Many years ago was given a couple of TI ADSL dev boards using the THS6002 ADSL chipset, and was told that it should make a good headphone driver. My understanding is that at least one of the high end headphone drivers TI sells is basically that chip without the Rx part in.
And why not. I believe (and sure Scott will correct me if wrong) but the Walt Jung composite line stage from 1996 also used an ADSL part.
Yes, I've done similar things---hadn't seen that patent, thanks. Cordell has a somewhat similar scheme, with the circuit shown in his book (pp. 368-370) a simplified one that assumes that the magnitudes of the negative and positive rails track (usually a pretty good assumption).
If you design your amps right, then random clipping will not be a problem. Of course, low overall negative feedback helps this to be so.
Yes, but a more conventional brute force part. ADSL drivers migrated to the geometric mean or Montichelli biasing.
That's OK, if you can hear -140dB noise while listening at normal levels good for you.
normal listening levels are particularly important with the perceptually weighted noise shaping - the better curves are only valid at near human audibility threshold - turning up the volume to listen to the dither noise isn't "fair" as Loudness effects change our hearing frequency sensitivity shape
few home systems can do clean 120 dB SPL at the listening position - good system gain structure would put digital source 0 dB full scale not too much higher
few home systems can do clean 120 dB SPL at the listening position - good system gain structure would put digital source 0 dB full scale not too much higher
In 2017, Norway will be first country to shut down FM radio
In 2017, Norway will be first country to shut down FM radio | The Verge
In 2017, Norway will be first country to shut down FM radio | The Verge
We (USA) already have digital combined with FM broadcast freq.... its called HD Radio. Thus, still keeping both analog FM and digital broadcasts.
-RNM
Last edited:
Richard,
I just wonder if the FCC will like they have with broadcast TV outlaw analog FM so they can steal some of the bandwidth of the FM band for other uses. There is no more analog TV signal so why wouldn't they do the same with radio?
I am still trying to understand what you are going to do with the dither information such as which is the best method of dither usage? Even if you know and understand this what as a consumer of music and not a producer of music can you possibly hope to use this information for?
I just wonder if the FCC will like they have with broadcast TV outlaw analog FM so they can steal some of the bandwidth of the FM band for other uses. There is no more analog TV signal so why wouldn't they do the same with radio?
I am still trying to understand what you are going to do with the dither information such as which is the best method of dither usage? Even if you know and understand this what as a consumer of music and not a producer of music can you possibly hope to use this information for?
Last edited:
It is because, you know one of the advantages of current feedback amplifiers: their bandwidths don't vary with gain, contrary to VFAs, where it decrease as their gain increase.
In blue: VFA 1 channel in
in green: VFA 32 channels in
in red and yellow: CFA, 1 & 32 Channels in
That is what noticed my wife from the kitchen which is built in the middle of all the recording studios, as everybody knows.
Attachments
Last edited:
Why wouldnt I want to know how to make the best digital recordings? What some of the pit-falls may be? Best practices?
Really?!
We just went thru a few pages hitting on how LP are made right and wrong ways and best practices.
And, who says I wouldnt again record and not just play music?
-RNM
Last edited:
True and that's not bad for us...I'll have to find the exact number,
we can perceive a significantly higher resolution than our computers
screens provide, I want to say something in the order of 11,000 or 17,000
lines per inch.
Thinking the audio perception range is 2 - 4 time our hearing bandwidth.
Stewart Hegeman and others have described the research. I don't think
I've ever read the original or primary research papers only secondary
if someone has a primary source and care to share I would appreciate it.
Thanks Elvee and Brad, that's instructive. Seems a little more easy than building a 0.0001% analog sine generator 😎
Jan
Okay Richard,
If you actually intend to do some recording I can understand that. But for the consumer I don't see where dither information would ever be available or necessary. One question would be do the engineers doing final mix down even have a clue what the engineers before them have done, is there even any type of documentation in the least that keeps track of what has happened at each level or each track?
If you actually intend to do some recording I can understand that. But for the consumer I don't see where dither information would ever be available or necessary. One question would be do the engineers doing final mix down even have a clue what the engineers before them have done, is there even any type of documentation in the least that keeps track of what has happened at each level or each track?
You mean the DIM30 test? Is that more sensitive than Holman's square wave test? Both exercise the amp dynamically. The DIM30 (or DIM100) I think looks at intermodulation; Holman's test looks to me more directly looking at transfer curve non-linearity. But in practise yes DIM30 has eclipse the Holman test.
Jan
But why is that in practical amps a disadvantage? You design your amp with a specific gain and bandwidth, and that's that, right?
I can imagine that it is of importance in say switchable gain instrumentation amps, but in audio amps?
I know that there can be gain/bandwidth modulation in less well designed amps but that's minimal, if it is there at all.
Jan
I would think you would have to take a cd and the high rez file and compare them bit for bit. I highly doubt that the producer is creating two different versions, so the question would be where would any changes come into play and why would the two media have any differences. We surely aren't talking the same thing as comparing the CD or High Rex files to a down sampled low bit rate MP3, then I would expect to see very different information if you compared files.
So we will have to wait and see if you can find and measure any difference between the Hi-Rez and CD files, I would think the dither again would be identical between files.
So we will have to wait and see if you can find and measure any difference between the Hi-Rez and CD files, I would think the dither again would be identical between files.
We were talking of mixing desks bus preamps. They work in inverting mode. Each time you plug-in a new track in the mix, the gain of the OPA increase automatically.
I noticed that, when you listen to a single track, if you plugged many other muted tracks, on most of the mixing desks (VFA), its sound turned dull, compared to the same all alone.
According to my wife from the kitchen, CFAs cured the issue, to the great delight of our friend Waly. ;-)
Last edited:
- Status
- Not open for further replies.