ezDAC v.1.5 Builders Thread

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
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
 

Attachments

  • ezdac.jpg
    ezdac.jpg
    97.2 KB · Views: 4,512
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.:)
 
Re: Broken Wire

stonedowner said:
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.:)


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.
 
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:
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.


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.
 
stonedowner said:
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.

:bigeyes: 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 :no:.

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!
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.