Update
Hello,
Tomorrow I will arrive in the city in Vietnam that is famous for having the biggest most famous mental hospital.
My friend lives in this city and he has done some test with the ll2733 with some friends and they all live outside the fence. ( does anyone remember the song "" the lunatics have taken over the asylum "?)
We will see what they have to tell.
Greetings, Eduard
Hello,
Tomorrow I will arrive in the city in Vietnam that is famous for having the biggest most famous mental hospital.
My friend lives in this city and he has done some test with the ll2733 with some friends and they all live outside the fence. ( does anyone remember the song "" the lunatics have taken over the asylum "?)
We will see what they have to tell.
Greetings, Eduard
Hello Mr Tho & Eduard
Having had only one day in VN, not enough time to visit the outsiders of that famous hospital to admire Mr Tho chef d’œuvres class A amp, I was as pillion passenger for 2 hours on “ Uber Ride” to the Saigon “chợ điện tử” (electronics market), guided by the rider, for a roll of 1mm copper (so excited by the price that make me forgotten of how much I spent) and a Chinese made hand winder (16 Au$).
By the way, is there any simple procedure for a qualitatively recording the performance of PS filtering (LC, CLC, CRC...etc).
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Hello,
Tho and me visited his friend who is using Tho to build the electronics for him.
He changed from capacitor input into choke input for his phono stage, his line preamp and finally for the Nelson Pass power amp..
The improvements were BIG .as you can see in Tho 's photos the wiring of the power supply can be improved by moving things around. In my high current designs using ll2733 I mounted the diodes on the choke terminals. That is easy using diodes which do not require heathsink..But using 4 small individual heatsink I am sure you can reduce the wire length a lot. You can mount the diodes closer to the transformer but then will imply reducing the cables coming from the transformer. Lundahl chokes are not sensitive to magnetic/ electric fields so reducing cable length is an easy improvement.
People always tell that reducing cable length on the input side of the choke is the most
let us see who will switch to choke input....
Greetings, Eduard
Tho and me visited his friend who is using Tho to build the electronics for him.
He changed from capacitor input into choke input for his phono stage, his line preamp and finally for the Nelson Pass power amp..
The improvements were BIG .as you can see in Tho 's photos the wiring of the power supply can be improved by moving things around. In my high current designs using ll2733 I mounted the diodes on the choke terminals. That is easy using diodes which do not require heathsink..But using 4 small individual heatsink I am sure you can reduce the wire length a lot. You can mount the diodes closer to the transformer but then will imply reducing the cables coming from the transformer. Lundahl chokes are not sensitive to magnetic/ electric fields so reducing cable length is an easy improvement.
People always tell that reducing cable length on the input side of the choke is the most
let us see who will switch to choke input....
Greetings, Eduard
Hello,
The French people from la maison de l'audiophile in Paris have done the same using a choke with two coils to be used with one winding in the positive and the other one in the negative side of the power supply. But I have been told it is constructed in another way then the Lundahl.
Long time ago I did ask if the Lundahl chokes can be used in the same way. He said but the currents through the positive and the negative coil so to say have to be identical.
That French choke was used in a low voltage low current pre amp maybe there a problem would not easily occur. BUT maybe with a higher current transistor power amp things could be different. Someone should try. The amp posted by Tho has a single rail power supply and the choke is used in a way that Lundahl calls serial connection for improved common mode rejection. From the bridge there will go two wires to the first capacitor and every wire is "" interrupted "" by a coil with 1,7 ohm dcr. Current drawn by each channel( left and right have separate winding, rectifier, choke and cap) is above 1A . The amp heats up a lot.
So NOW everybody will tell the 1,7 ohm will make the amp run out of energy. Didn't notice that all.
Greetings, Eduard
Useful calculator for choke input on this page...
Hagerman Technology LLC: Design Theory
IMO LCLC is the way to go
316a
Hagerman Technology LLC: Design Theory
IMO LCLC is the way to go
316a
Pass DIY Addict
Joined 2000
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Useful - yes.
For high current draw, class A, solid state designs - not so much...
For comfort, safety, and piece of mind, such a choke needs to be able to handle a continuous 5A without saturation and overheating.
This thread went down a rabbit hole fast and doesn't show any signs of returning...
For high current draw, class A, solid state designs - not so much...
For comfort, safety, and piece of mind, such a choke needs to be able to handle a continuous 5A without saturation and overheating.
This thread went down a rabbit hole fast and doesn't show any signs of returning...
Hello,
Better ask Dave Slagle for advice.
I think using air coils with 2 mH will not give the best return on investment.
It will be like using Google translate for translation into English when your own language is likely to disappear within a few decades.
Greetings, Eduad
Hello,
Here is the
intact audio
As you can see and read this supply is rated at 3.5 A maximum and output voltage is to low but I think both can be tackled.
Can ask Dave to give the choke a bigger air gap and/or thicker wire.
Caps needs to be changed into those having higher working voltage.
Of course this choke is used in a choke input configuration. Ask Dave how to proceed to get the best results in your set up.
In general a properly set up choke input will outperform a CLC power supply
Sorry no L word in this text.
Ask you can read Dave Slagle blog there are already people asking for a higher current version.
This solution will not come at a cheap price I guess but you get exactly what you are looking for.
Greetings Eduard
Here is the
intact audio
As you can see and read this supply is rated at 3.5 A maximum and output voltage is to low but I think both can be tackled.
Can ask Dave to give the choke a bigger air gap and/or thicker wire.
Caps needs to be changed into those having higher working voltage.
Of course this choke is used in a choke input configuration. Ask Dave how to proceed to get the best results in your set up.
In general a properly set up choke input will outperform a CLC power supply
Sorry no L word in this text.
Ask you can read Dave Slagle blog there are already people asking for a higher current version.
This solution will not come at a cheap price I guess but you get exactly what you are looking for.
Greetings Eduard
you read it wrong
nobody here is belittling performance of proper choke input filter , or practically any type containing choke , in fact exactly contrary
what we are really doing here is sharing informations and insights in various topologies , contemplating about values and what is possible to achieve and make best compromise
usually only in later stages of discussion we are talking about exact products and brands,usually looking for alternatives
maybe that wasn't your intention , but (at least I had impression) you were more advocating a brand than proper approach , ignoring what others have to say about specific type of product you were mentioning
anyway , FYI , I had my share of working with Lundahl chokes ,have few of their xformers on the shelf , I'm right now listening the music through Intact Audio autoformers ;
term compromise is of most importance in (audio) electronics - one need to find proper value and then proper element of that value for some position ...... sometimes taking great and sometimes lesser amount of care for price of part
anyway , I'm sure Lundahl is more than capable to make appropriate choke for sand crowd (not just tube guys) , having two windings of ,say , 20mH each , current capability of 6A , which would be awesome solution for both LC and CLC , used in differential mode.......capable for common stereo PSU duty
nobody here is belittling performance of proper choke input filter , or practically any type containing choke , in fact exactly contrary
what we are really doing here is sharing informations and insights in various topologies , contemplating about values and what is possible to achieve and make best compromise
usually only in later stages of discussion we are talking about exact products and brands,usually looking for alternatives
maybe that wasn't your intention , but (at least I had impression) you were more advocating a brand than proper approach , ignoring what others have to say about specific type of product you were mentioning
anyway , FYI , I had my share of working with Lundahl chokes ,have few of their xformers on the shelf , I'm right now listening the music through Intact Audio autoformers ;
term compromise is of most importance in (audio) electronics - one need to find proper value and then proper element of that value for some position ...... sometimes taking great and sometimes lesser amount of care for price of part
anyway , I'm sure Lundahl is more than capable to make appropriate choke for sand crowd (not just tube guys) , having two windings of ,say , 20mH each , current capability of 6A , which would be awesome solution for both LC and CLC , used in differential mode.......capable for common stereo PSU duty
Hello again,
I believe that you evaluate PS by listening and bias by brand name/price tag factor.
Just look at Lundahl spec sheet for your famous dual coils C core choke, I realise your topo is a “serial connection for improved common mode rejection” based on Mr Tho photo
In fact to my knowledge, it is a differential mode (phase reversal of 2 coils) not a common mode at all.
Well, I have to show you how I evaluate my PS, otherwise this thread is going down to a rabbit hole as commented by one reader.
My setup for PS filter evaluation
Soundcard and SA software.
Dummy load, chosen as close as possible to R load.
Current, voltage and power monitoring
Voltage divider and Zener diodes for soundcard protection.
HF radio receiver for EMI detection (SMPS)
Cheers from Pascal
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Hello,
Yes there are more people who have told me that Lundahl uses the wrong name for their third option mentioned in their pdf files.
I am not more biased than the rest of the members here.
In Vietnam people are more biased towards Tango/Tamara than to Lundahl who only recently established a dealership in Hcmc. I have some Tango chokes in stock because they have been replaced by Lundahl. Why the Lundahl were better I don't know. They were connected in differential mode, they had higher number of Henries ( which all9ws a much lower blender current).. The tango chokes were the ones designed especially for choke input and all of then were used in choke input power supplies.
So maybe you could give the original posters some results you measured on high current chokes, with and without cores and 5A as a load. It might help us all!!!
Greetings, eduard
Yes there are more people who have told me that Lundahl uses the wrong name for their third option mentioned in their pdf files.
I am not more biased than the rest of the members here.
In Vietnam people are more biased towards Tango/Tamara than to Lundahl who only recently established a dealership in Hcmc. I have some Tango chokes in stock because they have been replaced by Lundahl. Why the Lundahl were better I don't know. They were connected in differential mode, they had higher number of Henries ( which all9ws a much lower blender current).. The tango chokes were the ones designed especially for choke input and all of then were used in choke input power supplies.
So maybe you could give the original posters some results you measured on high current chokes, with and without cores and 5A as a load. It might help us all!!!
Greetings, eduard
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