Filter Capacitance


Hello Audiogonners! 

Perhaps this should be placed in tech talk - not sure.... 

In my own clumsy way, I'm building more understanding of amplifiers. I have no electrical training, save some very awkward swings of that hot gun that interacts with solder and a PCB, back in High School, about 400 years ago!

So, I see there are two players in the amp game that I do not understand, about which I am studying (more study of other pieces of the system, later): Filter capacitance and transformer size. Until a few days ago, I might have (entirely) mixed the two in my head... now it's only a partial mix... So, I'm interested to see, for example, that the Schiit Aegir has the following hardware, so far as is described on a Schiit-Euro site:

"The power supply is completely linear, with 600VA transformer, over 150,000uF of filter capacitance." 

That seems like A LOT of capacitance, and I'm totally confounded as to why this doesn't translate into higher output. As you know, the Aegir is described as 20 watts per channel into 8 ohms, and maybe 40 into 4 ohms. Seems like low wattage for all that transformer and capacitance weight! 

The Vidar runs the same size transformer but only 40,000uF of filter capacitance - 20K per side! AND it's a 100w into 8ohm amp - 200 into 4ohms. 

I own the STA200 by Nuforce and I cannot find anything describing capacitance, nor transformer size... I'm studying amplifier tech because I'm running into some difficulty when running the STA200 into my Moabs, at high volumes characterized by significant bass extension: think giant BOOM and you get the idea. Most of what I listen to is jazz/acoustic, so it's not a big issue until I move over to something that emphasizes boom, so I'm curious as to how the tech shows up in these applications...
listening99

Showing 3 responses by millercarbon

OP said:
I'm studying amplifier tech because I'm running into some difficulty when running the STA200 into my Moabs, at high volumes characterized by significant bass extension: think giant BOOM and you get the idea. Most of what I listen to is jazz/acoustic, so it's not a big issue until I move over to something that emphasizes boom, so I'm curious as to how the tech shows up in these applications..

I mock this stuff because it is so eminently mockable. But the fact of the matter is it is also nice stuff to know. You just need to keep straight that its nice stuff to know, and not drink the Kool aid and start thinking you can actually build a music system with it. You can't. You can only build a music system by listening and evaluating by ear. 

Look, some of these tech stories are really well crafted. For sure. Heck I start to believe them myself sometimes! Over the years though I noticed some things. Several tube amps would drive speakers just as loud as I wanted, and feel more powerful doing so, and have greater bass slam and extension, than some other amps that were on paper much more powerful. Smaller power supplies, less capacitance, more powerful sounding. 

Now listening99 I hope you are listening because I want you to listen to this. Someone gonna attack me for this on the basis of some technical reason or other. They will in doing so glide right past the fact it sounded better, more powerful, with greater extension. A lot of them know this to be true. Heck a lot of them have heard it, actually experienced it themselves. So they know, on some level, the pointlessness of the tech talk. Nevertheless they persist. Nevertheless they try and explain away reality. Just watch.

The technical reason for this, at least the one we are given, is bandwidth. The claim is made that transformers with greater bandwidth sound more open, dynamic, and powerful. So there is a technical explanation. Might be right. Then again, might not. 
Well when you put it that way then yes there may well be "a relationship between the specs and the workings of these amps, as envisaged and contrasted in the lineup of a single amp manufacturer of numerous models". When you put it that way. Which is not the way I put it. Which was "All the BS above falls apart (and I do mean all of it) the second you listen."

Do you see the difference? You're talking measuring. I'm talking listening. That's the secret.
I'm curious as to how the tech shows up in these applications...

If you figure it out let me know. All the BS above falls apart (and I do mean all of it) the second you listen to a little 34 watt Raven or other good tube amp and realize it sounds way more powerful than you would ever guess based on tech specs. 

At best tech specs like capacitance correlate only vaguely and occasionally to what is actually heard. More often what happens is guys who memorized some talking points regurgitate every chance they get without regard to any actual real-world experience. Then because this happens so often it becomes common wisdom.

Well, it ain't wisdom. But it is common.