The latest mod I've done made a huge improvement in everything. Core noise is down further by a factor of 10.
This supports my thesis that a factor of 10 of less noise in the LT3081 brings a considerable advantage.
150uF is what I used with the stock resistors, it has the lowest leakage around 1uA.
Supercap supplies are quite different from the supplies used in the 004.
Yes, the start and stop system of the power supply that I want to design will be managed by a small pic microcontroller, it is very important what you mention that the start of the dac microcontroller must be the last thing to send the initial parameters to the 9038pro that must already be previously operative, in addition this pic must intervene with an output dedicated to the initial control of the silence relays before everything is operative. I am going to buy an evaluation module from a well-known brand of chips for supercaps control, there is a lot to study, also supercapacitors have a discharge period to take into account, I see it as a nice project, the risk of using supercapacitors that can blow up a pcb in microseconds in the event of a short circuit, the life of the designer and that of 004 himself are at risk until everything is not perfect, exciting project, crazy but exciting. It is something that certainly takes away the boredom if you have time to dedicate to it.
As I have been studying it seems that for every 100F of capacity a current of 0.3AH can be obtained, (300mA for one hour and 2.7v), with 2 supercapacitors of 3000F in series we obtain 1500F and up to 5.4v of maximum voltage, which gives a current capacity of 4.5AH for a cost of about $ 100 for these two supercapacitors with an expected life of 10 years, it seems that it would be useful for listening periods of a few hours of clean power with only a previous charge of several minutes If these data are accurate it does not seem like a far-fetched idea to use them only on the most noise sensitive power supplies of the dac.
Got a display and remote from Jinbo, works like a charm!
Charging time of the supercap is an important aspect.
El manejo de la corriente de recarga es algo fundamental o la situación se vuelve muy peligrosa, por eso compré un kit de evaluación para ver a qué me estoy enfrentando y ver en la práctica que conclusiones saco de esto, si es seguro y factible lo haré, pero si no es confiable o útil quizás tomaré otro camino, pero está bien y me gusta aprender sobre este tema de supercaps y ver los pros y los contras. También veo que los últimos reguladores LDO (LT1763 y TPS7A4700) deben permanecer allí por seguridad y garantizar 1.3vy 3.3v y tendrán su propio ruido interno incluso si obtienen energía limpia.
I'm glad you can enjoy it, it turned out very well.Got a display and remote from Jinbo, works like a charm!
Again many thanks to you all
That is a 350kHz switched mode controller, noisy.
Yes indeed that Maxim chip charges at a frequency of 350khz, in theory I did not see it as important because in the charging process the dac will be totally inactive, once the supercap is loaded, the pic would be notified of it by an input, disconnect the charging process and the oscillator, and it would be just waiting a user start button, before all that it would not be possible to turn on the dac, you have to put an input from the pic that detects low voltage and another high voltage from the supercap, perhaps with a few simple zener diodes that control transistors that set the level high or low to each entry would be enough, some LEDs could indicate the status of the process. What I saw very interesting about this Maxim evaluation kit is that they give you everything, even the supercapacitors, it is a fully assembled and tested module for only € 27, which is very interesting to do a safe load test of the supercaps and a subsequent test of the sound with clean energy in different supply points of the 004.
