Peufeu,
Right, thats an error on page 16, so in case of doubt there is also the graph showing the PCM SHARP ROLL-OFF FILTER RESPONSE, and there one can notice the ~ 6-10 dB att. at 0.5 Fs, as is cited by Bruno.
The slow roll off is just that - ~no filtering at Nyquist freq.
But I'm far from criticizing - only wanted to clarify! It's up to the designer to decide, and obviously Dustin did not made a bad choice given the warm welcome from the listeners!
What regards the vanity, hope that the author will jump in!
And, given that it's not straightforward to use that board as a correct digital filter, if You think You can do something similar, but I2s in I2s out...
Ciao, George
Right, thats an error on page 16, so in case of doubt there is also the graph showing the PCM SHARP ROLL-OFF FILTER RESPONSE, and there one can notice the ~ 6-10 dB att. at 0.5 Fs, as is cited by Bruno.
The slow roll off is just that - ~no filtering at Nyquist freq.
But I'm far from criticizing - only wanted to clarify! It's up to the designer to decide, and obviously Dustin did not made a bad choice given the warm welcome from the listeners!
What regards the vanity, hope that the author will jump in!
And, given that it's not straightforward to use that board as a correct digital filter, if You think You can do something similar, but I2s in I2s out...
Ciao, George
Hi everybody,
As I'm gonna start prototyping, I'll have to buy 5 Sabre DACs.
Boards from CustomPCB come by two, at least.
So I'll have 1 spare "eval board" (board with just the DAC, all things that can't be modified, and pin connectors for everything else), and 2 DAC's (I keep two for myself) as spares.
So people wanting DACs or an "eval board" with the DAC (I'd prefer to sell it non soldered, but I may cook the SMD for you), just tell me!
As I'm gonna start prototyping, I'll have to buy 5 Sabre DACs.
Boards from CustomPCB come by two, at least.
So I'll have 1 spare "eval board" (board with just the DAC, all things that can't be modified, and pin connectors for everything else), and 2 DAC's (I keep two for myself) as spares.
So people wanting DACs or an "eval board" with the DAC (I'd prefer to sell it non soldered, but I may cook the SMD for you), just tell me!
OK I take the chip.
What's your price for the board ?
Uh,
- download Xilinx ISE free web edition
- write I²S encoder/decoder (done)
- write random number generator (done)
- instantiate Xilinx FIR filter core for filtering the audio
- instantiate Xilinx FIR filter core for shaping the noise
- a comparator for dither
- little bits of glue
- program chip
- you'll need a few HCT oc LCX chips to interface 3.3V and 5V signals and obviously some way to get a clean clock since the FPGA is a high-noise part.
It is a sunday afternoon project if you know Verilog and the Xilinx tools, if you need a cheap FPGA fast, get the one from SparkFun.
All the juicy bits are in designing the FIR filter. That is not a sunday afternoon project.
* of course the Vanity is more complicated since it handles DSD etc, but if you want a quick & dirty FIR, it's really easy since you can waste resources
What's your price for the board ?
And, given that it's not straightforward to use that board as a correct digital filter, if You think You can do something similar, but I2s in I2s out...
Ciao, George
Uh,
- download Xilinx ISE free web edition
- write I²S encoder/decoder (done)
- write random number generator (done)
- instantiate Xilinx FIR filter core for filtering the audio
- instantiate Xilinx FIR filter core for shaping the noise
- a comparator for dither
- little bits of glue
- program chip
- you'll need a few HCT oc LCX chips to interface 3.3V and 5V signals and obviously some way to get a clean clock since the FPGA is a high-noise part.
It is a sunday afternoon project if you know Verilog and the Xilinx tools, if you need a cheap FPGA fast, get the one from SparkFun.
All the juicy bits are in designing the FIR filter. That is not a sunday afternoon project.
* of course the Vanity is more complicated since it handles DSD etc, but if you want a quick & dirty FIR, it's really easy since you can waste resources
For the board,
CustomPCB:
"2 PCB Soldermask & Silkscreen 78$"
So this is the price of the board, + 19$ for shipping.
So I'd sell you the board for 50$, half the price of 2 boards - I don't make any money on it. Plus you pay the shipping costs for me to send it to you. Would be 40$ without silkscreen, I don't know if I take it.
Price of the Sabre should be around 50$ if I remember correctly.
CustomPCB:
"2 PCB Soldermask & Silkscreen 78$"
So this is the price of the board, + 19$ for shipping.
So I'd sell you the board for 50$, half the price of 2 boards - I don't make any money on it. Plus you pay the shipping costs for me to send it to you. Would be 40$ without silkscreen, I don't know if I take it.
Price of the Sabre should be around 50$ if I remember correctly.
I was talking about boards, not chips.
However if more people want boards it's no problem for me to buy several!
Oh, I forgot the price of the stencil (35$ inc shipping). And I'll stencil it.
EDIT:
I found this one:
http://www.pcbfabexpress.com
Way better! Cheaper and does boards any size I want.
And the more boards I order really cheaper it gets.
So how many people here would be interested?
Price would be:
- The Sabre (around 50$)
- The board (60$ if only 1 people wants one; 20$ if 4; even less if more)
- Stenciling (price of the stencil/number of people)
However if more people want boards it's no problem for me to buy several!
Oh, I forgot the price of the stencil (35$ inc shipping). And I'll stencil it.
EDIT:
I found this one:
http://www.pcbfabexpress.com
Way better! Cheaper and does boards any size I want.
And the more boards I order really cheaper it gets.
So how many people here would be interested?
Price would be:
- The Sabre (around 50$)
- The board (60$ if only 1 people wants one; 20$ if 4; even less if more)
- Stenciling (price of the stencil/number of people)
OK, so I will take 2 DAC chips. Thanks for the offer
As for the board, I need to see the layout first to check if it will fit in my current project.
Please contact me privately for arranging the transaction (PM on this site).
Check http://www.olimex.com/pcb/index.html
Very cheap for double sided.
Hey. This site says you're french from Lyon. J'habite dans le 7è, voilà qui serait pratique !
As for the board, I need to see the layout first to check if it will fit in my current project.
Please contact me privately for arranging the transaction (PM on this site).
Check http://www.olimex.com/pcb/index.html
Very cheap for double sided.
Hey. This site says you're french from Lyon. J'habite dans le 7è, voilà qui serait pratique !
Firmware for volume controlled Buffalo
Hey Folks,
I am very pleased with the volume control of the Sabre DAC. Well I am pleased with the DAC in every regard...
I wrote this firmware to use with my Buffalo DAC.
It is written for Hi-TECH C (free for DIY use with Hi Tide IDE) utilizing an old Joshua Tree controller board I had lying around.
A PCB is not really required. All you need is a PIC16F690,PIC16F685 or PIC16F687 any of those should work fine.
You will also need a 2-5K linear pot with the high side connected to VDD and the low side to GND. The wiper gets connected to AN0.
Anyway the code is pretty self explanatory. RC0 and RC1 are the I2C lines.
Some of you working on Sabre DAC projects may find useful tidbits in it. If you do that's great. If not, well I don't really care.
You could actually use a smaller PIC like a PIC12F675 and it would port very easily. You could even do this with the Buffalo board alone by using a PIC12F675 and keeping one of the switches open and connect the wiper to that switch position output. I may try that myself at some point.
Also it would port pretty easily to an AVR.
I just happened to have this PCB and chip handy.
The volume will track the pot. Its simple, and it works perfectly for me.
Enjoy!!!
We will have the modules ready to roll soon.
Cheers!
Russ
Hey Folks,
I am very pleased with the volume control of the Sabre DAC. Well I am pleased with the DAC in every regard...
I wrote this firmware to use with my Buffalo DAC.
It is written for Hi-TECH C (free for DIY use with Hi Tide IDE) utilizing an old Joshua Tree controller board I had lying around.
A PCB is not really required. All you need is a PIC16F690,PIC16F685 or PIC16F687 any of those should work fine.
You will also need a 2-5K linear pot with the high side connected to VDD and the low side to GND. The wiper gets connected to AN0.
Anyway the code is pretty self explanatory. RC0 and RC1 are the I2C lines.
Some of you working on Sabre DAC projects may find useful tidbits in it. If you do that's great. If not, well I don't really care.
You could actually use a smaller PIC like a PIC12F675 and it would port very easily. You could even do this with the Buffalo board alone by using a PIC12F675 and keeping one of the switches open and connect the wiper to that switch position output. I may try that myself at some point.
Also it would port pretty easily to an AVR.
I just happened to have this PCB and chip handy.
The volume will track the pot. Its simple, and it works perfectly for me.
Enjoy!!!
We will have the modules ready to roll soon.
Cheers!
Russ
Hi Russ,
I didn't notice that one. I did notice you are using the slow rolloff instead of the fast.
I did a listening test and didn't hear any reason to change it to slow. As some others have noted in the thread recently, the slow rolloff could result in some alias images.
I didn't do a thorough listen test. Did you set that based on a listen test? I decided to leave it at the default, which is the sharp rolloff beginning at .45 fs
I didn't notice that one. I did notice you are using the slow rolloff instead of the fast.
I did a listening test and didn't hear any reason to change it to slow. As some others have noted in the thread recently, the slow rolloff could result in some alias images.
I didn't do a thorough listen test. Did you set that based on a listen test? I decided to leave it at the default, which is the sharp rolloff beginning at .45 fs
Hi Ross,
I have been playing with it back and forth. Between sharp and slow. I just happen to have it at slow right now.
This is partly because I employ analog filtering at the IVY (about 100khz fc). So slow filter curve should not result in too many nasties.
It sounds really great either way and I would be hard pressed to note a difference.
Cheers!
Russ
I have been playing with it back and forth. Between sharp and slow. I just happen to have it at slow right now.
This is partly because I employ analog filtering at the IVY (about 100khz fc). So slow filter curve should not result in too many nasties.
It sounds really great either way and I would be hard pressed to note a difference.
Cheers!
Russ
My Brother Ken(Runs a recording studio here in Nashville) is here today and we are listening to 192/24 masters on the Buffalo. Incredibly nice, and he brought a great selection.
One the artists we are listening too is a local Violinist playing Brahms. So sweet and pure it is giving me goose pimples.
But That's not all, he also has some incredible local jazz band with a double bass that sounds like he is slapping it form just in front of the chair. Amazing. When the string is plucked, you hear (or feel) every nuance.
So I can say without a doubt this is the best DAC I have heard, especially for hi-res material.
I am using a 80mhz clock so I can do 192khz SPDIF/AES.
My brother is not leaving until I promise to build him one, of course that was already planned.
Cheers!
Russ
One the artists we are listening too is a local Violinist playing Brahms. So sweet and pure it is giving me goose pimples.
But That's not all, he also has some incredible local jazz band with a double bass that sounds like he is slapping it form just in front of the chair. Amazing. When the string is plucked, you hear (or feel) every nuance.
So I can say without a doubt this is the best DAC I have heard, especially for hi-res material.
I am using a 80mhz clock so I can do 192khz SPDIF/AES.
My brother is not leaving until I promise to build him one, of course that was already planned.
Cheers!
Russ
Russ,
That beer looks good. I'll take one right now!
I'm up for the "Dustin Challenge":
"1. Sabre in synchronous mode, with very high end transport with low jitter mclk.
2. Crappy transport full of jitter, then let the Sabre do its thing."
But your Buffalo has to support it -- will it have a switch for synchronous mode that takes out ASRC?
In addition to SPDIF, My Empirical Audio Pace Car "transport" also does I2S out with a SuperClock 4 as mclk.
Bill
That beer looks good. I'll take one right now!
I'm up for the "Dustin Challenge":
"1. Sabre in synchronous mode, with very high end transport with low jitter mclk.
2. Crappy transport full of jitter, then let the Sabre do its thing."
But your Buffalo has to support it -- will it have a switch for synchronous mode that takes out ASRC?
In addition to SPDIF, My Empirical Audio Pace Car "transport" also does I2S out with a SuperClock 4 as mclk.
Bill
Hi Cappy,
I have to say (modesty be damned) it's a hell of a good beer
Yes the Buffalo will support the "Jitter Reduction - Off" register as a switch. So you can feel free to experiment away with an ultra low jitter source.
As for me, I am perfectly happy with the jitter reduction.
You can disable the on board clock by bringing pin 1 of the XO low, or just omit the XO. And there are two pads next to the master clock for external master clock input.
Cheers!
Russ
I have to say (modesty be damned) it's a hell of a good beer
Yes the Buffalo will support the "Jitter Reduction - Off" register as a switch.
So you can feel free to experiment away with an ultra low jitter source.As for me, I am perfectly happy with the jitter reduction.
You can disable the on board clock by bringing pin 1 of the XO low, or just omit the XO. And there are two pads next to the master clock for external master clock input.
Cheers!
Russ