dlucy: Yup, 120 V/µs for the hk825 and 160 V/µs for the matching hk870, iirc - with the bandwidth reaching up to 180 kHz (-3 dB) for each. I didn't really buy my own 825/870 combo for that, though - but rather because it seemed nice and attractively priced, as it was on sale-out at that time. The only drawback was that they only had the 825 in champagne and the 870 in black - but that didn't disturb me. In fact it turned out that I even like it, that the pre-amp sticks out a bit from my otherwise predominantly black gear.
Just a pity I haven't used the combo for too long after a move - so that it now would most probably be in need of a thorough restoration. And as I couldn't do that myself (already for insufficient workspace, but also for it not being unlikely to exceed my skills...), a professional restoration would probably cost me about as much as the combo cost me new back then... Hence I'm still debating with myself, what I should do. Because on one hand I don't really have a need for it, especially as I listen via headphones most of the time anyway, but on the other hand I already own it, and it's still in pretty immaculate cosmetic condition - and it's not like I had absolutely no use for it... So I'm rather torn in that matter.