That does not make what the late Charles Hanson said an accurate analogy, but I think we can state pretty unequivocally that the goal of the power supply is to isolate the output (audio) from the input as best as possible. One thing you don't want to do it "modulate" the AC into the audio. Technically the diodes in the power supply perform a modulation function on the incoming AC which is why you get DC.
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but I think we can state pretty unequivocally that the goal of the power supply is to isolate the output (audio) from the input as best as possible.I would disagree with that statement. There is really no "isolation". They are all related. Technically the diodes in the power supply perform a modulation function on the incoming AC which is why you get DC.I think that is called "rectificatioin", not "modulation". With regard to the "Audioholics" vid, I actually agree with most of what he said on his other videos, but he probably is wrong with respect to power cable. |
I just finshed 2 DIY power cords, Pure copper ends with Home Depot 12 gague copper strand wire. AWESOME!!. can be seen in my latest YT upload. Type in SEAS Thos. I made 2, one for the big Jadis, 1 for the 220 V cayin cdp, and have another set of ends comming from china, 2-3 months ship time. a spool of 12 gague strand costs $15/50 feet. Just really super cord. Feeds the Jadis and cayin all the juice either can drink up. the basic 50 cent cord that comes with any unit you purchase (I bet Jadis's $100K JA800, comes with,,yep a Fifty cent power cord, cut any one open on your system, its either 18 or 22,22 gague wire,,,a few hair thin strands. Go ahead, try it, you will see. Go to youtube type in SEAS Thor, my latest vid will pop up. Beats any power cord on the market. Copper wire in my wall, copper ends, copper 12 gague stranded, = pure raw unfiltered 100% juice. |
Not to offend, but IMO - If you have a $10K amp. properly matched with your pre amp and speakers and it takes a $2K power cord to make it sound good, - I'd ditch that sucker and buy an amp with a decent power supply and save yourself a couple of grand......Jim
oh yeah I agree, ~~$2K power cord~~~ I mean power is power, grant it the 50 cent power cords that come with every amp you purchase (Even Jadis' JA800 @ $100K, I bet has that stinkin Fifty Cent power cord) cut one open, the strand is either 18 or even 20/222 gague,,= justa few hair thin strands,, which might be all it takes to juice my Defy7. who knows. But when you see that 70 lb beast,,sure seems to me 18-22 gague just ain;'t giving the juice. So I went 12 (10 gague was too thick for the copper ends), Now I am confident the Defy is getting all the juice she wants/needs/cares to drink. Why strave the amp on power? DIY power cord is something anyone can make, Very easy mod, in less than 30-45 minutes can be acheived. |
You can disagree but I get the impression you are not technically qualified to do any more than "disagree". No they are not "all related". A primary purpose of the power supply in an amplifier is to isolated completely the AC from its impact on the audio signal. Rectification is the electrical function, modulation is the signal processing operation that occurs. The rectification is a signal processing multiplication function, or modulation. Ideally you would only modulate the 60Hz AC with only 60Hz to yield 0Hz = DC, but the modulation function ends up being something more akin to a pulse (rectangular waveform) multiplied by a sine wave, hence you end up with all kinds of harmonics of 120Hz that you need the capacitors to filter out. Ideally you design your power supply with inductive filters to extend that "pulse" and reduce those high frequency harmonics to there is less ripple for the capacitors to filter. andy21,171 posts07-05-2020 10:28pmbut I think we can state pretty unequivocally that the goal of the power supply is to isolate the output (audio) from the input as best as possible.I would disagree with that statement. There is really no "isolation". They are all related. |
^^^ Well it seems like you're disagreeing with Charles Hanson who is actually a real designer ... sigh ... face palm ... Your description of rectification and modulate makes me laugh so hard. I suppose until you understand the difference between "rectification" and "modulation", there is not need to argue with you since it would be a waste of time. |
Why would I not agree with him if he makes a poor analogy? I don't idolize people who made interesting products but didn't contribute to moving the science or art forward. You laughing at my description of modulation shows you had no clue what I was talking about. No worries people who understand this stuff will know exactly what I mean or will at least know enough to ask the right questions. The joke is on you. Understand frequency domain analysis makes designing power supply filters much easier and the results more successful. That's the difference between tinkering and engineering I guess. |
I would have argued all day long that cables don’t make that much difference (all cables) until I tried an Audioquest power cable my local guy let me borrow for a few reasons. I was absolutely stunned. I would have never bet, nor at the time did I expect, such a dramatic change. And that was one of the lower end AQ cables. I’ve moved on to others now, but they 100% do make a difference. Baffles me, as current should be current (not) but there it is. |
You could just admit you don't have any real engineering knowledge ... andy21,176 posts07-06-2020 12:46am^^^ OK, whatever, so you're a pretty good at copy and paste. |
This is what Hanson said. As long as the power cord gets the current to the power supply it's doing its job, he's not talking about the freaking cord. It doesn't matter if it costs $1 or $1000. When you understand how an amplifier works—that you're making a copy of the signal by modulating the power supply—then you see that the power supply directly drives the speaker. Anything that's not right about the power supply is going straight into the speakers. That's why we use such a huge power supply—take off the lid and you'll see that about 90% of the innards are the power supply. We have a giant transformer, stacks of chokes, and all those filter capacitors to regulate the front-end. Compared to the audio circuitry, whether you're looking at board-space or cost, that stuff represents 80-90% of the design. |
It's almost like he is saying the goal of a power supply is to I-S-O-L-A-T-E the AC from the audio .... His analogy is a bit better when it is all there huh .... Of course if you don't understand what he means, you could come to the conclusion that matches what you want it to say. When you understand how an amplifier works—that you're making a copy of the signal by modulating the power supply—then you see that the power supply directly drives the speaker. Anything that's not right about the power supply is going straight into the speakers. That's why we use such a huge power supply—take off the lid and you'll see that about 90% of the innards are the power supply. We have a giant transformer, stacks of chokes, and all those filter capacitors to regulate the front-end. Compared to the audio circuitry, whether you're looking at board-space or cost, that stuff represents 80-90% of the design. |