impedance matching to a pro amp...

[MyNameIsJake]

hi all,

im looking to be building some home theater subs and was looking to purchase this amp to power them. now i did a search in here for impedance matching, but did not find much, if i missed something, i am sorry, then please direct me to the right section of the forum/thread. but anyway, my yamaha RX-V2500's sub pre-out is 500ohms and the amps unbalanced input is 10K ohms. i did a google search and found a product on P.E's site that looks like it would work here but there has got to be a better way.

in other words, what would be the best way to mach the impedance of both devices for best sound? i would prefer a active solution to minimize signal loss, but if a passive solution is best, i would like to know. whether its a diy circuit or a product on the market that i could use, i would like to know.

any advice would be much apresheated... thanks

[richie00boy]

I think you are confusing impedance matching (which is not necessary with audio line level signals, in fact you want low source impedance and high amp impedance) with unbalanced source/balanced amp driving.

If you want to take advantages of the balanced connection of the amp then you will need that box. Balanced lines offer you the ability to avoid ground loops and good interference rejection of long cable runs. If you aren't suffering with either of these then there is no pressing need to buy the little box and you just need a RCA > XLR lead.

[AndrewT]

Hi,
for ordinary audio interconnect between source and amplifier, it is normal to arrange for the source impedance to be less than 10% of the input impedance. Moving towards 1% will give a small improvement in noise rejection due to low source impedance.

Impedance matching is generally reserved for tube amplification, transformer coupling and RF/VHF transmission lines. In general audio can ignore it.