites and none of them list one like mine. I think I will contact Piezosource though to see if they have any info.

Keith

[norman bates]

yup, I doubt you will find it.

I'm now quite discouraged finding amps and receivers that sound wonderfull, but are now 20-30 years old. They cost little but falling apart and will need switchs / caps, etc. But they are 1/10th retail and nothing sounds as good unless it is the cost of a 2 year old car.

Speakers are a worse gamble.

Norman

[Inductor]

Hi Keith,
It's a pity that you don't have the reference for your tweeter.
Wayne P. from Pi Speakers, used to have a model of a speaker (kit) with a piezo (KSN1038 http://www.audioroundtable.com/PiSpe...ges/16150.html ). In the mean time some years ago he did the upgrade of the kit with a new tweeter that you could buy from him. Now I don't know what he is using anymore (I looked and is a DX25), but you sure can give a look for yourself and ask him in the forum or by mail. He also sells the xover (cap) to go with. What's the sensitivity of your speaker(s)?
http://www.pispeakers.com/Products.html

[ivorcally]

Thanks,

There are some interesting discussions on piezos in that forum. It seems the KSN1038 is a horn unit though. I have found out that the KSN1036 is a similar-sized direct-radiating piezo but it has different contruction (plastic case, grille on front etc).

I'll keep looking...

Cheers

[ivorcally]

I'm still searching, but in the mean time, I have put together a picture of all of the different Motorola piezos that I have found, along with their part numbers. This may be of use to someone other than me

Here is the pic...

[ivorcally]

I'm still searching. Surely somebody must know something about these elusive tweeters? Even a model number would help.

I have got hold of a ksn1036 and it is quite different to mine. I'll do some careful listening and perhaps some measurements to see if they are compatible.

Keith

[col]

why not give up and get a modern pair of compression drivers and waveguides? Check out the earl geddes threads.

col.