The casing is plastic. The amp runs off 12v from one of the switchmode supplies in the TV. The plugs that I installed are right next to the speakers (I actually put in a DPDT switch so I can switch between internal and external speakers, but I didn't want to complicate my earlier post). There was NO high voltage or mains connected wiring brought outside the chassis, or even touched for that matter. The speaker wires run away from all the circuit boards to the speakers and don't go anywhere near the high voltage areas (which are inside a metal casing). There's a picture of a similar TV here: http://en.allexperts.com/q/TV-VCR-Stereo-1749/2011/3/Vizio-42-LCD-tv.htm and you can see the speaker wires at the bottom of the picture.
There is no threat of electrocution, except maybe if you chewed on the speaker wire or maybe stabbed yourself with a speaker wire in each thumb (since even a lowly 9v battery can kill you under the right conditions 1999 Darwin Award: Resistance is Futile). I've wired up houses with both high and low voltage lines and have been mucking about with electronics for about 30 years, so I know the safety issues involved, and this was far safer than 90% of the diy projects on this site.
There is no threat of electrocution, except maybe if you chewed on the speaker wire or maybe stabbed yourself with a speaker wire in each thumb (since even a lowly 9v battery can kill you under the right conditions 1999 Darwin Award: Resistance is Futile). I've wired up houses with both high and low voltage lines and have been mucking about with electronics for about 30 years, so I know the safety issues involved, and this was far safer than 90% of the diy projects on this site.
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Hello,
Thanks for the inputs and ideas..
1. Regarding the power supply for the amplifier, I didn't looked into much details, thought to do after fixing the amplifier ic.
Initially thought if we may use the 65w, 19.5v laptop power supply. Is it ok or its better to go for transformer based linear power supply?
2. Regarding speakers, I was thinking to use car speakers, as here we can get branded car speakers like from JBL, sony etc, with 4ohm, rms 30-60w, and 90 - 93db sensitivity (which seems to be good sensitivity which will give loud sound with relatively less power). With branded speakers we may trust the quality of the speakers
thanks and regards
S Sarath
Thanks for the inputs and ideas..
1. Regarding the power supply for the amplifier, I didn't looked into much details, thought to do after fixing the amplifier ic.
Initially thought if we may use the 65w, 19.5v laptop power supply. Is it ok or its better to go for transformer based linear power supply?
2. Regarding speakers, I was thinking to use car speakers, as here we can get branded car speakers like from JBL, sony etc, with 4ohm, rms 30-60w, and 90 - 93db sensitivity (which seems to be good sensitivity which will give loud sound with relatively less power). With branded speakers we may trust the quality of the speakers
thanks and regards
S Sarath
50% of the chipamp performance is dependent on the power supply, 40% on layout, and 9.95% on parts. The actual chip contributes about 0.05% of the total performance of the design.
Not really, but close enough.
Also, the major contributor to sound quality of the entire system is the speaker and the room. Car speakers depend on cabin gain in the small space of a car, in a room they do not perform very well at all. And they are not 90dB in there either, think 86-87 or about the same as a regular domestic speaker.
You might be satisfied with such a system for a few months, till you actually hear a decent system. Then you'll wonder why you didn't plan it a little better.
Not really, but close enough.
Also, the major contributor to sound quality of the entire system is the speaker and the room. Car speakers depend on cabin gain in the small space of a car, in a room they do not perform very well at all. And they are not 90dB in there either, think 86-87 or about the same as a regular domestic speaker.
You might be satisfied with such a system for a few months, till you actually hear a decent system. Then you'll wonder why you didn't plan it a little better.
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Crossover yes, I think you need some well designed DIY speakers.
Speakers are the output.
Agree on not bringing speaker out wires outside the plastic TV enclosure.
Maybe you got one of the few fully floating/insulated TVs ... and even so you are doing something original designers didn´t even think some end user would do, and anyway that wiring was not present when they got that model tested and approved.
Anyway when suggesting these things in a public Forum, read by tens of thousands, and without restricting the advice to *one* very specific brand and model, there´s always the high chance that a noob will apply it to *his* particular TV and get fried by a hot chassis.
In these places it´s far safer levelling to the lower peaks, not the highest mountains
.
EDIT: now, if your TV has original audio outs (say, RCA connectors or even a humble earphone jack) , that one is guaranteed safe to connect external amplifiers or powered boxes.
Maybe you got one of the few fully floating/insulated TVs ... and even so you are doing something original designers didn´t even think some end user would do, and anyway that wiring was not present when they got that model tested and approved.
Anyway when suggesting these things in a public Forum, read by tens of thousands, and without restricting the advice to *one* very specific brand and model, there´s always the high chance that a noob will apply it to *his* particular TV and get fried by a hot chassis.
In these places it´s far safer levelling to the lower peaks, not the highest mountains
.EDIT: now, if your TV has original audio outs (say, RCA connectors or even a humble earphone jack) , that one is guaranteed safe to connect external amplifiers or powered boxes.
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