[regal]

What are the best caps to get in the 100-500pf range for use in an analog DAC filter? Silver Mica?

 

[Pars]

Mica or polystyrene are what I usually see recommended. MKPs or FKPs should be fine as well. Polycarbonates if you can find them might also work well.

 

[AudioCats]

russian teflon. you can open one up and un-wrap the foils to get the exact value you want.

 

[cobaltmute]

I've used silver mica in that type of role with good results.

 

[rds]

Panasonic PPS are a very good choice for analog filtering, in my opinion. Whether they get the audiophile stamp of approval I'm not sure.

 

[sachu]

I am finding that the output analog filters are screwing up the phase response of the DAC. especially in the 4-7kHz range. Something just sounds off. Using Multicap and relcap styrene caps. Will need to explore better reconstruction filter designs to get past the phase response issues, but otherwise these capacitors work like a charm. Great dynamics, transients and clear response

 

[regal]

Quote:

Originally Posted by sachu /img/forum/go_quote.gif I am finding that the output analog filters are screwing up the phase response of the DAC. especially in the 4-7kHz range. Something just sounds off. Using Multicap and relcap styrene caps. Will need to explore better reconstruction filter designs to get past the phase response issues, but otherwise these capacitors work like a charm. Great dynamics, transients and clear response

Yes they do, I think the key is using a good digital filter where you can get away with as little analog filtering as possible. I like to use a -3db 25khz 1st order filter, but I have tube amps with their own miller roll-off and don't need much filtering. If you have sibilance, most of the time its the DAC filters.

 

[qusp]

evox/rifa PPS and PET. you can get them and wima which are similar both in SMD too, perfect for the filter section of a dac IMO. i'm certainly using them to great effect

 

[diditmyself]

Use any standard polypropylene like WIMA. Small. Cheap. Thermal stability. Sounds good enough (most of us probably can't hear the difference between a straight wire and a pp cap). No need to worry about long leads with unwanted inductance, burnt polystyrene or an empty wallet.

 

[sachu]

Quote:

Originally Posted by regal /img/forum/go_quote.gif Yes they do, I think the key is using a good digital filter where you can get away with as little analog filtering as possible. I like to use a -3db 25khz 1st order filter, but I have tube amps with their own miller roll-off and don't need much filtering. If you have sibilance, most of the time its the DAC filters.

It isn't a problem with sibilance. Just something sounds off key.
The passive 3rd order filter is the culprit i feel here.
Toying with the possibility of converting it to a simple 1st order crossover at around 40kHz.