four pole capacitors

[jasper9395]

Hi, I was wondering if anyone has used four pole capacitors in their power supply. I was thinking of using M-lytic HV+ Electrolytic Capacitors. 

Here they are:

http://www.hificollective.co.uk/components/mundorf_mlytic_hv+.html

[Paul Birkeland]

A 550V electrolytic cap is way overkill for a power supply that peaks around 220V.  You'll end up spending extra money for that capability, and the caps will be huge. 

A 100uF 400V Solen film cap is competitively priced with these, and I'd be more excited by its performance. 

[jasper9395]

Ok but that would reduce the capacitance of the caps on the PS by half compared to the stock ones. This is the first time I have build a tube amp but as far as solid state goes more capacitance seems to be better. Also, I thought the final cap on the PS was supposed to be at least 2 times the value of the output coupling cap. I realize how big those mundorf caps are but I was planning on top mounting them. I was probably only going to use one to replace the first cap on the PS because these types of cap have the advantage that they create complete isolation between the stages.

[Paul Birkeland]

This is the first time I have build a tube amp

I'd recommend using the stock parts, then moving on to experiments thereafter.

The four pole capacitor does not create complete isolation between stages (if there is such a thing), they tend to be useful for filtering out high frequency garbage (they were originally implemented in SMPS's).

[jasper9395]

So you would recommend eventually replacing the PS caps with MKPs even if they have less capacitance than the stock caps then?

[Paul Birkeland]

If you can fit 220uF of film cap in there, go for it! 

I'd recommend running the stock caps.  They are very low ESR, very reliable, and very easy to work around.  I would be much more enticed by putting one power supply choke in and the Speedball well before altering the PSU caps.

[jasper9395]

Ok, thanks for that. I was already going to add the Speedball. What exactly is the advantage of the choke?

[Paul Birkeland]

The choke offers similar DC resistance to a resistor, but a higher impedance to AC (power supply noise is AC), so you get more ripple reduction without additional raw voltage drop.

[Grainger49]

Jasper,

You can replace an electrolytic cap with a smaller value film cap because the film is a lower ESR.  It will release the stored energy faster than electrolytics.  The key here is that they are so much faster that you don't need as much storage.

[jasper9395]

Ok, so I could even add two chokes in there. What are the best quality ones to use?

Then you could eventually replace the film caps with 100uf caps. But the last one is the most important right? Would I not want to keep that one the same capacitance as the stock caps?