I wonder if most of the DACs are even connecting the PE internally. Maybe only for a mains transformer shield to keep leakage low.budget DACs and Speaker-/HP-Amps from Topping, SMSL, etc are 3-prong,
I wonder if most of the DACs are even connecting the PE internally. Maybe only for a mains transformer shield to keep leakage low.budget DACs and Speaker-/HP-Amps from Topping, SMSL, etc are 3-prong,
They aren’t widely in use today and in all honesty had forgotten about them. A few years ago before retirement went to see an Electrical contractor on site the Architect had included them in the electrical specification think it was for a retro effect.I forgot about them. I understand what you mean now. However, it is purely academic. They are not general purpose sockets; you cannot plug in any device that is on sale within the UK. They are for speciality circuits, for instance for lights are switched from a wall switch. I haven’t seen them on any building other than some country house hotel.
If you mean Americans by "us" that is true.This this wonderful survey has concluded definitively that most of us have both 3 prong and 2 prong electrical gear. I think I could have guessed as much.
Well in areas where one has no choice then it is even less useful.If you mean Americans by "us" that is true.
My Luxman is the same.I found out that the power amplifier Yamaha A-S1200 and A-S1000 uses two prongs, but the Yamaha NP-S2000, the network player from that same series, uses three. Does that look random to you as well?
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Then there is this guy chilling
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About the same here, maybe more 2 prongs when I count the 5 Adcom 545 II amps.Tie. NAD M10 and Purifi are Class I. RME ADI-2 FS B and miniDSP 2x4 HD are Class II. I'm currently not running my subs (room space) but when I do set them up, they'll be powered by Sunfire woofer monoblocks (Class 1) or an Adcom 555 (2 prong, maybe not certified).
You do know that sticky black PVC tape will ruin the audio signal!
Hey!Yeah, vinyl has a way of ruining the sound…
I’m not sure if Americans comprehend that we have a fuse inside the plug.
When you see dual enclosing squares, it's 2-prong (class-II).
My house (in Denmark) still has fabric insulated wiring for the most part. And no earthed sockets anywhere ... ;-)Back then some older houses still had various round-pin plugs for appliances, and even wiring that had fabric and rubber insulation.
This would then be functional earth (for better EMC).I wonder if most of the DACs are even connecting the PE internally. Maybe only for a mains transformer shield to keep leakage low.
Not immediately illegal but a rare case and considered bad practice AFAIK.Not necessarily the case:
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Our radio station uses a number of Numark DJ-type CD players as they're cheap enough and include fast cueing and USB inputs. They all are double-insulated, and have the correct symbol, but use the three-pin IEC connector, with the earth pin left floating. I think it bad practice, but seems to be common.This would then be functional earth (for better EMC).
If they don't connect the chassis (and audio-GND) to PE the internals (power supply) then must be class-II and the device labeled as such. That is, unless a primary shield also doubles up as protective earthing means (quite unlikely).
Which gets us to this...
Not immediately illegal but a rare case and considered bad practice AFAIK.
It is not clear what's going here. The only thing we know from the labelling is that the device does not rely on PE for safety, that's what class-II is about. It's established by re-inforced insulation of mains-carrying parts and conductors, still protecting in a single-fault scenario.
But, did they just use a 3-prong inlet/fuse/switch combo because it was convenient and the PE is actually not connected to anything? Or did they use it for some form of functional earthing?
Is audio GND and chassis actually floating wrt to mains earth or not? This is the all important question here.
Overall, looking at the number of prongs is not 100% sufficient to tell if audio GND is floating or not but for most gear the correlation holds. 2-prong --> floating audio GND, 3-prong --> earthed audio GND (not necessarily a direct zero Ohms bond. In power amps we often see an "isolator" circuit between audio GND and PE which consists of antiparallel power diodes bridged with capacitor and/or resistor).