This is fantastic, John, Raimund, David, more.
Finally, after years of "might be this or might be that", things
"might" start to clear up.
Raimund, I think you remember our short mail conversation (3-4 years
ago??) about the LSxx and noise. Suppose we had had a block diagram!
It would have saved time and waist, certainly for me, and for you too, I th=
ink.
My mistake was to presume that the LSxx was a "kind of Sony" but with
a poorer input amp and different PIP and impedance.
Even though I don't agree with you about everything (I cannot
overlook the consequences of using a resistor load on a plug in power
input, for example) you have been doing, and are doing, a fantastic
job in clearing up the mess about consumer recorders.
Thank you!
Klas.
At 11:09 2012-12-23, you wrote:
> > > The manual of the TASCAM DR-680 for instance shows it's block
> diagram at page 55:
> > >
> > > http://www.avisoft.com/DR-680.pdf
> >
> > It's excellent that they use a separate amp for the line input,
> instead of padding the signal down to go through the mic preamp as
> many machines do. Not so good to have the limiter after the A/D; it
> won't prevent clipping the A/D.
>
>Dan,
>
>Yes, I guess that they moved the limiter behind the A/D in order to
>reduce the manufacturing costs. Everything that is implemented after
>the A/D can be done in the DSP firmware, which means that it does
>not affect the hardware costs. They might also argue that an analog
>limiter is seldom required nowadays because the dynamic range of the
>A/D converters is sufficiently large for covering the majority of
>recording situations.
>
>Bye the way, I just did another simple test on the Olympus LS 5
>(whose preamps are identical to the LS 10/11) in order to find out
>where the recording level wheel potentiometer is located in the
>analog signal path:
>
>I simply set the recording level wheel the zero position and then
>recorded the "silence" at both the HIGH and LOW SENSE settings (at
>24 bit resolution). Everyone can do this thest on his or her own
>recorder without any addition test equipment.
>
>As expected, the resulting noise floor changed between the two gain
>settings (the HIGH SENSE noise level is 16 dB higher than the LOW
>SENSE noise level).
>
>What does that mean? It just means that the recording level
>potentiometer is not located after the last preamp stage, but
>somewhere in the middle. So, even if the potentiometer is closed
>(level 0), we still record the input noise (EIN) of the last
>preamplifier stage.
>
>This is indeed a bit different from other recorders and it explains
>pretty nice why we have those different EIN values between the SENSE
>HIGH / level 2 and SENSE LOW / level 10 settings.
>
>Regards,
>Raimund
>
>
>
>
>------------------------------------
>
>"While a picture is worth a thousand words, a
>sound is worth a thousand pictures." R. Murray Schafer via Bernie Krause.
>
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>
>
>
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email:
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