More Kershaw

Mark mutetourettes@...
Tue Oct 22 10:55:46 CEST 2013


ello just a little note - in documenting the ripping it would probably
helpful to list the actual Analogue to digital converters (A/D) used -
that's a pivotal step jumping from the analogue to the digital realm and
seems to be somehow getting skipped in the trails people provide... ie
Nakamichi BX300 >> ??what A/D converter model /bit depth used /sample rate
used ?? >> Audacity etc

also NB the bit 'depth' and sample rate of the A/D process matters and is
not the same as (or even related to) the 'bit rate' of a compressed file
that you might then upload.

Even the point on the digital level scale (ie from 0db=clipping downwards)
you aim for with your average input levels matters, (e.g. 0vu analogue =
-?db digital .. were you were thrashing the ass off the poor analogue
electronics in the analogue side of your converter just to try and get
'more level'?) but I suppose few people are going to document that... :)

(the usual 'level' rule of thumb to IGNORE in this case: - if you're using
16-bit converters/files then yes, you do need to thrash the electronics way
out of their comfort zone and hope they're up to it, because you need the
peaks to be as near full-scale 0 (0dbFS) as you can get - but if you're
using 24bit converters/files then NOOOO don't thrash them... let the
analogue electronics work in their sweetspot which is going to be avaerage
signals about -18dbFS, peaks about -6dbFS)

(altered rule of thumb for sketchily taped radio broadcasts: - the reason
16-bit studio folks needed to keep the levels high is that the noise
'floor' for 16bit digital (ie where the jumps between 1s and 0s start to
sound lumpy/grainy/icy and 'dither' noise is applied to sooth it) is just a
little too close for comfort if you're using analogue-style amounts of
headroom (24bit digital has such a low noise-floor that even the self-noise
of a single resistor is greater, so it's a non-issue, have all the headroom
you fancy)... HOWEVER, for us with naff old tapes that digital noise floor
is rendered totally irrelevant by the huge crashing waves /jet engine
/pneumatic drill of noise floor of the tape itself which is an order of
magnitude higher.. so even at 16bit, you can keep your levels mellow!)

This isn't about the 'loudness war', by the way, just about the 'archiving'
A/D conversion into digital-land - by all means normalize the levels up to
-1db once it's in the computer if you feel the need, but please be aware
you're asking waaay more of the consumer's digital-to-analogue converters
that way (ie running them ragged), when their turning up their amp a little
would achieve the same, maybe better result ;) I think it also allows the
compression stage (e.g. to MP3) a little more freedom to make nicer results
when the levels are not pinned..

As ever this might not matter much here where we're talking about patchy
recording's made on yer dad's wonky grundig with the record level on max,
but just flagging it up, that it's an important part of the 'rip', probably
much more so than what software got used afterwards.. so if someone's keen
to document things, they can include that. Rampant OCD is an ever-present
danger down this particular rabbit hole..

oh gawd that turned into a big note.. sorry folks. take it with a pinch of
salt... and a rennie.


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