In my experience the ribbon tweeters which use a kapton or other polymer film as a substrate for the aluminum ribbon conductor- such as the Fountek "Neo" series ribbons - are quite a bit sturdier and harder to damage from amplifier mishaps when directly driven. Of course, a big turn-on "pop" from a 100-watt amplifier can destroy even these.... never mind what would happen if you pulled the RCA interconnect cable from the input of the amp while it was on sending a burst of 60 Hz to the tweeter... but if your amp is only ~5 watts, you're not likely to damage one of these "film substrate" type tweeters no matter what. (YMMV)
HOWEVER- the PLEATED FOIL type ribbons are VERY susceptible to damage. What happens is a "pop" or other pulse or low frequency signal will STRETCH OUT the ribbon, un-pleating it, and now your ribbon is a little dangling piece of foil, hanging limply in the tweeter- rather than being a little pleated "diaphragm" sitting nicely in the magnetic field, able to respond to high-frequency signals, it is now a floppy little dangling piece of foil, not properly oriented in the magnetic field, and not capable of responding properly to signals. This can happen even with a SMALL "pop" or burst of bass.
You can also un-pleat the ribbon by BLOWING on it, or allowing strong wind from an open window to blow directly on it, etc. THESE PLEATED RIBBONS ARE DELICATE. Treat them kindly and they will give years of service.
SO with pleated-foil type ribbons ALWAYS use a series capacitor to limit low frequency signals from reaching the tweeter, even when using a tube amp!
For the rare ribbon tweeters that work down to 1.5~1.8 kHz, I use a 100 uF Solen film cap. These are pretty good sounding caps and are not outrageously expensive. Dayton Audio also sells a reasonably-priced film cap at 100 uF. For crossovers higher up, you can use a 50 or even 25 uF cap.
HOWEVER- the PLEATED FOIL type ribbons are VERY susceptible to damage. What happens is a "pop" or other pulse or low frequency signal will STRETCH OUT the ribbon, un-pleating it, and now your ribbon is a little dangling piece of foil, hanging limply in the tweeter- rather than being a little pleated "diaphragm" sitting nicely in the magnetic field, able to respond to high-frequency signals, it is now a floppy little dangling piece of foil, not properly oriented in the magnetic field, and not capable of responding properly to signals. This can happen even with a SMALL "pop" or burst of bass.
You can also un-pleat the ribbon by BLOWING on it, or allowing strong wind from an open window to blow directly on it, etc. THESE PLEATED RIBBONS ARE DELICATE. Treat them kindly and they will give years of service.
SO with pleated-foil type ribbons ALWAYS use a series capacitor to limit low frequency signals from reaching the tweeter, even when using a tube amp!
For the rare ribbon tweeters that work down to 1.5~1.8 kHz, I use a 100 uF Solen film cap. These are pretty good sounding caps and are not outrageously expensive. Dayton Audio also sells a reasonably-priced film cap at 100 uF. For crossovers higher up, you can use a 50 or even 25 uF cap.
Hi. Sorry to jump in on this thread. I have a pair of Linn active LK140 power amps and recently bought a pair of Fountek CD3 ribbons which have transformers built in apparently. The active crossovers are set at around 2.7Khz. Do I need to use a capacitor on the + terminal? I have a pair of quality 600v 8uF crossover caps here. Any helpful advice would be very much appreciated. Thanks.
Fountek NeoCd3.0
I'd suggest using a cap, the transformer inside the tweeter will pass signals down to the bass range.
I've found that using these Fountek tweeters works best above 3~4 kHz. Their frequency response extends down further, but they exhibit harmonic distortion, especially 3rd order, at lower frequencies. See default page
I'd suggest using a cap, the transformer inside the tweeter will pass signals down to the bass range.
I've found that using these Fountek tweeters works best above 3~4 kHz. Their frequency response extends down further, but they exhibit harmonic distortion, especially 3rd order, at lower frequencies. See default page
1-most (not all ) Pleated ribbons are very susceptible to high energy "pop" at turn on. they get stretched out
2- Transformers on small tweeters will block DC BUT! their cores can saturate at low freqency higher power signal and will be a short to the amp. Use a cap to avoid this
3- The Founteks claim to "rugged sandwich construction ribbon" is suspect. The neo 2 s that I have dissected do not seem to have a sandwich foil at all. Just a .0005 inch thick foil. This is a fairly rugged unit however as ribbons go. No pleat, thicker foil. They can be made to work well but they are best crossed at 2.5k min. If you go lower distortion rules.
4- as far as sensativity goes, buy the time you get some baffle step correction on the woffer end you usually end up with quite a low sensitivity overall so just about any reasonable tweeter sens can be made to work
5- we need a small (3-4 inch) ribbon that can goto 1 khz, workin on that one
2- Transformers on small tweeters will block DC BUT! their cores can saturate at low freqency higher power signal and will be a short to the amp. Use a cap to avoid this
3- The Founteks claim to "rugged sandwich construction ribbon" is suspect. The neo 2 s that I have dissected do not seem to have a sandwich foil at all. Just a .0005 inch thick foil. This is a fairly rugged unit however as ribbons go. No pleat, thicker foil. They can be made to work well but they are best crossed at 2.5k min. If you go lower distortion rules.
4- as far as sensativity goes, buy the time you get some baffle step correction on the woffer end you usually end up with quite a low sensitivity overall so just about any reasonable tweeter sens can be made to work
5- we need a small (3-4 inch) ribbon that can goto 1 khz, workin on that one
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5- we need a small (3-4 inch) ribbon that can goto 1 khz, workin on that one
PM when you have a pair ready.
So you're telling me that using a Krell amplifier of 125W/8ohm (250/4ohm)
Directly connected to my RAAL 70-10 is risky?
My ribbons play from 3k5hz and up at 48db/oct.
Been doing it for 6+ months of daily use. No issue so far.
Blew one ribbon once on a mistake I've made but it was entirely my fault and the replacement ribbon are like $30...
Was using 10uf blocking cap before for safety (Mundorf Supreme) but sound improved vastly when I've changed to direct connection. Turned out, they been direct connected since (amp only throw ~4mV of DC offset)
When people say that the Mundorf are transparent, I almost burst laughing...
They're better than solen but certainty not transparent IMHO!
Directly connected to my RAAL 70-10 is risky?
My ribbons play from 3k5hz and up at 48db/oct.
Been doing it for 6+ months of daily use. No issue so far.
Blew one ribbon once on a mistake I've made but it was entirely my fault and the replacement ribbon are like $30...
Was using 10uf blocking cap before for safety (Mundorf Supreme) but sound improved vastly when I've changed to direct connection. Turned out, they been direct connected since (amp only throw ~4mV of DC offset)
When people say that the Mundorf are transparent, I almost burst laughing...
They're better than solen but certainty not transparent IMHO!
I see no problems with what your doing so long as no low freqs gets through that cross over. If they do then yes the transformer could present a short to the amp.
BTW the "10uf blocking cap" and the issue of transparency. If you are crossing over at 3khz at 48db then why are you using a 10uf cap? that cap value will likley have an effect on your 3khz crossover possably being part of the reason you can hear their effect so well. I would try a 30 uf cap. That way the cap isnt effecting your crossover point but will still block very low freqs.
BTW the "10uf blocking cap" and the issue of transparency. If you are crossing over at 3khz at 48db then why are you using a 10uf cap? that cap value will likley have an effect on your 3khz crossover possably being part of the reason you can hear their effect so well. I would try a 30 uf cap. That way the cap isnt effecting your crossover point but will still block very low freqs.
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