Amp that drives Ribbon Tweeter directly at low impedance?

[RedJacket]

Are there currently amps on the market that are able to drive the extremely low impedance Ribbon Tweeters (no transformer required)?

 

[TLS Guy]

Are there currently amps on the market that are able to drive the extremely low impedance Ribbon Tweeters (no transformer required)?

No. And you never drive a tweeter and especially not a ribbon directly. You always drive it via an inline cap, unless you want short half lives of your tweeters.

 

[Swerd]

No. And you never drive a tweeter and especially not a ribbon directly. You always drive it via an inline cap, unless you want short half lives of your tweeters.

+1!

In addition to what TLS Guy says, if you drive any tweeter directly from an amplifier, without any active or passive high-pass filter protection, you will probably void the manufacturer's warranty and have to pay for it's replacement yourself.

Edit:
Just in case you already realized that all tweeters must have some sort of high-pass filter protection, your original question, leads to this question:

Why do you want a separate amp to drive a tweeter? They aren't difficult to drive, and they don't require high power. That includes ribbon tweeters.

 

[RedJacket]

I guess a more general question is how to make ribbon tweeters transformerless? Can any amp match the incredibly low impedance? Perhaps current source amps?

 

[TLS Guy]

I guess a more general question is how to make ribbon tweeters transformerless? Can any amp match the incredibly low impedance? Perhaps current source amps?

The answer to that is no. There is no such thing as a current source amp. Voltage always drives current. Zero voltage equals zero amps.

Next tow questions.

What have you got against transformers?

Why are you so attached to ribbons, which on the whole are not as good as moving coil drivers?

 

[RedJacket]

http://www.firstwatt.com/pdf/art_cs_amps.pdf - guy claiming he has developed a current source amp that interfaces directly with a ribbon (no transformer required) and actually improves the sonics.

And anyone who has heard ribbons knows how good they are. But implementation challenges, including transformer design, have prevented their widespread use...I am interested in solving these challenges.

 

[AcuDefTechGuy]

And anyone who has heard ribbons knows how good they are.

Yeah, I've heard ribbons. I used to own speakers with ribbons. Been there. Done it. They do sound great. But not any better than other great speakers I've heard.

 

[slipperybidness]

http://www.firstwatt.com/pdf/art_cs_amps.pdf - guy claiming he has developed a current source amp that interfaces directly with a ribbon (no transformer required) and actually improves the sonics.

And anyone who has heard ribbons knows how good they are. But implementation challenges, including transformer design, have prevented their widespread use...I am interested in solving these challenges.

Well, it's not "some guy" making the claim, it's Nelson Pass making the claim!

I'll have to read up on this, but I am certainly interested in TLS's opinion on the matter.

 

[markw]

http://www.firstwatt.com/pdf/art_cs_amps.pdf - guy claiming he has developed a current source amp that interfaces directly with a ribbon (no transformer required) and actually improves the sonics.

And anyone who has heard ribbons knows how good they are. But implementation challenges, including transformer design, have prevented their widespread use...I am interested in solving these challenges.

Well then, it seems you've answered your own question. Discussion over.

You really have no idea who that "guy" is, do you?

 

[lsiberian]

Unless you are doing an active speaker I don't understand why you want this. What is your design goal for this loudspeakers project?

 

[RedJacket]

Design goal is to make a transformerless ribbon

 

[audiomagnate]

Design goal is to make a transformerless ribbon

Has anybody achieved this goal? I'm running double Aurum Cantus ribbons with an electronic crossover and a blocking cap and would love to hear what they sound like without the transformer.

 

[Swerd]

As far as I understand things, to work with a conventional audio amplifier, a ribbon tweeter requires a transformer. In all ribbon tweeters that I know of, the amplifier output is applied to a step-up transformer which provide very high voltage and low current to the ribbon/magnet assembly. In this sense, ribbon tweeters work similar to electrostatic drivers.

So I have to ask, what do you have against transformers? Without them, ribbon drivers cannot work with standard audio amplifiers.

 

[TLS Guy]

As far as I understand things, to work with a conventional audio amplifier, a ribbon tweeter requires a transformer. In all ribbon tweeters that I know of, the amplifier output is applied to a step-up transformer which provide very high voltage and low current to the ribbon/magnet assembly. In this sense, ribbon tweeters work similar to electrostatic drivers.

So I have to ask, what do you have against transformers? Without them, ribbon drivers cannot work with standard audio amplifiers.

Sorry to correct you, but a ribbon is the exact opposite of an electrostatic. The ribbon element presents an almost dead short as a load. So the transformer balances the extremely low impedance of the ribbon to the amp, by lowering the voltage and allowing for high current.

I know of no output devices that could possible cope with the very low impedance presented by the ribbon. For one ting the internal resistance of the devices would be much higher then the resistance of the ribbon.

 

[Swerd]

Sorry to correct you, but a ribbon is the exact opposite of an electrostatic. The ribbon element presents an almost dead short as a load. So the transformer balances the extremely low impedance of the ribbon to the amp, by lowering the voltage and allowing for high current.

I'm not sorry to be corrected if I'm wrong. After I posted that, I wondered if I got it backwards. Thanks.

Still, a ribbon and an electrostatic speaker both require transformers before they can work with standard audio amps.

 

[TLS Guy]

I'm not sorry to be corrected if I'm wrong. After I posted that, I wondered if I got it backwards. Thanks.

Still, a ribbon and an electrostatic speaker both require transformers before they can work with standard audio amps.

They do. Electrostatics have been driven from specialized tube amps right off the output stage without an output transformer though.

 

[psm]

- direct drive transformerless current or voltage drive is absolutely a possibility. However, it requires a specialized high current/low voltage amplifier located within centimeters of ribbon for IR loss reasons.
- The solution could work very well, but would be hard and expensive to implement as compared to a transformer and a passive crossover, and obviously would require an active crossover.
- AC coupling to the ribbon is not required if the amplifier is designed properly for the application.
- I'm not saying that this is easy. However, in the world outside audio there are plenty of applications where the load impedance is not 4 or 8 ohms. If there is a demand there could be market.