aaronpiet said:
You can add some more caps in your PS to enhance power storage and in this way mabe getting more bass!
In read something about the relation between caps value and bass sounding in an old thread:
http://www.diyaudio.com/forums/show...7&perpage=15&highlight=bass caps&pagenumber=4
I think that 30mF is a minimum to get suffiecent bass for this kind of amp.
I've used Sikorel caps in a 5.5 SoZ, and while really expensive (about half the overall monoblocks cost) I didn't regret it. They really perform very good. They are "fast" indeed, with an extremely low internal series resistance little dipendent with frequency. This avoids paralleling film caps with them... a tweak I don't always like. But mileage may vary, one could as well use many more smaller caps in parallel to obtain the same effect. But Sikorel are sturdier.joensd said:
For your question... I would say yes, Audio (and I believe class A even more) need an extremely good power supply to deliver the best... but in the end is the overall "system" that counts, not just the quality of a single element. On this subject (power supplies filtering) inductors, are as much (if not more) important as capacitors.
I've found them on RS-components. Through RS You can get them all over the world. Pity they just don't stock all the values... so if someone knows a place where they sell all Sikorel values I would like for sure to know.
ciao,
Roberto Amato
Thanks for your explanations Roberto.
I don´t know which value you´re looking for but you can buy the Sikorels at Buerklin .
Just search for "16D620".
You can get them at Farnell likewise.
The search function in the Farnell online catalog is not so convenient. I actually couldn´t find them directly but I have the paper catalog and they definitely stock them.
But they´re more expensive at Farnell.
Jens
It´s nice listening to comments about the german language.
A friend of mine (from Britain) used to make me think about the german language more than once.
It definitely has got some funny and strange sounding words and some curiosities.
I actually rather talk in English than german. (BTW:We can swap languages if you like.
)You can communicate with "less". In relation to English it´s definitely a more complicated language.
It´s like Passamps reproducing the music in the same (or better?)way with less (parts).
Jens
PsykoK
today I connected 40mF to the ps of my zen and the bass is again better. Then I reduced the current back to 1.3A , because the heatsinks are too small (0.45W/°C) for the 2A Version. The sound is still ok, i could not hear a difference. I stop now adding caps and start to build the case now. (I'll try to make it 'unkaputtbar' too)
I didn't want to use the word 'unbreakable', i thaought it is reserved for Bruce W.
It seems, that it's not only the ripple current of the caps but also the capacity itself that has big influence on the sound on these special class-A Amps, perhaps also the speed of the caps.
Thanks for helping finding these results.
today I connected 40mF to the ps of my zen and the bass is again better. Then I reduced the current back to 1.3A , because the heatsinks are too small (0.45W/°C) for the 2A Version. The sound is still ok, i could not hear a difference. I stop now adding caps and start to build the case now. (I'll try to make it 'unkaputtbar' too)
I didn't want to use the word 'unbreakable', i thaought it is reserved for Bruce W.
It seems, that it's not only the ripple current of the caps but also the capacity itself that has big influence on the sound on these special class-A Amps, perhaps also the speed of the caps.
Thanks for helping finding these results.
The more capacitance you add, more filtering (and less ripple) you get, so the sound changes for shure... when to say "stop, it's enough" it's another matter. Inductors do anyway a great job in filtering high frequency garbage (noticeable in smoother highs and increased listening easiness and ambience) much more than caps alone do... I couldn't do whithout.aaronpiet said:
I forgot to add an observation about Sikorel (but I think appliable to any other cap, especially big ones): they need a lot to "burn in". The sound "relax" a lot after many 10s hours. At first I thought was mosfet that needed so much time, but after having substituted the "burned in" ones (~400hrs) with a mint couple, the sound was very very close to what I was used to. That surprised me, without that try I would have never known.
ciao,
Roberto Amato
Roberto Amato said:
Roberto,
don't forget that the more cap you add, the more the ripple spectrum shifts to higher frequencies, where the rejection of the amp get worse. Indeed, it will for sure change the sound, but not necessarily for the better.
If you are interested, his has been discussed in other threads
ad nauseam
Jan Didden
Well... cost for sure. Bulkiness. They put a resistance in series with the supply, so you have to calculate the voltage drop and act accordingly... but so do NTCs. I've never used them but if Nelson does I'm sure they work very very good. If I recall well, Nelson does a CRCRCRC... filtering, don't remember how many CRC cells. Seems to me they have many advantages in terms of cost and space they free... but until I try them out I don't have a personal opinion about performance differences.aaronpiet said:
ciao,
Roberto Amato
CRCRC
I am sure that we have all seen the pictures in the Aleph-X thread, but for those that haven't, here is a link to the pictures of the XA-200 and brief descriptions of each by Mr. Pass.
XA-200 pictures from Aleph-X thread.
He has implemented RC filtering before, just look at the BOZ. Of course it is much easier to realize an RC filter when the current demands of a system are in the milliamp range. Speculating what the demands from the XA-200 power supply are, I can understand the use of the thermistors as part of the filter network for the power supply.
Also, as Jan has said, filtration capacity, its impact on diode conduction angle, and its effects on noise spectra have been throughly explored, albeit don't let that stop a thoughtful and lucid discussion from continuing.
Later,
I am sure that we have all seen the pictures in the Aleph-X thread, but for those that haven't, here is a link to the pictures of the XA-200 and brief descriptions of each by Mr. Pass.
XA-200 pictures from Aleph-X thread.
He has implemented RC filtering before, just look at the BOZ. Of course it is much easier to realize an RC filter when the current demands of a system are in the milliamp range. Speculating what the demands from the XA-200 power supply are, I can understand the use of the thermistors as part of the filter network for the power supply.
Also, as Jan has said, filtration capacity, its impact on diode conduction angle, and its effects on noise spectra have been throughly explored, albeit don't let that stop a thoughtful and lucid discussion from continuing.
Later,
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