[jules]

I'm considering the possibility of using a Burson buffer between my NAD 5420 CD player and my AKSA  gear. It seems the buffer is best suite to situations where the output impedance of the source is high. I have no idea what the output impedance of the NAD might be. Can anyone help me on this or alternatelty advise me if there's a way to figure it out?

jules

[Occam]

Jules,

Measure it. You'll need a test cd with a constant tone and a voltmeter of some sort that can measure  RMS voltage at audio frequencies. (I finally broke down and bought a usb based digital storage oscilloscope which have all sorts of these capabilities, the NZ based Cleverscope)
Measure the output voltage from the NAD while playing the specific single tone, single level track. Vo. Put a resistor, R, across the output and measure the voltage across that resistor, Vr, while playing that same track. 5k Ohm should work well; enough to put some load on the output device, but not enough to fry it.
By Ohm's Law -
Zo = R (Vo -Vr) / Vr

I use the stereophile test cd, but you can download test tones at various levels off the net and burn your own test cd.

EDIT - the current Nad 542 is specified as having a 150 ohm output impedance, so I'd imagine that Nad specified the 5420 similarly. FWIW

[jules]

Paul,

thanks ... you've covered everything and explained it beautifully, so that even I can understand it.

The 5420 is, I confess, nearly 20 years old so the similarity in its model number to current NADs might not mean much as far as impedance goes.

jules

[jules]

and the impedance is ... 120 Ohm!

jules

[Occam]

......
 

I've been looking for an excuse (however lame) to use Lonewolf's spiffy smiley.