FastEddy said:" ... Sure, it was only a revelation to discover 320kbps mp3s compared to 128 ..."
Yes ... and if you believe that your 16bit/44.1k source material has been converted to 128k or 192k or 320 k (mp3, etc.) quality, then fine. I may have a bridge that you might be interested in.
The 320kbps mp3 streams are presently played mostly at 16bit/44.1k around my house
One thought about transferring all those great classics to DVDA etc., I wonder how they will sound after so many transfer 'attempts' to CD already (due to bad CD mastering ...).
232: http://youtube.com/watch?v=3Gmex_4hreQ is what happens when 16bit stuff is compressed prior to recording, then when expanded by "up-converting" to 128k or higher = garbage in = garbage out ...
Hi All,
I just managed to finish my TAS5261 based project (when I finished uni). A quick note of thanks for everyone who has posted in this thread, there were some quite handy bits in there!
Its a 6ch (2 wireless) amp, Dolby/DTS decoder, DSP, graphical UI, and <16ms latency wireless link (48kHz, 24bit).
Currently working on a revision of the system, cant discuss too much, patents in progress for some bits.
Sorry for butting in to the conversation, but any help I can give, im happy too.
Sorry, Cant post a pic atm, have to find one that will fit.
Rough specs, Measured it with the uni's spectrum analyser, 0.00087% THD at 1KHz, 60W/channel, +-0.5dB (10Hz->22KHz) respsonse
Cheers,
Borg9
I just managed to finish my TAS5261 based project (when I finished uni). A quick note of thanks for everyone who has posted in this thread, there were some quite handy bits in there!
Its a 6ch (2 wireless) amp, Dolby/DTS decoder, DSP, graphical UI, and <16ms latency wireless link (48kHz, 24bit).
Currently working on a revision of the system, cant discuss too much, patents in progress for some bits.
Sorry for butting in to the conversation, but any help I can give, im happy too.
Sorry, Cant post a pic atm, have to find one that will fit.
Rough specs, Measured it with the uni's spectrum analyser, 0.00087% THD at 1KHz, 60W/channel, +-0.5dB (10Hz->22KHz) respsonse
Cheers,
Borg9
I'm in the middle of a TAS5261 + TAS5518 project also, there isn't that much information available but I do have some pictures at my website:
http://blog.area26.se/archives/category/audio
The ultimate goal of this project is to have a 100% DIY setup with a fully digital signal chain (except the last 1m or so, inside the speaker cabinet).
Each speaker will have a two or three channel TAS5518 + TAS5261 amp board, with the crossover implemented digitally.
This is the board I'm testing right now, it is basically a three-channel version of the EVM board from TI...
Next will come a PSVC-capable power supply board, and then all the stuff that is needed to take audio from various standard sources (S/PDIF, analog, HDMI...) and distribute to the individual speakers.
If there is enough interest, I probably will publish schematics and maybe PCB designs under some open license...
http://blog.area26.se/archives/category/audio
The ultimate goal of this project is to have a 100% DIY setup with a fully digital signal chain (except the last 1m or so, inside the speaker cabinet).
Each speaker will have a two or three channel TAS5518 + TAS5261 amp board, with the crossover implemented digitally.
This is the board I'm testing right now, it is basically a three-channel version of the EVM board from TI...
Next will come a PSVC-capable power supply board, and then all the stuff that is needed to take audio from various standard sources (S/PDIF, analog, HDMI...) and distribute to the individual speakers.
If there is enough interest, I probably will publish schematics and maybe PCB designs under some open license...
Nice work Cyr,
I looked at your blog site & see we have three areas in common - purepath digital amplifiers ( I have a Panasonic XR57), Ubuntu OS (mine is not servere) & Panasonic Lumix camera (mine, the very cheap FX12)!
What are you going to use for the PSVC - the TI schematic or another?
I have busted my Panasonic XR57 PS with one experiment too many - trying to run the low level supplies (5 & 3.3V) off battery. Why was I doing this? The sonic improvement in running the output stage direct from battery was so great that I wondered how running a clean 5 & 3.3V supply to the digital chips would sound? Anyway, fixing it (if I can) is on the back burner for the moment while I build some other amps.
What PS are you currently using?
I looked at your blog site & see we have three areas in common - purepath digital amplifiers ( I have a Panasonic XR57), Ubuntu OS (mine is not servere) & Panasonic Lumix camera (mine, the very cheap FX12)!
What are you going to use for the PSVC - the TI schematic or another?
I have busted my Panasonic XR57 PS with one experiment too many - trying to run the low level supplies (5 & 3.3V) off battery. Why was I doing this? The sonic improvement in running the output stage direct from battery was so great that I wondered how running a clean 5 & 3.3V supply to the digital chips would sound? Anyway, fixing it (if I can) is on the back burner for the moment while I build some other amps.
What PS are you currently using?
" ... I have busted my Panasonic XR57 PS with one experiment too many ... "
I busted my XR55 too. It seems that Panasonic was a bit generous in their specs, 100 watts > 4 to 8 ohms over an extended period = pop, a bit of smoke and a trip to the warranty center for repairs. (I have since "donated" it to my cousins in Omaha ...
)
TAS5261 = keep the faith. This chip set is a winner with great specs. My advise: add a couple of poly / plastic caps (~ 0.1 uF to ~1.0 uF) across or very close to any and all power pins, especially the analog side. This is one of the tricks that TI uses to get their great specs on most analog op-amps, etc. ...
I busted my XR55 too. It seems that Panasonic was a bit generous in their specs, 100 watts > 4 to 8 ohms over an extended period = pop, a bit of smoke and a trip to the warranty center for repairs. (I have since "donated" it to my cousins in Omaha ...
)TAS5261 = keep the faith. This chip set is a winner with great specs. My advise: add a couple of poly / plastic caps (~ 0.1 uF to ~1.0 uF) across or very close to any and all power pins, especially the analog side. This is one of the tricks that TI uses to get their great specs on most analog op-amps, etc. ...
jkeny said:
I'm going to base the PSVC board on the appnote from TI (slea038.pdf), with some small changes. I'm far from an expert on SMPS so I'm not going to stray far from the TI design...
I'll be feeding that board with ~50V from a generic SMPS I got from ebay (unless that turns out to be too crappy).
Right now I'm using a Voltcraft lab PSU for testing.
misconceptions about bit rates!
I know this is a while ago, but I saw it and had to comment:-
a cd playing uncompressed PCM is at a BIT rate of 1.4112 Megabits per second, 320K bits per second represents a compression of 4.4:1 in data that is 3/4 of the info has been binned; you are confusing samples per second with bit rate. 192K samples per second at 24bit resolution represents 4.608M bits per second.
while I agree when you up sample audio you only fill in the gaps, all MP3's downsample the audio and loose things- lets not forget MP3 is good for what it was designed for- portable audio- not HIFI
I know this is a while ago, but I saw it and had to comment:-
FastEddy said:" ... after copying CDs in 320kbps ..."
Copying at a hugher speed/bandwidth does not necessarily mean that the playback speed/bandwidth will be improved ... In the case of 16bit/44.1k or 16bit/48k CDs, playback bandwidth may then be "set" to a higher value as well, but the source material will not change or be improved one wit = the digital content can not be expanded , it can only be "enhanced" with digital filler in the form of extra "blank" bits.
Also the garbage in is still going to be the same garbage out ... if the material was compressed as it often is, any digital enhancements will also enhance the compression ...
Also internet radio is often available above 192k bandwidth ... whether 24bit or something else is not always evident.
a cd playing uncompressed PCM is at a BIT rate of 1.4112 Megabits per second, 320K bits per second represents a compression of 4.4:1 in data that is 3/4 of the info has been binned; you are confusing samples per second with bit rate. 192K samples per second at 24bit resolution represents 4.608M bits per second.
while I agree when you up sample audio you only fill in the gaps, all MP3's downsample the audio and loose things- lets not forget MP3 is good for what it was designed for- portable audio- not HIFI
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