Bridging NAD C270 with 6 ohm speakers.

[NISSE]

Hi, people.
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I have two NAD C270 amplifiers (in very good shape) that I want to bridge. My loadspeakers are a pair og Dali with 6 ohm impedance. Can I use these speakers in a bridged setup without dangering the speakers or amplifiers? The load on the system will be normal, nothing extra.
Thx

 

[staticV3]

Proceed at your own risk.

 

[Dassen]

I have the same setup. Dual NAD C270 and a pair of Dali 6 ohm speakers. Running the amps in mono will make them see your speakers as 3 ohm which increases the current demand and strain the amps. I find that running them in stereo one amp for each speaker results in much more control and efficiently running, giving more dynamic and detailed sound.

 

[NISSE]

I don`t understand. Are you running two C270s in stereo mode, one channel from each amp? How does that work? With respect, never heard of anything like it. That means there is one channel running on each amp with no load. Can`t be good for the unwired channel? Or do I misunderstand your setup?
Anyway, thx.

 

[Dassen]

Yes. Each NAD C270 is set to stereo mode, meaning both of its channels are operational. However, I'm connecting only one channel on each amplifier to drive a single speaker. The channel that isn't connected to a speaker is still powered on as you say, but not loaded. This is perfectly fine for a solid-state amp like ours. I wouldn't do it on a tube amp.

By using each amp for a single speaker, full power supply of the amp is available to that speaker, giving the amp more headroom and better control and channel separation.

 

[Mikig]

Yes. Each NAD C270 is set to stereo mode, meaning both of its channels are operational. However, I'm connecting only one channel on each amplifier to drive a single speaker. The channel that isn't connected to a speaker is still powered on as you say, but not loaded. This is perfectly fine for a solid-state amp like ours. I wouldn't do it on a tube amp.

By using each amp for a single speaker, full power supply of the amp is available to that speaker, giving the amp more headroom and better control and channel separation.

if I understand correctly, sorry for the question: why do you use two stereo amplifiers to use only half of each amplifier? so you can safely use one: 1/2 plus 1/2 equals 1. Why use two? The mono bridge increases the power, the whole system works for one channel. So it's another thing. If your speakers have two pairs of input terminals you can try bi-amping, with two stereo power amps... but using two in half seems strange to me...

 

[Dassen]

This config gives the best sound quality for my system. I've tested the amps in bridge mode, using a single stereo amp, and now with this configuration. The current setup gives me cleaner bass, better dynamics and tighter control over the speakers. It's not about "using half of each amp" but rather about dedicating the full potential of each amp to one speaker for best performance possible, splitting the load and signal across two amps.

My speakers, Dali Fazon F5, only have single input terminals, so bi-amping isn't an option. Otherwise that would off course be an interesting alternative.

 

[NISSE]

This config gives the best sound quality for my system. I've tested the amps in bridge mode, using a single stereo amp, and now with this configuration. The current setup gives me cleaner bass, better dynamics and tighter control over the speakers. It's not about "using half of each amp" but rather about dedicating the full potential of each amp to one speaker for best performance possible, splitting the load and signal across two amps.

The thing is that the Dalis are 6 ohm and outside the recomended speaker load for a bridged system. I will for sure try out Dassens setup, but I have my doubts, especially running one channel without load, over time. In bridge mode the amps should see 3 ohm (the C270 has it`s own tech to read the load) and with normal use I can not see any problem. The sound, specially increased distorsion, is another case.
We can agree upon one thing though, that the C270 is a mighty good amplifier. With a good pre and Dali speakers (Peter Lyngdorf, the founder of Dali, was and still is, a big contributer to NADs development) the C270 gives a lot of joy.
I will try to bridge the two amps (with my 6 ohm Dali speakers) and keep an eye, or both eyes, on heating.
Thx.

 

[Dassen]

You’re absolutely right—it's all about trying different setups and going with what works for your preferences.

I ran my C270s in bridge mode with my 6-ohm Dalis and, while they could be played at higher volumes, the amps got very hot even at moderate volumes. One even blew an internal fuse. The sound had more distortion and less clarity compared to stereo mode, where each amp drives one speaker. In stereo mode, the clarity and bass control were much better.

As for the unused channel in stereo mode, there’s no issue—it’s like an unused power socket in your house. It won’t harm the amp.

Let us know how it goes with your testing. Always fun to experiment!

 

[Svend P]

None of the proposed solutions will have any audible effect.

Bi-amping 101

This article provides a quick look at how bi-amplification works. The conventional scheme is to split the signal into two frequency bands before the power amplifiers that drive the speakers. The bass (LF) amp sees only LF signals and drives only the LF driver (woofer). The treble (HF) amp sees...

www.audiosciencereview.com

 

[Old_School_Brad]

Why do you want to bridge them? -What is your goal?

 

[pogo]

Do your Dalis offer the option of bi-amping?
If so, I would try out two variants.
1) Horizontal bi-amping.
2) Using a C270 for each speaker, i.e. one channel supplies the low frequency part and the other channel the mid-high frequency part (vertical bi-amping).
With both variants, all speaker outputs should be used if possible, i.e. speakers A+B.

 

[Svend P]

Do your Dalis offer the option of bi-amping?
If so, I would try out two variants.
1) Horizontal bi-amping.
2) Using a C270 for each speaker, i.e. one channel supplies the low frequency part and the other channel the mid-high frequency part (vertical bi-amping).
With both variants, all speaker outputs should be used if possible, i.e. speakers A+B.

Why? It will not sound any different.

 

[pogo]

Evidence?

 

[Svend P]

Evidence?

It is not possible to prove a negative. You have to provide proof that people can hear a difference in a level matched blind test.

 

[NISSE]

Why do you want to bridge them? -What is your goal?

More power overall.
Thx

 

[NISSE]

View attachment 417602

Proceed at your own risk.

I will. Bridging might not be the thing I need or want, but overall I want more power. My hope is that 2xC270 bridged will perform better, specially on lower levels, than one do in stereo. I will try with the 6 ohm Dalis and keep both eyes (and one hand) on heating. Again it`s all about what I hear, not what I read. The two C270 I have is in very good shape.
Thx. I

 

[staticV3]

My hope is that 2xC270 bridged will perform better, specially on lower levels

The most that bridging an Amp can achieve is increasing headroom, so enabling louder playback before the Amp clips.

Hoping for better low-volume playback is a pipe dream. There's no mechanism that could enable that.

 

[NISSE]

The most that bridging an Amp can achieve is increasing headroom, so enabling louder playback before the Amp clips.

Hoping for better low-volume playback is a pipe dream. There's no mechanism that could enable that.

Sorry, mate. What's a "pipe-dream"? Whishful thinking, so to say?
Thx for your input

 

[staticV3]

Sorry, mate. What's a "pipe-dream"?

See here: https://www.google.com/search?q=pipe+dream