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Showing content with the highest reputation on 02/20/2016 in all areas

  1. HAHAHAHHA!!!!!!!!!!!! Nice one Azureal. Surprisingly she is the only artist that I can listen to from that genre. I'm somewhat of a nerd/math-geek, and I have always admired and respected her as a professional vocal "technician." She is so mathematically pitch-perfect that it amazes me that a pair of natural vocal chords could produce notes and keys that technically and exactly perfect...That's about it for the soft pop genre for me. (well I admire Whitney for this too.) But the biggest reason I have her discography is to final test my analog magnetic tape equipment and tape equipment I refurbish for others. (Only analog..no DAT or DCC). Because of her aforementioned pitch perfection, I test the frequency mods and performance by driving some of her more demanding and versatile songs into the mag record heads and monitor the recorded result. She is ALWAYS my final test for my equipment because her songs are BY FAR the hardest to reproduce via analog delivery. Now you know why....LOL!!!!
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  2. Due to the nature of my work I cannot go into details. What I can say is when you overdraw the USB bus strange things can happen like uninitiated reboots or lockups. In extreme cases I have seen motherboard USB headers burned, motherboard traces burned. Small fires started by overdrawing current from the USB bus. Think about it. Most every item that has some sort of USB cradle has a seperate AC charger that plugs into the base of the charger. Why? Because in most cases the USB bus is not capable of providing the current necessary to charge modern day devices. There are items that can charge via USB like cell phones but the current draw is minimal. Most devices that don't have an AC charger connected to the base do not charge the device. Some devices that come immediately to mind are PDA's. The USB dock always has a seperate AC charger. There are MD units that cannot be charged via USB even though they have a USB dock. I have to take back my comment that it "can't" be done. Maybe I should reword it to say "Be very very careful!" As long as you fall within the USB specs for current draw you should be okay. National Semiconductor has an interesting article that is relevant to this discussion. It pertains to Li-Ion charging but maybe some knowledge can be gained from looking at the schematic they have for the charger they propose: http://www.national.com/appbriefs/files/AppBrief101.pdf
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  3. Actually the MD units are usually rated at 3V which is what the concern was about. I don't know about the new Hi-MD units but the older non-Hi-MD units mainly came pacakaged with transformer-type AC adapters. The float output from a 3V AC adapter is therefore above 5V and as you explained (very well I might add ) which is why the original person thought that 5V from the USB was okay. There was a concern that since the transformer adapter would go to closer to 3V under load that 5V constant (from the USB) is too much. However that just isn't true because of the fact that I described above--the newer MD units have a degree of protection--if they are overvoltaged they display a warning on the display and lock out the power to the unit. Actually I'd say it was a pretty darn good breakdown!
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  4. Allow me to tag a "little bit" on to this thread. Bear in mind that to charge a 3 volt battery, you would need to put more that 3 volts across it. Basically, best way to remove doubt is to measure what the official Sony PSU is putting into the player when under the load of charging. Yes, reasonably new units should be pretty well protected, though I can understand a reluctance to shove unknown quantities into expensive gear. The newer Sony PSUs, as with most around now, appear to be switch-mode. That makes 'em smaller and cheaper than their transformer-based counterparts. Another advantage of that is that they are multi-region (I bought my NW-HD3 in the UK, and can use the same charger here in Canada. Provided I use an adapter to allow the UK plug to fit in the Canadian socket, of course). If you look on one of these PSUs, it even states "input: AC 100-240V~". Switch-mode has certain other implications to take into account. Transformer-based PSUs rely on stepping down voltage according to a ratio of independent primary and secondary windings on an iron or ferrite core. For example, a transformer with 1000 primary turns and 200 secondary turns will produce an output at 200 divided by 1000, 20%. 100 volts in yields 20 volts out. Transformers drop power as the load increases because the windings themselves are not perfect conductors, and will be subject to Ohm's law, V=I*R. The current being pulled through the transformer, multiplied by the resistance of the windings, equals the voltage that will lost to that effect, which will be dissipated as heat. Okay, so it's a little more complicated than that, inductive loads, AC and so forth, but that's the jist of it. I shall ignore the bit of electronics responsible for AC-DC conversion for now, though it of course has an effect too (as someone here previously pointed out, a silicon diode, as used in rectification, has a 0.6V difference between anode and cathode). The idea behind switch mode supplies is that the desired output is created electronically by taking the input voltage and switching it on and off really quickly through a whole bunch of coils, capacitors and other assorted crap. The controlling electronics monitor the output and vary the switching rate when required. If the load increases and the output voltage starts to dip, the 'tronics will pump more juice in, until the required voltage is once again restored. This is why they can generally handle multi region. They just switch the input at a different rate. The switching happens very quickly, which is why switch-mode supplies, like laptop charges, make a kinda squeaky, squealy noise, whereas transformers make that 50-60Hz buzzing sound. So, where am I going with all this switch-mode talk, and how is it relevant to this, and what the hell am I talking about? Well essentially, switch-mode power supplies, by nature of how they work, are regulated. Not necessarily super-clean, but reasonably consistent under load (at least until the switching process is pushed to the point where it breaks down, or where the current limiter kicks in). The output voltage is rated at 6V on my NW-HD3 charger, and 6V is what ya get, whatever the load. As for transformers, when they are rated at for example 12V @ 500mA, that means the voltage out of it is around 12V when under load, ie when you are drawing half an amp from it. When not under load at all, the output is more likely to be around 14-15V. If a transformer-based Sony charger is rated at 5V @ 300mA, that means when under a 300mA load (ie charging the battery), the voltage from the supply should be at 5V (...not that Sony would ever deviate from an established rating convention like that, no sireee...). As far as this case is concerned, PCs use switch-mode supplies, and the motherboard voltage regulators are also switch-mode, on account of better efficiency and lower heat when compared to linear regulators. If the minidisc is rated at 5 volts, in theory it should be absolutely fine to feed it 5 volts from the USB, provided the USB can supply the required current. This is a somewhat crude breakdown of the theory, but hopefully may prove of some use to those exploring this avenue of alternative charging methods.
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  5. Line out is not supposed to sound nice, it is supposed to be used for transferring sound between machines. There is no equalisation or any type of effect for that matter. The idea is that the machine which your line out is connected to will be able to do exactly that, and if you send it a signal which has been run through a weird EQ setting, then there is no way it will be able to play the original flat sound. Just a question though - why do you have both Bass and Treble turned all the way up? If I remember rightly from one of my older Sony Walkmen, then that would have exactly the same effect as turning up the volume. Why not just turn the volume up and use the EQ for something a bit more useful (like making it sound better )
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