IMHO FDA-1 in balance mode with some power regulator mod is still sounds good compares to the original setup. Not to mention if you feed the DAC with I2S source direct from a good digital source you won't be worried with the latest addition of the FDA-1B setups...they still one of the best DAC you could play around
The All New FETaudio FDA-1B
I have completed Spencer’s spanking new FDA-1B and had a chance to listen to it, comparing it to his previous FDA-1 Balanced, which was my DAC!
The DAC kit was packed in the usual way, with each individual component packed in separate bags. These were properly labeled and made assembly much easier and quicker.
This time, Spencer also provided a chart for each resistor and cap value making finding the locations dead easy. I must have saved a few hours using these charts alone.
In a moment of absolute heroism (after watching Battleship), I asked Spencer not to solder the WM8804 and 1794A. Some may call this craziness, and I would agree with them too!! Anyway, after a few hours of ‘How to Solder SMT Components’ on Youtube, I got the suggested non-residue flux pen and soldiered on. I used an extra fine tip for these three chips and felt that the most difficult part was to get the chips to align and tacking one of the pins. I think this is where a third hand would have been really helpful!!!! Ha ha. And did I mention that the pins were the tiniest of tiny?? Anyway, I somehow managed with the help of the flux, some solder wick and a 5X magnifying glass. Frankly, I still can’t believe I did it.
I noticed that the board was designed to accept both TH and SMT parts, which will be very handy for us modders. Just think of the possibilities.
Once past the SMT parts, the rest of the work was fairly straight forward except when I put 2 resistors in the wrong locations but in the weeee hours of the morning (and after my 5th espresso)!
There was a design flaw that required the C1815 transistors to be soldered differently. This was highlighted in the manual so no worries here.
Anyway, after 2 days of flux smoke induced madness and sleep deprivation (not to mention the numerous glares from the other half), I finished the assembly.
I applied power to the board and heard the familiar click from one of the relays. That is good news. I then checked DC voltages (5V, 3.3V, +20V and -20V). Everything just clicked and I was getting really excited. I then proceeded to adjust the DC offset. I can’t believe it but I managed to do that too. So all that was left was to hookup the DAC and hope that it sings!! And boy did it….
The new kit also comes with a front panel selector switch with a toggle switch. We can now easily cycle through the various input options; RCA SPDIF, XLR SPDIF, TOSlink and I2S. The smallest chip of the build is on this panel. It is as tiny as an 8 legged ant. Crazy!!
Anyway, so how does the new DAC sound? In a word, ASTOUNDING!!! If you like the FDA-1, you will just love the FDA-1B. The soundstage is even cleaner and music even more transparent. The presentation is now more airy and instruments just seem to be floating within the soundstage. The bass is tighter and more extended. The music just seems to bring the singers into our world.
By comparison, the old FDA-1 sounds ‘dark – laid back’. Furthermore, we now have the option of ‘tuning’ the sound through the SRC daughter board, which I will be getting, once it is available. I will be getting the AD1896 chip as it seems to offer the best sound.
Perhaps the switch to the WM8804, the use of lower noise SMT components (even replaced the PIO’s low pass filter caps) and 50ppm TH resistors together with the layout improvements (over 7 design prototypes – according to the manual) have produced this result. Whatever it is, I am in a new heaven now …… What a rush!
Here are some photos of the DAC. Photography is my other hobby.
I was so busy listening to it that I haven’t boxed it yet. That will be for another day….
Frankly, I still can't believe I got it right the first time! Unbelievable! I think it must be the caffine!!!
Enjoy!!!!
TC
I have completed Spencer’s spanking new FDA-1B and had a chance to listen to it, comparing it to his previous FDA-1 Balanced, which was my DAC!
The DAC kit was packed in the usual way, with each individual component packed in separate bags. These were properly labeled and made assembly much easier and quicker.
This time, Spencer also provided a chart for each resistor and cap value making finding the locations dead easy. I must have saved a few hours using these charts alone.
In a moment of absolute heroism (after watching Battleship), I asked Spencer not to solder the WM8804 and 1794A. Some may call this craziness, and I would agree with them too!! Anyway, after a few hours of ‘How to Solder SMT Components’ on Youtube, I got the suggested non-residue flux pen and soldiered on. I used an extra fine tip for these three chips and felt that the most difficult part was to get the chips to align and tacking one of the pins. I think this is where a third hand would have been really helpful!!!! Ha ha. And did I mention that the pins were the tiniest of tiny?? Anyway, I somehow managed with the help of the flux, some solder wick and a 5X magnifying glass. Frankly, I still can’t believe I did it.
I noticed that the board was designed to accept both TH and SMT parts, which will be very handy for us modders. Just think of the possibilities.
Once past the SMT parts, the rest of the work was fairly straight forward except when I put 2 resistors in the wrong locations but in the weeee hours of the morning (and after my 5th espresso)!
There was a design flaw that required the C1815 transistors to be soldered differently. This was highlighted in the manual so no worries here.
Anyway, after 2 days of flux smoke induced madness and sleep deprivation (not to mention the numerous glares from the other half), I finished the assembly.
I applied power to the board and heard the familiar click from one of the relays. That is good news. I then checked DC voltages (5V, 3.3V, +20V and -20V). Everything just clicked and I was getting really excited. I then proceeded to adjust the DC offset. I can’t believe it but I managed to do that too. So all that was left was to hookup the DAC and hope that it sings!! And boy did it….
The new kit also comes with a front panel selector switch with a toggle switch. We can now easily cycle through the various input options; RCA SPDIF, XLR SPDIF, TOSlink and I2S. The smallest chip of the build is on this panel. It is as tiny as an 8 legged ant. Crazy!!
Anyway, so how does the new DAC sound? In a word, ASTOUNDING!!! If you like the FDA-1, you will just love the FDA-1B. The soundstage is even cleaner and music even more transparent. The presentation is now more airy and instruments just seem to be floating within the soundstage. The bass is tighter and more extended. The music just seems to bring the singers into our world.
By comparison, the old FDA-1 sounds ‘dark – laid back’. Furthermore, we now have the option of ‘tuning’ the sound through the SRC daughter board, which I will be getting, once it is available. I will be getting the AD1896 chip as it seems to offer the best sound.
Perhaps the switch to the WM8804, the use of lower noise SMT components (even replaced the PIO’s low pass filter caps) and 50ppm TH resistors together with the layout improvements (over 7 design prototypes – according to the manual) have produced this result. Whatever it is, I am in a new heaven now …… What a rush!
Here are some photos of the DAC. Photography is my other hobby.
I was so busy listening to it that I haven’t boxed it yet. That will be for another day….
Frankly, I still can't believe I got it right the first time! Unbelievable! I think it must be the caffine!!!
Enjoy!!!!
TC
Attachments
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I asked Spencer earlier about upgrading my FDA-1 and his reponse was 'it is technically not possible' but perhaps you should write to him too. Maybe if he gets enough emails, he may change that to a 'yes'. Maybe wishful thinking but .....
Best wishes
TC
Best wishes
TC
I had done a lot of test (reclocker, SPDIF Sources, I2S) with the FDA1, but i think it is in generel and first i did not belife it, but the digital source, digital stage, jitter and other stuff impact the sound strongly, really... even though it is only binary.. so my guess is the biggest improvement of B Kit is the digitial part !
Regards
Marcus
Marcus
How did you guess that .... ha ha... Frankly, this diy stuff is very addictive. Once I start, I can't stop. So board 2 is entirely possible ...
Best wishes
TC
How did you guess that .... ha ha... Frankly, this diy stuff is very addictive. Once I start, I can't stop. So board 2 is entirely possible ...
Best wishes
TC
PS : It feel as you want to gain your solder skill by solder once again, i will check the result
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Boxing Complete!!
Hi
I used the old case so there are some unused holes at the back ha ha…. You should see the base plate. There are so many holes there that it looks more like a sieve!!
I added an Aluminum plate to hopefully shield the board from the transformer. I am not sure if this makes any difference but hey, it was fun doing it.
The face plate input selector is really useful. I can now cycle through the various options by pressing the toggle switch.
Looks like the set is now really complete!
TC
Hi
I used the old case so there are some unused holes at the back ha ha…. You should see the base plate. There are so many holes there that it looks more like a sieve!!
I added an Aluminum plate to hopefully shield the board from the transformer. I am not sure if this makes any difference but hey, it was fun doing it.
The face plate input selector is really useful. I can now cycle through the various options by pressing the toggle switch.
Looks like the set is now really complete!
TC
Attachments
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As the designer of FDA-1B kit, I would like to provide some comments here:
The fact is that layout of the FDA-1B is the most important to the final result of the same circuit. Accumulation of the proper layout is very important to prevent any issue but some designs will only be accumulation of issues to give worsen result.
Few points that I want to highlight again:
1. Careful layout of every sections of the DAC.
2. Use symmetric design as far as possible for the full balance output.
3. Align the digital bus timing for all 4 I2S signals as well as left and right channel timing for minimum phase error.
4. Choose the best WM8804 digital receiver chip.
5. Choose the regulators that give most optimized sound.
I cannot say the current design FDA-1B is perfect but I would say it progress a lot since the FDA-1 layout from 1.5 years ago. I always design everything in a single board unless there is no choice because I can control the consistence of the connections to ensure consistence of result. FDA-1 is a Single End design from day one and it is not optimized to work in full balance mode. Thus FDA-1 is not able to reach a higher level of performance.
Thank you for all your support in FDA-1 and I am sure there will be more fun and enjoyment for those who decide to try FDA-1B.
The fact is that layout of the FDA-1B is the most important to the final result of the same circuit. Accumulation of the proper layout is very important to prevent any issue but some designs will only be accumulation of issues to give worsen result.
Few points that I want to highlight again:
1. Careful layout of every sections of the DAC.
2. Use symmetric design as far as possible for the full balance output.
3. Align the digital bus timing for all 4 I2S signals as well as left and right channel timing for minimum phase error.
4. Choose the best WM8804 digital receiver chip.
5. Choose the regulators that give most optimized sound.
I cannot say the current design FDA-1B is perfect but I would say it progress a lot since the FDA-1 layout from 1.5 years ago. I always design everything in a single board unless there is no choice because I can control the consistence of the connections to ensure consistence of result. FDA-1 is a Single End design from day one and it is not optimized to work in full balance mode. Thus FDA-1 is not able to reach a higher level of performance.
Thank you for all your support in FDA-1 and I am sure there will be more fun and enjoyment for those who decide to try FDA-1B.
I second that! Despite the improvements of the FDA-1B, the FDA-1 is still very capable. You should definitely go for it...
TC
TC
@florentino:
believe me the FDA-1 is a really cool project! It sounds great!! I use it every day
br recorder
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Akira,
In my comment number 4, the WM8804 just make the DAC sound almost perfect. I can hardly tell the difference between XMOS --> I2S input and 16bit/44.1k SPDIF input now. Refer to the jitter measurement on the manual, the jitter rejection by WM8804 is really excellent. Thus I have no more urgency to switch to XMOS (USB) input as the SPDIF input sound same good!
No 3 is also very important as there are now two DAC chips and the I2S signal must reach the two chips at the same timing to avoid any phase error for left and right channels. This can be easily heard in the sound stage and 3D improvement.
For other improvement, refer to my previous comments.
For a 100 point scale of improvement, the WM8804 will contribute 50% and no. 3 contributes another 30% and the rest 20% by others.
In my comment number 4, the WM8804 just make the DAC sound almost perfect. I can hardly tell the difference between XMOS --> I2S input and 16bit/44.1k SPDIF input now. Refer to the jitter measurement on the manual, the jitter rejection by WM8804 is really excellent. Thus I have no more urgency to switch to XMOS (USB) input as the SPDIF input sound same good!
No 3 is also very important as there are now two DAC chips and the I2S signal must reach the two chips at the same timing to avoid any phase error for left and right channels. This can be easily heard in the sound stage and 3D improvement.
For other improvement, refer to my previous comments.
For a 100 point scale of improvement, the WM8804 will contribute 50% and no. 3 contributes another 30% and the rest 20% by others.
Thank´s recorder!@florentino:
believe me the FDA-1 is a really cool project! It sounds great!! I use it every day
br recorder
ok I will finish it!
but one question to have the best performance!
What is the best connection between PC and FDA-1!?
I thought of the M2Tech HiFace USB interface?
Or is optically better?
thanks for helping
florentino
Hi Spencer,
many thanks for your comments and information about the new design.
One additional question :
Refere to the pictures it seems no Vishay Dale RN / CMF Resistors populated anymore as used in many places ( I/V and output stage) of Kit A. Did you had done some tests with resistors, how was the result ?
Many thanks,
regards
Marcus
UMarcus,
I do not want to comment too much on part selection but please read this very good article by Audio Precision in below link. Create a account if you cannot download it.
AP High Performance Audio Analyzer & Audio Test Instruments : Home
I do not want to comment too much on part selection but please read this very good article by Audio Precision in below link. Create a account if you cannot download it.
AP High Performance Audio Analyzer & Audio Test Instruments : Home
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