Hi abraxalito,
I've been following the development of your DACs on hackaday for a while, and am hoping to buy a Dorati kit. However, as I've created my account today, I am unable to message you with my information. I'd also like to buy a LM317-based board for it, as well as possibly as a card for USB->I2S, depending on their prices.
I have all of the tools required, as well as (I believe) the experience to solder it all together. Can you please PM me?
Thanks
I've been following the development of your DACs on hackaday for a while, and am hoping to buy a Dorati kit. However, as I've created my account today, I am unable to message you with my information. I'd also like to buy a LM317-based board for it, as well as possibly as a card for USB->I2S, depending on their prices.
I have all of the tools required, as well as (I believe) the experience to solder it all together. Can you please PM me?
Thanks
abraxalito Sorry if this has been discussed, does it ship from China? Can I order via AliPay and send to an address in China?
Yes it ships from China, you can definitely pay via Alipay and we are very happy to ship to an address in China.
It turns out that Dorati cannot accept anything above 44.100? Or maybe it will sound bad because of the filter set to 44.100?
Dorati definitely can accept higher than 44k1, definitely 96k and probably 192k too. The last stage output filter applies a small HF boost to correct the response at 44k1 so if you run higher, you'll get slightly raised HF. But if you choose the sample rate you want to run at and stick to it then the output filter can be adjusted back to flat for that rate.
It’s great if I order, of course I’m interested in how honest 44.100 will sound, but I’m also interested in how it will sound when upsampled using HQPlayer Embeded. Which also works as a very good digital filter. I understand that this will break the concept of the NOS buzz, but I still wonder how it will be...
I currently have Miro's DIY NOS on the AD1862 and listen to it from HQPE a lot.
I currently have Miro's DIY NOS on the AD1862 and listen to it from HQPE a lot.
When I run 2X oversampled I notice the very slight HF lift but barely any other change in the sound. But I haven't spent a long time listening at 2X so other aspects may come to light with more listening.
Comrades, I still don’t have a Dorati in my hands, but I hope to be the owner soon. I talked to my well-qualified friend, who suggested that the TDA1387 are in parallel. And the output signal level slightly depends on the temperature of the chip - if the temperature is equalized, then there will be less instability at the output.
This is of course not exact, but suddenly it will really affect the sound positively. It is necessary to glue one single cooling radiator to all chips.
This is of course not exact, but suddenly it will really affect the sound positively. It is necessary to glue one single cooling radiator to all chips.
Thank you very much for the link, I'll have to try it. I think you shouldn’t chase grades j or K. It turns out that these are original microcircuits, and there are no fakes.
Hello @abraxalito !
Finally managed to solder the Doraty kit completely. I did everything step by step according to the Step1 - Step3 map. Measurements at the Step1 - Step3 control points were within tolerance. Did not play music via I2S.
Then I decided to replace the power supply (the voltage is the same 13.5 V) and carelessly mixed up the polarity during a short-term connection.
I corrected the polarity of the power supply, turned on the music via I2S - the music plays, but with distortion and hiss. I checked the voltage at the Step2 - Step3 control points - it changed.
Now the measurements are:
TP1 4.825v
TP2 2.485v
TP3 1.659v
TP8 4.988v
TP6 5.503v (6V 0.1v)
TP9 6.650v (7V 0.2v)
TP10 5.350v (6V 0.1v)
TP12 6.560v (7V 0.2v)
TP4 4.230v (4.8V 0.2v)
TP7 4.220v (4.8V 0.2v)
I disconnected the I2S connector on the board - the voltage of Step2 and Step3 changed:
TP6 5.840v (6V 0.1v)
TP9 6.693v (7V 0.2v)
TP10 6.359v (6V 0.1v)
TP12 7.540v (7V 0.2v)
TP4 4.607v (4.8V 0.2v)
TP7 5.230v (4.8V 0.2v)
I take the I2S signal from reclocker KALI+RPI 3b
Finally managed to solder the Doraty kit completely. I did everything step by step according to the Step1 - Step3 map. Measurements at the Step1 - Step3 control points were within tolerance. Did not play music via I2S.
Then I decided to replace the power supply (the voltage is the same 13.5 V) and carelessly mixed up the polarity during a short-term connection.
I corrected the polarity of the power supply, turned on the music via I2S - the music plays, but with distortion and hiss. I checked the voltage at the Step2 - Step3 control points - it changed.
Now the measurements are:
TP1 4.825v
TP2 2.485v
TP3 1.659v
TP8 4.988v
TP6 5.503v (6V 0.1v)
TP9 6.650v (7V 0.2v)
TP10 5.350v (6V 0.1v)
TP12 6.560v (7V 0.2v)
TP4 4.230v (4.8V 0.2v)
TP7 4.220v (4.8V 0.2v)
I disconnected the I2S connector on the board - the voltage of Step2 and Step3 changed:
TP6 5.840v (6V 0.1v)
TP9 6.693v (7V 0.2v)
TP10 6.359v (6V 0.1v)
TP12 7.540v (7V 0.2v)
TP4 4.607v (4.8V 0.2v)
TP7 5.230v (4.8V 0.2v)
I take the I2S signal from reclocker KALI+RPI 3b
Attachments
Hi @rpin,
Sorry to hear of your mishap with the power supply reversal. When you disconnect the I2S its quite normal for the TPs you measured to change, as the DAC's outputs get 'frozen' in time at the last sample received before the I2S was disconnected. Whereas with music playing the average DAC output is zero.
As for the damage sustained to your Dorati I can only guess that one (or more) of the DAC chips got fried. The reason I think this is you still got music even though with added 'mess' and your TPs all changed as if one chip has died and is no longer contributing current to the total output. You might be able to diagnose which chip by shorting pin7 of each to pin4 in turn. If the DAC chip is working the output (TP4,TP7) will go down when its pin7 is shorted in this way. The DAC chip that makes no change to those TPs when its pin7 is shorted to pin4 is broken.
I'm afraid that's about all the help I can give at this stage - good luck with tracking down the issue.
Sorry to hear of your mishap with the power supply reversal. When you disconnect the I2S its quite normal for the TPs you measured to change, as the DAC's outputs get 'frozen' in time at the last sample received before the I2S was disconnected. Whereas with music playing the average DAC output is zero.
As for the damage sustained to your Dorati I can only guess that one (or more) of the DAC chips got fried. The reason I think this is you still got music even though with added 'mess' and your TPs all changed as if one chip has died and is no longer contributing current to the total output. You might be able to diagnose which chip by shorting pin7 of each to pin4 in turn. If the DAC chip is working the output (TP4,TP7) will go down when its pin7 is shorted in this way. The DAC chip that makes no change to those TPs when its pin7 is shorted to pin4 is broken.
I'm afraid that's about all the help I can give at this stage - good luck with tracking down the issue.
I diagnosed according to your recommendations - TP4=4.49v, TP7=4.38v, Then cpin7 of the DAC chip is shorted to ground - TP4=3.86v, TP7=3.76v. This applies to all pin7 of the DAC chip. Now there is no sound at all in the right and left channels, constant voltage 6.8v
No, of course each pin7 separately on each DAC chip. I did it for 6 DAC chips and measured the voltage drop for TP4=3.86v, TP7=3.76v. The values are approximately the same for all 6 DAC chips. All chips reduce the voltage.
I'm still curious how you reached no sound at all by only shorting one DAC at a time, I can't figure out how that works. When you short pin7 to GND on all the chips (one by one) is there any time that there isn't distortion/noise?
Or are you saying that shorting the pin7s has caused more damage so that the DAC now plays no music at all?
Or are you saying that shorting the pin7s has caused more damage so that the DAC now plays no music at all?
When measuring, I used Amanero 384 (like
https://sl.aliexpress.ru/p?key=nSuwrcF) as an I2S source, connected it via USB to the sound source, connected Amanero and Doraty via I2S and applied voltage, values TP4=4.49v, TP7=4.38v. I made 12 measurements on DAC chips, shorting pin7 to ground, values TP4=3.86v, TP7=3.76v.
I measured the output voltage of the right and left channels - 6.8v, it does not change. I connected the Doraty output to the input of the power amplifier and speakers - there is no sound.
Of course, I do not think that the lack of sound is the result of my actions with pin7. This is a complete description of my latest measurements.
I am upset (((
https://sl.aliexpress.ru/p?key=nSuwrcF) as an I2S source, connected it via USB to the sound source, connected Amanero and Doraty via I2S and applied voltage, values TP4=4.49v, TP7=4.38v. I made 12 measurements on DAC chips, shorting pin7 to ground, values TP4=3.86v, TP7=3.76v.
I measured the output voltage of the right and left channels - 6.8v, it does not change. I connected the Doraty output to the input of the power amplifier and speakers - there is no sound.
Of course, I do not think that the lack of sound is the result of my actions with pin7. This is a complete description of my latest measurements.
I am upset (((
To sum up then you're reporting TP4,7 about 4.4V and TP9,12 at nearly 7V? If so then those voltages seem reasonable for the analog output stages (buffer, filter). My suspicion therefore falls on the stages prior to those.
When did the (distorted, noisy) sound stop? It would be best to go back to the stage just before the sound stopped coming out of the DAC and see what changed at that point.
When did the (distorted, noisy) sound stop? It would be best to go back to the stage just before the sound stopped coming out of the DAC and see what changed at that point.
I came back to this point. Voltage TP4,7 about 4.4V and TP9,12 at nearly 7V. Couldn't play sound (distorted, noisy) at the output, probably managed to damage something. What next steps?
What I was asking was not about the TPs but what did you do to the PCB just before the sound disappeared?
In trying to get sound back the next steps would start with checking that I2S is getting to the DAC chips. Do you have a 'scope? If not you can check in a general sense whether there are signals reaching the DACs by measuring the DC (average) voltage on pins1,2 and 3 of the TDA1387s. Relative to pin4 (GND). Music needs to be playing for this test.
In trying to get sound back the next steps would start with checking that I2S is getting to the DAC chips. Do you have a 'scope? If not you can check in a general sense whether there are signals reaching the DACs by measuring the DC (average) voltage on pins1,2 and 3 of the TDA1387s. Relative to pin4 (GND). Music needs to be playing for this test.