Hi,
I am a happy user of this kit (see mine in the attached picture). I modified the original kit by changing the original AD op-amps with LM4562. The only singular behavior, compared with the other dac I have (DAC 707 Superpro), is the higher output level of signal also reported by other people in this thread. I am using the coaxial PSDIF input connected asyncrhonous to a Mac via a M2tech usb interface.
However, since I switched to a chip amp I noted that the chip-amp was getting very warm even without playing music (not with the other dac or CD player I have). Then I measured at the new Gigawork dac 750mV DC at signal out when the dac is connected to the Mac on both channels. If the dac is disconnected from the Mac I measure 2mV.
Connected to the Mac, the Superpro dac gives 9mV out.
I can hear a very high hum noise from the speakers when the amp volume is at maximum level.
Is there something wrong?
Thank you for your feedback
Renato
I am a happy user of this kit (see mine in the attached picture). I modified the original kit by changing the original AD op-amps with LM4562. The only singular behavior, compared with the other dac I have (DAC 707 Superpro), is the higher output level of signal also reported by other people in this thread. I am using the coaxial PSDIF input connected asyncrhonous to a Mac via a M2tech usb interface.
However, since I switched to a chip amp I noted that the chip-amp was getting very warm even without playing music (not with the other dac or CD player I have). Then I measured at the new Gigawork dac 750mV DC at signal out when the dac is connected to the Mac on both channels. If the dac is disconnected from the Mac I measure 2mV.
Connected to the Mac, the Superpro dac gives 9mV out.
I can hear a very high hum noise from the speakers when the amp volume is at maximum level.
Is there something wrong?
Thank you for your feedback
Renato
Attachments
Sounds very good if you rebuild the analogic part on a separate (new) board. The included I\U and buffer are built with wrong components and is almost imposible to change the smd resistors/capacitors.
board resistor components!
I have to agree with Atupi, i own 2 of these DAC boards and both of them have components around the I/V an buffer stage with incorrect component values!
In my case even the two boards have both wrong component values but there are also differences between the two boards.
I use a seperate I/V stage to overcome these problems.
I have to agree with Atupi, i own 2 of these DAC boards and both of them have components around the I/V an buffer stage with incorrect component values!
In my case even the two boards have both wrong component values but there are also differences between the two boards.
I use a seperate I/V stage to overcome these problems.
Hi,
with reference to my post #245, I solved my problem by inserting an AC couplig cap at output (my amplifier is a DC coupled chipamp). Unlikely, I did not believe how much important was the influence of a cap on the audio signal: the cap added a veil to the music.
There is not sufficient space in the chassis to put a polypropilene cap, so I used a an electrolytic 4.7microF/35V Rubycon ZA.
Have you a suggestion for a better choice (forgetting BG N that I cannot find)?
Thank you
Renato
with reference to my post #245, I solved my problem by inserting an AC couplig cap at output (my amplifier is a DC coupled chipamp). Unlikely, I did not believe how much important was the influence of a cap on the audio signal: the cap added a veil to the music.
There is not sufficient space in the chassis to put a polypropilene cap, so I used a an electrolytic 4.7microF/35V Rubycon ZA.
Have you a suggestion for a better choice (forgetting BG N that I cannot find)?
Thank you
Renato
Hi northernsky,
I think i am having the sane issue.
I removed the multiplexer mute chip.
I Also added the four 470 ohms to reduce output voltage.
I realized one of my amps didn't work.
So I tried a little SEP amp with capacitors at it's inputs and it sounded well.
So I am guessing I have the same DC problem.
Now I am adding 2 PIO .33 UF caps to test with my main amp and see how it goes.
Even with this work arround, there should be a cleaner way of fixing this issue?
I am afraid of those bypass caps ruining the sound..
Cheers
I think i am having the sane issue.
I removed the multiplexer mute chip.
I Also added the four 470 ohms to reduce output voltage.
I realized one of my amps didn't work.
So I tried a little SEP amp with capacitors at it's inputs and it sounded well.
So I am guessing I have the same DC problem.
Now I am adding 2 PIO .33 UF caps to test with my main amp and see how it goes.
Even with this work arround, there should be a cleaner way of fixing this issue?
I am afraid of those bypass caps ruining the sound..
Cheers
Listening to the new setup now.
It sounds well, distortion seems to have dissapered.
I don't have a pre, just volume on a Mac.
My speakers are super sensitive so I guess I will adjust again those opamp resistors to reduce opamp gain a little more.
What makes me happy about this setup is that I am not noticing a high frequency roll-off as when using a potentiometer before the power amp Push Pull el84.
It sounds well, distortion seems to have dissapered.
I don't have a pre, just volume on a Mac.
My speakers are super sensitive so I guess I will adjust again those opamp resistors to reduce opamp gain a little more.
What makes me happy about this setup is that I am not noticing a high frequency roll-off as when using a potentiometer before the power amp Push Pull el84.
But even when my system performace has improved
Is a coupling CAP between dac and power ideal?
I guess, a less component approach is aleáis better when possible.
Ideas to remove opamp stage bias:
1) test upgrade opamp power supply?
2) matching resistors in opamp section?
3) or just use a very boutique cap ?
Thanks
Is a coupling CAP between dac and power ideal?
I guess, a less component approach is aleáis better when possible.
Ideas to remove opamp stage bias:
1) test upgrade opamp power supply?
2) matching resistors in opamp section?
3) or just use a very boutique cap ?
Thanks
So, somebody decided to problem of noise in pauses, after shorting mutes (short cut the 4056) It is very unnerving to hear the noise =))))))
If someone is interested in measuring of this DAС
lampucera.png ? Yandex.Disk
If someone is interested in measuring of this DAС
lampucera.png ? Yandex.Disk
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