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balanced output into 2 stereo amps a good idea?

davidismynaim

davidismynaim

pfm Member
Hi there. I am currently running active 2x250 naim power amps into a pair of SBLs. To satisfy a boy hood dream, I have recently picked up a pair of Yamaha NS1000M. I plan to try them out instead of the SBLs, if they impress, then i will sell SBLs and retain the NS1000s.

I use an M-DAC which supports balanced XLR output. My question is would a differential set-up make sense and work with Naim amps. I know I would have to make up a cable wired so that pin 2 (hot) of XLR is sent to left, and pin 3 (cold) sent to right. Then connect up the speaker to the red terminals only.

Am I right in assuming that this would benefit from the noise cancelling affect and yield double the power (bridged). Or am I talking nonsense. If this idea does not fly, what are the other options?

1. Sell 1 power amp
2. only drive 1 channel in each amp - seems a waste
3. figure out a hybrid active arrangement. 1 amp driving the bass, the other to drive the mid/tweeter - I assume I would have to get someone to build a new or modify the existing passive crossover to handle the split on the mid/hf, could I use the SNAXO for the bass to mid/hf split? or is this mad too?

Ideas, experience and thoughts appreciated.
 
it would work electrically since the two outputs are in antiphase and you are using them as two seperate unbalanced outputs to create a bridged setup.

there will be absolutely no noise cancelling going on.

there is no advantage in sound quality in bridged configuration as you are increasing the output impedance and increasing the amps damping factor as a result.

I would advise running the dac with cold strapped to earth and the speakers connected conventionally so you are comparing like with like.


I would be very surprised if you preferred NS1000's to SBL's.
 
You must be bored with the consistency with which you are wrong..

What is your opinion of my response to the actual question or do you just filter out the bits you like to disagree with?
 
I would try option 2 as you will be effectively using each 250 as a 135. The performance will improve as each channel has its own dedicated power supply.

Then take it from there.

I wouldn't bother with balanced inputs as these really come into their own with long cable runs and in a noisy environment like in a studio.

Cheers,

DV
 
You could parallel the channels for best results... Not a good idea if you don't have some test gear to check for stability issues etc though...
 
Given that Naim amps are said to have stability problems when not used with their own special wire I would be very wary about using them either bridged or in parallel, certainly without proper checks, as mentioned above.
 
It's certainly do-able but issues such as exact gain matching can be important so, as you would probably expect to see me say.... it would be best to send them to someone such as myself to do the job properly and check for any issues ;)
 
My understanding is that there would be balanced like benefits re noise. Ie both the hot and cold line would attract the same noise. Ie if the voltage is +3 and has 0.01 noise on the hot. And the cold is -3 it to will have +0.01 on it. The speaker will see the sum. Ie 3.01+2.99=6, thereby negating the noise. Have I got this wrong? What in this arrangement de-stablises the amp?
 
The noise is removed by inverting the cold then adding it to hot

This doubles the signal level and removes the picked up noise

You are not doing this in the bridged setup
 
Already got one thanks :) but looking to reduce links in the chain. Still don't see why the proposed arrangement would not negate any noise between DAC and amp.
 
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