On Thursday, February 26, 2009 4:12 PM, ADRIAN COSENTINI wrote:
> Can't speak for the cassette deck, BUT for preservation purposes
> the USB ION turntable... well... I'll stick to my SP-15, if ya know
> what I mean. Do it right or stay home :-)
Like Richard, I wouldn't trade in my Nakamichi CR-7As for the Alesis
TapeLink USB (similar to the Alesis USB Tape2PC). Like Adrian, I
generally agree that you should do it right the first time if you
can because you don't usually get a second chance.
This was going to be a quick response, but mushroomed into a more
considered reply because I think there are small archives looking
at products like the Alesis TapeLink USB and thinking "it isn't
perfect, but it could do the job".
So my goal here is to provide guidance on the types of projects
the Alesis TapeLink USB and other products of its ilk are
acceptable for, and which projects they should not be used for.
Starting off with specifications:
Specifications are often tweaked and "interpreted" differently by
each manufacturer. Some are more strict and open in their
intepretations, and others are more liberal and provide a single
number without any description of how it was derived. So
specifications as stated by a manufacturer should always be taken
with a grain of salt. It's usually better when the specifications
are verified by a third-party test.
Nonetheless, manufacturer specifications are all we have to go on
here. I decided to use a few well-known (alas, all out of
production) machines for this comparison exercise...
1. Frequency response comparison:
Alesis: 40-15000 (+/-3 dB Chrome)
Tascam 122 MkIII: 25-19000 (+/-3 dB Chrome)
Nakamichi DR-7A: 18-21000 (+/-3 dB Chrome)
Nakamichi Dragon: 20-21000 (+/-3 dB Chrome)
No where near the frequency response of the Nakamichi or even
Tascam decks, but certainly plenty good enough for non-music
recordings, and will do a decent job with music. In fact, I
wouldn't worry too much about frequency response with the Alesis
unless the cassette was originally recorded on a high quality
professional or prosumer cassette deck, however...
2. Wow-and-flutter comparison:
Alesis: <0.200% (DIN45500)
Tascam 122 MkIII: 0.040% (unspecified)
Nakamichi CR-7A: 0.027% RMS
Nakamichi Dragon: 0.019% RMS
This is a key specification when dealing with music recordings.
The Nakamichi decks are nearly one order of magnitude (10x) lower
(better) in wow-and-flutter, and the Tascam 5x better.
3. S/N ratio comparison:
Alesis: 58 dB (unspecified)
Tascam 122 MkIII: >70 dB (Dolby B, above 5 kHz)
Nakamichi CR-7A: >66 dB (Dolby B, A wtd, metal tape)
Nakamichi Dragon: >66 dB (Dolby B, A wtd, metal tape)
Hard to really compare S/N ratio given the variety of conditions
used to measure S/N.
4. Crosstalk comparison:
Alesis: 40 dB (unspecified)
Tascam 122 MkIII: unstated
Nakamichi CR-7A: >60 dB (1 kHz, 0 dB)
Nakamichi Dragon: >60 dB (1 kHz, 0 dB)
This is a measure of how much sound "bleeds" over from the
other side of the cassette (ie. how much you can hear of Side B
while listening to Side A).
40 dB is not particularly good, and could be a problem with
spoken word recordings where there are moments of silence
between words and cross-talk is especially noticeable.
A few more observations about the digital output of the Alesis
5. 16-bit word length
I'd prefer to see 24-bit, which would give better dynamic
range and make life a bit easier when it comes to avoiding
6. 44.1 kHz and 48 kHz sample rates
Acceptable for most cassette projects.
7. ADC jitter
If you think of jitter as the digital equivalent of analog
flutter, it would be interesting to know how accurate the clock
is in the Alesis. Given the poor wow-and-flutter performance
of the Alesis and its low price point, I have equally low
expectations for the clock jitter performance.
On anything but the smallest projects, labor is the biggest expense.
The cost of equipment (cassette deck, ADC, computer, software) is
such a small fraction of the labor cost. The poor quality of
low-cost equipment will show up in every transfer. If you're going
to do something right, do it right the first time if you can. It's
rare to get budget to preserve the same recording twice. I'm
repeating myself, but the "penny wise, pound foolish" adage applies.
So my first advice would be to go back to the proverbial well and
get a bit more budget for something better than the Alesis TapeLink
USB. The extra expense amortized over the entire project will only
add a little more cost per recording - it's generally worth it.
Assuming that the Alesis TapeLink USB would only be considered by
organizations on a shoestring budget - possibly without experienced
audio engineers to do the work - consider finding some money for
training, too. Learning as you go can be expensive in terms of
unnecessarily poor audio quality.
And if your project is small, strongly consider outsourcing it to
a preservation vendor. You'll get far better transfers for the same
amount of money as buying cheap hardware, and far less headache.
After the above excoriating remarks, I still believe the Alesis
TapeLink USB and similar products nonetheless could have a place
in an archive...
What I would use the Alesis TapeLink USB for:
- making access copies (NOT preservation masters) to simply
review and triage your collection to figure out exactly
which recordings really need to be preserved properly
- providing transcribers with copies of spoken word recordings
from which to work, the Alesis TapeLink USB could also be
adequate for that. If the audio is too poor for the
transcriber, machines with manually adjustable playback
azimuth (like the Nakamichi CR-7A) may be required.
- preserving less important recordings, and use outside
vendors (or wait for more budget) for the more important
recordings. I'm generally a fan of hybrid in-house and
outsourced efforts for stretching preservation dollars.
I would NOT use the Alesis TapeLink USB for:
- preserving high quality music recordings (due to poor
wow-and-flutter performance and 16-bit word length)
- preserving spoken word recordings destined for critical
listening like books-on-tape type applications (due to
poor crosstalk performance)
The Audio Archive, Inc.
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Disc and Tape Audio Transfer Services and Preservation Consulting