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Hi Eric
...
Sleeplessness
6. Remove R and replace it with L.
Cheers
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Oops, my apology, omitted in above tests due to my old age sighting.
Here is the updated spread sheet with 300Hz spur included.
Thanks for your comment.
Cheers
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Hello,
The cores of their chokes are not big . I know there are some dealers who sell the same choke like ll2733 with different airgaps to get a different number of current and mH rating. That is nice if you know the current will always be below 1A you can change a 1,7A choke into a 1A choke with higher mH which will considerably reduce the bleeder current needed.
Asking them to make a choke using the bigger core of a power transformer never did work.
A technician in my country if you really like to do it perfect for a choke input you should ask them to make a swinging choke!
There just are not to many companies willing to make a pair of these chokes if you ask them. Even with all the software available they still might need to make a prototype to see if it really works.
I did do some test with choke input with the ll2733 with a small A.C. voltage across the coils ( because using just 21 volts transformer) but double the rated current and it would be the 400va rated transformer start making the noise! I think if the winding is done properly vacuum impregnation should not be necessary.
I will ask Dave Slagle from intactaudio if he can make a higher current rating choke.
Greetings, Eduard
Hi Andrew,
Perhaps I misunderstood or not thoroughly comprehended your question.
To reply to your WHY, I think the odds are:
1. Omitted due to my visual acuity.
2. Omitted due to my crappy 10yo+ PC, unable to keep up with decent sampling rate, anything below -100 dBv is irrelevant to me.
3. Omitted by the filter, low pass cut-off by design.
4. All test done in my chook shed is qualitative and comparative, I never bother nor able to measure of how much is -70dBv, for power supply evaluation, according to my condition, 100Hz spur below -70dB is acceptable.
That’s all I can think off, for more answers you should post it in the Power Supply section.
Here we are discussing about which L for CLC topo, all results that I posted had purposely to convince Eric to spend only 3 bucks for CRC, good enough to supply any FW amps, money saving is much better spent on Tokin SITs, for an absolute high fidelity which is stood out of the mosfet Lundahl’s crowd.
Cheers from down under
Pascal
Hello,
Dave Slagle can make 5A rated chokes with 2 coils so probably you can use one coil on pos. Side and the other in neg. Side.
He asked me about the number of mH, how much ac and the maximum dcr.
Would be nice to get one that could be used for choke input as well.
Give me some ideas.
Greetings, Eduard
Dave Slagle can make 5A rated chokes with 2 coils so probably you can use one coil on pos. Side and the other in neg. Side.
He asked me about the number of mH, how much ac and the maximum dcr.
Would be nice to get one that could be used for choke input as well.
Give me some ideas.
Greetings, Eduard
Since this thread is about choke for CLC, don't you think that it will attract more relevant interest if you start a new thread about chokes for choke input LC PSU? Different budget range and interested group.
You may also want to contact member Magura (Morten Beyer) of Class A Labs for unconventional Class A choke adverture with SS Amps.
Hello,
To make it function correctly in a choke input supply it will need a minimum number of mH which can be calculated.
It does not have to be conceived to be used as a choke input. I have used the L chokes for both CLC and LC power supplies. The Dave Slagle chokes for the Coleman supplies are used in a choke input set up..
In a CLC you could use one coil for each side of the power supply.
If you need more mH for choke input put the two coils in series..If you fear high dcr or core saturation put the coils in series.
YES YES it will take some investment but I seriously believe that using an iron core choke will improve your amp more than 2,2 mH air cores.
My friend in Vietnam tested different caps and told me with choke input the difference between brands was smaller. He said probably because the caps have an easier life because it will be the choke that is doing the filtering.
Greetings, Eduard
To make it function correctly in a choke input supply it will need a minimum number of mH which can be calculated.
It does not have to be conceived to be used as a choke input. I have used the L chokes for both CLC and LC power supplies. The Dave Slagle chokes for the Coleman supplies are used in a choke input set up..
In a CLC you could use one coil for each side of the power supply.
If you need more mH for choke input put the two coils in series..If you fear high dcr or core saturation put the coils in series.
YES YES it will take some investment but I seriously believe that using an iron core choke will improve your amp more than 2,2 mH air cores.
My friend in Vietnam tested different caps and told me with choke input the difference between brands was smaller. He said probably because the caps have an easier life because it will be the choke that is doing the filtering.
Greetings, Eduard
I am going to build a FW F6 clone and have ordered allready most of the parts
Instead of CRC power supply I would like to use CLC power supply.
Transformer is a 400VA 2x18 + dual mono power supply board board like this:
Super heavy duty powr supply board CRC for Pass or class A dual mono PCB ! | eBay
So current over filter choke wil be less than in a power supply board used for both channels.
Which one of the chokes you would use?
Hammond 159ZG 15mH, 4A, 0.25 Ohms
Hammond 159ZJ 10mH, 5A, 0.16 Ohms
BR,
Arne
Instead of CRC power supply I would like to use CLC power supply.
Transformer is a 400VA 2x18 + dual mono power supply board board like this:
Super heavy duty powr supply board CRC for Pass or class A dual mono PCB ! | eBay
So current over filter choke wil be less than in a power supply board used for both channels.
Which one of the chokes you would use?
Hammond 159ZG 15mH, 4A, 0.25 Ohms
Hammond 159ZJ 10mH, 5A, 0.16 Ohms
BR,
Arne
He he he ..., you miss Magura's flagship air core chokes.
He made 160mH 1.4 ohm DCR 25 kg air core chokes. No point in mentioning him for sissy 2mH off the shelf crossover chokes. 4 units being used for LCLC PSU will be over 120kg including casing, caps and transformer. No nonsense performance, no hysteresis in air core.
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LRC is much more better than LCL, L= 10-15mh is nearly nothing.
If L= 10-15mh, Use diyaudio PSU and add 1or2 LC will help Pass amp sound more tubelike.
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Any schematics or calculator for LRC supply filtering? Could not find any, looks not like common technique.
Meanwhile for LC filtering I found a usefull calculator, but not sure if calculations are correct.
LC Ripple Filter Calculator
I suppose "DC resistance (ohms per henry)" should be just the resistance of the choke (not per Henry). Otherwise you get strange results calculated for DC drop.
Given the Hammond choke values the LC filtering results in notable ripple attenuation:
- LC filter with Hammond choke 159ZG 15mH, 4A, 0.25 Ohms --> -51.0 dB ripple attenuation (C=60.000 µF), 0.450 DC voltage drop
- LC filter with Hammond choke 159ZJ 10mH, 5A, 0.16 Ohms --> -47.5 dB ripple attenuation (C=60.000 µF), 0.288 DC voltage drop
- RC filter for comparision R=0.10 Ohm, C=60.000 µF --> -11.8 dB ripple attenuation, 0.2 V drop
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