Numbers don't have time

-
This article about several possible approaches to designing class D amplifiers like the Hexateq monos has lines that to me are more beautiful than some literature.
Like "the digital integrator takes the signal for what it means, whereas the analogue integrator takes it for what it looks like, regardless of any meaning."
Delightful, isn't it? Plus the article is typeset in TeX, a system I've grown fond of since hearing about it for the first time 20 years ago. A good number of the most pleasant and intelligent people in the world use it. They may sometimes need to bother with MS Word to communicate with dreary people, but all they really put an effort in doing, is explained about and shared using TeX.
The article was written for the 120th convention of a society of audio engineers, held in Paris in the spring of 2006. It must have been a wonderful spring meeting, with quotes like "Numbers don't have frequency, in the same way that they don't have time." That there is a place and a community discussing numbers in this way makes me trust the world a little more than I already did.
Of course I also read about amplifiers in the article. These people are dedicated to develop components and systems that make it possible to listen to recordings in your home or live concerts on stage with the beauty of thruthfulness in the sound quality.
What I like about this specific type of amplifiers is their digital heart. It's a system of tiny, powerful, ultra fast switches. Imagine a block of powered switches. Half of them are off when the other half is on and vice versa, alternating all the time, controlled by a central clock that itself measures time bits many times faster even than the switches. Like asynchronous rowers in boat that can move at great speed while following sometimes sharp curves. On this class D rowing boat the oars are pulled without power one stroke and pulled without moving the second. To make it do the curves and not just straight lines is the analog magic of the trick and to do it in a simple way is a challenge:
"In total, at least as many degrees of freedom are needed as there are variables to be controlled."
Again, I read about audio circuitry but it makes me think about more, much more.





Reacties

Een reactie posten

Populaire posts van deze blog

Finished Pavoni & Fuji PXG4 pid: Probe Inside the Ring

-
Afbeelding
Delicious cup: all the work was well invested! At the end of the previous blog about the pressostat and PID working together , I mentioned that I would like to clean up the xmas tree of wires and have as few cables and probes as possible to visually disturb the classic design of the La Pavoni. Getting rid of the probe that was fastened with copper tape to the top of the brew group was a priority. I wanted to hide a new probe in the cooling fin as close as possible to the brew group. This morning I asked Tije if he could do that. He would need to drill a straight hole of 3mm diameter in the 4mm inner ring of the cooling fin that sits as a tight clamp around the brew group. Always the optimist, Tije set to work: First, Tije made a piece of aluminum to fit the inside of the ring. Drilling a thin hole straight through the curved aluminum, if possible tangentially going through the inside of the ring to touch the brew head directly, you need the support of the temporary insid
Meer lezen

Tiny Cheap Fluid Bed Roaster by Tije and Jan

-
Afbeelding
(also see Daily Coffee News feature ) Tije designed and made the following structure for a tiny and cheap fluid bed roaster, to which Jan van der Weel added the Arduino parts, electronics and programming: Sketch by Tije de Jong Jan sourced a very cheap blower (€ 11) to start with, Tije developed and constructed the mechanics, Jan built together and programmed the TC4 / SSR electronics.  On his blog, Jan will specify exactly how the TC4 part is combined and programmed and I will copy these details into this blog entry, just as Jan will use this video in his blog. We did a few test roasts to make sure it works at all and it does. Towards the end, the first roast tended to get a flat BT line and airflow was slightly decreased. 200g seems max load of green beans. Second roast a little more power was given to the heater. Next we will try the Background Roast driven by the PID software of Artisan. A week later, with updated software that works better to change the fan
Meer lezen

KiwiSDR2 [radio]

-
Afbeelding
  Despite selling one and giving away two of the five monster vintage 'boat anchor' receivers that I had, I still enjoy listening to shartwave radio. The modern iCOM R8600 that I also have has a wider range plus some decoding options but it's not easy to figure out what encoding is used on which frequencies. The SDR-Control app from Marcus Roskosch at https://ham-radio-apps.com/ makes this much easier and also allows some remote control of the receiver so you can place it and an antenna at the top floor of your house while listening downstairs. I also got the SDRplay RSP1B box: This offers a great listening experience at a very low price compared to the iCOM hardware. I had one before and bought one again after a (somewhat limited) Mac version of the software became available. This device needs a computer to be connected to the receiver. For some time now a nifty little device has appeared which not only works standalone, it even allows you or anyone else to utilize the
Meer lezen