We call it direct (not hard). It saves time and makes things clear. You can have opinions as many as you wish but there is a system in making quality. That is what I want to make clear. See it as an art if you like. Look around you, you will see many mediocre stuff with flaws because of costcutting, lack of time to improve the design etc. Now adjust to think quality. Improve the skills. Use good materials and tools. Enjoy the art of building quality stuff. Building it safe and mechanically sound is the icing on the cake. Pride when you look at the stuff you built....and how it sounds.
To me it has no use running in circles and cutting corners when building stuff myself. If I would do that it would remind me of the things I dislike in seeing ready made poorly engineered stuff. Maybe you understand now that I will make a comment when I see boards attached with tieraps or just one screw. It is totally unneccesary to skip on quality as it is against the intention to build a good device.
I made this small list of uneconomical (in time and money ) choices that can make the difference. Choices that would be made the contrary way at work etc. :
1. building will take time anyway, so give it the extra time it needs to be excellent
2. why not strive to make it the best (or at least very good
) ?3. it will be more expensive than ready made stuff anyway so that proves point 2.
4. when there comes a choice between "cheaper" and "better" choose "better"...
Last edited:
Yes agree,
1) but when you don't know how to do, some general remarks are on the directness way of talking for nothing but pleasing yourself.
2)but sometimes unexperienced people like I am need more help than directness sentences empty of teaching. I am not guilty to like my hobby and to join your project (I hope so).
3) I think it is the way you are : demanding with you and others. It's a good thing; I think I am like this but more relaxing when it's not a job or others needs my good practice for heating every month (professional life is not a hobby). This difference give us some exchanges before...but always with a positiv mind I think. Your demanding needs a next level of diplomaty skill solmetimes for the others with adding water in the wine (or whisky)... or not, I'm the first to be direct...but for the not good willed people only who are not asking for 2). For me your good advices are often at the price of a STRONG" directness. That's all I wanted to say, it's a sinceer input.
see you
1) but when you don't know how to do, some general remarks are on the directness way of talking for nothing but pleasing yourself.
2)but sometimes unexperienced people like I am need more help than directness sentences empty of teaching. I am not guilty to like my hobby and to join your project (I hope so).
3) I think it is the way you are : demanding with you and others. It's a good thing; I think I am like this but more relaxing when it's not a job or others needs my good practice for heating every month (professional life is not a hobby). This difference give us some exchanges before...but always with a positiv mind I think. Your demanding needs a next level of diplomaty skill solmetimes for the others with adding water in the wine (or whisky)... or not, I'm the first to be direct...but for the not good willed people only who are not asking for 2). For me your good advices are often at the price of a STRONG" directness. That's all I wanted to say, it's a sinceer input.
see you
If I would do this to please myself I better had not done a GB
If my sentences are empty then I do have a problem with making stuff clear. I do not always answer to posts with 5 or more questions, that is true. Please think of the time I put in reading emails and posts almost every evening. This is not complaining. My small DAC project (I needed just 1 PCB....) takes 2 years now. I have more DACs than I could use in a lifetime. Buying a Krell would have been more economical
There seems to be a cultural difference of sorts. Let's keep it positive. We all are different and still we're equal. I am in no way the person to teach as I am an amateur myself.
BTW forget about diplomacy....it won't happen. Life is too short for that and we're amongst men that solder. No need for wrapping up words in nice paper. Now heat up that Weller !
If my sentences are empty then I do have a problem with making stuff clear. I do not always answer to posts with 5 or more questions, that is true. Please think of the time I put in reading emails and posts almost every evening. This is not complaining. My small DAC project (I needed just 1 PCB....) takes 2 years now. I have more DACs than I could use in a lifetime. Buying a Krell would have been more economical
There seems to be a cultural difference of sorts. Let's keep it positive. We all are different and still we're equal. I am in no way the person to teach as I am an amateur myself.
BTW forget about diplomacy....it won't happen. Life is too short for that and we're amongst men that solder. No need for wrapping up words in nice paper. Now heat up that Weller !
Last edited:
...just wondering if the PSU is too close to the DAC?
No but I would turn the PSU board 180 degrees to the right. I think you will have a problem with putting the wires in the connectors otherwise. You will have to place the power switch to the left then. I like switches to be in the middle of the case but then 230 V wiring will be close to audio circuits. It is way more practical to place 230 V switches at the spot where the 230 V input and transformer are. In other words: keep all 230 V stuff at one small spot.
Also keep some distance between boards and back cover. It will prevent cabling from being forced against that back panel or the difficulty of routing the wiring to the RCA connectors.
Last edited:
BTW keeping 230 V stuff at the right side of the board so at the SPDIF side would make things more convenient and away from the L and R outputs. So the power switch placed on the right side, PSU turned 180 degrees to the left. That is a choice depending slightly on your other gear and taste...
Last edited:
Thanks JP. Do you mean 90 degree? ...so both boards are parallel to each other and the transformer will be on the right side?
Where a cable enters a sealed box with a screen, that screen should be connected to the box with a very low impedance connection at RF frequencies, the best way to achieve this is a ring of low value small case ceramic caps (X7R or COG) this will provide a low impedance path for RF (EMI) and prevent a possible ground loop problem...
I am a noob here. Thanks for pointing out.
Should I use a washer or rubber instead of a Nut ?
Actually I am using a 75 ohms cable. I was facing difficulties soldering these cables since they have a ground wire on top of main wire unlike other cables which run in parallel.
So i have used two cables. In one cable, I am only using the main wire and not using the ground. Vice versa for other cable. Trust me it is much easier to work.
Last edited:
Its also wrong, you would be better of with twisted pair same as your audio rather than what you have at the moment. If you are using co-ax cable then you should use only one with the signal going down the centre core and the shield should carry the return (GND).
As it is you just have two wires carrying the signal and its return, and for the ultimate SPDIF signal integrity these should be in close contact either via a single co-ax or as a twisted pair, not separated as you have them.
As it is you just have two wires carrying the signal and its return, and for the ultimate SPDIF signal integrity these should be in close contact either via a single co-ax or as a twisted pair, not separated as you have them.
Marc,
I think you're not seeing the forest for the trees. I've been a big advocate of insuring the entire SPDIF chain is 75 ohms every step of the way. But a lot of people don't want to be bothered changing connectors from RCA to 75 ohm BNC and ensuring that all their cables are 75 ohm.
If I look at the picture of Darshan's build, I see that he's still using an RCA jack for the SPDIF. Given that fact, worrying about the details of the wiring from the jack is probably a 2nd order effect. His DAC is working right now, so unless he wants to rebuild it with better connectors down the road then I wouldn't worry about that particular detail. So yes you are right, but I'm not sure it's worth fixing.
---Gary
Any ANY discontinuities between a digital signal and its return path cause problems including increased jitter, instead of using two cables as shown he would be much better of using twisted cables as shown on his audio connections. This is much more serious than a slight impedance mismatch in terms of signal integrity, so no ground return discontinuities are more serious to signal integrity than slight impedance mismatches with the frequency and usual rise times employed for SPDIF transmission.
Yes it is worth fixing.
Have a look at the first two comments in Henry Otts humorous look at EMC problems (also remember that EMC and signal integrity are two sides of the same coin.
The 10 Best Ways to Maximize Emission from Your Product
Considering the audio is twisted pair then why not show the same care for the SPDIF. I would never route a digital signal of wire one with a return path discontinuity, and in this case it is as critical if not more so than ultimate impedance matching down the line, this is a 1st order problem.
Yes it is worth fixing.
Have a look at the first two comments in Henry Otts humorous look at EMC problems (also remember that EMC and signal integrity are two sides of the same coin.
The 10 Best Ways to Maximize Emission from Your Product
Considering the audio is twisted pair then why not show the same care for the SPDIF. I would never route a digital signal of wire one with a return path discontinuity, and in this case it is as critical if not more so than ultimate impedance matching down the line, this is a 1st order problem.
Darshanjoni,
If you have not all the jacks & plugs in BNC for 75 ohms, don't mix 75 ohms plugs with non 75 ohms RCA sockets. First use the 75 ohms TV cable with RCA if you already bought a RCA for the spidf input on the DAC and to make the spidf wire with a TV cable
Then If you can on your source : try a coax 75 ohms cable for TV but this time directly soldered on the two pcbs (soldered on the top of the trough hole for the signal : the center coax insulation make a good protection against a short with the gnd wire shield of the coax you have to solder on the GND through hole)
You will have here a way to test for nothing a true 75 ohms (if a real 75 ohms TV cable) connection to hear the difference.
For the audio signals with RCA, just use two plastice circles by RCA plugs to isolate from the case the RCA body as the scew (none on them of course ahs to touch the case for an insulation). For SOTA design follow after Marce inputs but this the icing on the cake, you need first to use the correct wires then plugs. (50 ohms RCA for analog signal ; 75 ohms BNC for digital).
These diy will permitt you to wait your next purchase about all the conectors you need and listen to quickly the differences with your existing photograph above.
If you have not all the jacks & plugs in BNC for 75 ohms, don't mix 75 ohms plugs with non 75 ohms RCA sockets. First use the 75 ohms TV cable with RCA if you already bought a RCA for the spidf input on the DAC and to make the spidf wire with a TV cable
Then If you can on your source : try a coax 75 ohms cable for TV but this time directly soldered on the two pcbs (soldered on the top of the trough hole for the signal : the center coax insulation make a good protection against a short with the gnd wire shield of the coax you have to solder on the GND through hole)
You will have here a way to test for nothing a true 75 ohms (if a real 75 ohms TV cable) connection to hear the difference.
For the audio signals with RCA, just use two plastice circles by RCA plugs to isolate from the case the RCA body as the scew (none on them of course ahs to touch the case for an insulation). For SOTA design follow after Marce inputs but this the icing on the cake, you need first to use the correct wires then plugs. (50 ohms RCA for analog signal ; 75 ohms BNC for digital).
These diy will permitt you to wait your next purchase about all the conectors you need and listen to quickly the differences with your existing photograph above.
Thanks Guys for all the Inputs !!
I will do below things :
- Isolate Analog ground from the case using plastic ring or similar.
- Change Analog cables from Cat 6 to 50 ohms.
- Change the Spdif Input connector to BNC (Female) and use one single wire from BNC to PCB.
- I can take a SPDIF Out from my PC with 75 Ohms cable and terminate BNC connector (Male) at another end.
These things will make entire chain 75 ohms for digital and 50 ohms for analog.
I have below questions :
- Is there any way we can check resistance of a cable ?
- I have seen some of DIY cases of Pre and Power amp of my friends. Analog RCA's are terminated just as I did in my photo. Is that wrong?
- If you see the photos of my case, PCBs are also grounded to the case with the help of screws. Is that correct or it has to to be isolated from case ?
Thanks !!
I will do below things :
- Isolate Analog ground from the case using plastic ring or similar.
- Change Analog cables from Cat 6 to 50 ohms.
- Change the Spdif Input connector to BNC (Female) and use one single wire from BNC to PCB.
- I can take a SPDIF Out from my PC with 75 Ohms cable and terminate BNC connector (Male) at another end.
These things will make entire chain 75 ohms for digital and 50 ohms for analog.
I have below questions :
- Is there any way we can check resistance of a cable ?
- I have seen some of DIY cases of Pre and Power amp of my friends. Analog RCA's are terminated just as I did in my photo. Is that wrong?
- If you see the photos of my case, PCBs are also grounded to the case with the help of screws. Is that correct or it has to to be isolated from case ?
Thanks !!