Blue Ray Player from the US

[venkatcr]

Is it really true that a equipment can be voltage locked? Just wanted to know as I would be more careful when buying gadgets from US.

The 'voltage lock' as you call it happens automatically because of the differences in voltage and frequency of the A/c current.

In the US, voltage is supplied to homes at 110 volts and the A/c cycles at 60Hz. In India, voltage is supplied at 220 volts and the A/c cycles at 50Hz. In most electronic units, an internal transformer unit accepts these voltages and converts them to DC current or even A/c current where needed. Unless a unit specifically says 110-240 volts (universal voltage), what it can accept is only 110 or 220 volts. If you send 220 volts to an unit that can take only 110, you will burn the internal systems.

This issue is somewhat taken care of by using an external step-down transformer. This converts a 220 volts to 110 volts. But remember, the A/C cycle is not changed. That means you will be supplying 110 at 50Hz to a system that is expecting 110 volts as 60Hz. Does it matter? Yes, particularly for video units as the frame rate used for display is based on the A/C cycle.

Even for other units that use A/c current as output (such as amplifiers), there will be a subtle change in tonal quality as well as quality of output.

That is why better quality products will stick to a particular voltage/cycle. Some manufacturers provide a physical switch, meaning there are two separate transformers/rectifiers inside that handle the two power supplies differently. This will, of course, increase the price.

Cheers

 

[mathan]

The 'voltage lock' as you call it happens automatically because of the differences in voltage and frequency of the A/c current.

In the US, voltage is supplied to homes at 110 volts and the A/c cycles at 60Hz. In India, voltage is supplied at 220 volts and the A/c cycles at 50Hz. In most electronic units, an internal transformer unit accepts these voltages and converts them to DC current or even A/c current where needed. Unless a unit specifically says 110-240 volts (universal voltage), what it can accept is only 110 or 220 volts. If you send 220 volts to an unit that can take only 110, you will burn the internal systems.

This issue is somewhat taken care of by using an external step-down transformer. This converts a 220 volts to 110 volts. But remember, the A/C cycle is not changed. That means you will be supplying 110 at 50Hz to a system that is expecting 110 volts as 60Hz. Does it matter? Yes, particularly for video units as the frame rate used for display is based on the A/C cycle.

Even for other units that use A/c current as output (such as amplifiers), there will be a subtle change in tonal quality as well as quality of output.

That is why better quality products will stick to a particular voltage/cycle. Some manufacturers provide a physical switch, meaning there are two separate transformers/rectifiers inside that handle the two power supplies differently. This will, of course, increase the price.

Cheers

That was very useful post Venkat. Moving forward I would get it only if it has Universal voltage or dual voltage system.

 

[amithmith]

I have a LG BD550 player. I got it in India, it costed me 8K two months back, if you are lucky you'll get for a cheaper price in India (definitely within your 200$) budget. You can get region free blu ray discs available in amazon.com and play it on that player. It works for me.

 

[sanjay0864]

But remember, the A/C cycle is not changed. That means you will be supplying 110 at 50Hz to a system that is expecting 110 volts as 60Hz. Does it matter? Yes, particularly for video units as the frame rate used for display is based on the A/C cycle.

Even for other units that use A/c current as output (such as amplifiers), there will be a subtle change in tonal quality as well as quality of output.

That is why better quality products will stick to a particular voltage/cycle. Some manufacturers provide a physical switch, meaning there are two separate transformers/rectifiers inside that handle the two power supplies differently. This will, of course, increase the price.

No offence, but this is not exactly correct. Simply because, almost all video equipment is finally run on DC power, ie. the player internally converts the AC (alternating current) to DC (direct current), which is what finally powers the player. Since the 50Hz/60Hz cycles are irrelevant in DC (direct current), there is absolutely no loss in quality or functionality by using a 220v/240v - 110v/100v step down transformer.

Ofcourse, specifically in the case of 'amplifiers', a 220volt unit will generally be better than a 110volt unit. But, this too has nothing to do with stepping down of 220volts to 110volts.

That was very useful post Venkat. Moving forward I would get it only if it has Universal voltage or dual voltage system.

My personal advice would be to not give too much importance to this issue. Bottom line is that 220v to 110 volt conversion is a non issue.

 

[venkatcr]

No offence, but this is not exactly correct.

No offence taken, At the same time, if you dwelve deep into the functioning of an amplifier, you will understand what I mean. The DC supply to the amp circuit is provided by the power unit. As the flow of charge changes direction, the power supply will convert it into direct current. The power supply also smooths out the current to generate an absolutely even and uninterrupted DC signal. Now a power supply designed for 110 volts at 60 Hz will understand the flow of charges when it changes at 60 cycles. If the flow changes instead at 50 cycles, it does matter to the power supply. It will actually miss 10 cycles per second of charges and not be able to supply absolutely smooth DC to the amp circuit.

Though the differences are small, it affects the amplifier in three ways. One; the biasing of the transistors could go haywire. In the case of bipolar transistors, the driver stage will not be able to supply enough current to the output transistors at the critical juncture. With MOSFETs, the driver may not be able to charge and discharge the gate-source capacitance quickly enough. With valves, the issue may not be much as the grid draws very little or no current.

I have heard 110 volts amplifiers powered by step-down transformers change the speed of a song. The effect is subtle, but it is certainly there.

With regard to video, CRTs are certainly directly affected by the A/c cycle. With digital TVs this will not be a major issue, but as there is both audio and video signal amplification inside a TV, the colors, brightness and other factors can be affected.

Cheers

 

[sam9s]

@Sam is your Panasonic BD60 region free or you unlocked it. I hear that the Blue ray are region specific.

Bluray players comes in all variants, region locked and region free as well, and then there are those which can be made region free by mod kits. my player belongs in this category. I bought a mod kit online and got the modding done here.

 

[roseboy24]

Samsung C6900 iam using and performance is very good 3D capability and playing all format via USB /BD disk and internet online contents via Wifi USB which comes with player .

 

[mathan]

I have a LG BD550 player. I got it in India, it costed me 8K two months back, if you are lucky you'll get for a cheaper price in India (definitely within your 200$) budget. You can get region free blu ray discs available in amazon.com and play it on that player. It works for me.

I'm trying to get a basic BD player but except for Sony there is no stock for other players like LG, Samsung or Panasonic in Chennai. I'm skeptical buying a Sony as sometimes it does not play normal dvd discs itself.

 

[chiron]

I am also in the same boat. One of my friend is coming from US and I was thinking about getting a sony s570 (DLNA certified and within 140 USD till 25th Dec) but it region locked for DVDs as well. I can live with region A locked blu ray player but having a region locked DVD player is hardly appealing. Don't know how to proceed and unlocked it as I don't have a universal remote either.
I really wanted to buy something within that price bracket.

Any help in this regard will be highly appreciated.

Best regards

 

[nandac]

i got my panasonic bd60 from usa thru ebay.in - global easy buy. use a convertor for 120 v. works fine.