Hi Alesandro,
I had a look at your picture of the waveform and in my opinion this is not such a bad thing. The good thing about that waveform is that the rise time seems to be very fast, and the edges are clean (but hard to tell with that photo). Data is clocked on either the low to high, or the high to low transition. The appearance of the top and bottom of the waveform is unimportant, as the data has already been clocked before the wave even gets to the top or bottom.
Perhaps you could set your CRO to look at the exact rise time
from low to high signal, and see if you are getting any distortions or unevenness to the edges?
Perhaps it is an issue with noise on the voltage rails? Have you checked the DC input to the microprocessor to see is there is noise on the DC rails? Perhaps you could add some capacitors near the power supply pins to remove any noise that might be causing the unevenness on top and bottom of the waveform.
anyway did you notice a difference to the sound after removing the CS8406?
I had a look at your picture of the waveform and in my opinion this is not such a bad thing. The good thing about that waveform is that the rise time seems to be very fast, and the edges are clean (but hard to tell with that photo). Data is clocked on either the low to high, or the high to low transition. The appearance of the top and bottom of the waveform is unimportant, as the data has already been clocked before the wave even gets to the top or bottom.
Perhaps you could set your CRO to look at the exact rise time
from low to high signal, and see if you are getting any distortions or unevenness to the edges?
Perhaps it is an issue with noise on the voltage rails? Have you checked the DC input to the microprocessor to see is there is noise on the DC rails? Perhaps you could add some capacitors near the power supply pins to remove any noise that might be causing the unevenness on top and bottom of the waveform.
anyway did you notice a difference to the sound after removing the CS8406?
I bet you would get an even better sound if you made those wires shorter.....
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i cant trim too much,its like that for r&d purpose.i might use diffrent caps in the future.when i get the combination right i will then make them short as possible.
the only thing i am looking for is more weight.so close to my cd94 marantz.
next is some of the 4.7k resistors change smd ones to some allen bradely or takman
made a lot of progress.it sounds like music not digital.
i give demos in perth all the time to show others what smd devices actually do(caps,resistors) also use car battery as power supply and diodes bypassed
i started to solder the wima caps from the centre out of the player.its a bit tricky but it can be done.
i give demos in perth all the time to show others what smd devices actually do(caps,resistors) also use car battery as power supply and diodes bypassed
i started to solder the wima caps from the centre out of the player.its a bit tricky but it can be done.
Thanks for the update.
Have you ever tried smd film caps?
I spoke to a fella who gets rid of all the ceramic caps on any of his gear
and claims that this sounds way more analog.
I got some from Panasonic that I have tried to use in the past.
I will use a conductive glue (wire glue) to
put them on the pads as they fell apart when I tried to solder them last
time.
Klaus
Buying at QLS
I purchased a unit at QLS three days ago via PayPal,
but there is no response at all from QLS.
Also, by entering the site a malicious
software warning comes up.
Did any of you have this kind of problems with QLS?
How long did it take them to reply that they received your order?
Greets,
Klaus
I purchased a unit at QLS three days ago via PayPal,
but there is no response at all from QLS.
Also, by entering the site a malicious
software warning comes up.
Did any of you have this kind of problems with QLS?
How long did it take them to reply that they received your order?
Greets,
Klaus
I
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Hi Erin,
thank you for your e-mail.
this weekend after a new mod I can agree with you: the oscilaltions on the top & bottom of the waveform are not so important.
To prove that I made a decuplig board using four IL710 digital isolators.
The oscillations on top & bottom disappeared, the squarewave where clean but sound seemed less "quick" and precise.
So I turned back to my previous setting: a simple 74ALS244 i use to strenghten the I2S waves. ( I had problems with the L/R clock signal: it was very "weak" and could not drive my dac).
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Thank you for your advice: I've bought a bunch of Murata 10uf SMD Caps. I'll try to paralles / substitute previus cap. Hope to succeed: SMD caps are sooo little
---------
Yes, oscillations on top/bottom seemed to incresed, but sound appeared to me "quicker" and "deeper".
I've attached a photo of the boards I've built:
-on the center the IL710 decoupling board (not conencted)
-on top the simple line driver with 74ALS 244.
-on the bottom left you can find the X0 clock from guido Tent ( battery powered)
-on the top right our little QA
( battery powered)
I'm planning to build also a new clock generator for BCK and L/RCK using a circuit based on 74169 as shown in Bunpei thread to see if sounds improves.
Bye alessandro
--------------
Hi Erin,
thank you for your e-mail.
this weekend after a new mod I can agree with you: the oscilaltions on the top & bottom of the waveform are not so important.
To prove that I made a decuplig board using four IL710 digital isolators.
The oscillations on top & bottom disappeared, the squarewave where clean but sound seemed less "quick" and precise.
So I turned back to my previous setting: a simple 74ALS244 i use to strenghten the I2S waves. ( I had problems with the L/R clock signal: it was very "weak" and could not drive my dac).
-------------
----------
Thank you for your advice: I've bought a bunch of Murata 10uf SMD Caps. I'll try to paralles / substitute previus cap. Hope to succeed: SMD caps are sooo little
---------
-----------
Yes, oscillations on top/bottom seemed to incresed, but sound appeared to me "quicker" and "deeper".
I've attached a photo of the boards I've built:
-on the center the IL710 decoupling board (not conencted)
-on top the simple line driver with 74ALS 244.
-on the bottom left you can find the X0 clock from guido Tent ( battery powered)
-on the top right our little QA
( battery powered)I'm planning to build also a new clock generator for BCK and L/RCK using a circuit based on 74169 as shown in Bunpei thread to see if sounds improves.
Bye alessandro
Attachments
QA-550 SPDIF output
Hi, I gave just bought QA-550 and connected it to my DAC. There is some audible hum in my headpohnes (~ 100 Hz). When QA-550 is off there is no hum. It only appears when QA-550 is on so I think DAC is ok and the problem is in QA-550. The hum is independent on volume level set at the output of DAC. I have QA-550 version with output transformer (ST-DV709) but it seems to me that the shielding of output RCA connector is connected to GND. Does somebody have similar epxerience? Is it ok that output RCA is grounded? Thanks
Hi, I gave just bought QA-550 and connected it to my DAC. There is some audible hum in my headpohnes (~ 100 Hz). When QA-550 is off there is no hum. It only appears when QA-550 is on so I think DAC is ok and the problem is in QA-550. The hum is independent on volume level set at the output of DAC. I have QA-550 version with output transformer (ST-DV709) but it seems to me that the shielding of output RCA connector is connected to GND. Does somebody have similar epxerience? Is it ok that output RCA is grounded? Thanks
I would guess that you have an earth loop.
Try connecting the QA-550 power supply to the same mains outlet as your DAC.
Yes the RCA connector shield is meant to be grounded.
Someone bought a ES9022 module from me to try with his QA550,
http://www.diyaudio.com/forums/digi...card-16-44-1-wav-transport-3.html#post2092994
and this was his first response, "the DAC sounds superb, almost as good as my heavily tweaked tda1541".
The ES9022 is probably the most underrated DAC around at a real bargain price. And people just don't know what they are missing.
Patrick
http://www.diyaudio.com/forums/digi...card-16-44-1-wav-transport-3.html#post2092994
and this was his first response, "the DAC sounds superb, almost as good as my heavily tweaked tda1541".
The ES9022 is probably the most underrated DAC around at a real bargain price. And people just don't know what they are missing.
Patrick
Hi Patrick,
So the ES9022 is only $1.68 at:
ismosys.com
At that price its worth trying.
Do you happen to know where I can get the datasheet?
No point in buying it without the datasheet.
I use a TDA1541 and I'm very happy with it.
Apart from playing higher sample rates, what is the advantage of the ES9022 over TDA1541?
Your friend says that the ES9022 is not as good as TDA1541.
Is there going to be anything in it for me or is the ES9022 just another contender that does not win the race?
So the ES9022 is only $1.68 at:
ismosys.com
At that price its worth trying.
Do you happen to know where I can get the datasheet?
No point in buying it without the datasheet.
I use a TDA1541 and I'm very happy with it.
Apart from playing higher sample rates, what is the advantage of the ES9022 over TDA1541?
Your friend says that the ES9022 is not as good as TDA1541.
Is there going to be anything in it for me or is the ES9022 just another contender that does not win the race?
a) By the time you finishing paying all the surcharges at ismosys, the price will more than double, even if you buy 20 pieces.
b) Datasheet only available from authorisied agents by signing an NDA. So I cannot share mine.
c) If you are happy with what you got, then you should not change, IMHO.
Whether one DAC is better (in what area, by how much, .......) than the other is all subjective.
If you do it right, they are all nice, even the (highly) distorted, old Philips TDAs.
http://www.diyaudio.com/forums/digi...card-16-44-1-wav-transport-2.html#post1965932
Patrick
b) Datasheet only available from authorisied agents by signing an NDA. So I cannot share mine.
c) If you are happy with what you got, then you should not change, IMHO.
Whether one DAC is better (in what area, by how much, .......) than the other is all subjective.
If you do it right, they are all nice, even the (highly) distorted, old Philips TDAs.
http://www.diyaudio.com/forums/digi...card-16-44-1-wav-transport-2.html#post1965932
Patrick
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I've just tried ES9022 from EUVL,coupled with qm-550.What can i say...
I've compared it with my arcam alpha cd5+ cd player(tda1541),modified,with nazar's DAC overture output:
Post tagged Overture v3.0 - Nazar audio innovations
And i can proudly say thar es9022 can do allmost as much as tda1541 tweaked heavily,and it will surely outperform tda1541 with any stock output (even tubed).
There were very small differences in sound stage depth ant top end,but when i saw the guts of my qa-550 i now there is much to do there as well,becouse power supply is very poor...But even with that,qa-550 with es9022 is one of the best sounding sources i've ever heard.
The listenigs were made with 12'' vintage diy coaxial drivers (horn tweeter) and jean hiraga's le monstre in pair with andrea ciufolli's power mosfet follower driven by e88cc pre.
I've compared it with my arcam alpha cd5+ cd player(tda1541),modified,with nazar's DAC overture output:
Post tagged Overture v3.0 - Nazar audio innovations
And i can proudly say thar es9022 can do allmost as much as tda1541 tweaked heavily,and it will surely outperform tda1541 with any stock output (even tubed).
There were very small differences in sound stage depth ant top end,but when i saw the guts of my qa-550 i now there is much to do there as well,becouse power supply is very poor...But even with that,qa-550 with es9022 is one of the best sounding sources i've ever heard.
The listenigs were made with 12'' vintage diy coaxial drivers (horn tweeter) and jean hiraga's le monstre in pair with andrea ciufolli's power mosfet follower driven by e88cc pre.
That is the advantage of the Sabre -- it can live with a poorly timed source very well.
And as tolikas said, one can also do quite a bit to improve power supply for the QA550.
Even if you don't use all the stuff on my design and just use datasheet schematics, the ES9022 will still beat a LOT of much more expensive DACs.
You need to use a low jitter clock close to it, something between 40 & 50MHz.
I have been AB testing against my Meridian 508 (modded) for almost 3 months now and I still cannot believe how good the ES9022 is.
But of course I am totally biased.
Patrick
And as tolikas said, one can also do quite a bit to improve power supply for the QA550.
Even if you don't use all the stuff on my design and just use datasheet schematics, the ES9022 will still beat a LOT of much more expensive DACs.
You need to use a low jitter clock close to it, something between 40 & 50MHz.
I have been AB testing against my Meridian 508 (modded) for almost 3 months now and I still cannot believe how good the ES9022 is.
But of course I am totally biased.
Patrick
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