Keantoken's CFP cap multiplier

[TNT]

OK for me also. I 'm eager to build one but will probably not be able until beginning of next week.

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[alexkosha]

Thank you.

 

[TNT]

Built it: yes.
Start it: No.

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[TNT]

Start it: Yes - OK
Loaded it: Yes - NOK

Minus side blew up!? Plus seems OK. Have an unsymmetrical load (Sörens DAM DAC).

What size cap on the output is recommended?

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[sikahr]

Start it: Yes - OK
Loaded it: Yes - NOK

Minus side blew up!? Plus seems OK. Have an unsymmetrical load (Sörens DAM DAC).

What size cap on the output is recommended?

//

Did you try to load it with light resistor load just for testing?

 

[alexkosha]

Got my K-Multy PCBs last Saturday. All 12 pieces look very nice. Can find any issue, at least via visual inspection. Yesterday assembled one and it works like champ. Sikahr, very nice Gerber work and DertyPCB made dissent PCBs. Thank you.

 

[sikahr]

Alex, thanks for building board & confirming board working OK.
What's your plan to power with these boards?

 

[alexkosha]

Alex, thanks for building board & confirming board working OK.
What's your plan to power with these boards?

I'm using this first PCB to power-up my Linkwitz filter for subwoofer. I already used these devices in Salas Raw DC for his FSP with an excellent results.
It dropped my V ripple substantially and Salas Phono with about 72 dB is very quite. Also, I used it in my J-Mo Mk II Headphone amplifier. Also with perfect result. Now I have 11 boards left and I plan to use them widely in my projects, but definitely and only when its really needed. That you for these nice PCBs.

P.S. I can find you Raw DC with snubbers on DertyPCB. Is it ready?

 

[TNT]

Is there a difference if one hook up the load to an already started Kmult or if the load is first connected and then, Kmult is fed power. In terms of insecure current etc?

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[keantoken]

You should never connect a powered PSU to an unpowered circuit. Everything should be connected before you turn the PSU on. The PSU capacitors can discharge into the load and destroy things.

 

[Mooly]

New thread here,
http://www.diyaudio.com/forums/power-supplies/274109-10x8-raw-dc-board-cr-l-c-filter.html

 

[TNT]

Finally have 2 KCCMs working. One for the DAM R2R DAC and one for JG buffer stage. The DAM draws:

Positive Rail: .18A, 10V
Negative Rail: 0.06A, 10V
Total: 2.4W

so maybe one should bleed the minus side to get the output imp down?

Already they seem to have improved my sound and taken away a little harshness in the top and also made for a more solid foundation in general. Very nice!

Thanks you for your contributions.

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[alexkosha]

Sent from my iPhone using Tapatalk

 

[TNT]

I should say also that they filter these:

https://www.meanwell-web.com/en/pro...y/enclosed-type/0-40-w/rs-15/product/RS-15-24

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[keantoken]

After 100mA is diminishing returns if you are loading to reduce impedance. The KM webpage has a list of impedance at different loads.

 

[jameshillj]

A bit off the subject here but is a Cmultiplier (&/or gyrator) actually classed as a feedback device like a regulator?

 

[TNT]

I suppose it is rather a filter. In itself it makes use of feedback!?

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[keantoken]

The output circuit uses intentional feedback to reduce output impedance. The filter circuit has no intentional feedback. It doesn't have to have global feedback to be a filter, you can just use one transistor and that removes the feedback and the low output impedance (and gives you an ordinary C-multiplier).

 

[jameshillj]

Thanks for info - we are have a bit of a 'discussion' here about using a CMx or a KMx to the B+ rail of the valve amp input stage (an 845) - a resistance to anything more complicated than simple R, L, C filters is so ingrained, it seems, that not willing to try these out.

 

[rensli]

Max input ripple before saturation: 1.5V pk-pk (0.46Vrms on an AC multimeter)

It means k-multiplier filters cant be used if there is a 2V drop across the filter capacitors ?

Right now i am powering 8 opamps via 337/317 regulators. Transformer is 6VA, two windings.

WITH no LOAD: +/-31V DC before the regs.
WITH LOAD: 28.8V DC before the regs.
Note: Load is constant (34mA from the Regulators output to the opamps)

Is it good idea to try k-multiplier filter in that setup ?