just finished
Hi all,
here we go:
ezDAC V1.5 in my Sony XA-50es.
Powered by two Audiocom Super Regulators for 3,3V and 5V with its own transformer/rectifier unit, made of super-fast recovery diodes and 10000uF load capacitor.
The oscillator is a Tentlabs XO with a maximum jitter of 3ps rms.
The inputs are 16 bit right justified format taken directly from the Sony chip (CXD2545Q). That is the reason for the absence of an input receiver on the ezDAC PCB.
The analog outputs are directly taken from the PCM1794 to a LC-Audio Zapfilter 2. So the I/V conversion and all the analog stuff is done there. Discrete parts are the way to go, not opamps (just kidding)!
As you can see in the attached file this modified ezDAC does not need to many parts anymore. That saves some time for the build of course.
Finally one word about the most important, the sound:
Just WOW!
If you have any questions left about the modifications, just ask.
Greets,
Martin
Hi all,
here we go:
ezDAC V1.5 in my Sony XA-50es.
Powered by two Audiocom Super Regulators for 3,3V and 5V with its own transformer/rectifier unit, made of super-fast recovery diodes and 10000uF load capacitor.
The oscillator is a Tentlabs XO with a maximum jitter of 3ps rms.
The inputs are 16 bit right justified format taken directly from the Sony chip (CXD2545Q). That is the reason for the absence of an input receiver on the ezDAC PCB.
The analog outputs are directly taken from the PCM1794 to a LC-Audio Zapfilter 2. So the I/V conversion and all the analog stuff is done there. Discrete parts are the way to go, not opamps (just kidding)!
As you can see in the attached file this modified ezDAC does not need to many parts anymore. That saves some time for the build of course.
Finally one word about the most important, the sound:
Just WOW!
If you have any questions left about the modifications, just ask.
Greets,
Martin
Attachments
The XO does not care about the voltage to much.
It accepts either 3,3V or 5V. So in this case it is 3,3V of course.
Greets,
Martin
It accepts either 3,3V or 5V. So in this case it is 3,3V of course.
Greets,
Martin
Broken Wire
The problem I was having with no output was down to a broken wire on the digital input. Fixed now and sounding great. Albeit quiet.
I'm running the output directly into a headphone amp and to listen at normal volume requires the amp to be turned right up. It looks like the output of the DAC is designed to be about the output level of a CD player about 150mV I would imagine. What is the actual output and can I increase this to line level, so I can directly feed some power amps?
Secondly to add a couple of extra inputs, would I just add extra sockets going to, say, a three way switch and then to the input for the board?
Thanks for a great sounding design.🙂
The problem I was having with no output was down to a broken wire on the digital input. Fixed now and sounding great. Albeit quiet.
I'm running the output directly into a headphone amp and to listen at normal volume requires the amp to be turned right up. It looks like the output of the DAC is designed to be about the output level of a CD player about 150mV I would imagine. What is the actual output and can I increase this to line level, so I can directly feed some power amps?
Secondly to add a couple of extra inputs, would I just add extra sockets going to, say, a three way switch and then to the input for the board?
Thanks for a great sounding design.🙂
Re: Broken Wire
Glad to hear it's working (hopefully, you can attach some pics).
Line level is about 2V, and that should be roughly what you're getting if you used the R values given in the BOM.
As to the other questions, I would recommend making your switch occur before the DAC input. That way, each signal can go through the transformer.
stonedowner said:
Glad to hear it's working (hopefully, you can attach some pics).
Line level is about 2V, and that should be roughly what you're getting if you used the R values given in the BOM.
As to the other questions, I would recommend making your switch occur before the DAC input. That way, each signal can go through the transformer.
Could you confirm the component values. In the standard BOM R27 and 28 are 3K where as in the fancy BOM they are 1.5K. R25 and 26 are the same in both at 27R as are R25 and 26 at 100R.
If I remember the rationale (it's been a while), PCM1794 ("fancy") has about twice the output current of PCM1798 (standard), so I adjusted the resistor values to account for that.
The ones you mentioned, R27, R28, plus R33, R34. If you're using PCM1798, try raising those resistors to 3K.
At last I found the problem. R12 the pesky little thing wasn't soldered properly. Resoldered the resistor and low and behold wonderful loud music. A great project. Thanks
Peter 😀
Peter 😀
What's the max output of the op amps. As configured the output is about 2V which is about the same as the output of a CD player. When connected to the CD input of an amp it produces the correct sound levels. What I would like to do is connect the output from the DAC to a stepped attenuator then to some power amps . The output from the op amps needs to be about 8V. Are they capable of this and if so,what value of resistors should I use. Or would I be better using a line amp.
stonedowner said:
I think it's the current you mean?
Regardless, I use exactly this setup for my ezDAC: ezDAC->attenuators->Parasound amp.
I have used Endler attenuators for several years now, and am very happy with the results.
Hi Evan,
Great to see everything is going well with the ezDAC 1.5!
Mine's from the first 1.5 batch, but I couldn't resist 🙂
Regards,
Ray
Great to see everything is going well with the ezDAC 1.5!
Mine's from the first 1.5 batch, but I couldn't resist 🙂
Regards,
Ray
Attachments
stonedowner said:
What kind of attenuator is that?? Or does the amp need 8V input? You can change the 2k0 resistors in the output stage to increase the output voltage, but if it has to be 8Vrms that will not be possible, that's too much for a +/- 12V supply 
.Ray
It works...sort of...
I am getting sound out of both channels on the first hookup! ezDual is putting out perfect -13.8 and +13.8 on both leads. When playing back a song through it I am getting popping every so often in each channel, any idea what could cause that? I am still troubleshooting, (slowly, I have a final this week), just want to see if anyone could direct me down a path!
I am getting sound out of both channels on the first hookup! ezDual is putting out perfect -13.8 and +13.8 on both leads. When playing back a song through it I am getting popping every so often in each channel, any idea what could cause that? I am still troubleshooting, (slowly, I have a final this week), just want to see if anyone could direct me down a path!
Maybe there's a faulty connection to the output stage. Have you checked the solder joints are "clean"?
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