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-   -   BG Neo3 PDR ribbons... (http://www.diyaudio.com/forums/swap-meet/18097-bg-neo3-pdr-ribbons.html)

CV 23rd July 2003 05:00 PM

BG Neo3 PDR ribbons...
 
Hello

Have 48 pieces to sell of the raw version, some very lightly used, most untouched. Originally intended for use in a line array, plans change...

Sensible offers invited for the lot.

eg

http://www.partsexpress.com/pe/pshow...=264-714&DID=7

cheers
Chris

Andypairo 24th July 2003 03:51 PM

I think you'd receive more offers selling pairs...

How much would you ask for a couple of 'em?

Cheers

Andrea

CV 24th July 2003 04:57 PM

Neo3 PDR pairs
 
Hello Andrea,

35 a pair seem reasonable?

cheers
Chris

Andypairo 24th July 2003 05:35 PM

It depends;)

Other important factors are the shipping costs and the way of payment, since bank transfers are very costly.
Paypal would be the best choice.

The one you have is the version without faceplate, right?
Can they be employed as a normal tweeter or only as a dipole?

Cheers

Andrea

CV 25th July 2003 11:06 AM

Hello Andrea,

Correct - the ones I have are the "raw" driver - no faceplate.

They certainly don't have to be used as dipoles; just be sure to control the backwave if you are using them as monopoles.

As for shipping/payment, I'm not setup on PayPal (it's high time I were...)- if someone wanted to take the whole lot, I've got a couple of friends who are setup, but I wouldn't want to pester them with lots of little orders.

Actually, I'd gladly take Euros sent by registered mail, if that suits, as I'll probably be visiting Europe in a few months time. If not, I'll happily swap them for a couple of bottles of Barolo :-)

Posting a pair of Neos to Italy wouldn't cost much at all - they're very thin and could be quite safely packed in a large envelope.

Best,
cv

fdegrove 25th July 2003 11:26 AM

Hi,

Quote:

They certainly don't have to be used as dipoles; just be sure to control the backwave if you are using them as monopoles.
Just be aware that boxing a dipole tweeter will inevitably roll-off some high frequency.


Cheers,;)

CV 25th July 2003 12:59 PM

Actually Frank, there is a version with a backchamber where the response is extended relative to the dipole; waterfall and sonics not quite as clean apparently. I'd guess constructive interference/resonance at the very top extending the response to 40k.

But in any case, just curious - why would boxing a dipole give an earlier LF rolloff?

I was planning to use these as a line array, all in series, to give a nice 80-100 ohm load for OTLs, so at least you'd approve of the amp choice :-)

cheers

fdegrove 25th July 2003 02:09 PM

Hi,

Quote:

I'd guess constructive interference/resonance at the very top extending the response to 40k.
If the membrane does this naturally then fine.
If not then what you see on the frequency plot are resonances and reflection from the back of the chamber.

Either way I was just pointing out the risks involved.

If you check on the B&G website you'll see that the boxed versions only reach to 18KHz.
This is to be expected since, in order to avoid exciting resonances, they need to use damping which inevitably takes away energy at the top frequencies.

FWIW I use a ribbon tweeter in my speakers as well, not a dipole though.
Actually since you're in the U.K you may know them: SD Acoustics SD1. It's the first one they made from the mid-eighties.

The tweeter is a unit from Visaton, it's out of production now but the one they're still manufacturing is very close, maybe even better.


Quote:

I was planning to use these as a line array, all in series, to give a nice 80-100 ohm load for OTLs, so at least you'd approve of the amp choice :-)
That's a lot of unit's in series.:cool:
BTW, the OTL would be just as happy driving an 8 Ohm resistive load, even 4 Ohm would be fine.
That's the beauty of ribbons, they're so easy on the amp...

I won't mention a certain U.S. brand, of course.:rolleyes:

So, you gave up on the speaker project and the OTL or just one of them?

Cheers,;)

capslock 25th July 2003 02:14 PM

Is it the i-Version, i.e. does the label read "Neo3-PDR-i"?

Regards,

Eric

CV 25th July 2003 02:18 PM

Hi Frank,

Yeah - I concur, nice smooth resistive load - even if the absolute impedance level is difficult, the frequency response with an OTL will still be smooth. I was thinking 6C33 SRPP into 100 ohms would make quite a nice treble amp...small coupling caps too.

Why I'm looking to sell? Well, I was planning to use the tweeters in conjunction with ESL mids cos I was afraid the amps I've got planned wouldn't drive the ESLs into the treble (slew and frequency response). Some preliminary experiments indicate that I should be ok; and if not, I've been looking for an excuse to build a plasma tweeter for ages....

That, and I need the cash...

best,
cv


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