I've a pair of -6dB Goldenjacks on my I/Cs to attenuate the overly healthy output of my CDP into my pre. (both valved). My attenuators can be used either way as I end up with male RCAs anyway. However, it makes sense to me to put them at the pre. end simply because the signal is truncated with the smallest path to preamplification.
I've never tried it t'other way around (maybe I should), but when VINNY says they are directional, I assume that I cannot use them at the CDP end, unless he's referring to s.q. rather than actual signal.
I can, it seems, either keep the I/Cs as is and simply insert the attenuators at the CDP end or just reverse the whole shebang, thus reversing the I/C polarity (not keen on that one).
I still can't get over the amazement when I first fitted them that there was no discernible effect on s.q., whereas -10 and -15dB attenuators I'd tried previously had a marked negative effect.