Hello,
Have been doing some test with a high voltage power supply that demonstrates very well the effect of a choke.
I need a supply that can supply around 715 volts and 70 mA dc.
I made a capacitor input and a choke input using the same transformer, capacitor and rectifier.
First C input with a 20 uF cap will give a 25 volts ripple. Increasing the load with 30% will make the output voltage drop around 16 volts and ripple go up from 25 to 31 volts.
Then same cap with a 30H choke input. Used another secundary winding because LC needs more voltage to get at the same output!. So with 715 volts output i get 4,3 volts ripple. Increasing the current with 30% ripple will stay the same and output voltage will drop to 709 volts.
Good bye see you next month, Eduard
P.s photo is the test setup n the kitchen table
Have been doing some test with a high voltage power supply that demonstrates very well the effect of a choke.
I need a supply that can supply around 715 volts and 70 mA dc.
I made a capacitor input and a choke input using the same transformer, capacitor and rectifier.
First C input with a 20 uF cap will give a 25 volts ripple. Increasing the load with 30% will make the output voltage drop around 16 volts and ripple go up from 25 to 31 volts.
Then same cap with a 30H choke input. Used another secundary winding because LC needs more voltage to get at the same output!. So with 715 volts output i get 4,3 volts ripple. Increasing the current with 30% ripple will stay the same and output voltage will drop to 709 volts.
Good bye see you next month, Eduard
P.s photo is the test setup n the kitchen table
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Hi,
as I will not use the SPDIF Input on my dddac, I was wondering if there could be a benefit from bypassing the octal Buffer and SPDIF switcheroo and going directly into the delay circuit like it was on the old board? Or should i "just" cut the Clock and spdif Receiver chip from power to reduce some more noise. Thus leaving the 74hct244am in the i2s circuit as i2s Buffer/linedriver?
If no one has tried this, I guess I'll have to wait until i get my Hands on a decent oscilloscope to check if it's doing anything to the i2s Ssgnal thats measurable as i think I won't be able to A/B this ^^
as I will not use the SPDIF Input on my dddac, I was wondering if there could be a benefit from bypassing the octal Buffer and SPDIF switcheroo and going directly into the delay circuit like it was on the old board? Or should i "just" cut the Clock and spdif Receiver chip from power to reduce some more noise. Thus leaving the 74hct244am in the i2s circuit as i2s Buffer/linedriver?
If no one has tried this, I guess I'll have to wait until i get my Hands on a decent oscilloscope to check if it's doing anything to the i2s Ssgnal thats measurable as i think I won't be able to A/B this ^^
You can do further cleaning by feeding directly the DAC deck with right justified reclocked I2S from a digital streamer (already done with Beaglebone Black + Cronus and Hermes).
This way, providing you add the I/V circuit, you don't need the mainboard.
I understand it is additional work, but it's a straight path to the top you can achieve regarding inputs. If you strongly need USB, then you have to find your intermediate trick.
This way, providing you add the I/V circuit, you don't need the mainboard.
I understand it is additional work, but it's a straight path to the top you can achieve regarding inputs. If you strongly need USB, then you have to find your intermediate trick.
Hi Oli, if you omit the buffer, your source will be far back through connectors and cables back to whatever source - hence I added the buffer. It drives very ruggedly the sometimes many dac boards behind it - I would not by pass it
I am already using a pi and a kali reclocker to feed the i2s (so not using USB anyway), but i thougt the pcm1794 needs right justified to work in nos mode. I thougzt thats the whole reason for the 74HC164 shift registers on the mainboard, did i geht this wrong?
I wanted to cut out the spdif circuitry, to clean up the i2s signal further (if that makes sense).
Edit: ah thanks for the info doede. Do you think its of any use to do this or wouldn't it matter anyway
Edit2: I guess cutting power to the tent clock and spdif chip would be the best and easiest way?
I wanted to cut out the spdif circuitry, to clean up the i2s signal further (if that makes sense).
Edit: ah thanks for the info doede. Do you think its of any use to do this or wouldn't it matter anyway
Edit2: I guess cutting power to the tent clock and spdif chip would be the best and easiest way?
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As I have 4 boards I will see f I can find the easiest switchable way to cut out the spdif(leaving the buffer where it is), and check for myself if it does something to the i2s signal coming from the kali
Perhaps i'll play a little around with and see what will work as direct connecting the Kali to the DAC boards with software "converted" right justified signal. Thanks for the hint g600
Perhaps i'll play a little around with and see what will work as direct connecting the Kali to the DAC boards with software "converted" right justified signal. Thanks for the hint g600
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Just in case anyone else wants to know here: harry from ropieeee told me that its not easy to get a right justified signal out of the pi (at least when using ropieee I guess) and I should stick with the hardware conversion. Also it seems like the shift registers and the octal buffer are in the low picoseconds jitter wise, so probably not a concern anyways.
Hello folks, there are a few DACs which have an option of receiving I2S signals over HDMI. Since our DDDAC also operates on I2S, is there any way we can use CD players/transports which have an HDMI based I2S output? I am looking at a Jay's Audio transport to be paired with the DDDAC and was wondering if any converter/etc. could make this connection possible? Any inputs are welcome.
As a side note: in case any one of you uses the Jay's Audio transport CDT2 Mk2, any impressions will be very helpful. Specially when paired with the DDDAC.
Thanks
As a side note: in case any one of you uses the Jay's Audio transport CDT2 Mk2, any impressions will be very helpful. Specially when paired with the DDDAC.
Thanks
I guess it won't be a problem to feed the mainboard with any I2S signal.
The mainboard will provide the half clock delay.
A thing I cannot remember is the right justified data, I suspect that the mainboard takes care of all, other will correct me if I'm wrong.
I don't know how I2S behaves inside HDMI, but a general rule is to keep the connections short. Any need of a buffer for I2S input, guys?
The mainboard will provide the half clock delay.
A thing I cannot remember is the right justified data, I suspect that the mainboard takes care of all, other will correct me if I'm wrong.
I don't know how I2S behaves inside HDMI, but a general rule is to keep the connections short. Any need of a buffer for I2S input, guys?
Sure, I have already crossed those I2S over HDMI, but always suspicious because this data is fragile and everybody wants the shortest possible connection. Maybe a technical solution resides inside the many I2S-HDMI modules.
Regarding a shared I2S input between HDMI and another source like WaveIO, it is not very straghtforward.
I think you have to search an HDMI receiver board that features a selector.
For example this one HDMI I2S LVDS to I2S Input Module HDMI I2S LVDS to I2S Output - Audiophonics instead of this one AUDIO-GD DIY HDMI to I2S Input Module - Audiophonics
Or a selector like Four-way Audio I2S input to one I2S out Switching Module - Audiophonics
Regarding a shared I2S input between HDMI and another source like WaveIO, it is not very straghtforward.
I think you have to search an HDMI receiver board that features a selector.
For example this one HDMI I2S LVDS to I2S Input Module HDMI I2S LVDS to I2S Output - Audiophonics instead of this one AUDIO-GD DIY HDMI to I2S Input Module - Audiophonics
Or a selector like Four-way Audio I2S input to one I2S out Switching Module - Audiophonics
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Hi,
I talked with Doede and it seems Sowter is quite busy at the moment, so I have to wait quite some time until I can upgrade to transformer output :/
So in the meantime I want to go balanced out but have only the one capacitor which was included in the kit (I guess i would need one capacitor in line with pos and one in line with neg), so if i buy some extra caps now I wouldn't need them anymore when the sowters arrive. So it seems a bit like a waste of Money...
If I would go direct in the meantime I could save the money for the caps.
My preamp is dc coupled, I yet have to check the circuit on my tube power amp to see if there is a capacitor in line…
Can I destroy something by going direct balanced out, or can I just try it out without knowing the circuit of my power amp?
Greetings
Oli
I talked with Doede and it seems Sowter is quite busy at the moment, so I have to wait quite some time until I can upgrade to transformer output :/
So in the meantime I want to go balanced out but have only the one capacitor which was included in the kit (I guess i would need one capacitor in line with pos and one in line with neg), so if i buy some extra caps now I wouldn't need them anymore when the sowters arrive. So it seems a bit like a waste of Money...
If I would go direct in the meantime I could save the money for the caps.
My preamp is dc coupled, I yet have to check the circuit on my tube power amp to see if there is a capacitor in line…
Can I destroy something by going direct balanced out, or can I just try it out without knowing the circuit of my power amp?
Greetings
Oli
Hi,
I talked with Doede and it seems Sowter is quite busy at the moment, so I have to wait quite some time until I can upgrade to transformer output :/
So in the meantime I want to go balanced out but have only the one capacitor which was included in the kit (I guess i would need one capacitor in line with pos and one in line with neg), so if i buy some extra caps now I wouldn't need them anymore when the sowters arrive. So it seems a bit like a waste of Money...
If I would go direct in the meantime I could save the money for the caps.
My preamp is dc coupled, I yet have to check the circuit on my tube power amp to see if there is a capacitor in line…
Can I destroy something by going direct balanced out, or can I just try it out without knowing the circuit of my power amp?
I guess your amp is DC protected. Still gain of say 20x and an offset in the DAC of may be 10mV - you will have 200mV DC at the output - I guess that will trip the protection?
I would be very careful to try this
I can send you a few good couple caps for the time you wait for your Sowers? just PM me...
Greetings
Oli
I am using caps to couple the DDDAC to my balanced preamp. Going balanced was a big improvement for my system. To try balanced you could pick up some reasonably priced film caps. That way you will know exactly what you are getting from the Sowters. If you switch from SE directly to Sowter balanced you won’t know what changes are from the transformers and what are from the SE/balanced change.
I plan to upgrade to more boards in the future and then consider the Sowters. Right now the balanced connection is a big upgrade for me.
I plan to upgrade to more boards in the future and then consider the Sowters. Right now the balanced connection is a big upgrade for me.
Thanks a lot doede! Thats really nice, pm is out.
@Bfpca: i already have a good balanced DAC, nice xlr interconnects and a true balanced pre. That's why it hurts so bad to connect the dddac (which does sound really(!) nice even with single ended connection) in se mode and with the crappy rca cables which are the only ones I have ... Such a waste of potential :/
@Bfpca: i already have a good balanced DAC, nice xlr interconnects and a true balanced pre. That's why it hurts so bad to connect the dddac (which does sound really(!) nice even with single ended connection) in se mode and with the crappy rca cables which are the only ones I have ... Such a waste of potential :/