ASC oil caps vs M-tube cap for ps

[phrarod]

I'm running the ASC Oil-Filled Polypropylene X386 in my line stage power supply project. I'm just about done voicing and in thinking of a case these monsters present a problem.

Has anyone compare the MTube cap against these? I would like to get a little more speed. I don't know if the ASC caps have the old 'oil is slow' quality or not. The MTube sure are more manageable.

Anyone compare these two sonically?

[Gluca]

more speed?

[phrarod]

Faster. As is speed of attack and impact.

[Gluca]

are you sure it's the PSU and the caps?

(btw X386 are my preferred so far for PSUs)

[phrarod]

Speed, attack, impact -- in my experience is an effect of the psu. All the rest is in the amp circuit.

[boywonder]

Originally Posted by phrarod

Speed, attack, impact -- in my experience is an effect of the psu.

In general, what PS attributes are required for good speed/attack?

[kmtang]

I have tried both ASC oil and M-Tube Cap but I don't like them much in my preamp.

I have mostly Blackgates for the B+ filtering and cathode bypass.


Johnny

[ChrisA]

Originally Posted by Gluca

more speed?

He is using "audiophile speak", a sub-dialect of English.

An engineer would say he wants to lower the output impedance of his power supply by using lower ESR caps in the filter section. Same end result.

To answer the question I was browsing the Allied Elect. web site and found some caps made by GE. They are poly film but with good specs values like 100uf (or more) and 850V and under $20 each. They seem to be a low-pain upgrade from aluminium electrolictis for the last stage of CRC power supply filters. I almost was going to order but thought I'd wait until a few days before I really could put one to use. I forgot the intended application but it might have been microwaves or x-ray machines

[phrarod]

Originally Posted by ChrisA

He is using "audiophile speak", a sub-dialect of English.

Sorry I thought this was an "audio" forum.

The ASC caps are oil and metalized polypropylene not oil and paper caps. They have bandwidth of over 100kHz with excellent slew rates and very low dielectric absorption. IMHO they sounded better than the best electrolytics I've tried - yes including the black gate. I do not like black gates because they need to reform if left without electricity for long periods of time ie they have to break in again. I've witnessed this with Audio Note gear and the owner admits this. If they are left energized all the time ie power left on then they're ok.

As a friend stated speed is really determined by the dynamic output impedance of the power supply. That is determine by resistance, lead length and type, wire length, the DCR of the power transformer secondary , choke and the dynamic “K’ factor of the rectifier tube.

A capacitor has a slew or charging and dissipation rate, has dielectric absorption and a frequency bandwidth. In general order of ranking.

Film and foil
Metalized film
Oil and Paper
Electrolytic

In other word ChrisA is right. I just would like a smaller package.

[pirastro]

May I know how you connect the additional capacitor? In series to the AC in or parallel across ground (live to ground)?

Thanks