Getting started

RNPQuickstartV050 Page 4 of 10
FMR Audio, [phone] www.fmraudio.com
sought-after vintage micpre noise levels are much worse than the RNPs, so in
actual use, I concluded that many folks (particularly those “in-the-know”), when
a choice must be made, prefer tone to low-noise. Second, even though we have
internal versions of the RNP with a “competitive” EIN, we’d have to charge more
for the privilege of meeting lab measurements that few actual applications would
challenge. Third, the trend in microphone development has been to raise the out-
put level of microphones, thereby reducing overall gain requirements of external
micpres. Are there some applications that the RNP may be problematic? Yes. Will
most of us encounter them? No.
• The RNP has coarse gain steps of 6dB/step — Under ideal circumstances,
when gain staging your signal path, you want to only use as much gain as neces-
sary to do the job. Too much gain and you possibly run out of headroom. Too
much or too little gain and you possibly get more noise than you’d like for a given
application. So, why not use a gain pot or a switch with more positions to allow
finer gain steps? First, pots are notoriously inconsistent and imprecise for gain
setting (see John Hardy’s discussion of this) without using a two stage pot...one
stage for low gains and the other for high gains. That’s OK, but I personally don’t
like to have a “gain range” switch that can cause the gain to jump 30dB or more.
This is primarily ‘cause I’ve been known to inadvertently push the button at an
inopportune time (don’t tell anyone)! Second, 16 and more positions make for a
very expensive switch! In an ideal world, I’d have a switch with an infinite num-
ber of steps to allow us to smoothly and precisely maximize the micpre’s dynamic
range...allowing us to exactly dial-in the gain we need without too much noise or
too low of a clip point. Given these situations, we’ve made the RNP go from 0dB
of gain with a clip point of almost +28dBu in twelve steps. Even though this
requires that we (the users) are more careful in setting the maximum gain before
clipping, at least it’s gain setting is a little less critical given the high clip point.
Q UICKSTART
Even for those of you who are very experienced, there are some different operational features that you
need to be aware of. To use the RNP right away, there are two things you must do:
• Connect the RNP
• Let the RNP stabilize after power-up
In more detail: