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Post by szoze on Apr 19, 2012 10:28:56 GMT
Yes, Alex IS very experienced, he IS wise but he certainly isn't "rude".... he'll call a spade a spade, not "rude" just says it as it is. I don't know Alex, I just read some of his threads. I admit I overreacted a bit and I do appologize. But as much as Alex, I also know what I hear when I listen to something. My hearing may be trained in other contexts (piano tuning and instrument playing) but I am very aware of "colors", pitches and "balances" in sound. I have basic knowledge and understanding in electronics too and am aware of phenomena that "possibly can occur" in an electronic circuit. I have also learnt to beleive in logic and measurements but even to trust in what I hear when I compare different sounds objectively (it comes from my profession maybe) and I don't fear to say it as it is when I know I have ground to stand on. |
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Post by szoze on Apr 19, 2012 12:00:32 GMT
Is it ok to go back to my question about RF/EMI? If anyone is knowledgeble to instruct me here.
My X-can V3 has a housing in metal (aluminium) and is, more or less perfectly shielded, save the gap between the volume knob and the housing. Even there I guess the distance is on the micrometer level.
RF waves have definately too large wavelengths (several centimeters) to pass through into the amp. If I am not mistaken the gap must be at least a quarter of the wavelength in size in order for the EM wave to pass through.
How can these waves interfere with the capacitor leads or any other components inside the amp and why should we care about EMI in this specific case?
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XTRProf
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Post by XTRProf on Apr 19, 2012 13:32:35 GMT
Is it ok to go back to my question about RF/EMI? If anyone is knowledgeble to instruct me here. My X-can V3 has a housing in metal (aluminium) and is, more or less perfectly shielded, save the gap between the volume knob and the housing. Even there I guess the distance is on the micrometer level. RF waves have definately too large wavelengths (several centimeters) to pass through into the amp. If I am not mistaken the gap must be at least a quarter of the wavelength in size in order for the EM wave to pass through. How can these waves interfere with the capacitor leads or any other components inside the amp and why should we care about EMI in this specific case? Ok everybody back to the topic and I thought the topic is on heatsink  . To give my frank opinion, even if there is no RFI to be detected, there is always a Good Practice Methodolgy that people go about designing and manufacturing. As we can see, designers put in dc decoupling bipolar caps at the inputs and outputs. Why? Also, designers and technical notes always recommend putting 0.1uf as a filter after and before dc regulators. Why? In all PCBA plants, wrist straps and electrostatic mats must be used at all times in the assembly areas even in super high humidity Singapore. Why? All HDDs must be powered down and the rotor stationary before moving to another location during assembly. Why? And many more ............. So what ever were written here, whether true or didn't have an impact, must be practiced. That was what were always done and has been until today. So sometimes it's better to ask and you decide for yourself. Further questioning can become quite insensible as that's the practice in the professional world.  Btw, a lot of the people here are pros in their fields before they retired or still in service. |
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Post by szoze on Apr 19, 2012 14:01:20 GMT
Thanks Chong. I am well aware of everything you say and I understand exactly how Good Practice Methodology works. I am also experienced professional in my own field.
But as I asked in my last sentence: How is the question of RF important in my specific case (when modding my amplifier)? It is the core question. Is it something that can influence SQ in my system? After all we are not designing a new amp we are just modding an already existing one and we know exactly how it is constructed and how it behaves. Of course if you (the board members) think my questioning is insensible then I will try to find answers somewhere else.
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XTRProf
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Post by XTRProf on Apr 19, 2012 15:08:00 GMT
But as I asked in my last sentence: How is the question of RF important in my specific case (when modding my amplifier)? It is the core question. It is something that can influence SQ in my system. After all we are not designing a new amp we are just modding an already existing one and we know exactly how it is constructed and how it behaves. Of course if you (the board members) think my questioning is insensible then I will try to find answers somewhere else. The question is ok but the answers had already been given if you reread again. In the opinions of the rest, there is a possibility of degradetion. Like I had said and reiterated here again, it's your prerogative to decide what to do after this. To me your question is sensible but then you are insisting and asking something again that had already been answered. That makes it becomes insensible to the rest. I'm A-Ok as it's just a discussion. So now you know what I mean? Going to other forums will also give you more or less these same answers if they are engineers. So going back to square one, you will have to decide for yourself after all the views, whether you accepted or not. Don't go into the insensible loop of what I mean. |
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Post by Deleted on Apr 19, 2012 15:26:08 GMT
Working professionally in the the EMC field I can tell with great certainty there is no simple answer to this seemingly simple question.
The elaborate answer would have to incorporate everything that is connected to it (power supply, music source, headphone) and it's relation to 'earth' (the actual ground we walk on, not the safety earth of a wall sockeet) and the current paths (frequency, level, impedance) that are created when this all is connected.
Also it would need to involve knowing the fieldstrenghts polarity and polarisation and spectral intensity of all frequencies that are present to determine if it has a potential risk of inducing signals.
The nature of the signals (burst/continuous/modulation) also needs to be accounted for as well as the coupling methods.
Fortunately none of this is the audiophiles daily concern.
In simple words... the amp is shielded so parts (other than those in sensitive feedback or power supply decoupling) should not experience any influences from outside, regardless of componet wire lengths or surface as there are no generating or oscillating parts in there.
At least not if the amp isn't modded to far 'by ear' in the wrong places.
As stated this does NOT include power supply decoupling and feedback loop sensitive/determining parts.
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Post by szoze on Apr 19, 2012 16:17:30 GMT
The question is ok but the answers had already been given if you reread again. In the opinions of the rest, there is a possibility of degradetion. Actually the answers I received were general and didn't apply to the shielded x-can v3. Nobody even mentioned shielding until now (see Frans' answer). One of the (angry) answers I received mentioned switching rectifier (there is no such in the x-can). The other answer said that the leads' connection to a capacitor would make difference, ie make that component more prone to EMI. But then the input capacitor is, I beleive, also connected through a long wire to the volume pot. That shouldn't be any different. |
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Post by szoze on Apr 19, 2012 16:22:07 GMT
In simple words... the amp is shielded so parts (other than those in sensitive feedback or power supply decoupling) should not experience any influences from outside, regardless of componet wire lengths or surface as there are no generating or oscillating parts in there. At least not if the amp isn't modded to far 'by ear' in the wrong places. As stated this does NOT include power supply decoupling and feedback loop sensitive/determining parts. Thanks Frans. A simple answer, easy to understand and accept as plausible from what I know about EMI.  |
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XTRProf
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Post by XTRProf on Apr 19, 2012 17:32:09 GMT
One of the (angry) answers I received mentioned switching rectifier (there is no such in the x-can). The other answer said that the leads' connection to a capacitor would make difference, ie make that component more prone to EMI. But then the input capacitor is, I beleive, also connected through a long wire to the volume pot. That shouldn't be any different. Oh, it does have the rectifiers inside the X-Can V3 as the X-PSU V3 is just an AC traffo outputing AC +/-. I'm not too sure about the X-Can V3 PCB. But the X-Dac V3 has a much better PCB as it has a good double sided ground plane incorporated in that PCB. So the noise level will be lower when signal is going thru that PCB compared to a dangling lead to the RCA. Really, I'm not sure about the X-Can V3 PCB construction as I don't own a V3. |
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Post by szoze on Apr 21, 2012 16:40:27 GMT
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Btw, a lot of the people here are pros in their fields before they retired or still in service.
