Hello James,
Maybe you should do some test to find out the proper orientation of the chokes and transformers related to each other. You can measure it with a volt meter see the post a few days back. Could use the scope for that too i guess. Also take a look at this. It is from French article from 20 watt Hiraga power amp.
They did hear some kind of buzz. The caps used are much bigger but the current is about the same as the dac if you use 4 boards with shunts.
You can see the '' mass terminal '' is right in the middle.
The + and - they also take in the centre between the 2 connections.
Because the currents in the dac are a bit bigger then lets say a pre amp you need to take good care of the wiring. Sometimes just turning one thing 90 degrees and the noiser will be gone. The solution could be real simple.
It seems Stefan did create a filter without the real advantages of the chokes.
I hope you can try it with a real choke input too.
What will happen if you connect the bleeder after the second choke? You never know. You will have less voltage for sure.
The common mode wiring could be nice too. The French did have a pre amp in the past with such a choke.
Sincere greetings, edward
Maybe you should do some test to find out the proper orientation of the chokes and transformers related to each other. You can measure it with a volt meter see the post a few days back. Could use the scope for that too i guess. Also take a look at this. It is from French article from 20 watt Hiraga power amp.
They did hear some kind of buzz. The caps used are much bigger but the current is about the same as the dac if you use 4 boards with shunts.
You can see the '' mass terminal '' is right in the middle.
The + and - they also take in the centre between the 2 connections.
Because the currents in the dac are a bit bigger then lets say a pre amp you need to take good care of the wiring. Sometimes just turning one thing 90 degrees and the noiser will be gone. The solution could be real simple.
It seems Stefan did create a filter without the real advantages of the chokes.
I hope you can try it with a real choke input too.
What will happen if you connect the bleeder after the second choke? You never know. You will have less voltage for sure.
The common mode wiring could be nice too. The French did have a pre amp in the past with such a choke.
Sincere greetings, edward
Attachments
I seem to always be tracking down a hum or a noise - you mentioned a wavering hum which makes me wonder if it could be the dreaded DC in your AC.
One of the drawbacks of toroids. One of those cases where an isolation transformer (EI, only) could be useful.
Another thing is getting your transformers in phase with each other.
Try reversing your primary leads one at a time and see if makes any difference. Are all transformers using the same power cord? Not that that is a problem, just curious.
I experience this problem with my multi amplifier setup. In fact, I am chasing down a similar noise. It is a slow process that requires methodical patience and a notebook so you do not repeat the same steps.
Wish I could say I have made as much progress as you have.
Another thought, you are using your chokes as inputs, I believe. This does make them much more vocal than using them later down the line. These might need to be shielded from the rest of your circuit. They are taking that pulse and the energy has to be released.
Gratifying to see your progress.
One of the drawbacks of toroids. One of those cases where an isolation transformer (EI, only) could be useful.
Another thing is getting your transformers in phase with each other.
Try reversing your primary leads one at a time and see if makes any difference. Are all transformers using the same power cord? Not that that is a problem, just curious.
I experience this problem with my multi amplifier setup. In fact, I am chasing down a similar noise. It is a slow process that requires methodical patience and a notebook so you do not repeat the same steps.
Wish I could say I have made as much progress as you have.
Another thought, you are using your chokes as inputs, I believe. This does make them much more vocal than using them later down the line. These might need to be shielded from the rest of your circuit. They are taking that pulse and the energy has to be released.
Gratifying to see your progress.
Great info again. Nice!🙂
In my case I know the NEG side is connected to ground at the amplifier end. As far as I can tell, it wouldn't make much sense connecting NEG to the DAC's PS star ground. In that case you might as well use POS/COMMON, and be connected to the star ground through the DAC's ground plain.
That's an annoying sounding buzz. If it was mains related I would expect a different buzz depending on the type of PS.. Try and isolate the problem as much as possible. Is it on both channels, with or without the Wave IO, with/without your Wifi etc..?
Thanks guys. Tried some basic troubleshooting just now, starting with unplugging everything else in the building (it's in an outbuilding) with no joy, but then the main annoying extra part of the noise stopped and hasn't come back yet. So I'm satisfied that it's external to my box of tricks. The only things I can think of that intermittently turn on and off are the freezer and the deep freeze. They're on different spurs, but I guess it's all fundamentally linked. More experimentation needed there.
It'd be nice to try one of the chokes in common-mode rejection mode and run the ground through it too. Is there any reason this couldn't be the second choke?
It'd be nice to try one of the chokes in common-mode rejection mode and run the ground through it too. Is there any reason this couldn't be the second choke?
If you are on single phase it is highly likely that it could be a cycle of something else running, and it may not be in your room, could be a house down the street. Being fed from the secondary you will get the crap from everyone else. Inverter air conditioning and solar inverters make an unholy noise and cause alot of hf hash that can be heard.
If you could get a good isolation trans and run your system off that, from the 5-6 kva up, as an ei, it may all well go away.
Chuz,
Drew.
If you could get a good isolation trans and run your system off that, from the 5-6 kva up, as an ei, it may all well go away.
Chuz,
Drew.
Hello james,
Always better to dtop the garbage from the net as soon as possible. I have a transformer that has the primary and secundary windings next to each other. I did have it made at least a decade ago. The man who did make it said doing like this would be nice for direct heated triodes. It has a 10 volt 4A and a 5 volt 4A winding. Putting them in series would be nice for use with a choke input. Primary is 210 220 230 and 240 volts. I have two so if you like i can send you one and you can tell the community how it does sound.
I have some projects running but i will start the dac after getting used to my new stuff.
If the 15 volts will give the perfect tension i will compare it to the r core that jean hiraga is using that one has a static screen as an extra benefit.
Sincere greetings, edward
Always better to dtop the garbage from the net as soon as possible. I have a transformer that has the primary and secundary windings next to each other. I did have it made at least a decade ago. The man who did make it said doing like this would be nice for direct heated triodes. It has a 10 volt 4A and a 5 volt 4A winding. Putting them in series would be nice for use with a choke input. Primary is 210 220 230 and 240 volts. I have two so if you like i can send you one and you can tell the community how it does sound.
I have some projects running but i will start the dac after getting used to my new stuff.
If the 15 volts will give the perfect tension i will compare it to the r core that jean hiraga is using that one has a static screen as an extra benefit.
Sincere greetings, edward
Hello,
Some more info. Would be nice to see if you can see the effects with your basic scope. Maybe the frequency range where the choke will work will be limited. Maybe use one with and the next one without the snubber.
One trick with a choke and 120Hz ripple is to mount a capacitor in parallel with the choke to resonate at 120Hz.divide the size of the choke,in Henries,into 1.7.Therefore with a choke of ten henries 1.7/10 =.17uf which would be a .1 and two .033 all in parallel with the choke.Now all I gotta do is find out what the equation is so I can work it out for 100Hz.
The equation you're looking for is
f = 1 / ( 2 x pi x sqr( L x C ) )
or (rearranged)
C = 1 / L x ( 2 x pi x f )^2
For 120 (2x60) hz
C = 1 / L x 568e+3 (result in F)
= 1 / L x .568 (result in uF)
e.g. 10H -> .17 uF
For 100 (2x50) hz
C = 1 / L x 395e+3 (F)
= 1 / L x .395 (uF)
e.g., 10H -> .25 uF
C = 1 / L x ( 2 x pi x f )^2
Does the ^2 mean squared
:
: For 120 (2x60) hz
: C = 1 / L x 568e+3 (result in F)
: = 1 / L x .568 (result in uF)
and does the e+3 mean divide by 1k
Why not put .../1000
:
: Yeah I found the one point seven today as the square root of pi.I'm quite good at math but I left school early and have a bit a chore just getting to know algebra and symbols.Just found out what the roundy w is today.Can't remember the actual descriptive term but I know its to do with the instantaneous point on a sine wave.40 years old and starting all over again.
It is a simple copy and paste but once the exact value for the cap is calculated and confirmed by scope then we can just copy. Egland and the rest of Europe all have 50 hertz if i am right.
Sincere greetings, Edward
Some more info. Would be nice to see if you can see the effects with your basic scope. Maybe the frequency range where the choke will work will be limited. Maybe use one with and the next one without the snubber.
One trick with a choke and 120Hz ripple is to mount a capacitor in parallel with the choke to resonate at 120Hz.divide the size of the choke,in Henries,into 1.7.Therefore with a choke of ten henries 1.7/10 =.17uf which would be a .1 and two .033 all in parallel with the choke.Now all I gotta do is find out what the equation is so I can work it out for 100Hz.
The equation you're looking for is
f = 1 / ( 2 x pi x sqr( L x C ) )
or (rearranged)
C = 1 / L x ( 2 x pi x f )^2
For 120 (2x60) hz
C = 1 / L x 568e+3 (result in F)
= 1 / L x .568 (result in uF)
e.g. 10H -> .17 uF
For 100 (2x50) hz
C = 1 / L x 395e+3 (F)
= 1 / L x .395 (uF)
e.g., 10H -> .25 uF
C = 1 / L x ( 2 x pi x f )^2
Does the ^2 mean squared
:
: For 120 (2x60) hz
: C = 1 / L x 568e+3 (result in F)
: = 1 / L x .568 (result in uF)
and does the e+3 mean divide by 1k
Why not put .../1000
:
: Yeah I found the one point seven today as the square root of pi.I'm quite good at math but I left school early and have a bit a chore just getting to know algebra and symbols.Just found out what the roundy w is today.Can't remember the actual descriptive term but I know its to do with the instantaneous point on a sine wave.40 years old and starting all over again.
It is a simple copy and paste but once the exact value for the cap is calculated and confirmed by scope then we can just copy. Egland and the rest of Europe all have 50 hertz if i am right.
Sincere greetings, Edward
http://www.dhtrob.com/impressies/afbeeldingen/common_mode_choke_ae_psu.gif
Hello take a look. Could be helpfull
Sincere greetings edward
Hello take a look. Could be helpfull
Sincere greetings edward
Last edited:
Thanks guys, very helpful. I'm off for a few days, but when I'm back, I'll see if I can work out how to quantify the noise using my scope. Then I can measure any improvement from using mains conditioners and running one of the chokes in common mode rejection mode.
Hi James,
Listening to your video it seems to me that this is noise being picked up by wiring and as such a common noise type. I do not think it is generated in the power supply.
You might have created a loop in the power supply wiring.
I have had a similar problem in my amps; the cause was a ground loop with an interstage wiring, I put the +\- wires together and it was gone.
You can start with tidying up the wiring by making straight routes of closely twisted +/-wires.
Is it possible that the noise is generated in your tube amps?
Don't ground your rca as it is now floating in balanced mode.
Your measurments with the different supply setups look nice. You should try to measure the currents. The current flow is greatly influenced by using choke input.
Btw. I made a mistake in wiring the lundahl chokes, I wired them like I do my tamura chokes (I did not check the datasheet) I wired the two coils in opposite direction and that is not recommended. I changed that a while ago.
Sorry if I have confused anybody 🙁
Regards,
Listening to your video it seems to me that this is noise being picked up by wiring and as such a common noise type. I do not think it is generated in the power supply.
You might have created a loop in the power supply wiring.
I have had a similar problem in my amps; the cause was a ground loop with an interstage wiring, I put the +\- wires together and it was gone.
You can start with tidying up the wiring by making straight routes of closely twisted +/-wires.
Is it possible that the noise is generated in your tube amps?
Don't ground your rca as it is now floating in balanced mode.
Your measurments with the different supply setups look nice. You should try to measure the currents. The current flow is greatly influenced by using choke input.
Btw. I made a mistake in wiring the lundahl chokes, I wired them like I do my tamura chokes (I did not check the datasheet) I wired the two coils in opposite direction and that is not recommended. I changed that a while ago.
Sorry if I have confused anybody 🙁
Regards,
Last edited:
For the choke users 😉
Thought of a possible easy tweak for existing users with the dddac power supplies...
Did any one of you try the following with the 12 Volt PSU?
At the position of the fuse link the choke in series (with or without fuse)
This would give the choke not too much work (load and noise) and will filter strongly before any rectifying kicks in..
I am slowly picking up my Hobby again, after a few crazy months at work/private life, so I am really Close to start doing some stuff myself again.... (This is more a Promise to myself 🙄 )
Thought of a possible easy tweak for existing users with the dddac power supplies...
Did any one of you try the following with the 12 Volt PSU?
At the position of the fuse link the choke in series (with or without fuse)
This would give the choke not too much work (load and noise) and will filter strongly before any rectifying kicks in..
I am slowly picking up my Hobby again, after a few crazy months at work/private life, so I am really Close to start doing some stuff myself again.... (This is more a Promise to myself 🙄 )
Hello,
I have question regarding DDDAC motherboard without spdif. There are two sets of i2s inputs and disclaimer "use only one".
I was planning to use it with rpi, but after installing it and playing with volumio I see that it horribly skips on high definition files. Therfore I changed my plans - use rpi through lan to my file server for standard definition files and waveio usb/i2s converter through usb to my htpc for high definition files, using dpdt switch on 5v psu to select which device to start before switching dddac power on.
Are there potentially any adverse effects if both devices will be connected to dddac motherboard simultaneously, but powered only one, depending on what I plan to listen to? Anyone tried that already?
I have question regarding DDDAC motherboard without spdif. There are two sets of i2s inputs and disclaimer "use only one".
I was planning to use it with rpi, but after installing it and playing with volumio I see that it horribly skips on high definition files. Therfore I changed my plans - use rpi through lan to my file server for standard definition files and waveio usb/i2s converter through usb to my htpc for high definition files, using dpdt switch on 5v psu to select which device to start before switching dddac power on.
Are there potentially any adverse effects if both devices will be connected to dddac motherboard simultaneously, but powered only one, depending on what I plan to listen to? Anyone tried that already?
Hello Doede,
This reminds of using my first choke input long time ago. At the time i did have a tube pre amplifier with a tube rectifier and after the rectifier there was a small resistor to limit the current and protect the rectifier. I did read that the resisator i did use was a bit to low in value but i didnt have the right value in my boxes. It was was weekend so i said i will just put a surplus choke that had the right serie resistance. Didnt check dc tension just connect it to my system again.
Triple wow, why the big change in sound. At that time no internet for me so i did do some reading after seeing that there was a big voltage drop.
It seems some people are getting into chokes with the your Dac. I will do too after the new dac boards come available. Maybe you could do a poll to see how many people are interested once there is a board that can accept the shunts in a more elegant way.
Sincere greetings, Edward.
P.s we will wait for James to do some more test. Chokes arent that common any more. Maybe we need some input from retired electronic engineers to direct us in the right direction.
This reminds of using my first choke input long time ago. At the time i did have a tube pre amplifier with a tube rectifier and after the rectifier there was a small resistor to limit the current and protect the rectifier. I did read that the resisator i did use was a bit to low in value but i didnt have the right value in my boxes. It was was weekend so i said i will just put a surplus choke that had the right serie resistance. Didnt check dc tension just connect it to my system again.
Triple wow, why the big change in sound. At that time no internet for me so i did do some reading after seeing that there was a big voltage drop.
It seems some people are getting into chokes with the your Dac. I will do too after the new dac boards come available. Maybe you could do a poll to see how many people are interested once there is a board that can accept the shunts in a more elegant way.
Sincere greetings, Edward.
P.s we will wait for James to do some more test. Chokes arent that common any more. Maybe we need some input from retired electronic engineers to direct us in the right direction.
as they are hard wired together, it is only a choice which connector you use. a convenience thing so to speak. now if you connect them together, even if they are powered down, the output stage of the non powered board, may influence the signals coming from the other. Better to use a switch or relais to switch between the two.....
I tried with my tube amplifiers also regulated power supplies and passive CLCLC versions. the latter always gives the most analogue natural sound.
now making chokes for high voltage low mA tube environments is easier then low voltage applications. the Lundahl I see here is "only" 160mH in series use, where tube amplifiers take easily 10 or 20 Henry..... points is they cannot handle that easy up to 1 ampere of current.
so what we may need is some big chap choke? like as much Henry as we can get, but with maximum 1 Ohm DC resistance....
Hello,
Yes, it would be nice if there was a higher inductance high current model available. The lundahl can be used at a current that can provide the energy for four dac boards with shunts. With low tension it is much easier to have high value caps. You can put the 2 windings in parallel to reduce the serie resistance but you will end up with reduced inductance too. Dont know which one will filter the most.
In the past the French did use chokes in solid state designs too. One in a pre amp with a double winding technique and big caps. Before the choke 4700mf and after 2*33000mf for each rail. The power amps one 100000before the choke and 2* 100000mf after. My power amp 100000 and 2*330000mf for each rail. The chokes were all 200mH 2A 0.8 ohm.
With tubes it is easy getting high inductance because the current rating of the wire and core can be much lower.
I think because of the shunts mounted '' on top '' of the location where they need to be the impedance of the power supply will be close to perfect so i am not sure if adding more cap value would be the way to go. Dc voltage being low and using choke input and the right bleeder the voltage will not rise way up above the value during '' service ''during switch on. So the last cap could be 16 volts i guess. Can get some more capacity compared to a 25 volts type of equal seize.
Sincere greetings, edward
Yes, it would be nice if there was a higher inductance high current model available. The lundahl can be used at a current that can provide the energy for four dac boards with shunts. With low tension it is much easier to have high value caps. You can put the 2 windings in parallel to reduce the serie resistance but you will end up with reduced inductance too. Dont know which one will filter the most.
In the past the French did use chokes in solid state designs too. One in a pre amp with a double winding technique and big caps. Before the choke 4700mf and after 2*33000mf for each rail. The power amps one 100000before the choke and 2* 100000mf after. My power amp 100000 and 2*330000mf for each rail. The chokes were all 200mH 2A 0.8 ohm.
With tubes it is easy getting high inductance because the current rating of the wire and core can be much lower.
I think because of the shunts mounted '' on top '' of the location where they need to be the impedance of the power supply will be close to perfect so i am not sure if adding more cap value would be the way to go. Dc voltage being low and using choke input and the right bleeder the voltage will not rise way up above the value during '' service ''during switch on. So the last cap could be 16 volts i guess. Can get some more capacity compared to a 25 volts type of equal seize.
Sincere greetings, edward
The series configuration (as higher inductance) will filter most ....
More CAP is always good, but my experience is that the effect does not improve audibly the same rate as theory would predict (it stays Audio 😀 )
More CAP is always good, but my experience is that the effect does not improve audibly the same rate as theory would predict (it stays Audio 😀 )
Hi Doede,
Nice to hear that you are gaining some time for your beloved hobby again 😉
Regarding the choke discussion, I am not a choke expert but these are my thoughts:
In power supplies we are dealing with energy/power. The power is current x voltage.
With a tube amp there is low current but high voltage, in the dac there is low voltage and high current.
A capacitor in a tube amp is normally a value of 100uf/500v or so, the capacitance is not so big compaired to a low voltage 2200uf/25v but still the energy reserve is not that different.
If you just multiply:
100x500=50000
2200x25=55000
So it looks like the energy amount is fairly the same!
I suppose the same will yield for the choke. The core is the energy reserve. You can wind thick wire for high current and that will give you low inductance, or thin wire with lots of turns for high inductance. If the core size is the same would the energy reserve not also be the same?
The above is not scientifically checked by me but it makes sense.
I just changed my setup into choke input. Needed to wire both chokes in parallel and remove the bleeder to keep enough voltage for the dac; around 10v now.
First listening tests are nice, very nice! It seems there is some more compactness in voices and better separation.
But that is just my first 10minutes of listening........
I do not notice any negative effects due to the lower inductance, on the other hand the series resistance is also lower and that will also have a positive effect.
Regards,
Nice to hear that you are gaining some time for your beloved hobby again 😉
Regarding the choke discussion, I am not a choke expert but these are my thoughts:
In power supplies we are dealing with energy/power. The power is current x voltage.
With a tube amp there is low current but high voltage, in the dac there is low voltage and high current.
A capacitor in a tube amp is normally a value of 100uf/500v or so, the capacitance is not so big compaired to a low voltage 2200uf/25v but still the energy reserve is not that different.
If you just multiply:
100x500=50000
2200x25=55000
So it looks like the energy amount is fairly the same!
I suppose the same will yield for the choke. The core is the energy reserve. You can wind thick wire for high current and that will give you low inductance, or thin wire with lots of turns for high inductance. If the core size is the same would the energy reserve not also be the same?
The above is not scientifically checked by me but it makes sense.
I just changed my setup into choke input. Needed to wire both chokes in parallel and remove the bleeder to keep enough voltage for the dac; around 10v now.
First listening tests are nice, very nice! It seems there is some more compactness in voices and better separation.
But that is just my first 10minutes of listening........
I do not notice any negative effects due to the lower inductance, on the other hand the series resistance is also lower and that will also have a positive effect.
Regards,
Hello,
The late Allen Wright did describe the choke as an electronic or electric? flywheel. Like a kind of energy storage devive.
If i am right when you double the voltage with the same capacity you will end up with four times the energy.
Tube circuits are high impedance circuits so usually the power supply will have a lower impedance even when using chokes.
The currents with solid state are bigger and solid state have lower impedance so there the tube circuit has some advantages.
Usually my experience with choke inputs is like very easy, powerfull, melodic.
I remember reading that the same transformer can supply about 30% more current with a choke input compared to cap input.
Supersurfer, If you wanna try a 10+5 v 4A with primary and secundary coils next to each other you can lend one of mine. You might be able to use the raise induction
Sincere greetings, Edward
The late Allen Wright did describe the choke as an electronic or electric? flywheel. Like a kind of energy storage devive.
If i am right when you double the voltage with the same capacity you will end up with four times the energy.
Tube circuits are high impedance circuits so usually the power supply will have a lower impedance even when using chokes.
The currents with solid state are bigger and solid state have lower impedance so there the tube circuit has some advantages.
Usually my experience with choke inputs is like very easy, powerfull, melodic.
I remember reading that the same transformer can supply about 30% more current with a choke input compared to cap input.
Supersurfer, If you wanna try a 10+5 v 4A with primary and secundary coils next to each other you can lend one of mine. You might be able to use the raise induction
Sincere greetings, Edward
brok3n 12v ddac power supply 4 free
Hello all,
My first welding projecy unfortunately ended up with broken pcdlb traces after I changed out the heatsinks. The power supply is no longer working and I don't have any experience, so if anyone is interested, he or she can have it for free.
Let ke know (@ dcd_gaston@hotmail.com).
Hello all,
My first welding projecy unfortunately ended up with broken pcdlb traces after I changed out the heatsinks. The power supply is no longer working and I don't have any experience, so if anyone is interested, he or she can have it for free.
Let ke know (@ dcd_gaston@hotmail.com).