Driving 4 and 8 ohm speakers at once

[Brockybear]

I have a set of Klipschorns and Palladiums and wondered if I can drive both together from the output transformer on my Cary 211 Triode amps? I have 4, 8 and 16 ohm taps on the transformer but dont want to do any damage. Is this ok or a No No?

[tube fanatic]

Firstly, why would you want to drive both simultaneously? I'm editing what I posted a few minutes ago- just had my coffee and realized that you said that the Palladiums are rated for 4 ohms. Do you know what the minimum impedance of those is? If it's down around 2 ohms, putting that in parallel with the K-horns will result in an extremely low impedance load across the amp at certain frequencies. While it would probably work at low volume (using the 4 ohm tap), the distortion will be high. You could try putting the speakers in series and using either the 4 or 8 ohm taps to see how things sound. I'm not familiar with that amp and don't know the characteristics of the output transformer and how Cary set up the circuit. Generally, I'm not in favor of doing that with tube amps, preferring SS amps for that application. More info would be useful.

[Brockybear]

I just wondered how they would sound together. The Khorns are just sitting unused now and thought I could do someting with them. I thought running both at once would probably put the wrong load on the amps.

[NOSValves]

Sure you can...run them in series and try the 8 and then the 16 ohm taps. Here is how you do it.

First attach the negative speaker wire from speaker #1 to the negative terminal of the amplifier, then attach the positive speaker wire from speaker #1 to the negative terminal of speaker #2, Now attach the positive speaker wire of speaker #2 to the 16 or 8 ohm positive terminal of the amplifier. By wiring them in series you now have a nominal impedance of 12 ohms. My bet is it will sound better on the 8 ohm tap but try both. Whatever sounds better to you is better..

[tube fanatic]

Sure you can...run them in series and try the 8 and then the 16 ohm taps. Here is how you do it.

First attach the negative speaker wire from speaker #1 to the negative terminal of the amplifier, then attach the positive speaker wire from speaker #1 to the negative terminal of speaker #2, Now attach the positive speaker wire of speaker #2 to the 16 or 8 ohm positive terminal of the amplifier. By wiring them in series you now have a nominal impedance of 12 ohms. My bet is it will sound better on the 8 ohm tap but try both. Whatever sounds better to you is better..

Remember though that the reactive/capacitive components of dissimilar speakers like that could cause frequency response issues for both, especially since the characteristics of the opts aren't known (at least not to me.) Btw, if I win the lottery, I may consider cutting you in for a share....................... Cheers

[Brockybear]

What if I just plug the Palladiums into the 4 ohm taps and the Khorns on the 8 ohm taps instead of wiring them in series?

[djk]

Put both in parallel and hook the pair between the 16Ω and 8Ω taps.

[tube fanatic]

Put both in parallel and hook the pair between the 16Ω and 8Ω taps.

djk is correct. I ran exact calculations and using those taps will correspond to 1.4 ohms. While I was at it, I also ran calcs for other tap combinations- if you need them, feel free to email.

Maynard