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[audiobill]

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[admin]

Hi Bill.
First, that is one hell of a good sized room you got there. That must be great, especially for speakers like maggies that really like their space.

As your question. I think the answer is that 140 wpc is very good for maggies. Even though they are not efficient speakers, I've heard maggies played with 30 watt tube amps and they sounded excellent at reasonable listening levels. Now with that said. Maggies really like power. The resistance of the speakers can drop well below the 4 ohm range on the lower notes and having the extra power to handle that will often bring the speaker to life.

140 watts is certainly enough but if it's feasible to go higher, then I would recommend it. Again, not because 140 wpc is inadequate, but rather to take the sound to that extra level.

You could always test out the biamp set up on a single speaker before committing to a purchase of two more amps.

[audiobill]

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[admin]

Oh, ok. I misunderstood. In that case I think you should just try both configurations and see which one sounds better! I think they will be rather similar but you may get better response on the low end with the bridged formation as you will have more power available for those lower resistance troughs.

[audiobill]

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[jeffreybehr]

First, as I understand it (and I certainly could be wrong), the two channels of a tubed poweramp CANNOT be 'bridged'.. Grossly oversimplified, 'bridging' is a way to convert two channels of a solidstate amp into a potentially LOTS-higher-power amp by, essentially, running the two channels in parallel but in opposite polarity.. This has the effect of doubling the powersupply Voltage and thereby quadrupling maximum power..

One POTENTIALLY can wire two channels of a tubed stero amp* in PARALLEL, which will create a single-channel amp of twice the max. power into one-half the rated impedance of one channel.. IOW, your stereo amp of 140 Watts max. power per channel into 4 Ohms becomes a max.-280-Watts-into-TWO-Ohms single-channel amp, which IMHO is exactly what you want to do for your sometimes-quite-low-impedance 'Pans.. FWIW, biamping a speaker system that consumes much less power into its higher-frequency 'half' wastes a good bit of the power of the channel that drives the higher frequencies.. IOW, you're using a quite-expensive 140-Watt amp to drive a maximum of 5? 10? 20? watts into the MR and tweeter of your speakers.

Definitely check with c-j for the exact way to do this.

* and some SS poweramps like my former First Watt J2s.
.

[audiobill]

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[admin]

Hi audiobill,
Perhaps my information is incorrect but I thought I read that magnepan speakers due have a tendency to drop their resistance quite a bit, especially on the mid-low end. Admittedly, I have never done the measurements myself so I can certainly be wrong. It could also vary depending on their speaker model as well?

This is an article about the magnepan LRS with measurement dips into the upper 2 ohm region. https://www.stereophile.com/content/mag ... asurements

[audiobill]

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[admin]

Very interesting. I didn't think that the different models would have such different resistance patterns. Good information, thanks.

[roberto]

Hola,

On the other hand, doubling the power, will provide only +3dB of SPL...take this into consideration. Remember, +3dB means double of power.

https://geoffthegreygeek.com/amplifier-power/

Happy listening¡

[audiobill]

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[joeinid]

Excellent news! Happy to see everything is working great.

Some speakers like Magnepan love the extra juice. Well done.