[Coco] Audio recording on CoCo

[Steven Hirsch]

On Mon, 21 Nov 2011, gene heskett wrote:

> On Monday, November 21, 2011 12:31:59 AM Joel Ewy did opine:
>
>> On 11/20/2011 09:57 PM, Brian G wrote:
>>> I would like some advice on how to transfer LP music to CD.
>>> What equipment, software is needed? I have a turntable that I have not
>>> used in years, so starting from that, what do I need?
>>
>> Computer with sound card.  Preamp to get the LP to line level audio.
>> Cable from preamp to audio in jack on computer's sound card.  Some kind
>> of recording software on the PC.  Audacity is Free / Open Source, and
>> runs under Linux and I believe Windows and Mac.
>
> You forgot what is probably the single most important item, the record
> turner, and the 'tone arm' and the cartridge mounted in it.  If a magnetic
> cartridge, you will need a preamp that converts the magnetic cartridges
> velocity mode output into an amplitude mode output, commonly call an RIAA
> preamp.
>
> When records were king, there was no better playback cartridge than the
> Shure RE-15's, but the arm they were mounted in had to be capable of being
> adjusted to 1.5 grams tracking weight, and so friction free it would follow
> the recording groove faithfully at that pressure.

I'll second that recommendation.  I used V15s (consumer version of RE15, I 
believe) for years.  And, yes, they required a "high compliance" arm and 
are not something you'd blindly refit to a low-end turntable/arm combo. 
IIRC, the V15 had a more delicate stylus and would start to collapse at 
about 1.5 grams!  The only other cartridge I bonded with was a Dynavector 
moving-coil unit, but the stylus eventually was ruined from clumsiness and 
the company is long gone.

I recently went through the exercise of digitizing part of my (large) LP 
record collection.  The cheap phono-to-USB converters I tried were simply 
terrible sounding.  All the hard-won lessons about analog op-amp 
application to audio have been forgotten over the past 30 years or so. 
There's nothing more grating on my ears than an audio stage with obvious 
slew-rate problems (Walt Jung, where are you?).

Ended up taking the "straight line" output from a high-end pre-amp 
(discrete FET input stages - no op-amps!) and running it through a Burwen 
analog tick and pop suppressor into the Intel sound chip on my Linux box. 
When adjusted properly, the Burwen does a noticably better job of quieting 
transient groove noise than the Audacity algorithms.  Then, I used 
Audacity to clean-up the residual steady-state noise by auto-correlation. 
The results are almost indistinguishable from a digital-mastered CD.

I was fortunate enough to have a Technics SL1200Mk2 turntable left over 
from a previous life in the audio biz.  Which is fortunate, because good 
turntables are not easy to acquire anymore without paying stupid prices on 
eBay.

Steve



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