How to split pre out to connect power amp and sub

Re the resistor, this is the particular one I suggested, which is probably what you've just looked at:

http://www.radioshack.com/product/index.jsp?productId=2062288&tab=summary

The photo appears to not include the full length of the wires coming out of each end. Those wires are undoubtedly much longer than what is shown in the photo, which should allow you to simply connect the wire from one end directly to the red speaker terminal, and the wire from the other end directly to the black terminal (using one resistor for one channel and another resistor for the other channel).

Regards,
-- Al

Again, I must thank you very much for this detailled answer. You are a person of great advice, and though I'm really new to the field of Hifi, I managed to understand all of what you said (at least I think so..)

Cable lengh won't be a problem, I have kept it between 6 and 10 feet actually.

I've emailed Scandyna about the input impedance of the sub, I'll see what they say about it.

Fortunately, the shanling and the primaluna don't seem to be a mismatch, at least !!

I understand now that I can't take the risk of not connecting speakers (or a resistance) to the Shanling. But the fact that there is a pre-out still leaves me wondering. How do normal people like me do, who have no knowledge of physics ?? I mean, I read the manual, and it was clearly specified that the pre-out was to welcome a power amp if needed. How should I know that it will fry the Shanling if I really do so ! It's mad.. There might be a built in systeme as you say, but who would want to take the risk ?!

About the resistance, do you get them in a normal Hifi shop ?

Actually, Scandyna The Ball 2.1 input inpedance may be specified in this document : http://www.podspeakers.com/Files/Filer/specs/the_ball21.pdf

it reads :
L,R input sensitivity : Input @ 1kHz 450mVrms @ rate power output
Sub input sensitivity : Input @ 1kHz 270mVrms @ rate power output

Is it correct ?

Not sure if a typical hifi shop would have a suitable resistor or equivalent device. They commonly have accessories to convert speaker level outputs to line-level signals, but those are usually designed for use with solid state amps, and present a high impedance (rather than an 8 ohm or so impedance) to the amp output.

An electronic components distributor, such as digikey.com or mouser.com, would likely have something suitable.

The Scandyna specs you quoted do not indicate input impedance, just input sensitivity. An impedance rating would be specified in ohms (or "K," denoting thousands of ohms).

How do normal people like me do, who have no knowledge of physics ?? I mean, I read the manual, and it was clearly specified that the pre-out was to welcome a power amp if needed. How should I know that it will fry the Shanling if I really do so ! It's mad..

Good question! Reminds me of computers, about which I happen to be very expert. And sometimes when even I am struggling with a difficult problem, I wonder to myself how a typical non-technical computer user is supposed to be able to deal with such problems. :)

Again, it's possible that the design has some special provision to minimize the likelihood of damage, perhaps helped by the fact that the power output is so low, but I definitely would not want to take that chance. And attaching the resistors will be very simple, as long as you can obtain them in your area or by purchasing via the internet.

Good luck!
-- Al