I have made some filter simulations with full-balanced OPA-s. The -3dB freq. corner is about 200kHz, the output Vrms is 1,97V.
Another PS schematic to show that the board can be tested only with two regulators...
Another PS schematic to show that the board can be tested only with two regulators...
Attachments
It is not necessary to use all of the two IC-s, because there is no need for outside I/V conversion by this chip (the DAC has voltage outputs). The first stage can be simply shorted with a bridge...
Attachments
Last edited:
Nice, I have LX521 with a Najda and UCD amps.
What is LF50 and LF80 switching regs? If they are I would put an LC filter after them. If not 9V AC transformer to 3.3V is going to burn some heat. I had to switch to 6V transformers in another DAC I built as the 9V transformer with a 5V regulator made the heatsink way too hot for me to be happy with.
I have also recently had some custom voltage and current spec multi winding R Core transformers made in China and bought through Taobao. They were very cheap and really high quality. Absolutely no hum.
The problematic is if I want to use the 5V shunts, they need about 8-9V input DC. With one double seconder transformer (one side for analog and one for digital) I can not really choose different voltage values - perhaps a custom made from china...🙂
The LF50CV is a "Very low drop voltage regulator with inhibit function". I choosed it because of the low 50uV noise, 1A, and the simple TO-220 package. There is not a lot of type with this simple package and big current...
http://www.st.com/content/ccc/resou...df/jcr:content/translations/en.CD00000546.pdf
My actual questions are:
- should I supply the 1,8V regulator from the 3,3V or direct from the 5,0V?
- I should lower the shunt currents by the Vref pins, but I don't know how much current they really need!? A 2x5VA (556mA) transformer for 3 pcs. 60-70mA shunts and pre-regulator will be marginal (if at all)....
How do you like the LX speakers? 🙂
I am not so rich to have the best things, so I have the minis and a DIY DAC and amps...😛
The LF50CV is a "Very low drop voltage regulator with inhibit function". I choosed it because of the low 50uV noise, 1A, and the simple TO-220 package. There is not a lot of type with this simple package and big current...
http://www.st.com/content/ccc/resou...df/jcr:content/translations/en.CD00000546.pdf
My actual questions are:
- should I supply the 1,8V regulator from the 3,3V or direct from the 5,0V?
- I should lower the shunt currents by the Vref pins, but I don't know how much current they really need!? A 2x5VA (556mA) transformer for 3 pcs. 60-70mA shunts and pre-regulator will be marginal (if at all)....
How do you like the LX speakers? 🙂
I am not so rich to have the best things, so I have the minis and a DIY DAC and amps...😛
Last edited:
This is one I bought, has 12V x 2, 9V and 6V.
Is it a switcher? I can't tell and there doesn't seem to be any thermal information.
Probably depends on the quality of the 5V and how much heat will produced from the voltage drop. Regs on regs on regs can be a recipe for oscillation.
The DAC itself shouldn't need much current.
Ha ha, well I learned a long time ago to just bite the bullet and get what I want because I will always end up there eventually, saves money in the long run ...
I like them a lot, but like all dipoles they need the right sized room to work to their best. I don't have enough room around them where they are now and you can hear something which sounds a little like extra reverb has been added to some recordings. Others are so good it is amazing.
The minis are supposed to be almost as good, particularly if you have some subwoofers. The fact you can place them closer to the walls would actually help me where I am now.
I built my own amps and Najda, not cheap though. I used LM4780 chip amps for Orion but they are only really just about powerful enough.
Thanks for the pics, looks great!
This "Nadja" uses a 8ch Cirrus DAC or? Is it not a bad sounding...?
Ok, I'll make the PCB that the 1,8V can be supplied from the 5V direct.
I'll consider this 4x seconder r-core tranformer... There are 2x15+2x9V types but I must ask for other values or?
This "Nadja" uses a 8ch Cirrus DAC or? Is it not a bad sounding...?
Ok, I'll make the PCB that the 1,8V can be supplied from the 5V direct.
I'll consider this 4x seconder r-core tranformer... There are 2x15+2x9V types but I must ask for other values or?
Attachments
Last edited:
Yes the Najda uses a Cirrus chip. Sounds pretty good to me, I haven't easily been able to compare it my other DAC's but I have used it as a stereo DAC for Orion and to put in a little bit of DSP HF roll off as I prefer that sound, didn't seem lacking in that use.
I ordered my transformers direct from Zerozone on Taobao, I sent them a message with the voltages and current I needed and they built them to my specs. Size and core used depends on the current you want. I got one with 3 x 6V windings and another with 5 separate windings. Price was only slightly more than a 2x15 or 2x9 as I used a bigger core for more current.
I put the 3 x 6V one in this DAC to reduce the heat from the regs.
I have the Ali Wang messenger app on my computer and started with Chinese translation but they were good and replied to me in English. It isn't a really easy process but I am getting much better at communicating with the Chinese sellers.
I can't tell from that block diagram what is going on as that could be any regulator really.
Seems similar to the LM2941 which I thought was a switching regulator, maybe not?
Last edited:
Nice, you have already tried some DACs....🙂
The LFxx regulator idea comes originally from the DDDAC (google...)
The LFxx regulator idea comes originally from the DDDAC (google...)
Yes in the last 12 months I have built an ES9018, ES9018k2m, Dual AK4495 and I have the ES9016 in progress, audio is working but I am trying to get software control going. This is in comparison to a Peter Daniel TDA1541, ODAC, Najda and Focusrite 18i20. I think I have a DAC collection problem...
I know about the DDDAC, if it is used in that then It should be good.
Any ideas before I make the copper pours?
(I have made the DAC IC pads a little longer to have an easier soldering...)
(I have made the DAC IC pads a little longer to have an easier soldering...)
Attachments
Last edited:
Does somebody know how can I get technical support from AKM??
(I mean questions regarding DAC chip)
(I mean questions regarding DAC chip)
Use reversed geometry 0306 capacitors close to the power supply pins.
2.2uF right close to the chip pins..
http://www.mouser.se/ProductDetail/...c/P99DfXFOOgL5w6Tx4NfKZFpPGq03mVQ5UBWREWCeN93
Dont care about the 100nF bulls**t caps in the application examples. This cap has much lower ESR and ESL than any ordinary "standard" 100nF. And is 22 times bigger!
2.2uF right close to the chip pins..
http://www.mouser.se/ProductDetail/...c/P99DfXFOOgL5w6Tx4NfKZFpPGq03mVQ5UBWREWCeN93
Dont care about the 100nF bulls**t caps in the application examples. This cap has much lower ESR and ESL than any ordinary "standard" 100nF. And is 22 times bigger!
Increasing the value will affect the way the capacitor is able to decouple, which is why that value of capacitor is often placed in that situation?
X7R or CoG might be a better dielectric if they were available.
X7R or CoG might be a better dielectric if they were available.
I don't understand why shoud I take this ugly package!?
(could you please show me some diagrams?)
In 0805 form I have for example 1uF/25V X7R capacitors....
(could you please show me some diagrams?)
In 0805 form I have for example 1uF/25V X7R capacitors....
Last edited:
And has much more dc bias derating.. 🙄 Its not only ESR/ESL, it's at which frequency..
You sure you know what you're talking about?
What is the intend of the copper pour between the i2s/i2c lines near the connectors?
The u.fl connector has no series termination.
The u.fl connector has no series termination.
Signal isolation. This makes no a lot of I know, but more than nothing, or?
How do you mean no series termination?