Just to confirm, to get this 68 ohm, do you put in 2 33ohm resistors on the left channel on Ra and Rb and simlarly 2 33ohms on the right channel across Ra and Rb? I am also using the 4 deck version so just need to know if im putting these resistors properly.
Also, when one goes from capacitors to transformers on the output path, do these resistors values need to be changed from 68 ohms to something else?
I have put in the cinemags recently but i have put in the bleeder or loading ressitors as 10k ohms. Is it the proper value to work best with the DDDAC or should be 15k or higher?
Hi kartick
i use 68ohm on Ra and Rb...on both channel
i use a Sowter trafo on my output on the DDdac..and use 10kohm on the trafo
just need to know if it is alright to lower the I-V resistors
best Bjarne
i use 68ohm on Ra and Rb...on both channel
i use a Sowter trafo on my output on the DDdac..and use 10kohm on the trafo
just need to know if it is alright to lower the I-V resistors
best Bjarne
I think it should be 2 33 ohms on the left and 2 33 ohms resistors on the right channel. Others can confirm what is correct.
Also, when you use 68 ohms instead are you getting proper voltages across the left and right channels? What values please?
Also, when you use 68 ohms instead are you getting proper voltages across the left and right channels? What values please?
Hi all,
I have been away for quite some time after implementing the CCS on my 4 deck and recently managed to find some time to come back to this.
I am not sure whether it has already been mentioned, But just to share for those who is using Pi to drive the dddac1794 i2s maybe should try the Hifiberry dac+pro as in this thread.
http://www.diyaudio.com/forums/digital-line-level/285811-hifiberry-dac-pro-hw-mods-anybody-40.html
The hifiberry board set the Pi into slave and use the dac proper XO to drive the i2s. With some mod I managed to get much better music compared with my Pi.
BTW anyone knows where can I get the sowter transformer? I tried to contact Doede or Macro but they never reply my email. If Doede or Macro see this email please kindly PM me.
Regards,
Ck
Singapore
I have been away for quite some time after implementing the CCS on my 4 deck and recently managed to find some time to come back to this.
I am not sure whether it has already been mentioned, But just to share for those who is using Pi to drive the dddac1794 i2s maybe should try the Hifiberry dac+pro as in this thread.
http://www.diyaudio.com/forums/digital-line-level/285811-hifiberry-dac-pro-hw-mods-anybody-40.html
The hifiberry board set the Pi into slave and use the dac proper XO to drive the i2s. With some mod I managed to get much better music compared with my Pi.
BTW anyone knows where can I get the sowter transformer? I tried to contact Doede or Macro but they never reply my email. If Doede or Macro see this email please kindly PM me.
Regards,
Ck
Singapore
Hello,
I was confused too when i bought the resistors.
With 4 boards you need 4 33 ohm 2w resistors for the complete dac.
I dont know if you can change the gain by changing their value. BUT if i remember well Doede did go for the highest sound quality.
I use the special Sowters and they give me extra gain ( that is the reason why Doede contacted Sowter to make them. If i am right my Sowters can be connected in such a way that gain will reduced.
Maybe with the other transformers this could be done too??
There is no way to make your pre amp input less sensitive? Maybe add a resistor?
Greetings, Eduard.
P.s dddac still sounds wonderful
I was confused too when i bought the resistors.
With 4 boards you need 4 33 ohm 2w resistors for the complete dac.
I dont know if you can change the gain by changing their value. BUT if i remember well Doede did go for the highest sound quality.
I use the special Sowters and they give me extra gain ( that is the reason why Doede contacted Sowter to make them. If i am right my Sowters can be connected in such a way that gain will reduced.
Maybe with the other transformers this could be done too??
There is no way to make your pre amp input less sensitive? Maybe add a resistor?
Greetings, Eduard.
P.s dddac still sounds wonderful
I use a Sowter trafo,,not Doede,,and it is 1:1 ,,when i use a Cap output ,the output volt is just what i need,,but i like the sound from the Sowter ,,better than the cap
the reason i will like to have the lower output is when i play very low,,of course i can lower the output in my Jriver,,but will be better if i can lower the Dac a bit..
P.s yes, the sound is super,,without any opgrade,,i use Amb.org powersupply,,it is very good sounding
the reason i will like to have the lower output is when i play very low,,of course i can lower the output in my Jriver,,but will be better if i can lower the Dac a bit..
P.s yes, the sound is super,,without any opgrade,,i use Amb.org powersupply,,it is very good sounding
Changing the value of those resistors does not reduce or increase any gain as I aske this before
Doede confirmed to increase the gain was via the Sowters which makes sense
Doede confirmed to increase the gain was via the Sowters which makes sense
Ok, i can see i must use my Jriver to lower volume when i play low
does you know why a lower value I-V resistor not lower the output volt ?
does you know why a lower value I-V resistor not lower the output volt ?
Eh? The i/v resistors? I'm sure they do. I use 120r at the moment on my single deck and it's definitely quieter output than with the 133r ones.
That's correct. Lowering the iv resistors lowers the output. Not sure what other effects it might have but nothing audible going down to 120 ohm but offset v falls from 2.7 to 2.65
Would like to give some feedback for this, too. Have tried Odroid C2 with i2s connection and default installation of RuneAudio (music stored on my NAS / Odroid C2 with copper Ethernet connected to my NAS). Sound is now better compared to my previous WaveIO setup. Sound has getting more detailed, more space with bigger soundstage, tighter bass. Best of all: More natural sound (I also think there is less noise and distortion).I'm very happy with this change.
At the beginning I have used a RPI B+ with dddac over i2s. Then I changed to WaveIO. Sound between RPI and WaveIO was very close. But the PI was little bit slow with RuneAudio or Volumio and I had some problems with mono output when playing Red book audio. With Odroid C2 these problems are gone: Boot time with RuneAudio is between 5-10 seconds with a fast SD card. Controlling the device via web interface is very smooth and fast. It directly runs out of the RAM which means you can directly power off without doing a proper shutdown. But best of all: Sound quality is much better compared to Pi or WaveIO in my setup. So I can also highly recommend to give Odroid C2 a try.
I think the sound quality of WaveIO also depends on the device where it is connected to. I could hear differences between connected to my NAS directly and connected to a Win7 notebook (notebook with WaveIO driver sounded best). And I think that the sound quality of WaveIO in combination with the mentioned Aurender could be very good sounding solution, but unfortunately the price for this device is out of my range :-(.
Next step for me is either choke PSU for my single deck or a upgrade with second deck and Cinemag. Hard decision ...
Hmmm. i will try some lower I-v resistor,,and then here what it do to the sound. the problem is to compare the sound with different resistor type,,,i use now shinko,,but it is a bit costly to buy shinko, just for fun,,so maybe it will be hard to say what sound best,,the 33ohm value or a 20ohm value ,,with different resistor type
Would like to give some feedback for this, too. Have tried Odroid C2 with i2s connection and default installation of RuneAudio (music stored on my NAS / Odroid C2 with copper Ethernet connected to my NAS). Sound is now better compared to my previous WaveIO setup. Sound has getting more detailed, more space with bigger soundstage, tighter bass. Best of all: More natural sound (I also think there is less noise and distortion).I'm very happy with this change.
At the beginning I have used a RPI B+ with dddac over i2s. Then I changed to WaveIO. Sound between RPI and WaveIO was very close. But the PI was little bit slow with RuneAudio or Volumio and I had some problems with mono output when playing Red book audio. With Odroid C2 these problems are gone: Boot time with RuneAudio is between 5-10 seconds with a fast SD card. Controlling the device via web interface is very smooth and fast. It directly runs out of the RAM which means you can directly power off without doing a proper shutdown. But best of all: Sound quality is much better compared to Pi or WaveIO in my setup. So I can also highly recommend to give Odroid C2 a try.
I think the sound quality of WaveIO also depends on the device where it is connected to. I could hear differences between connected to my NAS directly and connected to a Win7 notebook (notebook with WaveIO driver sounded best). And I think that the sound quality of WaveIO in combination with the mentioned Aurender could be very good sounding solution, but unfortunately the price for this device is out of my range :-(.
Next step for me is either choke PSU for my single deck or a upgrade with second deck and Cinemag. Hard decision ...
Thanks for sharing your experience.
WaveI/O board requires an external source of audio files, i.e. a PC or a laptop. This information has to be transferred to WaveI/O by means of an inferior USB cable. These extras are inferior to an Odroid C2 "all-in-one player & converter".
WaveI/O requires a very good power supply, capable of producing as a minimum 0.5 A of constant current, while at the same time this supply has to be fast enough to cater for digital sound that is most of the time upsampled to at least 24 or 32 bits at 192khz. The final decoupling stage of this power supply has to be "very fast".
I tried the Cinemags and didn't like them at all. My suggestion is to focus on power supplies, avoid Cinemags and invest in new DDDAC boards.
Nick
Just remembered... use Ethernet CON2 on Odroid C2 -> it provides full galvanic isolation between NAS Ethernet and Odroid. I remember that one DIY-er reported very good results.
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Hello guys,
I am a new proud owner of a DDAC .. well still to be partially soldered 🙂
I managed to get the 12 volt power supply to work without blowing my house which is quite an achievement !!
Right now I am trying to figure out how I should solder the resistors on the mainboard knowing I have a 4 dac board configuration (the old version baords not the new Tent ones).
From the DDAC site I see I should use 68 OHMs for RA load and 68 OHMs for RB load. Can someone enlight me on how I should do on the mainboard itself. Should I solder 4 34 ohms resistors like in example 1 or only two 68 Ohms like in example 2??
Many Thanks,
A guy who can sloder but don't understand anything else to electronics ..
I am a new proud owner of a DDAC .. well still to be partially soldered 🙂
I managed to get the 12 volt power supply to work without blowing my house which is quite an achievement !!
Right now I am trying to figure out how I should solder the resistors on the mainboard knowing I have a 4 dac board configuration (the old version baords not the new Tent ones).
From the DDAC site I see I should use 68 OHMs for RA load and 68 OHMs for RB load. Can someone enlight me on how I should do on the mainboard itself. Should I solder 4 34 ohms resistors like in example 1 or only two 68 Ohms like in example 2??
Many Thanks,
A guy who can sloder but don't understand anything else to electronics ..
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Replace each 33 ohm resistor with two 16 ohm resistors in series and take the output from between the two 16 ohm resistors. This will reduce output by a factor 2. You can use different values in the voltage divider to get different attenuation, but make sure the sum is close to 33 ohm. Otherwise the bias if the DAC chips will be off.
Or use a transformer with different taps on the secondary, such as the Sowter 9335.
Hi again,
Finalising the understanding of the ddac soldring (I hope) I found the information about the cinemag wire setup.
As I learned the output impedance should be 15k Ohm (shared between the amplifier and the cinemag) I have to add the correct load.
My amplifier : A Mac 4100 has a input load of 100000 Ohms. If I add a 18K resistor between the yellow wire and the Orange black one of the cinemag I will land at a total resistor of 15.25K. Would it be a problem or should I do the maximum to get precisely 15K in total (like the drawing with a 27k and a 51k resistors in parralel)?
Sincerely Yours,
Lobo.
Finalising the understanding of the ddac soldring (I hope) I found the information about the cinemag wire setup.
As I learned the output impedance should be 15k Ohm (shared between the amplifier and the cinemag) I have to add the correct load.
My amplifier : A Mac 4100 has a input load of 100000 Ohms. If I add a 18K resistor between the yellow wire and the Orange black one of the cinemag I will land at a total resistor of 15.25K. Would it be a problem or should I do the maximum to get precisely 15K in total (like the drawing with a 27k and a 51k resistors in parralel)?
Sincerely Yours,
Lobo.
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Ok I checked what Doede stated to me and he confirmed the only way to seriously increase the gain was with transforms like Sowters