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Filter capacitance-how does it relate to amplifier performance?

I have a Unison Research Due amplifier that drives my Totem Forest Signature with ease. It has 100wpc in 8ohm and 180wpc in 4ohm. It has a filter capacitance of 80,000uF

I previously had a Atoll in100 amplifier 100wpc in 8 ohm, 140wpc in 4 ohm Capacitance of 31,474 uFMoving up the Atoll line the in200 has 120wpc in 8 ohm and 200wpc in 4 ohm and filter capacitance of 62,000uF
The Atoll in300 has 150wpc in 8 ohm and 260 Epcot in 4 ohm with a filter capacitance of 81,600uF. These also had no trouble driving my speakers.

My understanding of capacitors is that they store energy. Does this mean that my Due amplifier is just as powerful  as the on paper more powerful Atoll in300?

For comparison sake with my Due amplifier I demoed a Plinius Hautonga integrated amp with 200wpc in 8 ohm and 280wpc in 4 ohm. I did not hear any appreciable difference in bass or other frequencies.

So 3 questions.

1) Is my Due amplifier much more powerful than the wpc  indicates?
2) How does filter capacitance relate to power in an amplifier?

3) Why do manufacturers rarely publish this spec? I could only find a few examples.

Thanks
128x128traceyc
erik_squires
16,046 posts
 
No one will give you a great answer until you understand what it is doing.

Here's a helpful article:

https://makingcircuits.com/blog/calculate-filter-capacitor-smoothing-ripple/

But basically, bragging rights are the main benefit, followed by enabling low impedance drive are your answer.

Best,

E
xenolith's avatar
xenolith
123 posts
 
Hoping Ralph will comment on the situation with my custom built 100 watt 4 x KT77 monoblocks (built by Charlie Cocci): when I took off the bottom plate to admire Charlie's work, I was shocked to see only 2 x 47mF 630 volt capacitors in the power supply section.  By comparison, my Jon Soderberg updated (200 w/ch.) Threshold Stasis 2 has 4 x 63,000mF capacitors in the power supply section! 

When I asked Charlie about this, he told me (paraphrasing) 'When you've got enough voltage, you don't need as much capacitance.'  I'm thinking that this may be a statement of the Work equation that Ralph posted.  

By the way, the tube amps absolutely kill the Threshold in bass response...much better control of the big 12" woofers in the NorthCreek crossovered Matrix 801 S2s and what sounds like an extra half octave of response.  The tube amps kill the Threshold in every other way as well, but the bass response was a real surprise.  

Thanks for any insight from anyone into how this can be!
georgehifi's avatar
georgehifi
10,312 posts
 
By the way, the tube amps absolutely kill the Threshold in bass response...much better control of the big 12" woofers in the NorthCreek crossovered Matrix 801 S2s
Understandable when you look at the very "benign impedance load" of the 801’s
https://www.stereophile.com/images/archivesart/bwll801fig01.jpg

But put something like a Focal No3 Sopra with a magnitude of 2.75 ohms at 96Hz and a combination of 4 ohms and a –56° negative phase angle, then you find the Threshold will be the better.
https://www.stereophile.com/images/417FSop3fig1.jpg

It's all horses for courses.

Cheers George
xenolith's avatar
xenolith
123 posts
 
Thanks George!  I really think a lot of people have really missed the boat with Matrix 801s, myself included for a long time....the oft repeated 'need for big solid state amplification' just isn't so in my experience...and in fact, is contraindicated for best sound in my experience.

Still puzzled by the total of 94mF capacitance in the power supply of these killer amps...

 
audioman58's avatar
audioman58
4,133 posts
 
Filter capacitance is instrumental for speed and the quality of the performance capacitors do count Nichicon super through, are excellent as well as Nippon ,Rubicon .I have owned highly modified electronics and speakers for years, coupling capsif circuit uses them also as well as 1% resistors and very noise regulators like top ofthe line Bellison ,even Solder like WBT , or Cardas 
effect how natural  it sounds as well as quality wiring ,
pin oututs get rid of the brass connectors on electronics and speakers,over 85% are gold Copper 3 x better conductor much more natural sounding from a purist perspective.
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