Hi all DIYers and Audio lovers
Please help!
I design many amplifiers but they are all DC-coupled.
Recently, I have been trying to design some good
quality car audio systems and find it very difficult not
to put a capacitor in the signal path. I don't know of
any good sounding caps as caps in the signal path is
against my design philosophy.
Could anyone INTRODUCE me to the world of capacitors?
I would appreciate much for your help. Please tell me
the type (MKP, Ceramic .....), where to source them,
how much and popularity.
I don't mind "subjective" opinions as listening to sounds
and enjoying it is subjective in essence anyway.
Go on, share your opinions!
James Yung
Please help!
I design many amplifiers but they are all DC-coupled.
Recently, I have been trying to design some good
quality car audio systems and find it very difficult not
to put a capacitor in the signal path. I don't know of
any good sounding caps as caps in the signal path is
against my design philosophy.
Could anyone INTRODUCE me to the world of capacitors?
I would appreciate much for your help. Please tell me
the type (MKP, Ceramic .....), where to source them,
how much and popularity.
I don't mind "subjective" opinions as listening to sounds
and enjoying it is subjective in essence anyway.
Go on, share your opinions!
James Yung
quote>>I design many amplifiers but they are all DC-coupled.
Recently, I have been trying to design some good
quality car audio systems and find it very difficult not
to put a capacitor in the signal path. I don't know of
any good sounding caps as caps in the signal path is
against my design philosophy.
If you design audio systems then you must know about the question you have asked??????
Recently, I have been trying to design some good
quality car audio systems and find it very difficult not
to put a capacitor in the signal path. I don't know of
any good sounding caps as caps in the signal path is
against my design philosophy.
If you design audio systems then you must know about the question you have asked??????
analog_sa said:
To be honest, I don't really know how I got to the present
no-caps design approach. But of course, I can give you many
reasons:
1 If you don't need a component in the signal path, scrap it.
2 phase shift, worse: different phase shift at different frequency.
3 subjective: my love of JFETs --- depletion mode devices.
I don't know ..... Since I don't normally use caps, I don't reserach
for them. That's why I don't even know which type of caps
are suitable for audio.
James
Hi,
High time you should, both as an RC coupling element as in the PS....
Designs that don't use caps are far and in between, although it can be done with lots of iron...
Let's face it, you do use caps, in the PS at least and these too are candidates for sonic degradation.
We're a PITA, aren't we?
Cheers,
High time you should, both as an RC coupling element as in the PS....
Designs that don't use caps are far and in between, although it can be done with lots of iron...
Let's face it, you do use caps, in the PS at least and these too are candidates for sonic degradation.
We're a PITA, aren't we?
Cheers,
"Why is it more difficult to avoid putting capacitors in the signal path of an in-car amplifier than any other type of amplifier?"
-probably because the car amp is run from a single supply battery and must be run in such a manner to function.
i'd avoid ceramics for the signal path. i'd probably reccomend - polycarbonate, polystyrene (make sure the amp's insides don't get hot enogh to damage them), or polyproplyene. if you are worried about the phase shift, try for a lower cutoff frequency, likely meaning a high input impedance. Fets could be used here.
note that cap differences aren't as night and day as other things and if the car is in motion the noise floor will likely swamp any capacitor's sound.
also, you can use a signal level transformer to interface the signal. this will also allow you to add a single resistor and get an approximation of a balenced transmission system. likely not good for a CMRR over 30dB.
-probably because the car amp is run from a single supply battery and must be run in such a manner to function.
i'd avoid ceramics for the signal path. i'd probably reccomend - polycarbonate, polystyrene (make sure the amp's insides don't get hot enogh to damage them), or polyproplyene. if you are worried about the phase shift, try for a lower cutoff frequency, likely meaning a high input impedance. Fets could be used here.
note that cap differences aren't as night and day as other things and if the car is in motion the noise floor will likely swamp any capacitor's sound.
also, you can use a signal level transformer to interface the signal. this will also allow you to add a single resistor and get an approximation of a balenced transmission system. likely not good for a CMRR over 30dB.
Hello James,
I think that reading thishttp://www.capacitors.com/picking_capacitors/pickcap.htm will give you a lot of informations about caps.
Regards
Claudio
I think that reading thishttp://www.capacitors.com/picking_capacitors/pickcap.htm will give you a lot of informations about caps.
Regards
Claudio
Thanks
Hi sma,
Thanks for your input!
Yes, I have also tried Wima MKP many years ago and I found them pretty good.
Could you tell me where I can buy Wima MKP on the internet?
They are quite big for car amps.
Somehow I regretted putting the original message on the site because I have discovered a new way to DC couple the input with the car amp even though there are voltage offset. I'm going to submit to
magazine by end of next year after R&D.
James Yung
Praise! Audio
Hi sma,
Thanks for your input!
Yes, I have also tried Wima MKP many years ago and I found them pretty good.
Could you tell me where I can buy Wima MKP on the internet?
They are quite big for car amps.
Somehow I regretted putting the original message on the site because I have discovered a new way to DC couple the input with the car amp even though there are voltage offset. I'm going to submit to
magazine by end of next year after R&D.
James Yung
Praise! Audio
wima
Hi,
My friend tell me for purchase wima direct from germany,i will ask him if i meet..because you know same brand but different country of origin,mean different sound ....
I still love direct without cap,better transparent in high and vocal....and i think in solid state on car amp,you can design with no DC offset....Maybe that have risk,but very little if you make correct design.
i looking for low noise DC to Dc converter,how about your switching design?the main problem is for cut the noise from car alternator,i still looking for "clean" supply,because i need audiophile car amp.
Hi,
My friend tell me for purchase wima direct from germany,i will ask him if i meet..because you know same brand but different country of origin,mean different sound
....I still love direct without cap,better transparent in high and vocal....and i think in solid state on car amp,you can design with no DC offset....Maybe that have risk,but very little if you make correct design.
i looking for low noise DC to Dc converter,how about your switching design?the main problem is for cut the noise from car alternator,i still looking for "clean" supply,because i need audiophile car amp.
capacitors
Yes, I have also tried Wima MKP many years ago and I found them pretty good.
Could you tell me where I can buy Wima MKP on the internet?
They are quite big for car amps.
I've been using Wima's for over twenty years now. The recent MKS series are quite small and have a pitch of 5 mm (0.2') up to 1 microFarad!
If needed I could send you some just for the fun of it. You'll find a list of those available at: http://www.audio.nl/a2eng/prices/components.html
Regards
John
Yes, I have also tried Wima MKP many years ago and I found them pretty good.
Could you tell me where I can buy Wima MKP on the internet?
They are quite big for car amps.
I've been using Wima's for over twenty years now. The recent MKS series are quite small and have a pitch of 5 mm (0.2') up to 1 microFarad!
If needed I could send you some just for the fun of it. You'll find a list of those available at: http://www.audio.nl/a2eng/prices/components.html
Regards
John
farnell have wima MKS caps (and they are in Aus) they're not that cheap though. Just go to www.farnell.com and click on the ausie flag.
Just bought some 68nF ones today from Jaycar too (25c each compared to $1.04 at Farnell, though I'm not 100% sure they are the same series, Both are red is about all I can say!, they don't say if they are MKS or MKP (jaycar are selling them as MKT) the only thing that may distinguish is that they had J5 at the bottom, can't find any info on Wimas site.
That was the only size I saw they had that were wima, everything else was no-brand. Hopefully Jaycar are going to start stocking good quality caps at good prices!
Tony.
Just bought some 68nF ones today from Jaycar too (25c each compared to $1.04 at Farnell, though I'm not 100% sure they are the same series, Both are red is about all I can say!, they don't say if they are MKS or MKP (jaycar are selling them as MKT) the only thing that may distinguish is that they had J5 at the bottom, can't find any info on Wimas site.
That was the only size I saw they had that were wima, everything else was no-brand. Hopefully Jaycar are going to start stocking good quality caps at good prices!
Tony.
Re: wima
My switiching power supply is not at all professional. Incidentally, I found the same kind of design in "the arts of electronics" by horowitz and hill. 2nd edition. page ?? sorry couldn't find it. If you want to know, send me a email and I promise you I'll take the effort of finding it and send it to you by post/mail.
sma said:Hi,
My friend tell me for purchase wima direct from germany,i will ask him if i meet..because you know same brand but different country of origin,mean different sound
>> Yes, please do tell me. I have a phono SE amp on the drawing board so I may have to drop the DC coupling philosophy. (I have a DC coupled SE line amp though) bty, do you know where to get 1k pieces of Toshiba 2SK389-V at low prices? Farnell quoted me approx. @AU$3.00.
I still love direct without cap,better transparent in high and vocal....and i think in solid state on car amp,you can design with no DC offset....Maybe that have risk,but very little if you make correct design.
>>Thanks for the input. I love DC coupling too. In fact I think I'm stubborn and won't let go of "no cap in signal path" thing.
i looking for low noise DC to Dc converter,how about your switching design?the main problem is for cut the noise from car alternator,i still looking for "clean" supply,because i need audiophile car amp.
My switiching power supply is not at all professional. Incidentally, I found the same kind of design in "the arts of electronics" by horowitz and hill. 2nd edition. page ?? sorry couldn't find it. If you want to know, send me a email and I promise you I'll take the effort of finding it and send it to you by post/mail.
Re: capacitors
Thanks for the offer John, I really appreciate it. But if I can get those caps in Australia, I'll get them in Australia. If I can't, then I will accept your kind offer!
Thanks for the input !
sma said:Hi,
My friend tell me for purchase wima direct from germany,i will ask him if i meet..because you know same brand but different country of origin,mean different sound
I still love direct without cap,better transparent in high and vocal....and i think in solid state on car amp,you can design with no DC offset....Maybe that have risk,but very little if you make correct design.
i looking for low noise DC to Dc converter,how about your switching design?the main problem is for cut the noise from car alternator,i still looking for "clean" supply,because i need audiophile car amp.
johnrtd said:
Thanks for the offer John, I really appreciate it. But if I can get those caps in Australia, I'll get them in Australia. If I can't, then I will accept your kind offer!
Thanks for the input !
Re: capacitors
>>Thanks for the input, Tony. I don't normally buy stuff from Jaycar except for prototyping just to see if the design work. I really doubt that those caps you bought are truely Wima. If they are big and truely Wima, they would have the Wima logo on, what do you think?
It's nice to know there are Aussies in DIY audio. BTY, I have a 25W class A amp design to be published next year in the magazine Silicon Chip. It features an ultra-linear ultra-fast FET output stage
design that is quite unconventional.
Give me a email whenever you like!
James Yung
Praise! Audio
sma said:Hi,
My friend tell me for purchase wima direct from germany,i will ask him if i meet..because you know same brand but different country of origin,mean different sound
I still love direct without cap,better transparent in high and vocal....and i think in solid state on car amp,you can design with no DC offset....Maybe that have risk,but very little if you make correct design.
i looking for low noise DC to Dc converter,how about your switching design?the main problem is for cut the noise from car alternator,i still looking for "clean" supply,because i need audiophile car amp.
johnrtd said:
wintermute said:
>>Thanks for the input, Tony. I don't normally buy stuff from Jaycar except for prototyping just to see if the design work. I really doubt that those caps you bought are truely Wima. If they are big and truely Wima, they would have the Wima logo on, what do you think?
It's nice to know there are Aussies in DIY audio. BTY, I have a 25W class A amp design to be published next year in the magazine Silicon Chip. It features an ultra-linear ultra-fast FET output stage
design that is quite unconventional.
Give me a email whenever you like!
James Yung
Praise! Audio
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