Test CD s, which ones to get.

Get the Ayre Irrational, but Efficacious system enhancement disc.
Talk about a shortcut to greatness.
This disc will wake up your system by putting it through the ringer.
There's no music to impress your friends when they come over, rather,
full frequency sweeps, pink, brown and white noise, in and out of phase, and whatever else it does, it does it extremely well. Any gear that passes a signal will benefit from it.
After that, just about anything you play will sound great, if not better.
You can get the best price from Elusive Disc. They gave me an unadvertised discount of 15% and offer USPS which is all you need for shipping. Every other site didn't which dramatically increased the cost.

All the best,
Nonoise

Yep, the Ayre is a good one.

If you talking about proper technicians test cd's then you can't go passed.

1:  http://www.stereophile.com/content/recording-november-1988-ipierre-verany-digital-test-cdi#IQ1OYpDXIOxd1TJ4.97

2: http://www.allmusic.com/album/denon-audio-technical-cd-mw0000150515

These are the ones I have, not cheap but good tools.

Cheers George

Good offers- George.