hi guys is this ok?
An externally hosted image should be here but it was not working when we last tested it.
but if i clic on it it works
hi friends,
I have spend whole my last weak with this amp and winding inductors.. finally I could able to remove all switching noise.. sound is so perfect now..very low heat (only got the noise coming out from my PC
) and I learnt a lot of things about inductors. there are many things to concern when winding an inductor. not an easy task and to explain just by a post.. I ended up with winding my core on a ferrite stick taken by an E core.. (The 'I' part of an E-core) It was the best result .. may be I couldn't find a required toroid in my country sadly. I will send you more pictures later.. I should sleep a day now at least because I haven't sleep well for a week i guess 
regards,
Lycanlk
I have spend whole my last weak with this amp and winding inductors.. finally I could able to remove all switching noise.. sound is so perfect now..very low heat (only got the noise coming out from my PC
) and I learnt a lot of things about inductors. there are many things to concern when winding an inductor. not an easy task and to explain just by a post.. I ended up with winding my core on a ferrite stick taken by an E core.. (The 'I' part of an E-core) It was the best result .. may be I couldn't find a required toroid in my country sadly. I will send you more pictures later.. I should sleep a day now at least because I haven't sleep well for a week i guess regards,
Lycanlk
Speaker out and ground is swapped !
The right order is
+ve / GND / SPK-GND / SPK-OUT / -ve
Ended my amp with a good result..
I could reduce 100% noise, I guess because I cant hear any simply the amp wont generate noise.. It was my bad that I didn't measure the inductance.. (I didn't have a tool to measure) only followed theory.. but the real values are different. I did so many experiments with the amp. It doesn't even need a ground plane to work well !!! neither a dual layer PCB.. All you need to worry is to have a good inductor !
Still my inductor warms up due to low no of turns.. The coil heats up not the core! but its natural. i cant change no of turns caz it will affect to the inductance again. I can only try with a large core.
each and every ferrite has a working frequency.. if you go beyond that it will heat up! According to the author this amp works at 250Khz so if you select a toroid core at that frequencies, to achieve 30-40 uh you may only need 1 or 2 turns.. The amp will work well but the coil might burn in few seconds.. hahahaha.. so eventually you need to increase the no of turns.. but it will rise the inductance again.. Then the other option is select a toroid work on low frequencies.. then again the core will heat up ! This is so funny.. but its the nature where I could think out of the box !
I never give up on things easily.. So I do more and more experiments.. I found that I part of an E-Core gives a better result.. about 30 turns works well and less heat.. then I wound it on my broken toroid ..again 30 turns and 44uH.. amp works fine heating slightly.. I think about 70-80 Celsius..
I think ferrite sticks are the best solution!.. air coil is also good but it will be large and high resistance. Use common sense and do experiments and wind your own coil about 30-40uH. Amp will work well ! Its a nice design.. very simple and amazing sound.. many thanks to Ejtagle once again! and also Andrewlebon for starting this thread !
keep in mind more heat will change the inductance of the coil.. and it will start noising again due to change in uH value !
consider that low gage wire has skin effect on high frequency !
American Wire Gauge table and AWG Electrical Current Load Limits with skin depth frequencies
I should remind my friend Carlos.. Destroyer X was My first class AB Amp where I learnt a lot from his thread now I learnt a lot about UCD by experiments, not with designing UCDs but its behavior at least..
Enjoy the amp!
regards,
Lycanlk
I could reduce 100% noise, I guess because I cant hear any
simply the amp wont generate noise.. It was my bad that I didn't measure the inductance.. (I didn't have a tool to measure) only followed theory.. but the real values are different. I did so many experiments with the amp. It doesn't even need a ground plane to work well !!! neither a dual layer PCB.. All you need to worry is to have a good inductor !Still my inductor warms up due to low no of turns.. The coil heats up not the core! but its natural. i cant change no of turns caz it will affect to the inductance again. I can only try with a large core.
each and every ferrite has a working frequency.. if you go beyond that it will heat up! According to the author this amp works at 250Khz so if you select a toroid core at that frequencies, to achieve 30-40 uh you may only need 1 or 2 turns.. The amp will work well but the coil might burn in few seconds.. hahahaha.. so eventually you need to increase the no of turns.. but it will rise the inductance again.. Then the other option is select a toroid work on low frequencies.. then again the core will heat up ! This is so funny.. but its the nature where I could think out of the box !
I never give up on things easily.. So I do more and more experiments.. I found that I part of an E-Core gives a better result.. about 30 turns works well and less heat.. then I wound it on my broken toroid ..again 30 turns and 44uH.. amp works fine heating slightly.. I think about 70-80 Celsius..
I think ferrite sticks are the best solution!.. air coil is also good but it will be large and high resistance. Use common sense and do experiments and wind your own coil about 30-40uH. Amp will work well ! Its a nice design.. very simple and amazing sound.. many thanks to Ejtagle once again! and also Andrewlebon for starting this thread !
keep in mind more heat will change the inductance of the coil.. and it will start noising again due to change in uH value !
consider that low gage wire has skin effect on high frequency !
American Wire Gauge table and AWG Electrical Current Load Limits with skin depth frequencies
I should remind my friend Carlos.. Destroyer X was My first class AB Amp where I learnt a lot from his thread
now I learnt a lot about UCD by experiments, not with designing UCDs but its behavior at least..Enjoy the amp!
regards,
Lycanlk
Attachments
God to see so many actually building this amp ..... great to see something other than Tripath 20W amps
And I think the construction is not at all bad (thumps up to the creator of the amp) .... it will not be high end, but it can come to work quite well I think .... and can be made to produce a lot of power no doubth
Also I think UcD is just so easy to get to oscillate right, which makes it perfect for a first amp ... and maybe also the the "last"
About the noise problems. I totally agree with Pafi that these problems are probably related to paracitics and induced noise. Class d is so much about proper layout.
I think you will find it hard to get rid of using single sided PCBs, and smd components would also help.
If some of the problems comes from GND noise flowing into the input stage, a possible solution (or reducing/mending of the problem) could be to place a 10 ohm resistor between signal ground and GND (class-ab amp style) ..... haven't tried it in my own amps yet, but intend to ...
I for one have had a lot of trouble with noise (Pafi is much more skilled in this matter), and my experience is that the smaller the layout and the more care you take about component placement, the less noise.
I'm not sure why you keep using IRFP240 or IRFP250 ..... these are realy old and slow FETs ..... a much better choice would be something like IRFP5620 (which is easy to get hold on from Digikey or the like) or the oldie but goodie IRF640N ..... all these are faster and has lees inductance(TO-220 better for class-d) .... and all good up to something like 300 W in 8 ohm ... sort of the same as IRFP240
Using the LM311 in the input could also be improved by using LM319 ... also very easy the obtain, and using both channels would make it possible to create a balanced output, thereby getting rid of the little too slow LTP style level shift, and using two common base level shifters instead (would also reduce the setup by 2 transistors) ....
Doing the above would make it possible to raise the switching frequency to some 250 kHz (or more) and reduce the output filter coil to 20 uH / 1 uF
If I find the time in the next weekend I will try it out on a breadboard, if anyone is interested.
...
Has anyone tryed to connect a scope to one of the finished amps yet??? Would love to see some traces (output of comparator, input to IR2110 output from mosfets).
Keep it up guys
PS. And about coils ... use material 2 toroid (normally red) .... like the free samples Tekko is ordering ... dont use air core or rods ... they produce massive stray fields, which might make it all burn up at high levels caused by interferrence ..... .... and it's not the core that determines the frequency of the amp, but the filter together with the feedback network ... and the core material and the number of turns gives the inductance .....
And I think the construction is not at all bad (thumps up to the creator of the amp) .... it will not be high end, but it can come to work quite well I think
.... and can be made to produce a lot of power no doubth Also I think UcD is just so easy to get to oscillate right, which makes it perfect for a first amp ... and maybe also the the "last"
About the noise problems. I totally agree with Pafi that these problems are probably related to paracitics and induced noise. Class d is so much about proper layout.
I think you will find it hard to get rid of using single sided PCBs, and smd components would also help.
If some of the problems comes from GND noise flowing into the input stage, a possible solution (or reducing/mending of the problem) could be to place a 10 ohm resistor between signal ground and GND (class-ab amp style) ..... haven't tried it in my own amps yet, but intend to ...
I for one have had a lot of trouble with noise (Pafi is much more skilled in this matter
), and my experience is that the smaller the layout and the more care you take about component placement, the less noise.I'm not sure why you keep using IRFP240 or IRFP250 ..... these are realy old and slow FETs ..... a much better choice would be something like IRFP5620 (which is easy to get hold on from Digikey or the like) or the oldie but goodie IRF640N ..... all these are faster and has lees inductance(TO-220 better for class-d) .... and all good up to something like 300 W in 8 ohm ... sort of the same as IRFP240
Using the LM311 in the input could also be improved by using LM319 ... also very easy the obtain, and using both channels would make it possible to create a balanced output, thereby getting rid of the little too slow LTP style level shift, and using two common base level shifters instead (would also reduce the setup by 2 transistors) ....
Doing the above would make it possible to raise the switching frequency to some 250 kHz (or more) and reduce the output filter coil to 20 uH / 1 uF
If I find the time in the next weekend I will try it out on a breadboard, if anyone is interested.
...
Has anyone tryed to connect a scope to one of the finished amps yet??? Would love to see some traces (output of comparator, input to IR2110 output from mosfets).
Keep it up guys
PS. And about coils ... use material 2 toroid (normally red) .... like the free samples Tekko is ordering ... dont use air core or rods ... they produce massive stray fields, which might make it all burn up at high levels caused by interferrence ..... .... and it's not the core that determines the frequency of the amp, but the filter together with the feedback network ... and the core material and the number of turns gives the inductance .....
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Dear Baldin,
First of all I should thanks for the contribution. My design does not generate noise at all.. at least to a perfect ear.. hahahaha.. sadly I don't have a scope to show Components which I used are easy to find.. Tested up to 50V dual supply.. and single side boards are easy to find and build for DIYers and cheaper too.. still the amp works without any trouble!
I have tested with IRF540.. good result! and many like IRFz48n(but max 55V). All good !
The core displayed on picture will give 30uH for 2 turns.. Do you think it will work? core heats up like fire Even though the core determines the turn for inductance, selecting right core is a must! Amp (the design) determines its frequency as well as the core has its own working frequency without heating! because of cores are not designed only for class D amps.. your red core might fit to the design.. unfortunately I cant find them here. I will let you all to test with those and publish the results. For now, my broken core goes fine with 30 turns, 40uH with 1uF cap. and there are no any interferences.. may be I'm lucky .. hahahaha.. used 50v-50v SMPS (works at 60Khz) powered by a battery charger works at 50hz.. still no noise.. very smooth and super sound !
regards,
Lycanlk
First of all I should thanks for the contribution. My design does not generate noise at all.. at least to a perfect ear.. hahahaha.. sadly I don't have a scope to show
Components which I used are easy to find.. Tested up to 50V dual supply.. and single side boards are easy to find and build for DIYers and cheaper too.. still the amp works without any trouble!I have tested with IRF540.. good result! and many like IRFz48n(but max 55V). All good !
The core displayed on picture will give 30uH for 2 turns.. Do you think it will work? core heats up like fire
Even though the core determines the turn for inductance, selecting right core is a must! Amp (the design) determines its frequency as well as the core has its own working frequency without heating! because of cores are not designed only for class D amps.. your red core might fit to the design.. unfortunately I cant find them here. I will let you all to test with those and publish the results. For now, my broken core goes fine with 30 turns, 40uH with 1uF cap. and there are no any interferences.. may be I'm lucky .. hahahaha.. used 50v-50v SMPS (works at 60Khz) powered by a battery charger works at 50hz.. still no noise.. very smooth and super sound !regards,
Lycanlk
The core displayed on picture will give 30uH for 2 turns.. Do you think it will work? core heats up like fire
If it heats up in idle mode, then it is of course no good. Without any power being delivered to the load (no music) it should not get warm at all.
You cant just use a toroid from a SMPS, as these will notmally be running af much lower frequencies, which allows for use of cores with higher Al (different material) ... which means much more core loss at higher freq! .....
Again just order the ones that Tekko have ordered ... if they send them for free, there is nothing to think about!!!! I'm sure it's material 2, and you can easlily make it work with 20 uH .... guess it's these ones:
Coilcraft ED0006-AL Power Filter Inductor
Otherwise order cores here:
Toroids, Ferrites, Parts, Kits, Toroid King, QRP Erector Set
T106-2 with 40 turns gives 20uH
T130-2 with 52 turns gives 30uH
with 1mm magnet wire both will be ok up to at least 300W peak i think
hi lycanic
greetings on supplying 29 0 29 dc voltage to amplifier no sound from
amp but when i disconnect supply on touching input with finger amplifier comes
on only for 1 minute till supply is drained off dropping resitors used 1.5 k 2 watt
output transistors are irf 540.Can you tell voltage on ir2110 pins and emitter of
tip 31 i will use 50 0 50 dc voltage today all transistor pin connections are ok
can you please help me out
thanking you
andrew lebon
greetings on supplying 29 0 29 dc voltage to amplifier no sound from
amp but when i disconnect supply on touching input with finger amplifier comes
on only for 1 minute till supply is drained off dropping resitors used 1.5 k 2 watt
output transistors are irf 540.Can you tell voltage on ir2110 pins and emitter of
tip 31 i will use 50 0 50 dc voltage today all transistor pin connections are ok
can you please help me out
thanking you
andrew lebon
Sounds like it needs a little help in starting to oscillate ..
Does it start if you touch the input while connected to PSU?
I take it you get sound through (as you probably ane not using a scope) .... try to turn on the power again before it stops playing .....
Post a picture also of the coil ..... is it 30uH??
Print the diagram and write the voltages on that you measuer and then scan and post it here ..... otherwise it will be dificult to help I think .....
Does it start if you touch the input while connected to PSU?
I take it you get sound through (as you probably ane not using a scope) .... try to turn on the power again before it stops playing .....
Post a picture also of the coil ..... is it 30uH??
Print the diagram and write the voltages on that you measuer and then scan and post it here ..... otherwise it will be dificult to help I think .....
Agree with you ! we cant use toroid used for SMPS.. but its not because of low frequency.. but its because of the material they have made of. Because SMPS also works at high frequencies.. most of them are ferrite starting with FT numbers. They have high AL values.
Also Agree the material 2 (red) iron powder cores should work well ! but the best is material is 6 (yellow) anyway red cores are very much available on the web. follow the attached examples..
and thanks for the links! i'll try to get one.. at the moment their requesting server has got a problem. So I cant process my request !
regards,
Lycanlk
Attachments
Emitter of TIP31 should give you 12V with respect to minus rail.. It works as a 12v regulator. Do not worry about IFR540.. Do not increase the supply at once unless if you are sure there are no mistakes on your amp testing below 30v would be safe at the start
regards,
Lycanlk
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