Paul, excellent as always. Constructive criticism- your constant efforts to clarify/explain these videos to "Ohm's Law listeners" really drags down the presentation and flow of the video. Please stop it. Listeners only are a different audience and should have different expectations. Do the thing that you do well and stop apologizing and trying to appeal to too many channels.
I don't think it's that big of a deal to point out how he's illustrating something for non video people. That being said, he totally could have a separate RSS video containing the video version and make that available on iTunes for podcast listeners. Apple Podcasts works with video and other podcasts apps support video too.
I just measured DC voltage in my AC socket and it indicates 5V :) It's a lot. I think that's why i can still hear the noise from the trafo in my Hovland HP-100 even with my DC blocker.
Wow! That was instructional. Made this idiot computer programmer actually pull out a pen and start drawing bridge rectifiers and wave forms on a piece of paper. Big admiration for a knowledgeable person like Paul who will say "I don't know" when he's not sure.
Great video, but I don't understand how a transformer winding, which is DIFFERENTIAL in nature, will be affected by a DC voltage on BOTH ends of the winding.
A good digital voltmeter will give an accurate DC on AC measurement. I have about 420 mv on my house power. I use a surplus 1kvA industrial control xfmr on my bench. Works great.
Wamgo C thanks for your reply So is 420 MV considered OK and within acceptable limits ?. If not , what should be acceptable limits of DC or there should be none?
@@wamgoc3637 that is not necessarily true. A Fluke 87 certainly wont, it dances around all over the place when trying to measure DC on an AC supply its by no means a poor meter, its one of the best in fact, PS audio use them.
Where can you get these plans Paul, Why don't they put the full Bridge rectifier in front of the transformer why is it always behind? Or one either side. How do you determine which type of Bridge rectifier is suitable.
Paul McGowan hi you talk about means filtering using the Bridge rectifier that means your amplifier will be plugged into the unit? So that would mean the bridge... is before the transformer, I thought the bridge rectifier convert AC to DC.
Yes, you can put them together in the toys box. Normally it is not something useful, it is just something you would need if you have defects in your equipment quality level.
ROY FERNTORP From my understanding of how amplifiers work, which admittedly isn't grad school level, this would have nothing to do with that. And it's quite normal to have DC going to your speakers. You just maybe had too much, or you blew something, like a transistor maybe. There's a thing called DC offset, or DC bias. Where the signal isn't right, and it results in DC coming out of the speaker terminals. Like I said. A little is okay, and normal for most amps. A lot can fry your speakers. Most modern amps have protection, but some don't, like Adcom GFA 555 for instance. Some older Crowns don't either, like DC 300. Now I'm not positive if the speaker protection helps with the offset, but I assume so. I know it will work with a transistor blowing though. Well it will if it was designed, and working properly anyway. So yea. You probably blew a transistor, or need to adjust the offset. It's easy to measure the offset, and get an idea if the amp still works. If it doesn't. Then it's decision time I guess. Hopefully it is, and you can Google how to adjust it, or have a tech do it. And you can add a speaker protection circuit to the amp, and not have to worry about this again. But it may not be cheap. I don't have a clue on that. www.google.com/amp/s/m.wikihow.com/Measure-DC-Offset%3famp=1
My more modern gear has so much processing. You plug a laptop into the EV amps and set everything. Those old, heavy E-core Crowns are living in a shed somewhere or maybe holding a boat. And thanks for the education. Appreciated.
ROY FERNTORP EV? Electro Voice? Are they like the new Crown amps with the DSP built in? I like those amps. I've been thinking about getting one to use for subs. Way in the future though. I've still got more important things to buy for my system, and I don't have endless funds. But I really like that idea. Where you can control it all from the laptop. They have an interface on the front too I think. But using the computer seems much nicer. :) Do you do sound? Or you just prefer the pro audio gear? I ask, because I've read many conflicting thoughts on using them for home use. Many like them, and others say they just don't have the magic that audiophile gear does. That's part of why I was thinking of getting one for my subs. That way I can try it for my main speakers too, and make my own decision on how they sound. And do you recommend EV over Crown? BTW you're not the first person I've heard refer to those old Crowns as boat anchors. But I bet they have their charm too. I find I can enjoy most amps/receivers if they're set up properly, and I don't set my expectations too high. Heck I was in my deck using a cheap Bluetooth speaker today, and was actually impressed by what it does for the money.
I have a busy recording studio in Sydney Australia and every now and then I do audio gigs for bands. I love the Electro-Voice and Dynacord gear because it is reliable and sounds really good. You don't have to push to the limiters to get a good sound. The modern D-class amps are good but if you push them they don't keep up with subs. Behringer make some nice amps for the price. The Nuke range is pretty good but don't beleive the rating.
ROY FERNTORP So if I get one. I should get a class A/B one huh? I always thought that way, but have been looking at class D lately, and people say there's good ones, and I'm going to try one soon. But I was wondering about how they would keep up with a class A/B amp for subs. I know they're fine for regular speakers, but have read conflicting things about how they are when you really need the power for the lower frequencies. Some people say they're great, others say they're not. My thinking was. I'll try class D for speakers, but stick to the tried, and true technology for subs. Even though class A/B is less efficient, and produces more heat. I will say though. I had a class D amp in my car, and it was pretty powerful. PPI 900.5. 5 channel. The sub channel was 460 watts in 2 Ohms I think. And it was enough to get my single 12" Polk Audio sub shaking my little car up. And it sounded pretty clear on the inside speakers too. It was fatiguing though. But that might have been due to other parts of the signal chain for all I know. BTW I've been seriously shopping class D lately. And the Allo Volt+ for $69 is supposed to be an amazing little amp. Not powerful, but really good. I've also been looking at the TBI Millenia. That's a lot more though. And you can just buy an amp board from Ebay, and hook up a pretty supply for cheap. TPA3116 is great, or for more power. The TPA3251 is supposed to be really good. See this thread if playing with this new technology interests you at all. It's very interesting. And I know some of these guys. I've been a member there for a while, and go to the meet ups. If they say it's really good. It's probably really good. audiokarma.org/forums/index.php?threads/tpa-3116-vs-the-tripaths.574806/
It would be better to be more technical and have both simple explanation and detailed technical info in one video. I would prefer you to be much, much more technical.
Are you joking ? Normally you would want to power your equipment with DC and avoid noise in power supply. And it is the defect of the PSU that some c*ap like DC blockers are needed.
Paul, it depends on the quality of the transformer and its elements. Generally you are referring to the older way of making a power supply with a large transformer operating at the frequency of AC line. Note that it is not a correct way, it was done to be cost efficient. For some stupid reason, many just copied that schematics and basically increased the "performance" by using a larger transformer, which is totally wrong. Also, you are referring to rather cheap transformer made of iron alloy. The effect of hysteresis point shift is not so bad for ferrite core transformer, which should be used for high-end equipment. Also, note that you can use DC power lines at home, I know that they require more expensive switching and safety equipment, but still, you can use DC instead of AC, which solves a lot of problems with noise. It is kind of weird that you assume that power lines should be necessary AC.
Good job Professori McGowan!
Yes Paul, I was with you through that, great teaching. I like when you come with a little more meat on the bone! Keep us on our toes
Thanks for sharing!
Great and informative video as always.
And another thanks for doing it in 4K, I'm sure it takes more time and effort!
Is it necessary a second bridge or we could use 2 diodes in series with each pole, once we don’t have polarity inversion after the bridge???
Not sure about that circuit. I can imagine a configuration that would give the output waveform you drew but it wouldn't be wired like that.
Paul, excellent as always. Constructive criticism- your constant efforts to clarify/explain these videos to "Ohm's Law listeners" really drags down the presentation and flow of the video. Please stop it. Listeners only are a different audience and should have different expectations. Do the thing that you do well and stop apologizing and trying to appeal to too many channels.
I don't think it's that big of a deal to point out how he's illustrating something for non video people. That being said, he totally could have a separate RSS video containing the video version and make that available on iTunes for podcast listeners. Apple Podcasts works with video and other podcasts apps support video too.
Wouldn't you just add DC blocker to your amp design?
I just measured DC voltage in my AC socket and it indicates 5V :) It's a lot. I think that's why i can still hear the noise from the trafo in my Hovland HP-100 even with my DC blocker.
You didnt blow anything up 💥?? 😮
Toroidal transformers are very sensitive to DC from mains.
Wow! That was instructional. Made this idiot computer programmer actually pull out a pen and start drawing bridge rectifiers and wave forms on a piece of paper.
Big admiration for a knowledgeable person like Paul who will say "I don't know" when he's not sure.
Great video, but I don't understand how a transformer winding, which is DIFFERENTIAL in nature, will be affected by a DC voltage on BOTH ends of the winding.
Neal Staats the dc is across the winding and that will polarize the core.
A lot has to do with transformer saturation curves and a surprisingly little DC current can make a large difference.
How do we check if there is DC coming along with AC from our wall plug
A good digital voltmeter will give an accurate DC on AC measurement. I have about 420 mv on my house power. I use a surplus 1kvA industrial control xfmr on my bench. Works great.
Wamgo C thanks for your reply
So is 420 MV considered OK and within acceptable limits ?.
If not , what should be acceptable limits of DC or there should be none?
@@wamgoc3637 that is not necessarily true. A Fluke 87 certainly wont, it dances around all over the place when trying to measure DC on an AC supply its by no means a poor meter, its one of the best in fact, PS audio use them.
Electronics 💓
Where can you get these plans Paul, Why don't they put the full Bridge rectifier in front of the transformer why is it always behind? Or one either side. How do you determine which type of Bridge rectifier is suitable.
Paul McGowan hi you talk about means filtering using the Bridge rectifier that means your amplifier will be plugged into the unit? So that would mean the bridge... is before the transformer, I thought the bridge rectifier convert AC to DC.
If you have some noise harvester, is this blocker needed or do the same function? Can they be together?
Yes, you can put them together in the toys box. Normally it is not something useful, it is just something you would need if you have defects in your equipment quality level.
Wish my Crown amps had this. They went full DC and turned my speakers in to little electric heaters.
ROY FERNTORP From my understanding of how amplifiers work, which admittedly isn't grad school level, this would have nothing to do with that. And it's quite normal to have DC going to your speakers. You just maybe had too much, or you blew something, like a transistor maybe. There's a thing called DC offset, or DC bias. Where the signal isn't right, and it results in DC coming out of the speaker terminals. Like I said. A little is okay, and normal for most amps. A lot can fry your speakers. Most modern amps have protection, but some don't, like Adcom GFA 555 for instance. Some older Crowns don't either, like DC 300. Now I'm not positive if the speaker protection helps with the offset, but I assume so. I know it will work with a transistor blowing though. Well it will if it was designed, and working properly anyway. So yea. You probably blew a transistor, or need to adjust the offset. It's easy to measure the offset, and get an idea if the amp still works. If it doesn't. Then it's decision time I guess. Hopefully it is, and you can Google how to adjust it, or have a tech do it. And you can add a speaker protection circuit to the amp, and not have to worry about this again. But it may not be cheap. I don't have a clue on that.
www.google.com/amp/s/m.wikihow.com/Measure-DC-Offset%3famp=1
My more modern gear has so much processing. You plug a laptop into the EV amps and set everything. Those old, heavy E-core Crowns are living in a shed somewhere or maybe holding a boat. And thanks for the education. Appreciated.
ROY FERNTORP EV? Electro Voice?
Are they like the new Crown amps with the DSP built in? I like those amps. I've been thinking about getting one to use for subs. Way in the future though. I've still got more important things to buy for my system, and I don't have endless funds. But I really like that idea. Where you can control it all from the laptop. They have an interface on the front too I think. But using the computer seems much nicer. :)
Do you do sound? Or you just prefer the pro audio gear? I ask, because I've read many conflicting thoughts on using them for home use. Many like them, and others say they just don't have the magic that audiophile gear does. That's part of why I was thinking of getting one for my subs. That way I can try it for my main speakers too, and make my own decision on how they sound. And do you recommend EV over Crown?
BTW you're not the first person I've heard refer to those old Crowns as boat anchors. But I bet they have their charm too. I find I can enjoy most amps/receivers if they're set up properly, and I don't set my expectations too high. Heck I was in my deck using a cheap Bluetooth speaker today, and was actually impressed by what it does for the money.
I have a busy recording studio in Sydney Australia and every now and then I do audio gigs for bands. I love the Electro-Voice and Dynacord gear because it is reliable and sounds really good. You don't have to push to the limiters to get a good sound. The modern D-class amps are good but if you push them they don't keep up with subs. Behringer make some nice amps for the price. The Nuke range is pretty good but don't beleive the rating.
ROY FERNTORP So if I get one. I should get a class A/B one huh? I always thought that way, but have been looking at class D lately, and people say there's good ones, and I'm going to try one soon. But I was wondering about how they would keep up with a class A/B amp for subs. I know they're fine for regular speakers, but have read conflicting things about how they are when you really need the power for the lower frequencies. Some people say they're great, others say they're not. My thinking was. I'll try class D for speakers, but stick to the tried, and true technology for subs. Even though class A/B is less efficient, and produces more heat.
I will say though. I had a class D amp in my car, and it was pretty powerful. PPI 900.5. 5 channel. The sub channel was 460 watts in 2 Ohms I think. And it was enough to get my single 12" Polk Audio sub shaking my little car up. And it sounded pretty clear on the inside speakers too. It was fatiguing though. But that might have been due to other parts of the signal chain for all I know.
BTW I've been seriously shopping class D lately. And the Allo Volt+ for $69 is supposed to be an amazing little amp. Not powerful, but really good. I've also been looking at the TBI Millenia. That's a lot more though. And you can just buy an amp board from Ebay, and hook up a pretty supply for cheap. TPA3116 is great, or for more power. The TPA3251 is supposed to be really good.
See this thread if playing with this new technology interests you at all. It's very interesting. And I know some of these guys. I've been a member there for a while, and go to the meet ups. If they say it's really good. It's probably really good.
audiokarma.org/forums/index.php?threads/tpa-3116-vs-the-tripaths.574806/
awesome video
if dc magnetizes your transformer the many volts ac will demagnetize it. Hey Paul did you ever use a bulk tape demagnetizer??
ahhh...
Sorry Paul but huh ?
It would be better to be more technical and have both simple explanation and detailed technical info in one video. I would prefer you to be much, much more technical.
This was the most boring Ask Paul of all time. Way to geeky for me
Are you joking ? Normally you would want to power your equipment with DC and avoid noise in power supply. And it is the defect of the PSU that some c*ap like DC blockers are needed.
Paul, it depends on the quality of the transformer and its elements. Generally you are referring to the older way of making a power supply with a large transformer operating at the frequency of AC line. Note that it is not a correct way, it was done to be cost efficient. For some stupid reason, many just copied that schematics and basically increased the "performance" by using a larger transformer, which is totally wrong. Also, you are referring to rather cheap transformer made of iron alloy. The effect of hysteresis point shift is not so bad for ferrite core transformer, which should be used for high-end equipment.
Also, note that you can use DC power lines at home, I know that they require more expensive switching and safety equipment, but still, you can use DC instead of AC, which solves a lot of problems with noise. It is kind of weird that you assume that power lines should be necessary AC.