My attempts at a design of a 3 stage amplifier

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What can I use for music/audio playback besides a CD player and an mp player? A computer would use too much power and is bulky. Can I find a ready made but high quality playback device that supports a very wide range of music formats but also having high quality sound?
 
Off Topic:
What can I use for music/audio playback besides a CD player and an mp player? A computer would use too much power and is bulky. Can I find a ready made but high quality playback device that supports a very wide range of music formats but also having high quality sound?

Take a look at using a Raspberry Pi running Volumio (or Moode, amongst several others) and install an I2S DAC hat from IQAudio, for example. Very low power consumption and you can control it via any web browser such as a phone, tablet, PC etc. It plays FLAC, MP3 and many other formats from network storage, or a USB flash drive / USB hard disk. Many internet radio stations are available too. I use this set up in the kitchen and the family love the sound quality and versatility.
 
May I ask whether a newly purchased Raspberry Pi requires installation of an operating system? I am afraid of getting a Raspberry Pi without an operating system. I shudder of ending up with a dead Pi.

Notwithstanding of the above, this seems to be the best cost effective solution. The I2S DAC answers my questions about getting a decent sound card.
 
Hi edbarx,

The operating system is simplicity itself. If using Volumio, you download an image from their website and flash it to a micro SD card. It is Linux-based but doesn't require any prior knowledge of the operating system. Once the card is plugged into the Pi, it works immediately and requires minimal configuration to get the sound working. There is really no such thing as a dead Pi as the operating system resides entirely on the card and is easily swapped out or reprogrammed for new functionality. Follow the instructions in the download link at • Audiophile Music Player | DAP | Volumio

The sound quality is actually superb and you can use either a DAC with line output and a separate amplifier, or a DAC+Class D amplifier built-in. See Raspberry Pi Audio - IQaudIO Limited I have both the Pi-DigiAMP+ and the PiDAC+ for separate projects. Having several of these units around the house gives a multi-room audio system and the software allows for the control of all zones on your network from each web browser.

Disclaimer: I am not affiliated with any of the companies producing these products, just a happy customer!
 
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So, to clarify things for myself - not a youth here, but a mature and probably slow 51 year old man.

Which Raspberry Pi should I buy?
Which I2S DAC should I buy?
Which operating system?
Which software?

I am afraid these packages are intended for highly enthusiastic technically gifted adolescents and not for someone of my age. At my age, I need direct links. In fact, the thought of buying a Raspberry Pi to use for playing music, has been circling my neural networks for several years. Everytime I browse online, I am dissuaded with a webpage giving me endless promotional, and thus irrelevant information, instead of a list of what to buy and specifications.
 
So, to clarify things for myself - not a youth here, but a mature and probably slow 51 year old man.

Which Raspberry Pi should I buy?
Which I2S DAC should I buy?
Which operating system?
Which software?

I am afraid these packages are intended for highly enthusiastic technically gifted adolescents and not for someone of my age. At my age, I need direct links. In fact, the thought of buying a Raspberry Pi to use for playing music, has been circling my neural networks for several years. Everytime I browse online, I am dissuaded with a webpage giving me endless promotional, and thus irrelevant information, instead of a list of what to buy and specifications.

I'm not a youth either and several years older than your good self ;)

To address your questions:
  1. Raspberry Pi: Raspberry Pi 3B+ (Model B Plus). This has built-in wi-fi to connect to your network, although a cabled network connection is preferable. You will need a suitable power supply, case to accomodate a DAC and a compatible micro-SD card.
  2. DAC: I use the Pi-DAC PRO from IQAudio (for the specification, see Pi-DAC Pro I2S audiophile sound card for Raspberry Pi), although there are other compatible models from different manufacturers. You could also use a USB external DAC, or a DAC with an optical S/PDIF connection. HiFiBerry is another possibility. These DACS are plug-in modules and do not normally require any soldering. The IQAudio boards come with mounting pillars and screws to secure them to the Pi board.
  3. Operating system/software: I currently use Volumio. The downloaded Volumio image file for the SD card *is* the complete operating system and application software combined. It is an 'audiophile-friendly' minimal Linux build. Full instructions for flashing the SD card are in the Download section of Volumio's web site. Other similar possibilities are: Roon, Max2Play, Volumio, PiCorePlayer, etc. These are supported by the IQAudio DAC with no additional drivers needed.
For testing, you can use the 3.5mm stereo audio output jack on the Pi itself (before purchasing or fitting a DAC), however the sound quality is fairly mediocre.

This video shows a configuration set up for the Pi-DAC PRO using piCorePlayer, which is similar. A detailed Volumio-specific video explanation is here.

I use a standard 2.5A Raspberry Pi PSU to power the Pi and the DAC card obtains its power through the header pins from the Pi. There are linear low-noise power supply upgrades available if this is important to you.

Hope that helps.
 
Thanks currentflow, these answer many of my questions too.
Just another one, is it possible to play files stored locally in the Pi?
Hi Thimios,

By locally, I wouldn't advise using the main SD card itself for storage, but you can plug a USB flash drive directly into the Pi. For greater storage capacity, a USB hard drive with low power consumption (powered by the Pi), such as an SSD or 2.5 inch HDD with a USB interface would work well. Also, a USB SD card reader can be connected, such as this for example.

As an aside, for portability, I have powered the Pi and DAC by a USB battery "charger" pack. This uses the built-in wi-fi for connectivity, but it does need to be within range of the network wi-fi source if you wish to stream remote content. With such a set-up, an amplifier and speakers in the garden for parties can access the home file server.

No display or keyboard is needed as the music player is entirely headless. You use a cellphone, Android tablet, iPad, iPod or anything containing a web browser to control the system.
 
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To Currentflow:
With your help I ordered a Pi 3B+, power supply and Pi DAC Pro. The idea of having the DAC module securely mounted on top of the Pi is a great idea. The next step is to find a chassis (box) to place everything in.

Hi edbarx,

Excellent! Don't forget to order a micro SD card too, if you don't already have one. These are normally cheapest at 16GB these days and should ideally be a class 10 type. 8GB or 16GB would be equally fine. I'm confident you'll enjoy the end result.
 
Regarding the flashing of the SD card, is this procedure a normal file write to a file system? Or is it a lower level procedure where the write procedure replaces the entire file system on the SD card?

I strongly suspect, the write procedure is a brute force sector write procedure, as the processor, must know the exact sector from where to start loading the operating system kernel.

You're right in your second sentence. This process involves writing an IMG (image) file to the SD card so that it may be bootable by the Pi and is not the same as just copying across files. It is a very simple procedure as described here under "Flash It": Download |Get Started | Volumio

Your message to which this refers appears to have been deleted!
 
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Your message to which this refers appears to have been deleted!
It was not the moderators who deleted the message, by myself. I deleted the message, as soon as I found, that the SD card writing procedure replaces the entire file system. So, my post was no longer necessary, although the mention of class 10, is something I did not know about, and it seems, it speeds up the Pi accessing files.
 
It was not the moderators who deleted the message, by myself. I deleted the message, as soon as I found, that the SD card writing procedure replaces the entire file system. So, my post was no longer necessary, although the mention of class 10, is something I did not know about, and it seems, it speeds up the Pi accessing files.
No problem, although it's often useful to leave posts intact so that others who are following thread can see the conversation flow :)
 
Hi Thimios,

By locally, I wouldn't advise using the main SD card itself for storage, but you can plug a USB flash drive directly into the Pi. For greater storage capacity, a USB hard drive with low power consumption (powered by the Pi), such as an SSD or 2.5 inch HDD with a USB interface would work well. Also, a USB SD card reader can be connected, such as this for example.

As an aside, for portability, I have powered the Pi and DAC by a USB battery "charger" pack. This uses the built-in wi-fi for connectivity, but it does need to be within range of the network wi-fi source if you wish to stream remote content. With such a set-up, an amplifier and speakers in the garden for parties can access the home file server.

No display or keyboard is needed as the music player is entirely headless. You use a cellphone, Android tablet, iPad, iPod or anything containing a web browser to control the system.
Thanks!
I have read somewhere that the Rasbery usb is problematic.Is it trouth?
 
Debian has a package that can be used to draw PCB tracks directly much like MSPaint but with some autorouting. I will try to use it since it bypasses the requirement of precise footprints. I know that will most probably require readjusting component pins, but that is a disadvantage I have to live with at the moment. KiCad seems to be heavily biased towards SMDs, something I want to avoid like the worst of plagues.
 
Ladies and gentlemen, with pleasure we announce that the PCB has started to take shape. The input filter, input stage, voltage droppers and regulators are ready.

The PCB will be mounted with an L shaped aluminium bracket. The mounting will take place on the original amplifier board, so that, the overall mounting is sturdy and reliable.