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
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
Attachments
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
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
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
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
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
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
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
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
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/PiSpeakers/messages/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
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/PiSpeakers/messages/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
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
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
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
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
why not give up and get a modern pair of compression drivers and waveguides? Check out the earl geddes threads.
col.
col.
I have various models brand new original Motorola tweeters. Some of the later CTS units exactly the same. The original factory for the Motorola PZT (Under very strict security as it was a patented method) units were in Albuquerque NM. Ceramic was molded into a shaft and baked. Then it was cut into thin wafers with a water jet which formed the driver part. The Ceramic units was sent to Mexico where the actual plastic parts were added to complete the tweeters and drivers. Then it was shipped back to Albuquerque from where it was shipped world wide. Later this plant in NM was sold to a company called CTS and they carried on on the same premises with the same equipment running it the same way as Motorola did before. The only visible difference was the CTS marking instead of Motorola. Some tweeters had no markings at all Some were marked on the flare. But I could recognize any of them compared to copy units. Motorola plastic has a distinctive touch feel and texture. Later the NM plant stopped making tweeter parts as it was more economical to manufacture parts for the telecommunication industry. The Dies and Molds were sold to a company in CA. But prices shot up like crazy. We used to sell thousands of tweeters. It used to be very economical to build your own speakers but at some point our import taxes dropped and Chinese speakers started to flood our markets. Tweeter sales dropped. We could not even give away the stuff. No one wanted ceramic tweeters. The stock sat on my shelve and then a while ago I started to realize I am sitting on a good investment. I am starting to get more and more enquiries from all over. Average price $15
alvmatrix, as a new member your posts are moderated which means they must be read and approved before going live.
This is an old thread... if you have items for sale then please post them in 'Swap Meet' forum.
Thanks 🙂
I've used the KSN1036 type on a wooden horn driven with a matching transformer, smooth down to 800hz or so, very efficient.
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