A NOS 192/24 DAC with the PCM1794 (and WaveIO USB input)

I did it by playing a sine wave tone of 1kHz 0dBFS. Listen to the tone. If the BCK get corrupted, you will hear "crackling" sound. It will stop at a certain value. It is a pretty black & white thing. It crackles or ist just stops, not a slow degrading effect or so. I used a trimmer to find the value. it was like 250 Ohm. choose 220 for practical reasons....
 
I just realized; it is already 10 years ago I designed the first version of the DDDAC1794! :love:
So, I thought it to be a good idea to write a short chronicle of the DDDAC history and also create a tweaking and upgrade Guide :cool:
Go to my Blog Site to read the article!

also......
See you maybe on Feb 4th in Hengelo at the "Luisterdag" Audio event?
I will be there with my Clio setup to measure Loudspeakers for those who are interested...
Audio Event Info on Dutch audio forum

Hi Doude,
congrats with this jubilee.!

As it comes to DDDAC 1794 psu, is it possible to use the kit PSU with 2x 18V transformer in stead of 2x 15V for the mainboard and decks?
 
Hi Doede,
congrats with this jubilee.!

As it comes to DDDAC 1794 psu, is it possible to use the kit PSU with 2x 18V transformer in stead of 2x 15V for the mainboard and decks?


Technically this is no problem. Close to the limits though.... The 18 Volt will result in like 24-25V DC. De capacitors are rated with 25V. Still ok, they will not explode at 26Volt....
More could be an issue with heat dissipation in the TIP122. depending on what current you are going to draw from the power supply. You will have 3Vac more so roughly 4 Volt DC extra. If yo draw let say 500mA that is 2Watt extra. with the Heatsink specified at 6K/w that will be an increase of extra 12 degrees. With 1A extra 24 degrees, that might get a bit warmer then you want?

as said, yes, possible, but keep an eye on temperature and actual DC voltage at the input Capacitors

this blog is worth reading and covers in detail the above points....

Link to DDDAC power supply blog
 
Hi everyone
I'm new to the forum, my first post.
I'm in the process of upgrading my hifi and considering buying a dddac. I'm looking for general advice regarding what to purchase/future upgrade options etc.
Is this a good place to post these questions or should I be posting elsewhere?
Thanks, Richard
 
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Technically this is no problem. Close to the limits though.... The 18 Volt will result in like 24-25V DC. De capacitors are rated with 25V. Still ok, they will not explode at 26Volt....
More could be an issue with heat dissipation in the TIP122. depending on what current you are going to draw from the power supply. You will have 3Vac more so roughly 4 Volt DC extra. If yo draw let say 500mA that is 2Watt extra. with the Heatsink specified at 6K/w that will be an increase of extra 12 degrees. With 1A extra 24 degrees, that might get a bit warmer then you want?

as said, yes, possible, but keep an eye on temperature and actual DC voltage at the input Capacitors

this blog is worth reading and covers in detail the above points....

Link to DDDAC power supply blog
Hi Doede,
Thanks for your reponse. I keep a close eye on it.
 
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welcome Richard ! I just wrote a blog post about that. did you read that ? any questions left? happy to answer....

suggestions for start and upgrades are in the second part.... link to blog post
Thanks Doede, I have just read this blog and it's very useful thanks.
I think I want to purchase a single board dddac, with a view to further upgrades in the future. I agree with your advice that it's good to appreciate the improvements as you go.
I have a few questions, and would really appreciate any advice from members here - I've read a bit of this thread and I'm sure all my answers are here, but there's a lot to read!
I'm looking to achieve the best sounding streamer system that my budget allows, I'm currently using an Allo Usbridge running volumio, feeding a Khadas toneboard pro ( a great sound I think for less than £200 but this is where I'm hoping I can improve with the dddac)
I then have musical fidelity pre-amp and xa-200 monoblock power amps and Pensil 11 full range speakers.
My first priority is replacing the dac and pre-amp. My first question is should I stick with the Allo usbridge and I think I will need to buy the iowave board from luckit. Or I sell the usbridge, save on the iowave board and look at the Ian Canada solution?
My next question is just what I need to order from audiocreative. Do I just need the 12v PSU for the main board and 1 dac module. Is it worth buying the low noise regulator upgrade, and do I just need the 5v version?
I hope that all makes sense, I'm sure I'll have more questions to follow. Any advice much appreciated!
 
should I stick with the Allo usbridge and I think I will need to buy the iowave board from luckit. Or I sell the usbridge, save on the iowave board and look at the Ian Canada solution?
The Ian Canada stuff gives a cleaner I2S signal in my opinion. If you don't need the USB input to the DDDAC, I'd recommend the Ian Canada stuff (lot's of options...).
My next question is just what I need to order from audiocreative. Do I just need the 12v PSU for the main board and 1 dac module. Is it worth buying the low noise regulator upgrade, and do I just need the 5v version?
The 12 V PSU is for the DDDAC, while the 5 V PSU is meant for the USB WaveIO board. If you go with the Ian Canada stuff, you might also use this 5 V PSU (that's what I ended up with when I changed from the WaveIO to Ian Canada), but you might also consider some other PSU for the Ian Canada stuff.
 
I have built 5 DDDACs and it’s critical you enjoy the ride and start with the basics as Doede states.

You get a base point of sound which will be amazing and then step by step you make updates as needed and enjoy the journey

My super upgraded DAC with all the clocks and PSUs was a fun experience and I learnt so much…… enjoy it
 
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I have built 5 DDDACs and it’s critical you enjoy the ride and start with the basics as Doede states.

You get a base point of sound which will be amazing and then step by step you make updates as needed and enjoy the journey

My super upgraded DAC with all the clocks and PSUs was a fun experience and I learnt so much…… enjoy it
Many thanks Simon, that's very reassuring to hear. I guess part of my reason for joining this forum was to just get some reassurance that I was doing the right thing. Having never heard a dddac, I am relying on advice and reviews etc, and although I'm looking to start with the minimum entry level solution, I will still end up spending over £500.
 
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We are here to help you as when I started I needed tonnes of help! I am in the UK as well and can always have a call if needed and you are more than welcome to visit and have a listen.

there is a review on here of when I compared it to the Chord TT DAC with the Chord M scaler, bottom line is my friend was not happy as my DAC was far better.
 
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