Hello,
Most things about choke input have been discussed here. Listen to Pieter.
Maybe use these caps
Elco low voltage 47000uF-63V - Elektrodump
Kemet peh200 and peh169 ( harder to get) work very well.
If you go for 40 volts you will get more µF for the same seize.
The Lundahl will heat up a bit. They can handle it for sure but the caps dont like the heat that will be generated by them and the power transistors. Peh 169 can be used at higher temperature.
Personaly i think that the advantage of choke input will be bigger than doubling the seize of the caps.
Greetings, eduard
Most things about choke input have been discussed here. Listen to Pieter.
Maybe use these caps
Elco low voltage 47000uF-63V - Elektrodump
Kemet peh200 and peh169 ( harder to get) work very well.
If you go for 40 volts you will get more µF for the same seize.
The Lundahl will heat up a bit. They can handle it for sure but the caps dont like the heat that will be generated by them and the power transistors. Peh 169 can be used at higher temperature.
Personaly i think that the advantage of choke input will be bigger than doubling the seize of the caps.
Greetings, eduard
Thanks Eduard
I actually ordered 12 of these:
ALS70A114KF040 KEMET | Mouser United Kingdom
they are such great value! Means i get 0.66F (660000uf) on each channel
and the specs look adequate.
Now sourcing some good quality 2.2uf capacitors, thinking WIMA MKP.
Or some other brand, I just know WIMA or maybe VISHAY any suggestions welcome.
@sergiu2009 suggested this and also to try some variant of polarised 100~220uF.
Just ordering some good quality cables, i have reels of thick electrical cable which i used to renovate my home. It had all new electrics fitted, i have 2.5mm to 6mm. Couldn't i use this sort of cable? I mean this stuff is solid, i like the fact i can bend and shape it, means i can do nice runs of cables and make it neat.
For the capacitors i want to use a solid copper round bar:
99.9% Pure COPPER C101 ROUND BAR COPPER ROD OFFCUTS CHOOSE LENGTH | eBay
i know most people use flat bars and other shapes and form, but i want to build something different, think it would be nice if the copper bars are machined and polished (for me looking at good electronics, how they look etc is eye candy) Everything has to have it's place, its fitted well, tidy cables, nice layout etc.
i have a 3D printer which i plan to put to put to good use, i can make some nice covers, capacitor brackets and holders. Some cooling ducts with low noise fans, list is endless.
Soon as all the parts come i can start building, next is how to test the PSU and generally the whole amplifier when it's built!
Not worried as i have the dream team "diyaudio" as help!
I actually ordered 12 of these:
ALS70A114KF040 KEMET | Mouser United Kingdom
they are such great value! Means i get 0.66F (660000uf) on each channel
and the specs look adequate.Now sourcing some good quality 2.2uf capacitors, thinking WIMA MKP.
Or some other brand, I just know WIMA or maybe VISHAY any suggestions welcome.
@sergiu2009 suggested this and also to try some variant of polarised 100~220uF.
Just ordering some good quality cables, i have reels of thick electrical cable which i used to renovate my home. It had all new electrics fitted, i have 2.5mm to 6mm. Couldn't i use this sort of cable? I mean this stuff is solid, i like the fact i can bend and shape it, means i can do nice runs of cables and make it neat.
For the capacitors i want to use a solid copper round bar:
99.9% Pure COPPER C101 ROUND BAR COPPER ROD OFFCUTS CHOOSE LENGTH | eBay
i know most people use flat bars and other shapes and form, but i want to build something different, think it would be nice if the copper bars are machined and polished (for me looking at good electronics, how they look etc is eye candy) Everything has to have it's place, its fitted well, tidy cables, nice layout etc.
i have a 3D printer which i plan to put to put to good use, i can make some nice covers, capacitor brackets and holders. Some cooling ducts with low noise fans, list is endless.
Soon as all the parts come i can start building, next is how to test the PSU and generally the whole amplifier when it's built!
Not worried as i have the dream team "diyaudio" as help!
Hello,
hahaha how are you going to get a good connection to the terminals of the caps?
Better use a flat bar using the right hardware to get a firm grip.
How are you going to solder 2,5 mm copper. It will probably be to rigid . Once you move the circuit the tracks on the print will come loose.
I would use something like 1 or 1,5 mm like the wire that is used for the coils of the ll2733 chokes. Just use an old cross over coil with good quality wire otherwise you will end up with something looking like your diy Hiraga you posted one year ago.
greetings,Ed
hahaha how are you going to get a good connection to the terminals of the caps?
Better use a flat bar using the right hardware to get a firm grip.
How are you going to solder 2,5 mm copper. It will probably be to rigid . Once you move the circuit the tracks on the print will come loose.
I would use something like 1 or 1,5 mm like the wire that is used for the coils of the ll2733 chokes. Just use an old cross over coil with good quality wire otherwise you will end up with something looking like your diy Hiraga you posted one year ago.
greetings,Ed
Hello,
hahaha how are you going to get a good connection to the terminals of the caps?
Better use a flat bar using the right hardware to get a firm grip.
How are you going to solder 2,5 mm copper.
You make a fair point here, i have never tried to solder solid 2.5mm copper, ill do a test run see how it goes
It will probably be to rigid . Once you move the circuit the tracks on the print will come loose.
I would use something like 1 or 1,5 mm like the wire that is used for the coils of the ll2733 chokes. Just use an old cross over coil with good quality wire otherwise you will end up with something looking like your diy Hiraga you posted one year ago.
Good idea!
greetings,Ed
Hello,
The french wrote in the past about how to connect the caps to the bars. Cleaning the connection, using washers and some contact enhancer called electrolube.
Better use 1 mm with a good solder joint than 2,5 with a bad one.
A solid 1 mm can take a lot of current. If you use the wire from an old cross over coil it will be insulated or use magnetic wire the one used for transformers.
There have been discussions here about the right spot at a capacitor bank to connect the wire going into the circuit.Use search function here!
greetings,Eduard
The french wrote in the past about how to connect the caps to the bars. Cleaning the connection, using washers and some contact enhancer called electrolube.
Better use 1 mm with a good solder joint than 2,5 with a bad one.
A solid 1 mm can take a lot of current. If you use the wire from an old cross over coil it will be insulated or use magnetic wire the one used for transformers.
There have been discussions here about the right spot at a capacitor bank to connect the wire going into the circuit.Use search function here!
greetings,Eduard
It is important to make the rails equal and opposite. As for the dual mono bit - even though channel crosstalk is far less important, you can still have it. If it were me, I'd make one good dual rail supply, then split it (isolate the channels).
Ripple in a dual rail supply is differential mode. Connecting chokes in common mode will not work on the ripple. The current must flow in the same direction through the choke from rail to rail (ground doesn't receive this current).
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Hello,
Getting them connected in the way that Lundahl calls common mode would be nice. Dual mono will give the advantage of not having to much current going through the chokes. AND he already got two transformers.
BUT like Pieter and me said before using choke input would be the way to go. Pieter is famous for his transformers so we can be sure his advice is valid.
Greetings, Ed
Getting them connected in the way that Lundahl calls common mode would be nice. Dual mono will give the advantage of not having to much current going through the chokes. AND he already got two transformers.
BUT like Pieter and me said before using choke input would be the way to go. Pieter is famous for his transformers so we can be sure his advice is valid.
Greetings, Ed
Well Pieter it seems that your advice is highly regarded here, i'll be sticking with the dual mono route and Jazz's schematic.
I have ordered 12 KEMET ALS70A114KF040 capacitors, still wanting advice on the snubber capacitors (are they snubbers?) Do i need a pair of 2.2uf on the PSU?
Ill draw another final schematic of everything that has been proposed.
Thanks guys.
I have ordered 12 KEMET ALS70A114KF040 capacitors, still wanting advice on the snubber capacitors (are they snubbers?) Do i need a pair of 2.2uf on the PSU?
Ill draw another final schematic of everything that has been proposed.
Thanks guys.
Hello,
Because you are using double mono you can move the circuit closer to the power supply caps. The 2.2 µF are by pass caps. It could work and it could not work.
Maybe install them closer to the circuit.
I would install them in such a way that they can be easily removed. First start without them.
Greetings, Ed
Sure trust Pieter in this thread he is not promoting to buy his products. He never does.
Because you are using double mono you can move the circuit closer to the power supply caps. The 2.2 µF are by pass caps. It could work and it could not work.
Maybe install them closer to the circuit.
I would install them in such a way that they can be easily removed. First start without them.
Greetings, Ed
Sure trust Pieter in this thread he is not promoting to buy his products. He never does.
There should be no common mode ripple current. This kind of choke would need to be used the other way, in differential mode (in series between the rails), otherwise it will not be a choke input supply.
There may be common mode noise, for that I would consider this choke to have high interwinding capacitance and would prefer to use ferrite (either separates or common mode), with an early connection to ground.
Hi ...
If you do not have measurement equipment to precisely measure & calculate the snubber capacitor/resistor network an advice given in Linear Audio (linearaudio.net) was to use 1kohm in series with 1 nF capacitor placed across the transformer windings just before the rectifier diodes. This combination would work in most any case and not cause issues.
If you can measure the response of the transformer relative to the rest of the circuitry the article is in linear audio volume 5 (rectifier snubbing by Morgan Jones).
Good luck with your endeavors!
Jesper
If you do not have measurement equipment to precisely measure & calculate the snubber capacitor/resistor network an advice given in Linear Audio (linearaudio.net) was to use 1kohm in series with 1 nF capacitor placed across the transformer windings just before the rectifier diodes. This combination would work in most any case and not cause issues.
If you can measure the response of the transformer relative to the rest of the circuitry the article is in linear audio volume 5 (rectifier snubbing by Morgan Jones).
Good luck with your endeavors!
Jesper
Hi,
If I where you I would forget about snubbers, bypasses and such untill you've got everything working. You can experiment all you like after that.
please wait untill Pieter is back on line with info regarding connection of the choke/filter coils. AllenB clearly spoke out about connecting the coils as I showed in the schematic. Wait for Pieter to respond to this. remember I already stated my concerns about the function of the coils connected in this way
Here you showed some other coils. Don't mix different coils. get some extra lundahl coils or buy four new ones. Price would be about the same i'd guess.
However, again i would like to repeat my advice about getting another psu trannie and the psu board from diyaudio. connect the caps you have ordered with wire leads if need be (no, not nice). Learn some more here and then decide what you are going to do.
well, so many views and opinions. I do now however that Pieter is wel known and respected for his tube output transformers and such. I trust him.
Joris
If I where you I would forget about snubbers, bypasses and such untill you've got everything working. You can experiment all you like after that.
please wait untill Pieter is back on line with info regarding connection of the choke/filter coils. AllenB clearly spoke out about connecting the coils as I showed in the schematic. Wait for Pieter to respond to this. remember I already stated my concerns about the function of the coils connected in this way
Here you showed some other coils. Don't mix different coils. get some extra lundahl coils or buy four new ones. Price would be about the same i'd guess.
However, again i would like to repeat my advice about getting another psu trannie and the psu board from diyaudio. connect the caps you have ordered with wire leads if need be (no, not nice). Learn some more here and then decide what you are going to do.
well, so many views and opinions. I do now however that Pieter is wel known and respected for his tube output transformers and such. I trust him.
Joris
Hello,
He already has the power transformers. Yes wait for Pieter to tell us how to connect the choke because the Lundahl datasheet shows in a single rail power supply and here one coil will be in the + and one in the - lead.
Using the ll2733 for choke input you will get a considerable voltage drop. I know because i am using them.
Use one for each channel .
You could end up with 20 volts dc on the first cap after the choke. Yes 24 volts ac in and 20 volts dc out. So maybe you will have a 20 watt Hiraga instead of a 30 watt.
I am sure that a 20 watt with LCRC will outperform a 30 watt with CLC or CLCRC supply.
greetings, eduard
He already has the power transformers. Yes wait for Pieter to tell us how to connect the choke because the Lundahl datasheet shows in a single rail power supply and here one coil will be in the + and one in the - lead.
Using the ll2733 for choke input you will get a considerable voltage drop. I know because i am using them.
Use one for each channel .
You could end up with 20 volts dc on the first cap after the choke. Yes 24 volts ac in and 20 volts dc out. So maybe you will have a 20 watt Hiraga instead of a 30 watt.
I am sure that a 20 watt with LCRC will outperform a 30 watt with CLC or CLCRC supply.
greetings, eduard
I am sorry to hear that? You seem so highly regarded on this forum. Good luck to you.
that's one hell of a loss
Hi Pieter,
Sorry to see this. I consider this a big failure. thanks anyway, hope to meet you someday.
regards
Joris
Hi Pieter,
Sorry to see this. I consider this a big failure. thanks anyway, hope to meet you someday.
regards
Joris