MKP VS Electrolyte

[TunaFish]

Q1. Compare with Electrolyte Cap, MKP Cap and MKP Cap in Oil, for power supply filtering, which one is better in performance?

Q2. Since some of the high-end electrolyte cap (e.g. Black Gate, Jensen etc) is very $$$. When it compare with low/mid end MKP Cap (e.g. Solen) used in power supply filtering, which one is better?

Q3. Theoretical speaking, compare between electrolyte cap and MKP cap, which one is closer to the perfect cap characteristic?

Q4. Some of the MKP cap is kept inside a metal can in oil, what is the function of the oil? Compare with the non-oiled MKP, any different?


Thank you for your help.

Tuna Fish

[ThorstenL]

Konnichiwa,

Originally posted by TunaFish
Q1. Compare with Electrolyte Cap, MKP Cap and MKP Cap in Oil, for power supply filtering, which one is better in performance?

Depends who you ask. having compared most I'd say MKP suitably encased (plastic casing often preferable to metal casing).

Originally posted by TunaFish
Q2. Since some of the high-end electrolyte cap (e.g. Black Gate, Jensen etc) is very $$$. When it compare with low/mid end MKP Cap (e.g. Solen) used in power supply filtering, which one is better?

Usually MKP. What needs to be understood is that the metal can encasing of 'lytics and the "soft" layers between the foil plus the presence of a real metal foil can reduce microphonic and electrostatic effects compared to especially unencased MKP types. Encased MKP capacitors wound with sufficient tension are as good and better with respect to these effects.

The cheap unencased Solen/SRC capacitors are quite terrible WRT microphonics and can sound very bad.

Originally posted by TunaFish
Q3. Theoretical speaking, compare between electrolyte cap and MKP cap, which one is closer to the perfect cap characteristic?

MKP.

Originally posted by TunaFish
Q4. Some of the MKP cap is kept inside a metal can in oil, what is the function of the oil?

These capacitors are made for Motor Run/Start application and I believe the main function of the oil is to allow efficient heat exchange between the capacitor "core" and the (metal) casing to allow higher continous current level than in non filled capacitors.

Originally posted by TunaFish
Compare with the non-oiled MKP, any different?

Sometimes. The Oil can help damp resonances in the capacitor foil, but tehn if the capacitor solidly tension would and solidly encased the resonances are eliminated at the source.

Originally posted by TunaFish
Tuna Fish

For Tuna Fish encased in metal casings oil filling is definitly recommended....

Sayonara

[TunaFish]

Originally posted by Kuei Yang Wang
Konnichiwa,

The cheap unencased Solen/SRC capacitors are quite terrible WRT microphonics and can sound very bad.


For Tuna Fish encased in metal casings oil filling is definitly recommended....

Sayonara

Thank you for your help!

What is WRT?

I love you recommendation very much!!!

Tuna Fish

[Magura]

Look for motor run caps, they are cheap, of uniform good quality and very reliable.

You can get up to 100uF motor run caps for less than 100USD.

Most motor run caps are better quality than the "audio" MKP caps...unfortunately you will have to write "audio cap" on them yourself ;-)

I have recently sourced 50uF motor run caps for myself and a friend of mine, of great quality, for something like 35USD a piece.


Magura

[ThorstenL]

Konnichiwa,

Originally posted by TunaFish
What is WRT?

WRT = With Regards To

Originally posted by Magura
Look for motor run caps, they are cheap, of uniform good quality and very reliable.

Absolutely.

Originally posted by Magura
Most motor run caps are better quality than the "audio" MKP caps...unfortunately you will have to write "audio cap" on them yourself ;-)

Yup. One trick, cut away (or remove) the threaded stud often found, fill in and sand over smoothly any holes and then have them spraypaineted by a car painting place in metallic silver or whatever takes your fancy and place them on top of the amplifier on show. Print your own "Audible Pulchritude Capacitor - Specially for Audio" clear sticky labels with a nice 1930's style font and a big flash on it in a nice contrasting colour and stick them on....

Originally posted by Magura
I have recently sourced 50uF motor run caps for myself and a friend of mine, of great quality, for something like 35USD a piece.

Someone sure made a huge profit there....

Cricklewood Electronics sells rather nice Ducati made Polypropylenen Motor Run Capacitors 50uF/450VAC -
(equates to 630VDC minimum) for $US 12 each (actually 6.50 UK Pound), plus taxes.

Sayonara

[fdegrove]

Hi,

For Tuna Fish encased in metal casings oil filling is definitly recommended....

This one's for the smaller projects:

Sardine preamp, AKA the Aldi Project:

Cheers,

[karma]

cool gota pic of the inard's

[fdegrove]

Hi,

cool gota pic og the inard's

Sure...
No tube in sight though.....Ouch....an opamp.


Cheers,

[Circlotron]

Originally posted by Magura
Look for motor run caps, they are cheap, of uniform good quality and very reliable.

Are they the same thing as power factor correction caps like used in fluorescent light fixtures etc? I know a power factor cap is rated for across-the-mains usage but a motor-run cap is generally in series with a motor winding so it would not need to have as stringent a specification.

[ThorstenL]

Konnichiwa,

Originally posted by Circlotron
Are they the same thing as power factor correction caps like used in fluorescent light fixtures etc?

Not quiet. For safety Reasons the Lightning capaictors are often metalised Paper.

Originally posted by Circlotron
I know a power factor cap is rated for across-the-mains usage but a motor-run cap is generally in series with a motor winding so it would not need to have as stringent a specification.

This point is debatable. A Motor Run Capacitor needs to phaseshift the entire winding current (around 50% of the motors normap current consumption), often very significant current. As current and voltage go out of phase you often have high current flow with a significantly higher voltage than you find across the mains lines.

Ultimatly I would think both well usable.

Sayonara