Neil's Secondhand Naim Buyers Guide
PREAMPS (NAC)
32
The original preamp ran from one 24v rail (the supply was called a Snaps).
The circuits were printed on half a dozen little boards, which then
slotted onto a mother board. As well as the phono input, it had a tape,
tuner, and another aux input. Second hand price around 125 pounds.
42
Essentially the same amp as the 32, but the 42 series amps had one less
input than the 32 series (ie, only phono, tape and aux). The other
difference with the 42 series is that, with the exception of the phono
cards, the components were all put on the mother board. There was a slight
difference in appearance too, in that the 42 had large volume and selector
knobs whereas the 32 had smaller ones. Again, it ran from a single 24v
supply. Second hand price around 100 pounds.
32.5
The .5 extension denotes the next generation of preamps where the single
power rail is split in half, keeping the phono cards on a separate rail to
the rest of the preamp. The 32.5 (and 42.5) could then be used with the
newly introduced Hicap power supply, which supplied two 24v rails. The amp
was given two phono inputs for some reason (ie, 2 x phono, tape,tuner,
aux) but I don't see any reason why you couldn't use `straight through'
cards to effectively turn the second phono input into another line level
input (in fact I have done this in the past and it seems to work fine, and
I actually prefer the BNC connections).
This might be a consideration for those of you looking for a
second hand amp that'll handle tape/CD/tuner/video connections. On the .5
amps, there was slightly better earthing routing, and better volume and
balance pots too, and on the later (after about 1985) preamps, the
selector switching was done with a remote link that switched connections
near the actual input sockets at the back of the amp rather than running
wires to the front and back again. Also worth noting for tape users, the
32 and 72 series preamps had buffering on the tape output which help in
getting good recordings.
Second hand price around 225 pounds.
42.5
Same differences as between the 32 and 42, ie, one less aux input, and
also didn't have the second phono input of the 32.5, The components were
still on the mother board rather than slot-in boards. The 42.5 would run
from a Hicap in the same way as the 32.5. Second hand price around 200
pounds.
62
Basically a 32.5 but with the circuits printed on a mother board as in the
42.5. However it didn't have tape output buffering though (so perhaps
better to think of it as a revamped 42.5 with an extra input). Again Naim
improved the earthing routes slightly and put a better balance control
arrangement in. Powered from the Hicap as with the 32.5 and 42.5. The 62
straddled the change to the new styling (ie, you can get both second
hand). Old style second hand price around 250 pounds. New style is around
350 pounds. I have to say, this is by far my favourite amp in all of
Naim's repertoire for modding. It is simple, and responds wonderfully to a
little love and attention!
72
Same as the 62 to look at, but incorporating some slight circuit tweaks
and some improved components according to Naim. The components are on
slot-in boards as with the 32.5 (in fact you could buy some of the boards
to put in your 32.5). The amp is still powered from the two channel Hicap
arrangement (ie, separate power rails for the phono stage, and the rest of
the amp). Only has one phono input but has an extra line level input.
Again, tape output buffering.
Second hand price is around 350 to 400 pounds.