 In part 1 I looked at the update of my setup 1A, time resolution, the influence of that on the room acoustics and so on. In part 2 some answers and questions I received frequently in 2021. I do apologize for my voice, I have a cold, but in these times it's the better virus to catch I've learned in 2021 and no, it's not covid. Another thing I definitely learned in 2021 is that dogmas are impossible to destroy. A tube amp sounds warm, vinyl always sounds better, a linear power supply always beats a switch mode power supply, ladder converters sound better than oversampling DACs and there are many more. The truth is that any well engineered technique beats any poorly engineered technique. A viewer told me that he used a laptop power supply for his DAC. But the needs of a laptop differs from the needs of a DAC. A laptop consumes far more power than a DAC but is relatively insensitive to noise on the power rail. A DAC consumes less power but is hypersensitive to electric noise. The laptop brick was a 12.5 amps switch mode power supply and costed 45 euros for he has chosen a good one. He would have been better off with a 12 volt i5 audio i-Power 2 that does 1.8 amps and costs 69 euros. 1.8 amps is more than enough for the average DAC perhaps with the exception of some costly FPGA DACs. Which brings me to another dogma. FPGA DACs are better. FPGA is short fulfilled programmable gate array. In layman's terms a bunch of electronic switches, an array of gates that can easily be programmed and reprogrammed. You could call it a processor or microcomputer but its function depends on the program that is loaded. In a DAC it can be programmed to do the upsampling and conversion like in PS Audio and Core DACs. But it can also be programmed to switch resistors in a ladder converter, like those by Denafrips, Holo Audio and others. Or to do the upsampling in an upscaler like those by Aurelic and Chord. Or do the sample rate conversion in the Grimm Audio music player. FPGAs can be rather expensive. I've once heard prices up over 150 euros. If you then know that the final consumer price of a device is five times the production cost and component cost, you understand that adding such an FPGA will add 750 euros to the retail price. And that's for the dumb component, for without the programming it will do nothing. And writing code can be rather expensive. I'm no expert in this field but programming an FPGA to switch resistors in a ladder converter looks to me a logic driven task, perhaps with compensation for hardware limitations. But wiring code for upsampling and conversion is a different story. If a manufacturer of DACs would need to hire a specialist FPGA programmer he would almost certainly get into financial problems. The fact that we now can buy DACs that use FPGAs for upsampling and conversion has to do with the fact that some FPGA programmers are audio files that develop these codes out of personal interest. Rob Watts had developed his own DAC using an FPGA technology and demonstrated it to a friend of Chord's electronics founder, John Franks. He was introduced to Franks and the result was the Chord DAC64, the first FPGA DAC. Paul McGowan of PS Audio was called by a friend at a Sony SACD mastering plant in Boulder, Colorado to come listen to a prototype that Smith had developed in his own time. This later became the PS Audio Direct Stream DAC. I'm working on a review of the Grimm Audio MU1 music player that has an FPGA sample rate converter aboard and again the code was written by two people that had developed that code out of a hobby. So you can't say that when a DAC has an FPGA board it's an FPGA DAC and FPGA DACs don't all sound the same. Rob Watts told me he programmed the Mojo so cheaper equipment and headphones would sound agreeable. I have reviewed the Orelic and Chord upsamplers or upscalers as they call them now and now are working on the Grimm Audio player with a built-in up and down sampler and they all have their own qualities and sound. Just saying. Another dogma concerns the volume control. We all want analog volume control because we know digital volume control rejuices resolution. Well, that was two twenty years ago. Today chances are the digital volume control is more precise, has smaller difference between left and right and is less prone to wear. Again it all depends on the build quality and the code quality. But a digital volume control uses a show called rotary encoder. When the volume knob, if there is any, is turned it sends short pulses to the chip that does the volume control. An analog volume control normally is a track of carbon and a copper sliding contact. Depending on where the sliding contact is on the carbon track there is a certain resistance in series with the audio signal. The higher the resistance the lower the volume. There often is a small difference between left and right channel and the track will wear due to the travel of the sliding contact. This can be a problem too. We all know what contact spray can do for a volume control. Fix it for a week. High end equipment might have potential meters that use a conductive plastic track and those are more durable. Some amps, like my Airacoustic AX5, uses a motor driven multi position rotary switch with position resistors which is a costly but very fine solution. But usually today digital volume control is a better option. And talking about volume control, you're not one of those that believe that when the volume control is pointing to 12 o'clock you're at half power. It's like a water tap. The position of the water tap does not give a precise indication of how high the water flow is. That also depends on the water pressure. The volume control in an amp or pre-amp is an attenuator that brings the input level to the desired level for the power amp. If the input signal is the red book spec 2 volts, less attenuation is needed than when the input signal is 3 or 4 volts. And thus will the position of the volume control differ while the power amp outputs the same power. So the position of the volume control or the numerical readout of digital volume control has no direct relation to the loudness of the music nor to the output of the amp in watts. Wouldn't it be nice if you could use your laptop for your work during daytime and in the weekends connected to a DAC as a music player? That is a frequently returning question. Well, you actually can, but it will be limited in sound quality. Not a problem in a sub-1000 euro stereo, but if your stereo is somewhat better, special measures might be in order. Computers and in particular laptops cause a lot of electronic noise that will travel over the USB or speed of connection to the digital to analog converter, being it standalone or integrated in an amp or receiver. There it will pollute the power and ground lines that in turn will cause distortion. Next to that, computers use cheap clock crystals, for they suffice for that application. For audio far more precise clocks are needed. In a laptop both the signal lines and the clock signals get further polluted by the display drivers, powerful chips that make a lot of electronic noise. The next thing with computers and thus with laptops is that the standard music playing software and operating system will normally convert the music files to fit the computer's own audio system. So whether you use Windows Media Player or Apple's music, previously called iTunes, you will lose sound quality. To get all music bits unaltered, bit perfect, to the DAC, you need bit perfect software. The ones I occasionally work with are Olivana and J River Media Center. My favorite is Room. All three are paid software. I am sure there also is freeware around if you look for it. So yes, a laptop will work as will any computer with the right software. However, the sound quality is limited. Luckily there are solutions. The basic solution is simple. Don't connect the DAC directly to the laptop or any computer for that matter. We have to put a device in between the laptop or computer and the DAC that solves the problem. There are three ways to go about this. The digital converter, the network bridge or the network player. The first usually is abbreviated to DDC or named reclocker or USB reconditioner. It is connected between the output of the computer or laptop and an input on the DAC. A month ago I reviewed the Singser Audio SU6 and I was very pleased with it. Links to the reviews in the top right corner at the end of this video and in the notes below this video on YouTube. A network bridge does essentially the same but then over a network connection. So you can leave your laptop or computer at the study, switch it on of course, have it send audio files to the network bridge that is connected to your DAC and control what is playing using a smartphone or tablet. Not all music players software supports this but Oriavana, J River Media Center and Roondoo. If you want a free solution you can use the Squeezebox emulation in many but not all network bridges and install Logitech Media Server on your laptop or computer. I have reviewed a large number of network bridges, you find a link to the playlist at the earlier mentioned places. The third solution is to use a network player that plays music from your laptop or computer. Again I have reviewed quite a number of them and you find the link to the playlist at the usual places. You don't need all of this if you have a simple system in a box stereo but if sound quality matters to you, it's the way to go. These were some of the frequently returning questions in 2021. If you have heard my answers before, I do apologize. The channel gets more and more subscribers around 80.000 begin February 2022 and many of them apparently missed all the videos. That's not surprising since there now are over 400 videos online and the YouTube indexing is not very transparent. Anyway, it doesn't harm to hear in a second time for it is for many a complex matter. This week I'll be back with a review again, as usual on Friday at 5 p.m. Central European Time. If you don't want to miss that, subscribe to this channel or follow me on the social media so you will be informed when new videos are out. Help me reach even more people by giving this video a thumb up or link to this video in the social media, it is much appreciated. Many thanks to those viewers that support this channel financially. It keeps me independent and lets me improve the channel further. If that makes you feel like supporting my work too, the links are in the comments below this video in YouTube. I am Hans Beekhuyzen, thank you for watching and see you in the next show or on theHBproject.com. And whatever you do, enjoy the music.