Trying to plough through 1400+ posts and I've lost the will to live >.<
All I wanted was a hint as to which board was a good'un and which to avoid...
So, pushing to the front of the queue... anyone bought a board on Aliexpress that they can recommend? I would like a volume pot, but it's not mandatory.
All I wanted was a hint as to which board was a good'un and which to avoid...
So, pushing to the front of the queue... anyone bought a board on Aliexpress that they can recommend? I would like a volume pot, but it's not mandatory.
Oh, you didn't go there... >.<
I got thrown out of a shop for asking them the same question. It's the same with speaker wire... open your speakers up and look at what is connecting the posts to the crossover or the crossover to the driver. Open up your amp and see what's connecting your power plug to the transformer... or the transformer to the PCB.
For my home audio system, which is around 300w in the practice, I am using some cable meters I got from some outlet power extensions that I bought in the one dollar three store
. 1 dollar for about 2 meters and it easily can handle around 1000watts, that's what the specs said, and I think they are true because the copper section is pretty thick. One end is connected in the amplifier output, and the other end in the subwoofer terminals.
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You will be deaf if you use 300W. In general 1W is already quite loud in many cases. Anyhow, be careful with cheap cables. Many will agree copper being the best material to make cables of. A good cable is a pure copper cable and and more expensive copper cable has silver plating to prevent corrosion which is nice. Both types have a quality plastic coating to protect the user and the cable. Cable thickness defines how much current can go through the cable and we define this by standard diameter sizes in mm2 or AWG in other places. Speaker cable often is 2.5 mm2 or 4 mm2. With short lengths that is OK and maybe already overdimensioned
Very cheap cable nowadays might not be 100% copper. I have experienced this a few times last years. The stranded cable can not be soldered as it contains a mix of scrap metals. Sometimes they are even magnetic !!! Sound bad too. In most cases it were mains cables delivered with cheap Ebay/Aliexpress devices but I recently noticed internal cabling in devices being like this. I now have the habit using a new device with its delivered mains cable first and then compare with an old known good one. Suffice to say that you hear this immediately.
Ultra cheap cables sometimes corrode themselves as some stuff in the cheap plastic coating is aggressive to the metals used. More than once I have stripped away the insulation to find the cable corroding in its sleeve. The plastic is so bad that stripping the cable can be done with finger nails. After some time the plastic looses its flexibility and the cable is too hard to be used.
Lastly: since the cable can not be soldered it is crimped in the factory (same with copper cable) As we are in the lowest of the low quality regions quality control is not the best. With the first mains cable not conducting at all I was frowning. With the second failure I had one that got a large blob in the cable because of resistance of wrong crimping. Just the thought of fire made me to be careful with cables that come with devices.
Just use an A branded industrial cable and be done with it. If cheaper than cheap is what you are after ... keeping a minimum standard in quality still is advisable. The best electronics won't perform well with the weakest link being the cabling. Copper is now an expensive material that has drawn attention of scammers.
Very cheap cable nowadays might not be 100% copper. I have experienced this a few times last years. The stranded cable can not be soldered as it contains a mix of scrap metals. Sometimes they are even magnetic !!! Sound bad too. In most cases it were mains cables delivered with cheap Ebay/Aliexpress devices but I recently noticed internal cabling in devices being like this. I now have the habit using a new device with its delivered mains cable first and then compare with an old known good one. Suffice to say that you hear this immediately.
Ultra cheap cables sometimes corrode themselves as some stuff in the cheap plastic coating is aggressive to the metals used. More than once I have stripped away the insulation to find the cable corroding in its sleeve. The plastic is so bad that stripping the cable can be done with finger nails. After some time the plastic looses its flexibility and the cable is too hard to be used.
Lastly: since the cable can not be soldered it is crimped in the factory (same with copper cable) As we are in the lowest of the low quality regions quality control is not the best. With the first mains cable not conducting at all I was frowning. With the second failure I had one that got a large blob in the cable because of resistance of wrong crimping. Just the thought of fire made me to be careful with cables that come with devices.
Just use an A branded industrial cable and be done with it. If cheaper than cheap is what you are after ... keeping a minimum standard in quality still is advisable. The best electronics won't perform well with the weakest link being the cabling. Copper is now an expensive material that has drawn attention of scammers.
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Ironically its fairly easy to check the spot price of copper - and its showing a gradual decline over the past 5 years from around $4.50 in 2011 to just over $2 now.
5 Year Copper Prices and Copper Price Charts - InvestmentMine
5 Year Copper Prices and Copper Price Charts - InvestmentMine
Copper might be given for free, "they" still use the famous "any-metal" mix to produce cables. There even seems to be a gradual increase in production of this garbage.
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I bought a boxful of cat5 network cable a few years back which measured appreciably higher in resistance than a calculation based on published figures of copper's conductivity in 24AWG would indicate. So something's being used to adulterate the copper but I suspect it isn't aluminium as that's still fairly conductive.
@jean-paul Well, those 300w are only for subwoofer sound (which I think its the max rms supported for my sub), and I regularly feed it with about 120w when really want to feel the bass on my chest. What's disturbing for ears I think are the very loud highs and mids. I have a divider splitter on the source signal, one line feed a boss amplifier and the other one a pair of computer speakers that together deliver no more than 8 watts, they are what I use for mids and highs.
About the cheap extension cable, I simply thought that if its labeled to hold around 1200 watts, I definitely would have no problem using it in audio for purposes that will not drain more than a couple of hundred watts, which is my case, I took a look at the copper, which seems pretty good "thick, shinny and clear", so going to the store and buying something more specific was not my option.
About the cheap extension cable, I simply thought that if its labeled to hold around 1200 watts, I definitely would have no problem using it in audio for purposes that will not drain more than a couple of hundred watts, which is my case, I took a look at the copper, which seems pretty good "thick, shinny and clear", so going to the store and buying something more specific was not my option.
It seems like tin, zinc and even iron. Maybe a way to retrieve metals from cooking of old PCBs ?
http://www.vqronline.org/vqr-gallery/china’s-e-waste-city
We're tech guys right ? So we don't talk only about Watts but we mainly talk about Ampères when speaker cable is concerned. 1200 Watt can be 1200V x 1A or 1V at 1200A. The latter situation asks for a pretty thick copper bus while the first situation could do with a thin wire. A power amp generally does not put out 1200V. Speakers generally are low in (varying) impedance so they want mucho Ampères at a certain low voltage. We therefore choose speaker cabling mainly based on the current rating.
André-Marie Ampère. Only proven right 60 years after his death. Alessandro Volta had more luck. Georg Ohm waited 20 years for recognition....
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I knew that fact, that amplifier outputs low voltage bug big current, for example around 14v for 100W. I am certainly a novice in all this, but is not it like A LOT more than enough that cable for my speaker needs? After some calculations, I found that the cable is supposed to handle around 10A. How much current should my 15" boss speaker drain on a 2ohm load and around 200watts? I have no idea, anyway I touched the cable and runs cold, which means its ok. . The power supply that I am using to feed the amplifier, is 8A.
. The power supply that I am using to feed the amplifier, is 8A.
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This is what you need. Anyone working with electricity should know Ohms Law by head. After 30 years I still know nearly all formula variations (except the ones with root mean square for some reason) by head, it is of practical use nearly every day in my case.
BTW cable being hot or cold is oversimplified. A too thin wire becomes a resistor itself and may not be hot but causes other unwanted effects. Just try to calculate what happens if you put 40V DC on a 2 Ohm resistor (we call this the load) with 2 Ohm own resistance of the cabling. Then see what voltage there is over the load (the 2 Ohm resistor). Let's suppose the load (2 Ohm resistor) is a lightbulb designed for 40V operation. What will happen ?
BTW cable being hot or cold is oversimplified. A too thin wire becomes a resistor itself and may not be hot but causes other unwanted effects. Just try to calculate what happens if you put 40V DC on a 2 Ohm resistor (we call this the load) with 2 Ohm own resistance of the cabling. Then see what voltage there is over the load (the 2 Ohm resistor). Let's suppose the load (2 Ohm resistor) is a lightbulb designed for 40V operation. What will happen ?
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In that case, I think we will have a voltage drop because the cable consuming half of the current, so the bulb won't bright at 100% because only getting half of the energy?
You are in the right direction (but not right) with the wrong assumptions as you did not use Ohms Law. It would not burn at 100% that is true but what is the voltage at the bulb ?
The current is the same at all places in the chain, the voltage drops to half at the load. No Ohms Law, no real understanding of principles
I = U/R. Total resistance is 2 + 2 = 4 Ohm. 40V/4 Ohm = 10A.
U = I x R, so the load gets 10A x 2 Ohm = 20V
Bulb is designed for 40V but gets 20V.....no bright light.
Print out the Ohms Law circle, hang it at the wall of your workbench. Now use it and be enlightened. Wars are started by assumptions, peace is kept by calculations (that is Jean-Pauls Law BTW only to be recognised 30 years after my death)
The current is the same at all places in the chain, the voltage drops to half at the load. No Ohms Law, no real understanding of principles
I = U/R. Total resistance is 2 + 2 = 4 Ohm. 40V/4 Ohm = 10A.
U = I x R, so the load gets 10A x 2 Ohm = 20V
Bulb is designed for 40V but gets 20V.....no bright light.
Print out the Ohms Law circle, hang it at the wall of your workbench. Now use it and be enlightened. Wars are started by assumptions, peace is kept by calculations (that is Jean-Pauls Law BTW only to be recognised 30 years after my death)
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First of all, what chemicals are you talking about, air?? Second, whether the wire is sealed properly or not has most to do with the manufacturing process? Lastly, please clarify your statement with scientific data, or is this just your own "perception". I guess this is how "myth" propagate.
Lately, I am gravitating towards to use of network cables (Cat 6) as my hook up and signal wires, simply because I can get technical specifications on the wire e.g. insulation materials used, conducting material used. They may be a bit thin (24 AWG) but they are surprisingly strong for their size. Some people have used cat 5 cables to build inter-connect and even speaker cables (braiding them together) and reported good results.
Regards,