09-03-2018, 11:02 AM
(Modification du message : 09-03-2018, 11:42 AM par a supprimer merci.)
La production du nouveau DAC est en cours. Il y aura deux modèles: 16 bit et 24 bits. Les prix sont très raisonnables (moins de 1000€). Voici une photo.
![[Image: 4e9ebfe1a810dd52b8c181021c101644.md.jpg]](https://tof.cx/images/2018/09/03/4e9ebfe1a810dd52b8c181021c101644.md.jpg)
Pour mémoire, il s'agit d'un DAC avec entrée Toslink uniquement, alimentation sur batterie (très faible consommation), et utilisation de deux TDA1541A. La batterie de 10Ah fera fonctionner le DAC environ 600 heures. Le port USB en haut à gauche est utilisé pour recharger la batterie. Des techniques innovantes (voir précédents posts) permettent de réduire considérablement le bruit au sein du DAC. L'utilisation du Toslink, avec un reclocking dans le DAC, permet d'obtenir une immunité à la source (c'est ce qui est affirmé en tout cas). Si c'est le cas, et je n'ai pas de raison de douter leurs affirmations, compte tenue de la qualité de leur précédent DAC et des mesures qu'ils on produit, ce sera une petite révolution dans le monde de la demat ! Exit les streamers à plusieurs milliers d'euros et les solutions complexes à base de PC optimisés...
Le petit module présenté en bas sur la photo est un adaptateur USB - Toslink. Quelques mots sur ce module:
"This is a tiny (USB stick sized) USB to Toslink converter. It plugs directly into the computer, eliminating USB interlink issues. It has a low jitter master clock and a nano power CPU (33mW) for lowest obtainable noise levels. It has an on-board ultra low noise voltage regulator and all USB pins are protected by diodes..
It has a dedicated Toslink transmitter chip for low jitter Toslink output. Serial output can be used to drive external volume control units through PC, pad or smartphone. Because of the design we can offer optimal performance for a low cost. The USB audio source no longer seems critical at all as long as it's bit-perfect."
Trois autres produits seront disponibles: un contrôleur de volume, un lecteur de fichiers sur clé USB à base de processeur RISC à très faible bruit, avec sortie I2S et Toslink, et un amplificateur 2x25w.
Concernant le contrôleur de volume: "The professional circuit boards for the SVC (Servo volume control) also arrived. This volume control is based on two motorised Bourns high endurance carbon slider potentiometers (studio quality) controlled by a small micro controller. It is battery powered (single 3V7 Lithium Polymer battery). Prototype is already up and running, it was quite a challenge to design a digital servo system that uses very little power and can adjust the sliders to 0.1% accuracy. The motors move the slider from min to max within one second and the motor won't run at all with voltages below 5V, so these are the most difficult to drive servo systems imaginable. I use a DC-DC converter to get enough voltage for the motors from the 3V7 Lithium battery. Microcontroller and DC-DC converter switch-off after volume adjustment so there is zero interference after adjusting. The servo first performs fast course adjustment followed by micro-step fine adjustment. Volume control is completely pop and click free and the muting works with smooth fade in and fade out."
Concernant le lecteur de fichiers: "a purist battery powered WAV USB stick player (44.1/16 ... 96/16). It supports FAT and EXFAT, up to 99 CDs with each 99 tracks on one stick. The UPL can support highest capacity USB sticks available. It also has shuffle mode and comes with an innovative IR remote control based on two square control surfaces. each 4 x 4 cm control surface has up to 8 functions.This USB WAV player runs on a single RISC processor from ST (it produces far less interference than any PC or professional (PC) based streamer, it produces also far less interference than a RPI. Estimated power consumption is roughly 370 milli watts during playback. because we use ultra fast and silent DMA (Direct Memory Access) that only supports 16 bit blocks we cannot support 24 bits at the moment. Adding 24 bit support would require (partial) DMA bypass and this would require a far more powerful CPU with hardware USB to parallel converter (PHY chip) that could no longer be battery powered and would produce much more interference.
The UPL has both, Toslink and I2S outputs D, BCK, WS, MCK (RJ45 connector), so it is also interesting for driving existing DACs"
Et les amplis:
"It is based on a novel double delta input stage and has circuits that eliminate even smallest ripple and noise voltages (cascaded capacitance multipliers on the power rails and double low pass filtered bias reference voltage for the lateral MOFETs). Other unique feature is variable gain (5x, 10x, 20x) using a front panel 3 position switch and a display. This enables lower attenuation settings (by using lower gain setting) resulting very high resolution and extreme SN ratios that are not possible with existing amps.
Bandwidth is very high, 2 MHz @ 5x gain, 1Mhz @ 10x gain and 500 Khz @ 20x gain while maintaining excellent stability, this is possible with the double delta input stage. The large bandwidth ensures absolute minimum phase errors and a very realistic sound reproduction. The MBL is based on global feedback for very low distortion and very low output impedance, global feedback now works fine because of the ultra fast novel double delta input stage.
The MBL idles at approx. 12 watts (200mA bias) and outputs up to 25 watts in 4 / 8 Ohms. Both input and output are DC-coupled for optimal transparency"
Pour mémoire, il s'agit d'un DAC avec entrée Toslink uniquement, alimentation sur batterie (très faible consommation), et utilisation de deux TDA1541A. La batterie de 10Ah fera fonctionner le DAC environ 600 heures. Le port USB en haut à gauche est utilisé pour recharger la batterie. Des techniques innovantes (voir précédents posts) permettent de réduire considérablement le bruit au sein du DAC. L'utilisation du Toslink, avec un reclocking dans le DAC, permet d'obtenir une immunité à la source (c'est ce qui est affirmé en tout cas). Si c'est le cas, et je n'ai pas de raison de douter leurs affirmations, compte tenue de la qualité de leur précédent DAC et des mesures qu'ils on produit, ce sera une petite révolution dans le monde de la demat ! Exit les streamers à plusieurs milliers d'euros et les solutions complexes à base de PC optimisés...
Le petit module présenté en bas sur la photo est un adaptateur USB - Toslink. Quelques mots sur ce module:
"This is a tiny (USB stick sized) USB to Toslink converter. It plugs directly into the computer, eliminating USB interlink issues. It has a low jitter master clock and a nano power CPU (33mW) for lowest obtainable noise levels. It has an on-board ultra low noise voltage regulator and all USB pins are protected by diodes..
It has a dedicated Toslink transmitter chip for low jitter Toslink output. Serial output can be used to drive external volume control units through PC, pad or smartphone. Because of the design we can offer optimal performance for a low cost. The USB audio source no longer seems critical at all as long as it's bit-perfect."
Trois autres produits seront disponibles: un contrôleur de volume, un lecteur de fichiers sur clé USB à base de processeur RISC à très faible bruit, avec sortie I2S et Toslink, et un amplificateur 2x25w.
Concernant le contrôleur de volume: "The professional circuit boards for the SVC (Servo volume control) also arrived. This volume control is based on two motorised Bourns high endurance carbon slider potentiometers (studio quality) controlled by a small micro controller. It is battery powered (single 3V7 Lithium Polymer battery). Prototype is already up and running, it was quite a challenge to design a digital servo system that uses very little power and can adjust the sliders to 0.1% accuracy. The motors move the slider from min to max within one second and the motor won't run at all with voltages below 5V, so these are the most difficult to drive servo systems imaginable. I use a DC-DC converter to get enough voltage for the motors from the 3V7 Lithium battery. Microcontroller and DC-DC converter switch-off after volume adjustment so there is zero interference after adjusting. The servo first performs fast course adjustment followed by micro-step fine adjustment. Volume control is completely pop and click free and the muting works with smooth fade in and fade out."
Concernant le lecteur de fichiers: "a purist battery powered WAV USB stick player (44.1/16 ... 96/16). It supports FAT and EXFAT, up to 99 CDs with each 99 tracks on one stick. The UPL can support highest capacity USB sticks available. It also has shuffle mode and comes with an innovative IR remote control based on two square control surfaces. each 4 x 4 cm control surface has up to 8 functions.This USB WAV player runs on a single RISC processor from ST (it produces far less interference than any PC or professional (PC) based streamer, it produces also far less interference than a RPI. Estimated power consumption is roughly 370 milli watts during playback. because we use ultra fast and silent DMA (Direct Memory Access) that only supports 16 bit blocks we cannot support 24 bits at the moment. Adding 24 bit support would require (partial) DMA bypass and this would require a far more powerful CPU with hardware USB to parallel converter (PHY chip) that could no longer be battery powered and would produce much more interference.
The UPL has both, Toslink and I2S outputs D, BCK, WS, MCK (RJ45 connector), so it is also interesting for driving existing DACs"
Et les amplis:
"It is based on a novel double delta input stage and has circuits that eliminate even smallest ripple and noise voltages (cascaded capacitance multipliers on the power rails and double low pass filtered bias reference voltage for the lateral MOFETs). Other unique feature is variable gain (5x, 10x, 20x) using a front panel 3 position switch and a display. This enables lower attenuation settings (by using lower gain setting) resulting very high resolution and extreme SN ratios that are not possible with existing amps.
Bandwidth is very high, 2 MHz @ 5x gain, 1Mhz @ 10x gain and 500 Khz @ 20x gain while maintaining excellent stability, this is possible with the double delta input stage. The large bandwidth ensures absolute minimum phase errors and a very realistic sound reproduction. The MBL is based on global feedback for very low distortion and very low output impedance, global feedback now works fine because of the ultra fast novel double delta input stage.
The MBL idles at approx. 12 watts (200mA bias) and outputs up to 25 watts in 4 / 8 Ohms. Both input and output are DC-coupled for optimal transparency"