Ok I know this isn't 'pro-audio' equipment, but it's what I have to work with
and I will be making recordings using it, as well as for general use, so which
would you use for monitoring, if you were me? I'd like to hear comments from
people who appreciate the quality of 70s consumer hi-fi equipment.

JVC JR-S201 receiver - This a big receiver from 1980, before JVC started making
crap. I find the amplifier to be very quiet and it's what I'm currently using.
It has a subsonic filter to protect my speaker cones which the others don't
(I will be sampling from vinyl occasionally), and uses Darlington power packs.
Probably around 70watts per channel

Rotel RA-611 amplifier - This is an amplifier, probably from the late-70s.
It's smaller than the JVC's amplifier, probably around 40 watts per channel.
No subsonic filter, though.

Sansui 221 receiver - This is an early 1970s receiver from a line
highly-regarded by Sansui enthusiasts. It's very small, 20watts per channel.
Again, no subsonic filter.

So far I like the JVC the best, it has the subsonic filter, an extra 5-band EQ
that I rarely use but occasionally comes in handy when listening to spoken
lectures, and it seems to be very well-built. But Rotel is a better name, and
the Sansui has a pretty sweet sound - I've heard that smaller amplifiers
generally sound better at average volume levels than large amplifiers, is that
true? Also, both the Sansui and the JVC can accept 4ohm speakers on one set of
channels, whereas the Rotel's channels are both only rated for 8ohms, and
although I don't intend on using 4ohm speakers, it leads me to believe the
Sansui and JVC have more robust amplifiers than the Rotel.

Any comments other than telling me to go buy a better amplifier would
be appreciated! I do not go out and buy things when I think I need them. I
make do with what I have until something better comes along that is a really
good deal, which I then take advantage of.