Wow Guys! Seems like you are all making some progress with pin 20! I wonder if this new tweak is suitable for my 11-Decks setup with Shunt regs? Is Heat dissipation a concern?
Doede, I have captured the complete 11 DAC boards and in detail of a DAC board by itself, and also Mainboard without DAC in hi res, raw. I will later capture the complete 11-Decks as single unit like the one captured by my iPhone. Now where can I upload?
Cheers,
Chanh
hi Chanh, just send me a normal mail at mail@doede.de and I will open a Dropbox for you
will do this evening, so you will find it at breakfast I guess oh.... no heat dissipation to fear.... only few mWatt dissipation....
tbh i dont understand this stuff very well, in regards the output currents
the data sheet says on page 24
Analog output
The following table and Figure 31 show the relationship between the digital input code and analog output.
800000 (–FS) 000000 (BPZ) 7FFFFF (+FS)
IOUTN [mA] –2.3 –6.2 –10.1
IOUTP [mA] –10.1 –6.2 –2.3
VOUTN [V] –1.725 –4.65 –7.575
VOUTP [V] –7.575 –4.65 –1.725
VOUT [V] –2.821 0 2.821
i assumed this was for normal stereo mode and that as your design is mono and using 8v dc instead of 5v that this would change these datasheet figures substantially, maybe even doubled the output mA?
are there voltage levels on vcom or output bias that could be damaging?
can anyone explain this for me?,
cant seem to get my head round it
what is the max ouput currents for the mono dddac's?
surely the data sheet specs is for regular stereo mode?
no takers?
the data sheet says on page 24
Analog output
The following table and Figure 31 show the relationship between the digital input code and analog output.
800000 (–FS) 000000 (BPZ) 7FFFFF (+FS)
IOUTN [mA] –2.3 –6.2 –10.1
IOUTP [mA] –10.1 –6.2 –2.3
VOUTN [V] –1.725 –4.65 –7.575
VOUTP [V] –7.575 –4.65 –1.725
VOUT [V] –2.821 0 2.821
i assumed this was for normal stereo mode and that as your design is mono and using 8v dc instead of 5v that this would change these datasheet figures substantially, maybe even doubled the output mA?
are there voltage levels on vcom or output bias that could be damaging?
can anyone explain this for me?,
cant seem to get my head round it
what is the max ouput currents for the mono dddac's?
surely the data sheet specs is for regular stereo mode?
no takers?
Last edited:
Ross - if I or others comment or give you feedback on your work, it's a sign of appreciation of it, far from the opposite. I think I'm speaking in the spirit of all of us here... it's a forum and informed but honest and franc opinions are to be expected (and desired...). I hope we're all learning from each other here. I know I am!
I just mean this as a quick note to say thanks again for your hands-on tests, builds and results.
Radu.
Very good read. Can you put the transformer directly onto any left +- and right +- for the i/v passive conversion. I have if I remember a CS4397 DAC chip
Just a quick update, I've still got a few bits to do and want to listen more more more.
But I can confirm that a 165r resistor with an lm334 gives almost exactly bang on 400mA with 2.4v from pin 20.
I've done this for the moment. I'll probably add the extra diode and resistor to remove the temperature variation, then install properly
So far sounds lovely, but need to hear more. Anyone else been having a play with pin20 current sources?
But I can confirm that a 165r resistor with an lm334 gives almost exactly bang on 400mA with 2.4v from pin 20.
I've done this for the moment. I'll probably add the extra diode and resistor to remove the temperature variation, then install properly
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
So far sounds lovely, but need to hear more. Anyone else been having a play with pin20 current sources?
Very nice James!
Pity I will have to miss this nice tweak as it gets too complicate with 11-DAC boards. I happened to damage one board while assembling them together. Fortunately, a mate here was kind enough to let me have his so I can carry on. Now need to buy a new board for return back to him.
Quick update - I have now tested my DAC with Doede ps for this configuration, output voltage is spot on 2.74V on left and right for both neg and pos against common. Thank God no smoke come out! Doede ps running extremely hot after 1minute turning on. So I guess it won't do it.
Will do a preliminary listening test tomorrow after work, it's 10.40pm now so have to call it the day! LoL!
Edited: I will capture better photos tomorrow if there is interest?
Pity I will have to miss this nice tweak as it gets too complicate with 11-DAC boards. I happened to damage one board while assembling them together. Fortunately, a mate here was kind enough to let me have his so I can carry on. Now need to buy a new board for return back to him.
Quick update - I have now tested my DAC with Doede ps for this configuration, output voltage is spot on 2.74V on left and right for both neg and pos against common. Thank God no smoke come out!
Doede ps running extremely hot after 1minute turning on. So I guess it won't do it. Will do a preliminary listening test tomorrow after work, it's 10.40pm now so have to call it the day! LoL!
Edited: I will capture better photos tomorrow if there is interest?
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Last edited:
They look funky.
I suspect the tempco is a good idea. In my case, when the dac warms up I can expect a Iset fluctuation of about 10%How does it sound, is the main question on my mind?
Last edited:
Honestly Guys...! I swear to my Soul this is freaking amazing!!!! All hardworks, friction against the Mrs, criticisms, and time invested, all are worth it!!!
I say no more here, needless to say anyway. It is simply what I am looking for, an analog vinyl alike experience, and here I have it!
Here are more photos!
I say no more here, needless to say anyway. It is simply what I am looking for, an analog vinyl alike experience, and here I have it!
Here are more photos!
Btw, I didn't apply the filter caps for quantisation noise! There simply no need for them.
Findings so far:
1. 8V shunts running warm and radiate fair amount of heat.
2. Raw power supply can not keep up with the power demanding, the Nippon 2200uf 35V were simply burning and melting. 200VA tranny was saturated and very hot to point impossible to touch. Also need a18V secondary to bring to 12V into 8V shunts. Right now with 15V tranny, is outputting only 10.6V. Can someone please direct me on raw ps?
3. Sound freaking AMAZING..., did I mention that already?!? LoL!
Cheers,
Chanh
Findings so far:
1. 8V shunts running warm and radiate fair amount of heat.
2. Raw power supply can not keep up with the power demanding, the Nippon 2200uf 35V were simply burning and melting. 200VA tranny was saturated and very hot to point impossible to touch. Also need a18V secondary to bring to 12V into 8V shunts. Right now with 15V tranny, is outputting only 10.6V. Can someone please direct me on raw ps?
3. Sound freaking AMAZING..., did I mention that already?!? LoL!
Cheers,
Chanh
Hi Stijn,
I checked my raw ps again, the electrolytics were reversed polarity wired. Damn it!
All sorted now...., running like a charm... Touch wood!
Btw, I found i2s direct from the Pi worths trying if you guy haven't?
An externally hosted image should be here but it was not working when we last tested it.
Cheers.
Last edited:
Ok, presuming you reverst polarity at the recrifier, I'd be concerned about the health of the caps, especially since they ran hot. Maybe you want to think about swapping them out.
Also, I'm using a 18v transformer to get to 12.3Vdc (with a LCLC with 30Ohm bleeder). I suspect in your case, if you'd use an 18V Tranformer and 11 board you end up with a 100-to-150Ohm bleeder to get to +/-12vdc.
Also, I'm using a 18v transformer to get to 12.3Vdc (with a LCLC with 30Ohm bleeder). I suspect in your case, if you'd use an 18V Tranformer and 11 board you end up with a 100-to-150Ohm bleeder to get to +/-12vdc.
Thanks Guys!
As this is my first kick start the DAC, I would want to monitor it minute by minute. Therefore any abnormality was pickup quickly. In this case the electrolytics were no exception.
There was sign of heating up and swelling so I immediately shut it down. So far I tried 16bit 44.1khz, Eva Cassidy -SongBird had never sounded so real and alive! I will do 24bit tomorrow and with higher frequencies. e.g 88.2, 96, 192khz.
@Stijn-I replaced all caps on that raw ps. On 15V, there wasn't a need for bleeder resistor and I suspect at 18V might just gives me close to 12V without bleeder. However, I use 2.2Ohms drop down voltage on digital ps input.
If you haven't noticed, I have three power inlet connector on mainboard. One for analog and one for digital, but both sharing the same ground.
As this is my first kick start the DAC, I would want to monitor it minute by minute. Therefore any abnormality was pickup quickly. In this case the electrolytics were no exception.
There was sign of heating up and swelling so I immediately shut it down. So far I tried 16bit 44.1khz, Eva Cassidy -SongBird had never sounded so real and alive! I will do 24bit tomorrow and with higher frequencies. e.g 88.2, 96, 192khz.
@Stijn-I replaced all caps on that raw ps. On 15V, there wasn't a need for bleeder resistor and I suspect at 18V might just gives me close to 12V without bleeder. However, I use 2.2Ohms drop down voltage on digital ps input.
If you haven't noticed, I have three power inlet connector on mainboard. One for analog and one for digital, but both sharing the same ground.
Chanh,
congratulations to all your work and especially results from the bottom of my heart...
well, you are a lucky man now... and the next 200 hours burning in will bring you even more fullfilment... and the reproduction of higher resolutions will additionally round up your fantastic results...
but from my experiences "the aim" is not only to create an "analog vinyl alike experience"... it is much more, that much more that you will enter a completely "new" level in reproduction which - to my ears - and I had for some ten years EMI 927 with TSD15 and many others - simply is not capable, if... yes, if you are able to bring your new 500 horse powers on to the road...
to understand what I mean you should perhaps try to connect to Tuyen's Goto drivers - at least regarding the bass you will be overwhelmed what a revelation that is....
please, keep us all informed here with all your experiences and pictures...
vey, very, very well done.... my congratulations again...
congratulations to all your work and especially results from the bottom of my heart...
well, you are a lucky man now... and the next 200 hours burning in will bring you even more fullfilment... and the reproduction of higher resolutions will additionally round up your fantastic results...
but from my experiences "the aim" is not only to create an "analog vinyl alike experience"... it is much more, that much more that you will enter a completely "new" level in reproduction which - to my ears - and I had for some ten years EMI 927 with TSD15 and many others - simply is not capable, if... yes, if you are able to bring your new 500 horse powers on to the road...
to understand what I mean you should perhaps try to connect to Tuyen's Goto drivers - at least regarding the bass you will be overwhelmed what a revelation that is....
please, keep us all informed here with all your experiences and pictures...
vey, very, very well done.... my congratulations again...
Kindly thank you for your warmed words!
I will be take better photo with my pro gears for Doede. I can upload few here too.
Tuyen's goto Horns are very nice. I love the openness sounding from them.
to get the most out of it, just a question, did you already incorporate a separate 5 Volt controlled power supply for the entry (instead of the 5 Volt supply via USB-cable) ?
this will bring some incredible ameliorations - not at all to neglect them - but to my ears much more then a lot of "tiny" tweaks...