Regs please!
those 3 of LM1117's have a distortion of 3mV! instead of some uV or nV in high-end terms. horrible!
does anybody know a better regulator?
i found LM340P-5.0 in sot223 with 40uV any idea? or a better one?
but could not find anything for 3.3v LM1117. any contribution?
or separate psu?
thanks in advance
those 3 of LM1117's have a distortion of 3mV! instead of some uV or nV in high-end terms. horrible!
does anybody know a better regulator?
i found LM340P-5.0 in sot223 with 40uV any idea? or a better one?
but could not find anything for 3.3v LM1117. any contribution?
or separate psu?
thanks in advance
In post #877 I described a problem which I thought to be a dead CS8416. I ordered a couple of new 8416s and they arrived a few days ago. After killing one of the new chips with solder when it slipped out of position on the pads, I managed to install the other correctly and now the DAC works.
I have it running with a discrete low noise regulator for VCC and VDD on each main chip. while leaving the 3.3V LM1117 for the 74HC04. It is direct out through 47R Holco resistors and 10uF Elna Silmic bypassed by .1uF Roe 1837 MKP and I am more than pleased by the result.
However, I would be interested in any suggestions about the following:
1. Is there a better value (and type) for the resistor?
2. Is there a better value for the output cap. I plan to swap the 10uF Silmic for a film/foil cap like Mundorf MKP.
Next mod will be an active SPDIF input stage for the DAC.
I have it running with a discrete low noise regulator for VCC and VDD on each main chip. while leaving the 3.3V LM1117 for the 74HC04. It is direct out through 47R Holco resistors and 10uF Elna Silmic bypassed by .1uF Roe 1837 MKP and I am more than pleased by the result.
However, I would be interested in any suggestions about the following:
1. Is there a better value (and type) for the resistor?
2. Is there a better value for the output cap. I plan to swap the 10uF Silmic for a film/foil cap like Mundorf MKP.
Next mod will be an active SPDIF input stage for the DAC.
I am using discrete, very low noise and low impedance regulators designed by Greg Ball at SKA Audio here in Australia as a drop in replacement for the 78XX series three pin regs. It is called the Minireg. Noise less than 1uV, which is very impressive when the best 780X regs are about 10uV/Vout. I am using these on the CS8416 and AK4396 on this DAC. I have also used 8 of them on my heavily modified Rotel RCD965 CD player and a other projects. These regs are adjustable but can be formatted as fixed regs. Max current is 50mA or 100mA depending on the transistor used, i.e. BC547C or MPSA18.
Here is the URL for the Minireg low noise regulator thread. Probably good to read from the beginning:
SKA sponsored Audio Forum - MiniReg discrete low noise Regulator
Well i tried to build this dac, reading all those good things about it. I ordered the kit (not assembled) and gave it a try. The result was no sound and the power, 96k and error leds were constantly on. Forgot to mention that the 3 smd chips were badly soldered with visible solder bridges. So i thought cs8416 must be dead (as suggested in this thread). The seller agreed to sell me a board with just the three chips soldered. The soldering of the chips in the new board appeared to be visually perfect. I assembled the dac once more and the result.......................................3 bright leds always on and no sound again! The 78xx regulators are working ok, the 1117 regs are also ok....Does anybody has any ideas? If so please share, because im ready to give this dac a shock therapy
Hi Serge.
My SPDIF source is my Pioneer PD-D6 sacd player playing redbook. Currently i dont have a camera- i will try to find one and post pictures tomorrow.
Someone said that changing the digital signal cable with a better one improves quality. I have to confirm it, really does. I swapped a 30cm normal testing multi stranded cable with 20cm low-loss coaxial and there is more detail and spacing between the instruments now.
This DAC definitely blows away the analog output of my X-fi music.
This DAC definitely blows away the analog output of my X-fi music.
I agree on the 75Ohm and BNC connector. There have been several discussions, and some bun fights, on this and other forums pointing out that for a SPDIF coax to be 'true' 75 ohm it must have a BNC connector at both ends. Some members with extensive design experience in RF and SPDIF interfaces insist that an RCA connector can never be 75 Ohm, no matter what the marketeers try to tell us.
There are a couple of excellent threads here and at another forum which have schematics and discussions for properly terminated active SPDIF input and output stages. I have built and installed in my RCD965BX the active output stage shown in the link below. This made an immediate improvement in clarity and definition.
SPDIF output stage: http://www.diyaudio.com/forums/digital-source/3282-digital-transformer-2.html. The schema appears first on post #67 with discussion in the following posts.
I have just finished but not yet installed the active input stage shown in this link to another forum. I will soon be installing this input stage in the DAC under discussion in this thread.
DIYHiFi.org • View topic - Anyone interested in..............
For the schematic, go to page 2 and scroll down to the Jocko Homo post subject "Do I have to do everything around here.........…" . It's not quite as easy to use as this forum but worth the effort. The active stage is designed for the CS841X series of receivers. The discussion in the posts following is very useful.
Jocko also says that a long SPDIF cable is better, especially if you have a TDR to measure and correct the reflections. When I get the active stage installed and checked, I intend to try a 6.0m length of Canare cable. I don't have a TDR (who does?) but somewhere in that thread mention is made that 6.0m is a good starting point.
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Well i feel like a moron, should have checked this feature. With direct mode off, the dac works flawlessly Thanks for the suggestion ekidnah
What the most important reg that should be changed to a better reg like SALAS Shunt in the DAC?
CS8416:
VA- Analog power supply. +3.3
VD- Digital Power-Digital core power supply +3.3V
VL- Logic Power-Input/Output power supply +3.3V
AK4396:
DVDD- Digital Power supply +5.0 V
AVDD- Analog power supply +5.0 V
OPAMP:
+15.0 V AND -15.0 V
CS8416:
VA- Analog power supply. +3.3
VD- Digital Power-Digital core power supply +3.3V
VL- Logic Power-Input/Output power supply +3.3V
AK4396:
DVDD- Digital Power supply +5.0 V
AVDD- Analog power supply +5.0 V
OPAMP:
+15.0 V AND -15.0 V
AK4396:
AVDD- Analog power supply +5.0 V
I check the Gold reference regulator and the SALAS reg shunt ....
Much better with the SALAS reg shunt
OPAMP:
+15.0 V AND -15.0 V
Of course SALAS reg shunt
But it's my opinion
Serge
Hi Serge,
I do agree, after the opamp regulator the AVDD is the next one that would benefit more from a better PS.
Valve Output
Have a look at the Tubecad website for a BCF.
Broskie Cathode follower.
This circuit converts a balanced signal to an unbalanced signal.
As it is a cathode follower the is no gain, although the DAC is voltage out, you may not need any gain.
If gain is needed look at the unbalancer.
It seems a waste to me to only use one side of the signal and ignore the full voltage swing.
Both of these circuits provide excellent drive ( low source impedence).
I have tried the SRPP circuits as per Lampizator and did not prefer the sound.
You may like it
Have a look at the Tubecad website for a BCF.
Broskie Cathode follower.
This circuit converts a balanced signal to an unbalanced signal.
As it is a cathode follower the is no gain, although the DAC is voltage out, you may not need any gain.
If gain is needed look at the unbalancer.
It seems a waste to me to only use one side of the signal and ignore the full voltage swing.
Both of these circuits provide excellent drive ( low source impedence).
I have tried the SRPP circuits as per Lampizator and did not prefer the sound.
You may like it
