I'm not exactly the one to explain or defend the 24/192 hi-def craze. Like you, I'm more than happy with the "red book" standard (16/44), and, besides, can't hear above about 14KHz... (I'm 50, so no surprise there...)
But, I've been assembling and selling various computer (Linux) based audio servers for the past year and a half, and most of the guys who purchase these from me just won't touch anything that can't play 24/192... So, I have to go with the tide, regardless of how silly I might think that is.
Anyway, the RasPi and the Wolfson card sound really nice, and are actually something I can heartily recommend, as a highly portable, miniature, low on resources, and high-quality audio solution.
Oh, and did I mention cheap? (Well, relatively, compared to what you can buy ready-made in a hi-fi store....). The whole combo (RasPi + Wolfson card) costs way less than a low-cost external DAC alone, and you actually get a full-blown server, player and a DAC, all rolled into one miniature package. 🙂
I've been listening to this combo - playing on my TPA3116 - for about a month, and I really can't find any serious faults...
So, it was time to put at least some of my amps into more presentable form. One of those will be housed together with the RasPi+Wolfson combo in an "all-in-one" enclosure, with the LCD and remote sensor... Well, that's the next project on the line 🙂
But, I've been assembling and selling various computer (Linux) based audio servers for the past year and a half, and most of the guys who purchase these from me just won't touch anything that can't play 24/192... So, I have to go with the tide, regardless of how silly I might think that is.
Anyway, the RasPi and the Wolfson card sound really nice, and are actually something I can heartily recommend, as a highly portable, miniature, low on resources, and high-quality audio solution.
Oh, and did I mention cheap? (Well, relatively, compared to what you can buy ready-made in a hi-fi store....). The whole combo (RasPi + Wolfson card) costs way less than a low-cost external DAC alone, and you actually get a full-blown server, player and a DAC, all rolled into one miniature package. 🙂
I've been listening to this combo - playing on my TPA3116 - for about a month, and I really can't find any serious faults...
So, it was time to put at least some of my amps into more presentable form. One of those will be housed together with the RasPi+Wolfson combo in an "all-in-one" enclosure, with the LCD and remote sensor... Well, that's the next project on the line 🙂
The Wolfson card is a lot more than just a DAC, its a complete audio I/O card. There are some much cheaper options if you just want an I2S DAC attached to your Raspberry Pi. I like the ES9023 DACs and have used one of these Hifimediy ES9023 DAC, I2S and left justified input, 192Khz/24bit attached to the Pi for a very cost effective digital player combo.
Big subject and off topic, sorry!
Did you ever listen to 24/96 material ? Personally I think 192 kHz is a bit over the top but 24/96 is a step forward from 16/44.1. Even with old ears 😉
Ooops, sorry for derailing the thread... A big topic, sure, and not fit for this thread...
Anyway, back on topic - just wanted to add something else that might come in handy to other beginners like myself: when I "encased" my amps, I had a lot of hum initially, which increased when I touched the aluminium part of the enclosure....
After seeking advice from a more experienced friend, the problem was solved by grounding (i.e. connecting) the ground of the RCA input to the aluminium enclosure: presto, the hum is gone!
I just added a wire from the RCA common ground to the screw used to attach the wood back panel to the aluminium case...
USING FERRITE BEADS AS OUTPUT FILTER.
FERRITE BEAD FILTER CONSIDERATIONS
It is also possible to
accomplish this with only a low-cost ferrite bead filter. In this case it is necessary to carefully select the ferrite
bead used in the filter. One important aspect of the ferrite bead selection is the type of material used in the ferrite
bead. Not all ferrite material is alike, so it is important to select a material that is effective in the 10 to 100 MHz
range which is key to the operation of the class-D amplifier. Many of the specifications regulating consumer
electronics have emissions limits as low as 30 MHz. It is important to use the ferrite bead filter to block radiation
in the 30 MHz and above range from appearing on the speaker wires and the power supply lines which are good
antennas for these signals. The impedance of the ferrite bead can be used along with a small capacitor with a
value in the range of 1000 pF to reduce the frequency spectrum of the signal to an acceptable level. For best
performance, the resonant frequency of the ferrite bead/ capacitor filter should be less than 10 MHz.
The above is taken off page 22 of the TPA3116 datasheet.
Has anybody tried this ?
I need some help to select the correct beads from the Mouser as I am electronic illiterate .
Any health issue with this EMI radiation ?
I believe this will be a very transparent system with the YJ red board hanging of the back of the superpensil box for markaudio 12p.
THANKS
kp93300
FERRITE BEAD FILTER CONSIDERATIONS
It is also possible to
accomplish this with only a low-cost ferrite bead filter. In this case it is necessary to carefully select the ferrite
bead used in the filter. One important aspect of the ferrite bead selection is the type of material used in the ferrite
bead. Not all ferrite material is alike, so it is important to select a material that is effective in the 10 to 100 MHz
range which is key to the operation of the class-D amplifier. Many of the specifications regulating consumer
electronics have emissions limits as low as 30 MHz. It is important to use the ferrite bead filter to block radiation
in the 30 MHz and above range from appearing on the speaker wires and the power supply lines which are good
antennas for these signals. The impedance of the ferrite bead can be used along with a small capacitor with a
value in the range of 1000 pF to reduce the frequency spectrum of the signal to an acceptable level. For best
performance, the resonant frequency of the ferrite bead/ capacitor filter should be less than 10 MHz.
The above is taken off page 22 of the TPA3116 datasheet.
Has anybody tried this ?
I need some help to select the correct beads from the Mouser as I am electronic illiterate .
Any health issue with this EMI radiation ?
I believe this will be a very transparent system with the YJ red board hanging of the back of the superpensil box for markaudio 12p.
THANKS
kp93300
Ferrite beads were discussed earlier in the year - Saturnus looks to be a big fan of using them - http://www.diyaudio.com/forums/class-d/237086-tpa3116d2-amp-24.html#post3763977
You are so right about the Raspberry Pi !
Interesting, .....I am in the process of building an all-in-one music server based on an Audiobah, Rasp PI, HiFiBerry Dac etc.
There will be no other inputs other than directly from the HiFiBerry DAC PCB to the amp via an Alps Pot.
http://i0.wp.com/www.hifiberry.com/wp-content/uploads/2013/11/dac-diy-300-3_2.jpg?resize=251,167
Based on your comment would I need to ground this connection ? .. maybe from the pot ?
Cable lenght inside 12P Pensil might already exceed what TI specifies, but only you know if you built them🙂 If within maximum nothing to worry about if no other equipment starts to behave weird. You'll need to twist the speakerwires if you haven't done that already.
There is no s/pdif input from the pi. The Wolfson and the Hifiberry DAC are connected through the i2s interface of the pi.
I am currently running the 20db YJ/Danzz board with the ceramic xr7 bootstrap cap upgrade, coilcraft inductors, Panasonic 220uF 35v power cap mod, Wima MKP 1uF input cap mod, and all of the output caps upgraded to WIMA MKS caps along with the YJ 6n3 6z4 preamp with upgraded tubes--the US Navy JAN GE5670 military equivalents to the 6n3.
Have also used the YJ tube pre with a variety of less-modded YJ blue boards(including bone stock) all running at 20db .
I think the YJ tube pre definitely adds something to the sound in terms of presentation, soundstage, etc. even on the less modded boards--but with the simple tube upgrade to NOS 5670 tubes it really got better.
The one complaint people have with that particular pre is that there is a LOT of gain, so, you cannot turn it up very much--even with the power amp set at 20db.
But, to my ears, the YJ 6n3/6z4 is certainly a nice match for the Danzz 3116 blue/black board regardless of mods (as long as the board is set to 20db)
Have also used the YJ tube pre with a variety of less-modded YJ blue boards(including bone stock) all running at 20db .
I think the YJ tube pre definitely adds something to the sound in terms of presentation, soundstage, etc. even on the less modded boards--but with the simple tube upgrade to NOS 5670 tubes it really got better.
The one complaint people have with that particular pre is that there is a LOT of gain, so, you cannot turn it up very much--even with the power amp set at 20db.
But, to my ears, the YJ 6n3/6z4 is certainly a nice match for the Danzz 3116 blue/black board regardless of mods (as long as the board is set to 20db)
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Hi,
well, I can share my experience as I have a Rapsberry, a hifiberry and a TP3116.
In fact, I have two configurations:
1) for home, another minipc with a 9023 DAC + TPA 3116
2) for wy wife, Yoga teacher, raspberrypi + hifiberry + TPA3116 in a box with a battery (not finished yet)
Be carrefull with Hifiberry, it is loud, and there is no hardware volume control.
What I can say, is for a cheap equipment, it sounds good, except it is full of electric noise.
The raspberry architecture is not good for that.
A new raspberry pi is coming, well, some people say this issue is solved. So wait and see.....
Again, off topic and apologies. I have a R-Pi and I2S attached 9023 DAC - no noise or any such issues here. If you have noise maybe a software issue?
Yep, the way the I2S stream is derived on the Pi is far from optimal but to my ears its as good as the USB route.
Just had a quick look at the new B+ Pi, doesn't look like the issues that the original had around audio are addressed at first glance.
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The noise comes through the USB port, which is on the same bus as the ethernet. There is not much noise trough the i2s via the GPIO pins, no matter if a Hifiberry Digi or DAC is connected.
Well, I understood there are 2 issues:
One on the USB port, and it is correct to say by using I2S there is less noise.
Another problem on the power filter. For this one, Same noise issue with I2S and USB. Improvements done on new Raspberry.
New thread for Raspberry Pi & 3116 amp
I enjoy all of this DAC business but unless it is specific to connecting it to a 3316 its kind of OT. Let's try to get back on thread folks. I started a new thread called "Interfacing Rasp pi and TPA3116D2" thread to keep this discussion going. Seems like there is plenty of interest.
http://www.diyaudio.com/forums/class-d/259986-interfacing-raspberry-pi-tpa3116d2-amp.html#post4010789
I enjoy all of this DAC business but unless it is specific to connecting it to a 3316 its kind of OT. Let's try to get back on thread folks. I started a new thread called "Interfacing Rasp pi and TPA3116D2" thread to keep this discussion going. Seems like there is plenty of interest.
http://www.diyaudio.com/forums/class-d/259986-interfacing-raspberry-pi-tpa3116d2-amp.html#post4010789
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I would guess it is the same 330pF and 10R as the other filters are the same in PBTL. This includes the LC filter and post LC snubber.
Some PBTL come with 470nF bootstraps, 2 of them, and those feed the 4 bootstrap pins then, but filter should indeed remain the same, it is an outputfilter, not a bootstrap part🙂
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