Hi
read what phase wrote:
the regulator....not the diode
you checked the diodes....no.....look at the datasheet of the regulator
chris
I mentioned that about the regulators because it is important to keep in mind (before) while swapping any power supply capacitors around.
Without that it can be easy to add something with a very low esr, often a better quality part, and have a strange result that will sound better in some ways even over low quality parts.
Your caps on the incoming power should help, always has with me. I have used .1uf mostly.
Should be connected to the line and neutral and any exposed leads insulated with heat shrink sleeve or in a location where the leads won’t contact fingers or other conductive parts of your dac.
Those analog filter caps will likely make the most difference, followed by the power supply to the dac and op amp. When working around the dac, you need to be very careful not to overheat anything that could pass that heat through a trace and into the dac chip.
Without that it can be easy to add something with a very low esr, often a better quality part, and have a strange result that will sound better in some ways even over low quality parts.
Your caps on the incoming power should help, always has with me. I have used .1uf mostly.
Should be connected to the line and neutral and any exposed leads insulated with heat shrink sleeve or in a location where the leads won’t contact fingers or other conductive parts of your dac.
Those analog filter caps will likely make the most difference, followed by the power supply to the dac and op amp. When working around the dac, you need to be very careful not to overheat anything that could pass that heat through a trace and into the dac chip.
You are correct in that they will be shorting the affected frequencies. Most of the time, the noise is low enough such that the small amount of heat produced from this will not be a problem. On occasion, these parts in this application will breakdown, and fail. The reason to have chosen a “X” rated part is that these have a choice of materials and construction such that they won’t create flames when doing so. Two in series would work to lower the value as you have stated.
I would not place these into a wall outlet however, and instead suggest that a steel cabinet be used for any device plugged into a wall. Also to have the separate ground, if available, attached to the steel case. Placing anything foreign into a wall outlet will be a code violation as far as I know.
It is a basic form of a snubber circuit really. The ones used on diodes/transformers will consist of one value on its own, along with a higher value that has a resistor in series with it. The smaller value knocks the noise down in frequency, and the higher value along with some resistance to help dissipate the energy finishes it off. So even if it’s not perfect, will go a long ways to reduce the switching noise. Is more appreciated on dacs and preamps.
I would not place these into a wall outlet however, and instead suggest that a steel cabinet be used for any device plugged into a wall. Also to have the separate ground, if available, attached to the steel case. Placing anything foreign into a wall outlet will be a code violation as far as I know.
It is a basic form of a snubber circuit really. The ones used on diodes/transformers will consist of one value on its own, along with a higher value that has a resistor in series with it. The smaller value knocks the noise down in frequency, and the higher value along with some resistance to help dissipate the energy finishes it off. So even if it’s not perfect, will go a long ways to reduce the switching noise. Is more appreciated on dacs and preamps.
Ok, I'll be using that two 0.33uF in series until I get the 0.1uF 440V cap.
Regarding Cout: in fig. 13, the capacitor C3 is the Cout, right ?
They are showing it as a 1uF part !
EDIT:
I'll be keeping a list of parts to buy as buying one part at a time is costly when it comes to shipping charges !
So, the list as of now:
1.Ferrite ring (for choke purpose).
2. 4700uF 16V cap (for Cout filtration of LM317?), nichicon or any quality cap.
3. Double ferrite choked USB A to USB B cable.
4.
For "better performance" they mentioned putting a 0.1 & 10uF caps across ground and power input pins of the LM317. So, can I use the 0.1uF 306V X cap that I have ?
Regarding Cout: in fig. 13, the capacitor C3 is the Cout, right ?
They are showing it as a 1uF part !
EDIT:
I'll be keeping a list of parts to buy as buying one part at a time is costly when it comes to shipping charges !
So, the list as of now:
1.Ferrite ring (for choke purpose).
2. 4700uF 16V cap (for Cout filtration of LM317?), nichicon or any quality cap.
3. Double ferrite choked USB A to USB B cable.
4.
Last edited:
I'm ruling out tantalum even though it would have been much easier for me to source it because of the following reason.
4 types of capacitor for filtering applications in switch mode power supply systems – European Passive Components Institute
@phase I believe that your advice has not been registered/acknowledged and the build/modding of the power supply is entering into a dangerous stage for the OP. Maybe clearer explanation should be made in regards to the general rules governing the mains power outlet, the device's metal housing and the connectivity of the PHASE, NEUTRAL and EARTH wires. The Forum has a worldwide cover and we cannot be sure about all the Health & Safety regulations in place in most of the countries. I believe that the OP has shown some lack of insight regarding the building/modding of a device connected to the mains supply IMHO. Alternatively the OP should enlist the help of a local authorised electrician.
I was headed there...
So for a hobby device, namely your new dac, I cannot recommend strongly enough that you not build this on a piece of wood or less even, inside your home.
What I would do to protect yourself is to find a suitable metal enclosure, steel if at all possible to use.
What I have done for similar projects is to go to a scrap source, and find a metal box that already has a fused power connection built in. I also make sure to have feet on the bottom to allow for an air gap as well.
After mounting your transformer, and connecting the ground to the metal case, you will be ready to proceed. To make sure you have the hot side of the ac power going through the fuse is also something you will want to do.
That is something you will have to figure out, since I am not familiar with the standards for your location.
So for a hobby device, namely your new dac, I cannot recommend strongly enough that you not build this on a piece of wood or less even, inside your home.
What I would do to protect yourself is to find a suitable metal enclosure, steel if at all possible to use.
What I have done for similar projects is to go to a scrap source, and find a metal box that already has a fused power connection built in. I also make sure to have feet on the bottom to allow for an air gap as well.
After mounting your transformer, and connecting the ground to the metal case, you will be ready to proceed. To make sure you have the hot side of the ac power going through the fuse is also something you will want to do.
That is something you will have to figure out, since I am not familiar with the standards for your location.
Well, I have some SMPS for the LED lights lying around. Let me see if I can scavenge it.
BTW, Can I put the transformer and the DAC board in a single cabinet ?
It would be much simpler solution vs two individual boxes !
PS: I have contacted a Mouser distributor to see if I can score some components without the very shipping price Mouser demands. If it works out, getting components would be a cake walk.
BTW, Can I put the transformer and the DAC board in a single cabinet ?
It would be much simpler solution vs two individual boxes !
PS: I have contacted a Mouser distributor to see if I can score some components without the very shipping price Mouser demands. If it works out, getting components would be a cake walk.
Is Nippon Chemicon good ?
https://in.rsdelivers.com/product/n...-con-aluminium-electrolytic-capacitor/8118635
OK, I found an article that may help in selecting the right cap for the job regarding ESR.
Avnet: Quality Electronic Components & Services
https://in.rsdelivers.com/product/n...-con-aluminium-electrolytic-capacitor/8118635
OK, I found an article that may help in selecting the right cap for the job regarding ESR.
Avnet: Quality Electronic Components & Services
I got a reply from an official distributor of Mouser and they are asking for the BOM.
So, I need help regarding what kind of items should I order coz I'm not sure what are the general values of capacitors and other components generally used for DAC modding.
I'll order 4700uF 16V cap, 10uF 16v, 0.1uF ceramic and the choke.
What else I should buy ?
So, I need help regarding what kind of items should I order coz I'm not sure what are the general values of capacitors and other components generally used for DAC modding.
I'll order 4700uF 16V cap, 10uF 16v, 0.1uF ceramic and the choke.
What else I should buy ?
High ESR at high frequencies is the exact reason tantalum is used for bypassing. The ceramic cap in parallel does the bypass at those frequencies.
I would order some 10uf, and 47uf Nichicon KZ to replace those values.
Some Wima FKP2 4700pf 63v(analog filter), .01uf 63v(replace the .1uf power bypasses for op amp, and wm8740 analog supply).
Some of these for the analog filter;
KS 680pF 0.68nF 63V SIEMENS B31531-B5681-J000 Precision Precise Capacitors 10pcs | eBay
Leave the yellow ceramic caps over with the receiver chip.
A couple ceramic .1uf for the wm8740 digital bypass.
Some 100uf 25v Elna Silmic for the op amp supply, and some 10uf 16v also to play around with, swap out the KZ if needed.
Order extra of the smaller low cost parts too.
Don’t know where a 4,700uf cap would make much of a difference on this one.
Some Wima FKP2 4700pf 63v(analog filter), .01uf 63v(replace the .1uf power bypasses for op amp, and wm8740 analog supply).
Some of these for the analog filter;
KS 680pF 0.68nF 63V SIEMENS B31531-B5681-J000 Precision Precise Capacitors 10pcs | eBay
Leave the yellow ceramic caps over with the receiver chip.
A couple ceramic .1uf for the wm8740 digital bypass.
Some 100uf 25v Elna Silmic for the op amp supply, and some 10uf 16v also to play around with, swap out the KZ if needed.
Order extra of the smaller low cost parts too.
Don’t know where a 4,700uf cap would make much of a difference on this one.
Ok, interesting.
So, I'll buy some tantalums too.
Ceramic: Should I buy C0G caps or the regular x7 ones are enough ?
Thank you very much by the way for the detailed list
For decoupling duty you don't need to care about ripple current, though its a useful marker for ESR. The higher the ripple current rating, the lower the ESR - though this only applies when comparing caps in the same can size. Lower ESR is better but its also more demanding of good layout. Nichicon HZ has the lowest ESR of normal 'lytics, only slightly poorer than polymers.
Btw - don't use C0G for decoupling, X7R or X5R are the ceramics to use.
Btw - don't use C0G for decoupling, X7R or X5R are the ceramics to use.
The elecrolytics I suggested are made with an emphasis on low noise, work good for what you are doing, are pretty reasonable. What abroxolito said is very true, and resonance is all too easy to provoke.
I wouldn’t bother with tantalum caps, they do have a flat impedance curve, but are nothing special for audio, sound awful imo. They can last longer than an electrolytic in some industrial applications but are not what you are looking for I don’t think.
For the digital bulk capacitor I might grab some small Panasonic FM to use, maintaining the sizes from the data sheet, and low voltage rating will help to keep from going too low with the esr again there.
When you go to replace some of the caps near the wm8740, I would probably just bend the leads back and forth until they break, then carefully tack on the replacements. The risk of damage from too much heat while soldering is too high unless you do a lot of this type of work. Your soldering time on the joint should be about a second, have the leads tinned before, clean tip, small solder ball.
I trashed a dac from heat a while back, was a hassle to fix.
I wouldn’t bother with tantalum caps, they do have a flat impedance curve, but are nothing special for audio, sound awful imo. They can last longer than an electrolytic in some industrial applications but are not what you are looking for I don’t think.
For the digital bulk capacitor I might grab some small Panasonic FM to use, maintaining the sizes from the data sheet, and low voltage rating will help to keep from going too low with the esr again there.
When you go to replace some of the caps near the wm8740, I would probably just bend the leads back and forth until they break, then carefully tack on the replacements. The risk of damage from too much heat while soldering is too high unless you do a lot of this type of work. Your soldering time on the joint should be about a second, have the leads tinned before, clean tip, small solder ball.
I trashed a dac from heat a while back, was a hassle to fix.