"Bit Perfect" digital output from a computer.
To Hanzwillem and other using your computer as a source... I have been using the same DAC (you now have) for a couple years now, I bought a prototype from Peter. I listen to it 10+ hours a day.
The point I want to make is that you need to achieve "bit perfect" digital output from your computer before it will sound its best and be as good as a CD player as a digital source.
Without "bit perfect" it loses some sparkle to the music.
How do you know if you are "bit perfect"? You play a DTS file and send it to a receiver that decodes a DTS stream, if it lights up 5 channels you are "bit perfect". I keep an old DTS receiver around just for this test.
A DTS sample file can be found here:
http://www.kellyindustries.com/sounds.html
On a PC you can get "bit perfect" with the $40 sound card found in this thread:
http://www6.head-fi.org/forums/showthread.php?t=75844
Once you are "bit perfect" I also recommend WinAMP 5 as a player with MMD3 skin, ASIO, Flac, and Monkey's audio plugins (all free and top notch).
Note with "bit perfect" output you have no volume, balance or tone controls or it couldn't be bit perfect.
To Hanzwillem and other using your computer as a source... I have been using the same DAC (you now have) for a couple years now, I bought a prototype from Peter. I listen to it 10+ hours a day.
The point I want to make is that you need to achieve "bit perfect" digital output from your computer before it will sound its best and be as good as a CD player as a digital source.
Without "bit perfect" it loses some sparkle to the music.
How do you know if you are "bit perfect"? You play a DTS file and send it to a receiver that decodes a DTS stream, if it lights up 5 channels you are "bit perfect". I keep an old DTS receiver around just for this test.
A DTS sample file can be found here:
http://www.kellyindustries.com/sounds.html
On a PC you can get "bit perfect" with the $40 sound card found in this thread:
http://www6.head-fi.org/forums/showthread.php?t=75844
Once you are "bit perfect" I also recommend WinAMP 5 as a player with MMD3 skin, ASIO, Flac, and Monkey's audio plugins (all free and top notch).
Note with "bit perfect" output you have no volume, balance or tone controls or it couldn't be bit perfect.
I am not completely sure if I should announced the DAC kit info on my site. The commercial version of a DAC is using exactly same board (and sells for $900). This would create a conflict of interest of some sort. So for now, the DAC is only available from this thread, and the info can be found here: http://www.diyaudio.com/forums/showthread.php?postid=609968#post609968
I sold already about 30 of those kits (mostly in Europe)
As to the phono preamp, I have to built few circuits, compare results and tweak the best one. It took me year to come up with a DAC, it should be much less with a phono stage. Some interesting schematics can be found below. Because of great simplicity, all of them can be built p2p using a protoboard:
http://www.diyaudio.com/forums/showthread.php?s=&postid=643247#post643247
http://www.users.nac.net/markowitzgd/phonopre.html
http://www.metaxas.com/pages/technology/diy.html
I have almost finished OnoX, so will have a good reference point
I sold already about 30 of those kits (mostly in Europe)
As to the phono preamp, I have to built few circuits, compare results and tweak the best one. It took me year to come up with a DAC, it should be much less with a phono stage. Some interesting schematics can be found below. Because of great simplicity, all of them can be built p2p using a protoboard:
http://www.diyaudio.com/forums/showthread.php?s=&postid=643247#post643247
http://www.users.nac.net/markowitzgd/phonopre.html
http://www.metaxas.com/pages/technology/diy.html
I have almost finished OnoX, so will have a good reference point
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It is not a "conflict", but fulfilling the needs of a different target group. Very few people who buy the amp kits, would be actuly buying the complete amps. Besides, if the kits wouldn't be sold by me, somebody else would be selling them, so for me it's more of a neccessity than actual choice
With a DAC, I still want to be fulfilling the needs of eager diy-ers, but I don't want everybody to know that such kits are availble, as selling complete units is much more profitable. Those who are interested enough, will know where to find them.
The AMP-1 circuit is wired p2p, so there is no conflict with PCBs sold with the premium kits, although the parts being used (and schematic) are basically the same. The Premium kit, that was a basis for the whole GC kits enterprise, was developed initially for AMP-1, and only later posted by me on this forum.
With a DAC, I still want to be fulfilling the needs of eager diy-ers, but I don't want everybody to know that such kits are availble, as selling complete units is much more profitable. Those who are interested enough, will know where to find them.
The AMP-1 circuit is wired p2p, so there is no conflict with PCBs sold with the premium kits, although the parts being used (and schematic) are basically the same. The Premium kit, that was a basis for the whole GC kits enterprise, was developed initially for AMP-1, and only later posted by me on this forum.
LM4780 boards are $25/pc.
They are described here: http://www.diyaudio.com/forums/showthread.php?postid=636556#post636556
and allow option of using one half (of the board) in a stereo mode, so for 6 channels you may only end up with 1 and 1/2 board requirement.
I'm selling 1/2 of the board at 1/2 price ($12.50) which is currently the best deal on a stereo GC board.
They are described here: http://www.diyaudio.com/forums/showthread.php?postid=636556#post636556
and allow option of using one half (of the board) in a stereo mode, so for 6 channels you may only end up with 1 and 1/2 board requirement.
I'm selling 1/2 of the board at 1/2 price ($12.50) which is currently the best deal on a stereo GC board.
I got nicely surprised tonight when I found out about this article: http://www.6moons.com/audioreviews/audiosector/patek.html
That's a nice article Peter. The Patek really is a work of art. And so is the similarly styled DAC, which I only just got round to auditioning properly yesterday BTW.
It took me a while to source a digital cable. I ordered a Supra Trico and after three weeks of it not arriving I had it canceled and had a custom cable made using Belden 1695a terminated with crimped Canare 75 Ohm RCA/BNC. Sat down for about 5 hours yesterday mesmerised by the sound being produced in my living room.
The source was a cheap DVD player with digital out (I will try with the Shangling soon) into the DAC -> LM3875 premium kit -> newly finished W3-871S monitors. I haven't applied the notch yet so it was a little forward sounding in the mid highs but it didn't stop me listening, mouth-open, for several hours.
If I thought the LM3875 kit took my system up a rather large notch, then the DAC has just taken it up another. I may have to build some more now to slot in before each chip amp I've made.
It took me a while to source a digital cable. I ordered a Supra Trico and after three weeks of it not arriving I had it canceled and had a custom cable made using Belden 1695a terminated with crimped Canare 75 Ohm RCA/BNC. Sat down for about 5 hours yesterday mesmerised by the sound being produced in my living room.
The source was a cheap DVD player with digital out (I will try with the Shangling soon) into the DAC -> LM3875 premium kit -> newly finished W3-871S monitors. I haven't applied the notch yet so it was a little forward sounding in the mid highs but it didn't stop me listening, mouth-open, for several hours.
If I thought the LM3875 kit took my system up a rather large notch, then the DAC has just taken it up another. I may have to build some more now to slot in before each chip amp I've made.
How are you all doing?
This afternoon I thought about watching some DVDs so connected the DAC to the DVD player and it remained silent. I quickly found out that the stupid voltage that is on the shielding of the cable TV destroyed the input of the DAC. As can bee seen below. I bypassed the burned part but still the output of the receiverbuffer is dead.
My local supplier does not carry the SN71579. Could you please send me one (or two?). Of course I will transfer the costs to you through paypal.
regards, Hans-Willem
This afternoon I thought about watching some DVDs so connected the DAC to the DVD player and it remained silent. I quickly found out that the stupid voltage that is on the shielding of the cable TV destroyed the input of the DAC. As can bee seen below. I bypassed the burned part but still the output of the receiverbuffer is dead.
My local supplier does not carry the SN71579. Could you please send me one (or two?). Of course I will transfer the costs to you through paypal.
regards, Hans-Willem
An externally hosted image should be here but it was not working when we last tested it.
Hanzwillem said:
No problem, I will send it today. It will be $5 for two pcs, shipping included. Paypal to my e-mail adress which you can find in Contact section here: http://www.audiosector.com/
BTW, more info about the new Patek amp has been posted here: http://www.6moons.com/audioreviews/audiosector/patek_2.html
Please educate me on something:
How does this "snubberrized" rectifier approach translate into a better power supply?
True, convectional silicon rectifiers, have some switching delays that may be addressed by the "MUR" part types, but these times are measured in nanoseconds! And this is 60Hz!
And conduction losses between a .6V drop and a .3V drop are not relevant in a highly filtered, unregulated PS like this one.
And "snubber" really deals with providing a conduction path for backEMF or energy stored in an inductor, neither of which are present here (I've checked this with an oscilloscope).
Although it's easy to demonstrate that bridge rectifier switching sends sufficient current harmonics back into the power line to pollute the mains, this is not an issue with North American compliance, as it it with CE (a bridge rectifier won't pass CE without some form of power factor correction).
All in all, I have not been able to find any difference in sound quality measured at the Amplifier output with a "snubberized" Power Supply, versus a plain vanilla bridge.
If you have found different, what test setup did you use?
How does this "snubberrized" rectifier approach translate into a better power supply?
True, convectional silicon rectifiers, have some switching delays that may be addressed by the "MUR" part types, but these times are measured in nanoseconds! And this is 60Hz!
And conduction losses between a .6V drop and a .3V drop are not relevant in a highly filtered, unregulated PS like this one.
And "snubber" really deals with providing a conduction path for backEMF or energy stored in an inductor, neither of which are present here (I've checked this with an oscilloscope).
Although it's easy to demonstrate that bridge rectifier switching sends sufficient current harmonics back into the power line to pollute the mains, this is not an issue with North American compliance, as it it with CE (a bridge rectifier won't pass CE without some form of power factor correction).
All in all, I have not been able to find any difference in sound quality measured at the Amplifier output with a "snubberized" Power Supply, versus a plain vanilla bridge.
If you have found different, what test setup did you use?
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