John Curl's Blowtorch preamplifier part II

[KBK]

Recall the bit where I proposed many years back that data appears across frames (which is/was complementary to what Teranex was doing for stills in the military sat image field) in the video world, when scaling DVD's 640x480 resolution up to 1080P. This, due to the original telecine process being complimentary to the up-scaling as the original was 1080P frame grabbing in the digital domain and then intelligently scaled down.

There is some extant but minor analogy to this situation here.

What you are seemingly getting here is the data sometimes being there and sometimes not.... but the ear/brain system is the most complex and capable real time re-construction system that the human body has and utilizes ..thus it is no surprise, to me, that such sonic characteristics can be 'heard' so deep into the noise floor.

[Terry Demol]

Originally Posted by john curl

hhoyt, it is my personal opinion that 'some' relatable background material is lost with finite digitization. Both from sampling rate, and available bits at these low level signals.
Apparently, our brain utilizes this low level background material to create the reality that existed when the source was recorded.
If that were not so, I suspect that we would have given up on analog tape and vinyl records, long ago. Dithering may help, or at least cover up major errors like the generation of higher order distortion, but it is not the same material that was there in the first place. If, for example, you see a really HIGH RESOLUTION color photograph, it is uncanny in its realism, yet it is almost impossible to know why, as it is still just a 2 dimensional picture. I think it is the same with audio.

At 24 bits low level resolution is not an issue it's just a case of how close
sonically a 16 bit dithered down version comes to it's 24 bit counterpart, all
other things being equal.

I believe most mastering engineers will concur that with the best dithering
algorithms there's not a huge amount in it. Ref pic below of a VHQ DAC,
1kHz, -90dB tone at 16 and 24 bits.


cheers

Terry

[Rod Coleman]

Originally Posted by Terry Demol

I believe most mastering engineers will concur that with the best dithering
algorithms there's not a huge amount in it.

I would not take the whole Mastering community as an authority here. After all, they seemed to go silently along with the con that digital master tapes for 1980 LPs were an upgrade on the 1979 releases (thinking about the Decca and EMI classical releases, anyway). Comparing those LPs today shows just how much was thrown away in 16/44.1, for any kind of orchestral or choral music.

It was all the greater pity, since the 1979 Deccas, in particular, were spectacularly improved against the year before.

[jacco vermeulen]

Originally Posted by johnferrier

Is there a Law?

Take an input gain stage with the familiar TO220 MOSFETs at 60mA minimum, same +60mA biased output stage after volume attenuation, and multiply that by two for balanced operation.
Take a series stage, a parallel stage, add a push-pull regulating stage, another series stage (decide for yourself in which order), and bump up the raw Vdc of the powersupply by at least another 10 points.
Add a whole bunch of sealed relays for source switching and stepped balanced volume attenuation, the point where preamp kitchen things really start cooking and/or insanity becomes unsanitary.

[simon7000]

Originally Posted by Terry Demol

At 24 bits low level resolution is not an issue it's just a case of how close
sonically a 16 bit dithered down version comes to it's 24 bit counterpart, all
other things being equal.

I believe most mastering engineers will concur that with the best dithering
algorithms there's not a huge amount in it. Ref pic below of a VHQ DAC,
1kHz, -90dB tone at 16 and 24 bits.


cheers

Terry

I poked fun at the bit wars by asking about 64 bits. How many real 24 bit linear no missing code converters are there?

ES

[1audio]

Originally Posted by simon7000

I poked fun at the bit wars by asking about 64 bits. How many real 24 bit linear no missing code converters are there?

ES

A few, sampling at around 1000 Hz.

[simon7000]

Originally Posted by 1audio

A few, sampling at around 1000 Hz.

Ah yes the devices intended for digital scales have great resolution! A bit sloooow.

[Terry Demol]

Originally Posted by simon7000

I poked fun at the bit wars by asking about 64 bits. How many real 24 bit linear no missing code converters are there?

ES

None - of course. However quite a few people here, it appears, have the
misconception that only analog recording mediums, ie; tape machines
have the ability to store audio information well below the rms noise floor.

T

[1audio]

lets see, if you interleaved them, assuming they work to spec at 1 KHz and 48K sampling was OK you would need to somehow get 48 all working together. . . 192K would be a real challenge. A lot like building a Blue Gene computer.

[simon7000]

Originally Posted by 1audio

lets see, if you interleaved them, assuming they work to spec at 1 KHz and 48K sampling was OK you would need to somehow get 48 all working together. . . 192K would be a real challenge. A lot like building a Blue Gene computer.

Nah, you would still need to capture and hold the samples with 24 bit resolution in level and time!

Not as easy as some would think.