It is time to wake up this old thread, it has been a while, but there is a good reason for it. This will be a short story made long. I was thinking if I should post in a different place, like under digital source, might be more appropriate there... but than it is all the same project that Choky started talking here in in this thread in 2011.
Huh, 4 years... This endeavor is actually much longer, but lets say it started somewhere in 2010. It has been a real DIY project, started as one idea - a digital crossover, changed to something else (analog crossover) out of frustration since the first idea did not work, finished that one than went back to the original one and here we are in 2015.
During this process, I made a great friendships with people that supported me, and helped me so much. Without them I would not be able to finish - period. I learned so much, but it was such a frustration failing along the way. This project throw on me every challenge that is humanly possibly to imagine. I burned both DACs three times, I changed the design who knows how many times, if it was not hardware obstacle, than it was mechanical, if it was not mechanical, than it was software... It costed me arm and leg and some more. I was pushed to learn PCB design, toner transfer and etching, and sending it out for board manufacturing. I could say I am an expert now on wire crimping, hahaha.
I work at crazy place with absolutely crazy people, where my life goes to vacuum for several months since we work insane hours and weekends. When we are done with that, books we create go to press, than I go back to sort of normal hours and I could spend some time with family and my audio passion. So I start work on projects around 9PM and finish at 2 AM. By definition everything I burned happened at around 1:30 AM. I literally had situation where I was done... than I connected the last wire.... than all is gone in a split second.
So, not to put you to sleep, I will post this picture, make a break and continue in the next post. Here is the Sunfire digital processor, that I got from ebay relatively inexpensive. It was broken, fried, gone... and I thought it will be a great enclosure for my project. Pretty large so I could fit anything in it... So I thought. Unlike interior, exterior was in a mint shape.
Huh, 4 years... This endeavor is actually much longer, but lets say it started somewhere in 2010. It has been a real DIY project, started as one idea - a digital crossover, changed to something else (analog crossover) out of frustration since the first idea did not work, finished that one than went back to the original one and here we are in 2015.
During this process, I made a great friendships with people that supported me, and helped me so much. Without them I would not be able to finish - period. I learned so much, but it was such a frustration failing along the way. This project throw on me every challenge that is humanly possibly to imagine. I burned both DACs three times, I changed the design who knows how many times, if it was not hardware obstacle, than it was mechanical, if it was not mechanical, than it was software... It costed me arm and leg and some more. I was pushed to learn PCB design, toner transfer and etching, and sending it out for board manufacturing. I could say I am an expert now on wire crimping, hahaha.
I work at crazy place with absolutely crazy people, where my life goes to vacuum for several months since we work insane hours and weekends. When we are done with that, books we create go to press, than I go back to sort of normal hours and I could spend some time with family and my audio passion. So I start work on projects around 9PM and finish at 2 AM. By definition everything I burned happened at around 1:30 AM. I literally had situation where I was done... than I connected the last wire.... than all is gone in a split second.
So, not to put you to sleep, I will post this picture, make a break and continue in the next post. Here is the Sunfire digital processor, that I got from ebay relatively inexpensive. It was broken, fried, gone... and I thought it will be a great enclosure for my project. Pretty large so I could fit anything in it... So I thought. Unlike interior, exterior was in a mint shape.
Attachments
Now here are some technical details. I tried to make the best 4 channel digital crossover with DACs and source - 4 channel USB to I2S converter in synchronous mode, driven by high quality clock. DACs are completely isolated from any direction - I2S, I2C lines, Master clock lines... The special attention is given to power supplies, where every piece has its on transformer or separate winding, with the highest quality regulators, that are in many places double or triple regulated.
The digital crossover is consisted of:
Titan USB to I2S converter in slave synchronous mode from Light Harmonic, used in their DaVinci DAC
Da Vinci DAC MKII - Light Harmonic
2 of Acko DAC boards using ESS9012 chips. Each DAC uses 7 separate high quality regulators. They are fed from separate pre regulators.
DAC - ACKOLABS
Both source and DACs are provided with master clock from Turbo clock from Acko. Turbo clock uses 2 power supplies, 5 an 7 v, separately provided from Super Regulators from Sjostrom , but than again there are very high quality regulators to take it down to 3.3 V and 5 V
Sjöström Audio - Home
DACs are used in voltage mode. I use to have Lundahl transformers in the output, but I changed that to capacitors. First I installed 0.47uF M caps Supreme, but than had to change them to physically smaller teflon caps. They simply did not fit in the case.
Than dual balanced analog relay board volume control from Jos VanEjindhoven
RelaiXedSMD -- Documentation
And finally dual balanced buffers, based on Nelson Pass's buffer designed by Zen Mod and with my designed PCB Booards. These buffers are fed each with +- 15Vs by Sjoatroms Super regulators.
Arduino is used to control DACs parameters and VFD screen, but not for volume.
All of digital lines and signals are isolated by Ian's 4 wire isolator boards.
OK, time for some pictures: After gutting the case, this is how it was looking a the start. I ended up with 3 layers -floors, like this one shown.
The digital crossover is consisted of:
Titan USB to I2S converter in slave synchronous mode from Light Harmonic, used in their DaVinci DAC
Da Vinci DAC MKII - Light Harmonic
2 of Acko DAC boards using ESS9012 chips. Each DAC uses 7 separate high quality regulators. They are fed from separate pre regulators.
DAC - ACKOLABS
Both source and DACs are provided with master clock from Turbo clock from Acko. Turbo clock uses 2 power supplies, 5 an 7 v, separately provided from Super Regulators from Sjostrom , but than again there are very high quality regulators to take it down to 3.3 V and 5 V
Sjöström Audio - Home
DACs are used in voltage mode. I use to have Lundahl transformers in the output, but I changed that to capacitors. First I installed 0.47uF M caps Supreme, but than had to change them to physically smaller teflon caps. They simply did not fit in the case.
Than dual balanced analog relay board volume control from Jos VanEjindhoven
RelaiXedSMD -- Documentation
And finally dual balanced buffers, based on Nelson Pass's buffer designed by Zen Mod and with my designed PCB Booards. These buffers are fed each with +- 15Vs by Sjoatroms Super regulators.
Arduino is used to control DACs parameters and VFD screen, but not for volume.
All of digital lines and signals are isolated by Ian's 4 wire isolator boards.
OK, time for some pictures: After gutting the case, this is how it was looking a the start. I ended up with 3 layers -floors, like this one shown.
Attachments
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On a power supplies, there are 11 transformers total. They are ideally located separately on the left side of the case. I etched boards for those and each one seats on a separate fiberglass board since each level carries 120V. I have to say I was very happy with toner transfer technique and came out with pretty good results. Here are etched capacitors boards.
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All of the analog audio caring cables are three wire plus shield connected to the ground. There are so many various wires that shielding is a must. All of the I2S signals are W.FL or U.FL shielded cables, the same length, shortest possible. All of the power supplies cables are tightly twisted. As you could see on images I used al polarized connectors, to save myself from myself. It is hard learned lesson.
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Here are power supplies for DAC - preregulators and 7 regulators for each DAC, that makes is all together 18 regulators! Acko DAC in itself and connected. Than set of 6 Super regulators feeding buffers plus and minus 15V for each channel separately, 5v and 7V for Turbo clock and 7th one not shown for Titan providing 5V.
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Lastly all finished, before closing. How does it sound? Unreal, out of body experience, hehehe. Never heard anything like it. When no song playing it is absolutely dead quiet. I placed my ear on array of ribbons, shown at the beginning of this thread and I hear absolutely nothing. I guess all those isolators are doing its job. Stereo separation, imaging, details... just unreal. The idea for this unit was simplicity, haha, please do not laugh. It serves as preamp, DAC, volume control and sends signal straight to amp. It does not amplify signal that comes from DAC, all what it does it removes DC and passes signal through buffers so it is immune to whatever is connected after it.
I have been using for many years Lundahl transformers and for a first time switched to capacitors in output. Yes I am using the best caps - teflon ones, and I am extremely happy with the sound. Transformers are great, but with expense of added distortion bellow 1KHz. They are also sensitive to the impedances in front and behind them what sometimes limits choices.
Lastly I would like to say that I owe to so many people and would like to thank them for their support over the years - Acko for saving me three times with repairing DACs every time I burned them. Those DACs traveled the world more than many people
Than Ian for finding the solution for buffers and helping me advices, Nelson Pass for helping me with analog crossover at the time when I was almost ready to give up, and finally my psychotherapist Choky, Zen Mod who was there all along the way and guided me and answer the most ridiculous questions I had. Not to forget the DIYAudio community for sharing all the knowledge.
I have been using for many years Lundahl transformers and for a first time switched to capacitors in output. Yes I am using the best caps - teflon ones, and I am extremely happy with the sound. Transformers are great, but with expense of added distortion bellow 1KHz. They are also sensitive to the impedances in front and behind them what sometimes limits choices.
Lastly I would like to say that I owe to so many people and would like to thank them for their support over the years - Acko for saving me three times with repairing DACs every time I burned them. Those DACs traveled the world more than many people
Than Ian for finding the solution for buffers and helping me advices, Nelson Pass for helping me with analog crossover at the time when I was almost ready to give up, and finally my psychotherapist Choky, Zen Mod who was there all along the way and guided me and answer the most ridiculous questions I had. Not to forget the DIYAudio community for sharing all the knowledge.Attachments
well , yes ........ Fugly!
- but AR2 pretty well knows that word from #55 still means much more .......
B..E..N..Z..I..N
- but AR2 pretty well knows that word from #55 still means much more .......
B..E..N..Z..I..N
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