robert bristow-johnson <rbj@audioimagination.com> writes:> On 7/23/14 9:28 AM, Randy Yates wrote: >> Rick Lyons<R.Lyons@_BOGUS_ieee.org> writes: >> >>> On Sun, 20 Jul 2014 23:56:59 -0400, Randy Yates >>> <yates@digitalsignallabs.com> wrote: >>> >>>> Rick Lyons<R.Lyons@_BOGUS_ieee.org> writes: >>>> >>>>> On Sat, 19 Jul 2014 23:16:13 -0400, robert bristow-johnson >>>>> <rbj@audioimagination.com> wrote: >>>>> >>>>> [Snipped by Lyons] >>>>>>> >>>>>> >>>>>> that never worked for me. regular No. 2 pencils were just a little too >>>>>> skinny and just a little too rounded. but the original Bic pens (you >>>>>> know, they cost like 39 cents) fit those audio cassettes perfectly for >>>>>> manual winding (like after recovering from when the deck "ate" my tape). >>>>>> i also had music on a Teac 3340 real-to-real. that was *my* hi-fi in >>>>>> the 70s and 80s. >>>>> >>>>> Hi Roberto, >>>>> Reel-to-reel!! Ha ha. You must have been a >>>>> "reel" quality-audio nutcase. >>>>> >>>>> I liked the 8-track music tapes. You never had to >>>>> pop them out, flip them over, and reinsert them >>>>> as was needed by the smaller audio cassette tapes. >>>>> Oh well. Technology advances. >>>> >>>> CDs today are like 8-tracks 20 years ago. You can just stick in a usb >>>> thumbdrive with mp3's into my new Honda (and probably most new cars less >>>> than 3 years old) and start rockin'. >>> >>> Hi Randy, >>> What's an "mp3"? >> >> Hi Rick, >> >> Robert answered too, > > one of the cool things about getting to the AES conventions is besides > meeting folks like Randy Yates and Greg Berchin and Al Clark there > (dunno who i may have left out), you get to meet people who created a > little bit of history like Karlheinz Brandenburg and Kees Schouhamer > Immink and Bob Moog. never got to meet Ray Dolby and now he's gone > (so is Bob Moog) so i guess i never will.You over-honor me, Robert. I'm just a dude, you know that. I smoke my pot one one-hit bowl at a time... but thanks. But..., it is REALLY cool you've gotten to meet those folks. I hadn't heard Ray Dolby died. Sad. I can remember going to a couple of San Francisco AES chapter meetings (circa the late 80s) at Ray's private theater on Potrero Street (although I never got to meet him). It was way cool to be in that theater. I also got to hear Bob Adams give a lecture at one of those. I remember coming away from that thinking, "Bob Adams is an engineering MADMAN!" (said with the greatest of respect). -- Randy Yates Digital Signal Labs http://www.digitalsignallabs.com
Fourier series of sign(cos(.)) in simulation and practical mixer simulation
Started by ●July 15, 2014
Reply by ●July 24, 20142014-07-24
Reply by ●July 24, 20142014-07-24
On 7/23/14 11:21 PM, Randy Yates wrote:> robert bristow-johnson<rbj@audioimagination.com> writes: > >> On 7/23/14 9:28 AM, Randy Yates wrote: >>> Rick Lyons<R.Lyons@_BOGUS_ieee.org> writes: >>> >>>> On Sun, 20 Jul 2014 23:56:59 -0400, Randy Yates >>>> <yates@digitalsignallabs.com> wrote: >>>> >>>>> Rick Lyons<R.Lyons@_BOGUS_ieee.org> writes: >>>>> >>>>>> On Sat, 19 Jul 2014 23:16:13 -0400, robert bristow-johnson >>>>>> <rbj@audioimagination.com> wrote: >>>>>> >>>>>> [Snipped by Lyons] >>>>>>>> >>>>>>> >>>>>>> that never worked for me. regular No. 2 pencils were just a little too >>>>>>> skinny and just a little too rounded. but the original Bic pens (you >>>>>>> know, they cost like 39 cents) fit those audio cassettes perfectly for >>>>>>> manual winding (like after recovering from when the deck "ate" my tape). >>>>>>> i also had music on a Teac 3340 real-to-real. that was *my* hi-fi in >>>>>>> the 70s and 80s. >>>>>> >>>>>> Hi Roberto, >>>>>> Reel-to-reel!! Ha ha. You must have been a >>>>>> "reel" quality-audio nutcase. >>>>>> >>>>>> I liked the 8-track music tapes. You never had to >>>>>> pop them out, flip them over, and reinsert them >>>>>> as was needed by the smaller audio cassette tapes. >>>>>> Oh well. Technology advances. >>>>> >>>>> CDs today are like 8-tracks 20 years ago. You can just stick in a usb >>>>> thumbdrive with mp3's into my new Honda (and probably most new cars less >>>>> than 3 years old) and start rockin'. >>>> >>>> Hi Randy, >>>> What's an "mp3"? >>> >>> Hi Rick, >>> >>> Robert answered too, >> >> one of the cool things about getting to the AES conventions is besides >> meeting folks like Randy Yates and Greg Berchin and Al Clark there >> (dunno who i may have left out),well, now i do.>> you get to meet people who created a >> little bit of history like Karlheinz Brandenburg and Kees Schouhamer >> Immink and Bob Moog. never got to meet Ray Dolby and now he's gone >> (so is Bob Moog) so i guess i never will. > > You over-honor me, Robert. I'm just a dude, you know that. I smoke my > pot one one-hit bowl at a time... but thanks. > > But..., it is REALLY cool you've gotten to meet those folks. I hadn't > heard Ray Dolby died. Sad. I can remember going to a couple of San > Francisco AES chapter meetings (circa the late 80s) at Ray's private > theater on Potrero Street (although I never got to meet him). It was way > cool to be in that theater. > > I also got to hear Bob Adams give a lecture at one of those. I remember > coming away from that thinking, "Bob Adams is an engineering MADMAN!" > (said with the greatest of respect).and THAT's who i left out!!! goddammit! Bob, i shoulda included you in *both* lists, the comp.dsp schlubs at AES and the history makers at AES. woulda, shoulda, coulda. shit! sorry Bob. and thanks, Randy, for remembering. my brain has very nearly turned into gray pudding. maybe time to start pushing daisies. -- r b-j rbj@audioimagination.com "Imagination is more important than knowledge."
Reply by ●July 24, 20142014-07-24
On Wed, 23 Jul 2014 21:53:10 -0400, robert bristow-johnson <rbj@audioimagination.com> wrote:>On 7/23/14 9:44 PM, Rick Lyons wrote:>> Randy, while workin' for TRW in the mid 1990's, in that >> company I knew a EE who told me he'd just spent $3,000 >> on a super-stable, super-accurate, super-balanced >> turntable for playing record albums. > >direct drive, i s'pose. no friggin' rubber band it that one. (not that >i could ever hear the flutter in a good belt-driven turntable. let >alone any wow.)Without knowing the particulars of the turntable, my guess would be that it was *not* direct drive, which was frowned upon by the audiophiles of that era. (And may still be, for all I know.) They usually went for belt drive, and the high-end stuff was all about "bigger and heavier" platters. I was peripherally involved with the audiophile scene back then because my younger brother was a principal in one ot the top high-end audio stores in NYC. The impression I got was that many of his customers were looking for "impressive", and stuff like solid granite platters was obviously more impressive than an unseen bit of electronics. (The loooong coast-down when you turned the motor off was a major bragging point. Proved you had the most mass *and* the best bearings.) I think that "impressive" also sold/sells vacuum tube stuff. However, in defense of the belt drive over direct drive, there were reputed problems with the early direct drives (dunno about now), in that they didn't have a lot of torque and so couldn't drive a heavy platter. The low mass meant that they were susceptible to "cogging" flutter from each of the motor poles. Dunno how audible it was; like you, I never heard flutter or wow on any decent equipment of any type. Best regards, Bob Masta DAQARTA v7.60 Data AcQuisition And Real-Time Analysis www.daqarta.com Scope, Spectrum, Spectrogram, Sound Level Meter Frequency Counter, Pitch Track, Pitch-to-MIDI FREE Signal Generator, DaqMusiq generator Science with your sound card!
Reply by ●July 24, 20142014-07-24
On Thursday, July 24, 2014 8:07:06 AM UTC-4, Bob Masta wrote:> On Wed, 23 Jul 2014 21:53:10 -0400, robert bristow-johnson > > <rbj@audioimagination.com> wrote: > > > > >On 7/23/14 9:44 PM, Rick Lyons wrote: > > > > >> Randy, while workin' for TRW in the mid 1990's, in that > > >> company I knew a EE who told me he'd just spent $3,000 > > >> on a super-stable, super-accurate, super-balanced > > >> turntable for playing record albums. > > > > > >direct drive, i s'pose. no friggin' rubber band it that one. (not that > > >i could ever hear the flutter in a good belt-driven turntable. let > > >alone any wow.) > > > > Without knowing the particulars of the turntable, my guess > > would be that it was *not* direct drive, which was frowned > > upon by the audiophiles of that era. (And may still be, for > > all I know.) They usually went for belt drive, and the > > high-end stuff was all about "bigger and heavier" platters. > > > > I was peripherally involved with the audiophile scene back > > then because my younger brother was a principal in one ot > > the top high-end audio stores in NYC. The impression I got > > was that many of his customers were looking for > > "impressive", and stuff like solid granite platters was > > obviously more impressive than an unseen bit of electronics. > > (The loooong coast-down when you turned the motor off was a > > major bragging point. Proved you had the most mass *and* > > the best bearings.) > > > > I think that "impressive" also sold/sells vacuum tube stuff. > > > > However, in defense of the belt drive over direct drive, > > there were reputed problems with the early direct drives > > (dunno about now), in that they didn't have a lot of torque > > and so couldn't drive a heavy platter. The low mass meant > > that they were susceptible to "cogging" flutter from each of > > the motor poles. Dunno how audible it was; like you, I > > never heard flutter or wow on any decent equipment of any > > type. > > > > Best regards, > > > > > > Bob Masta > > > > DAQARTA v7.60 > > Data AcQuisition And Real-Time Analysis > > www.daqarta.com > > Scope, Spectrum, Spectrogram, Sound Level Meter > > Frequency Counter, Pitch Track, Pitch-to-MIDI > > FREE Signal Generator, DaqMusiq generator > > Science with your sound card!A friend of mine was one of the extreme audiophiles. His turntable used a large granite cylinder as the platter. I thought it looked like a civil war era millstone. Clay
Reply by ●July 24, 20142014-07-24
glen herrmannsfeldt wrote:> Rick Lyons <R.Lyons@_bogus_ieee.org> wrote: > > (snip of an analog recording question, then I wrote) > >>> For a problem that might be closer to DSP, what is the current >>> density in the wiring in integrated circuits? Hint: It is >>> a current that would melt a more ordinary sized wire just >>> about instantly, and is high enough that electromigration >>> (the current pushing the atoms along) can happen. > > (snip) > >> Ha. That's a neat question. Forgive me but what are the >> dimensions of current density? Amps per square meter? > > That would be the SI unit, but for some reason it is traditionally > amps/cm**2. > > Also, the current per transistor is decreasing slower than the number > of transistors is increasing. There are now processors with Icc > over 150 amps. >150 *AMPS*?? That's not a typo? Oh lawd.> http://www.intel.com/content/www/us/en/processors/itanium/itanium-9300-9500-datasheet.html > > (see page 42, for example) >Goodness me.> -- glen >-- Les Cargill
Reply by ●July 24, 20142014-07-24
Bob Masta wrote:> On Wed, 23 Jul 2014 21:53:10 -0400, robert bristow-johnson > <rbj@audioimagination.com> wrote: > >> On 7/23/14 9:44 PM, Rick Lyons wrote: > >>> Randy, while workin' for TRW in the mid 1990's, in that >>> company I knew a EE who told me he'd just spent $3,000 >>> on a super-stable, super-accurate, super-balanced >>> turntable for playing record albums. >> >> direct drive, i s'pose. no friggin' rubber band it that one. (not that >> i could ever hear the flutter in a good belt-driven turntable. let >> alone any wow.) > > Without knowing the particulars of the turntable, my guess > would be that it was *not* direct drive, which was frowned > upon by the audiophiles of that era. (And may still be, for > all I know.) They usually went for belt drive, and the > high-end stuff was all about "bigger and heavier" platters. > > I was peripherally involved with the audiophile scene back > then because my younger brother was a principal in one ot > the top high-end audio stores in NYC. The impression I got > was that many of his customers were looking for > "impressive", and stuff like solid granite platters was > obviously more impressive than an unseen bit of electronics. > (The loooong coast-down when you turned the motor off was a > major bragging point. Proved you had the most mass *and* > the best bearings.) > > I think that "impressive" also sold/sells vacuum tube stuff. >Hard to say. Some of the old vacuum tube stuff simply has been around longer. There are essentially no "no negative feedback" SS amps unless you follow certain designers. Whether negative feedback is good or bad is a thing of heresy.> However, in defense of the belt drive over direct drive, > there were reputed problems with the early direct drives > (dunno about now), in that they didn't have a lot of torque > and so couldn't drive a heavy platter. The low mass meant > that they were susceptible to "cogging" flutter from each of > the motor poles.Cogging is inherent to that type ( DC servo? I forget ) controlled flywheels. Whatever the ubiquitous Technics 1200 has. Belt drive is alleged to have less rumble, since there's less moving mass coupled to the platter. Mass was also a Bad Thing if you were shipping them from the Far East, so it may be that the legend came from self interest. Goood Lord don't look at the price of a new (whatever the follow on to the) technics 1200.> Dunno how audible it was; like you, I > never heard flutter or wow on any decent equipment of any > type. > > Best regards, > > > Bob Masta > > DAQARTA v7.60 > Data AcQuisition And Real-Time Analysis > www.daqarta.com > Scope, Spectrum, Spectrogram, Sound Level Meter > Frequency Counter, Pitch Track, Pitch-to-MIDI > FREE Signal Generator, DaqMusiq generator > Science with your sound card! >-- Les Cargill
Reply by ●July 24, 20142014-07-24
Les Cargill <lcargill99@comcast.com> wrote: (snip, I wrote)>> Also, the current per transistor is decreasing slower than the number >> of transistors is increasing. There are now processors with Icc >> over 150 amps.> 150 *AMPS*?? That's not a typo?(snip)>> http://www.intel.com/content/www/us/en/processors/itanium/itanium-9300-9500-datasheet.html>> (see page 42, for example)At about 1V, so 150 Watts, divided among 3.1 billion transistors, for about 50 nanowatts each. -- glen
Reply by ●July 25, 20142014-07-25
On 7/24/14 3:01 PM, glen herrmannsfeldt wrote:> Les Cargill<lcargill99@comcast.com> wrote: > > (snip, I wrote) >>> Also, the current per transistor is decreasing slower than the number >>> of transistors is increasing. There are now processors with Icc >>> over 150 amps. > >> 150 *AMPS*?? That's not a typo? > > (snip) > >>> http://www.intel.com/content/www/us/en/processors/itanium/itanium-9300-9500-datasheet.html > >>> (see page 42, for example) > > At about 1V, so 150 Watts, divided among 3.1 billion transistors, for > about 50 nanowatts each. >but at 3V, it's 50 Amps. that's still a fucking sonuvabitch. can hardly imagine a *chip* doing 50 Amps, let alone 150. -- r b-j rbj@audioimagination.com "Imagination is more important than knowledge."
Reply by ●July 25, 20142014-07-25
On 07/25/2014 12:45 PM, robert bristow-johnson wrote:> On 7/24/14 3:01 PM, glen herrmannsfeldt wrote: >> Les Cargill<lcargill99@comcast.com> wrote: >> >> (snip, I wrote) >>>> Also, the current per transistor is decreasing slower than the number >>>> of transistors is increasing. There are now processors with Icc >>>> over 150 amps. >> >>> 150 *AMPS*?? That's not a typo? >> >> (snip) >> >>>> http://www.intel.com/content/www/us/en/processors/itanium/itanium-9300-9500-datasheet.html >>>> >> >>>> (see page 42, for example) >> >> At about 1V, so 150 Watts, divided among 3.1 billion transistors, for >> about 50 nanowatts each. >> > > but at 3V, it's 50 Amps. that's still a fucking sonuvabitch. can > hardly imagine a *chip* doing 50 Amps, let alone 150.Its hard to imagine anything but a power device taking 50A at 3V. The main power draw for complex logic is always at a much lower voltage - e.g. 150A at around 1V. That's why the DC-to_DC converters producing the around 1V rail have to be really close to the chip. You can't tolerate the voltage drop you would see over longer wires of any reasonable thickness. Regards, Steve
