Dave Thomas (Leading Canadian Expert)wrote:
The M460 module was designed by Roger Beck to compete with the Neve 1081
modules during the mid 70's and was so successful that Ward Beck could not
keep up with orders from the Broadcast industry where the consoles outsold
Neve 2:1 into North America. Ward Beck never even considered marketing
these to the recording industry as they were so busy with broadcast clients
such as ABC, NBC and the CBC in Canada plus many small stations.
The M470 was designed after the M470 series and the input transformer is
similar to a Jensen while the M460 has a transformer similar to a the St
Ives used by Neve in the 1073/1081 modules.
The M460 has a gain of 70db in the preamp while the M470 has a gain of 60db
(more than adequate for pop music). The M470 has a more modern extended
high end than the M460 which has a 6db per octave rolloff built in after 50
khz. The difference is the high end is subtle especially when recording
into hard disk recorder because even at 96 khz sample rate the response is
sharply rolled off by the A/D filtering at about 70db/octave at 48 khz and
at a sample rate of the 44.1 khz the A/D rolls the response of at
70db/octave at 22khz.
The M460 has a frequency response 1db down at 20hz while the M470 has a
response down 1db at 30hz while both the M460 and M470 are flat out to
20khz. The M460 and M470 preamps both are discrete class "A" except
for the
output stage which is clas A/B this is why both the M460 and M470 have 6db
more headroom in the preamp stage than a Neve 1073 or 1081. The M460 has a
completely variable hp filter while the M470 has a 3 position hp filter.
The M460 will deliver +30dBM with .25% distortion while the M470 will
deliver +27dBM with .25% distortion. The M460 was meant to work into 600
ohm loads the old broadcast standard but by the time the M470 was designed
the line outputs were never loaded with more than 10k ohms. However, the
M470 is capable of delivering +30dBM with less than .25% distortion from the
insert send which is balanced. Both the M460 and M470 have balanced
outputs.
Some folks like the high end of the M470 while other prefer the M460. I
would think that the M460 would be a good choice for vocals and guitars
while the M470 would be nicer on percussion. Although, I have a friend who
owns a studio and prefers the M460 on piano over the M470.
The M460 modules are generally older than the M470 and require more
maintenance and re-conditioning. The M460 and the M470 both use high
quality tantalum capacitors in the audio chain which are more expensive than
electrolytics but do not dry out and breakdown like the electrolytic. The
tantalum produces odd harmonic distortion while an electrolytic produces
even harmonic distortion. Odd harmonic distortion is more musical.