Hi all,
I would like to make a line-in from a built-in TV speaker. It's a smart TV, doesn't have any analog outs. The 10kA+100k would be nice in a normal case, but this built-in amp TAS5749M isn't grounded at the outs - the speaker negatives are not connected. What can I do?
I thought I can steal the input signal of the amp, but that's digital...
I would like to make a line-in from a built-in TV speaker. It's a smart TV, doesn't have any analog outs. The 10kA+100k would be nice in a normal case, but this built-in amp TAS5749M isn't grounded at the outs - the speaker negatives are not connected. What can I do?
I thought I can steal the input signal of the amp, but that's digital...
Try a transformer coupled LOC
https://www.amazon.com/PAC-SNI-35-Variable-Line-Converter/dp/B001EAWS3W
Thanks,
Now I use it like this, with both the TV and the 2.1 speaker ungrounded:
Dots are spacings.
L+____5kA____________R5k__L-
...............|__R5k__Lout
L-____5kA____________R5k__L+
...............|__R5k__GNDmy
And the same for the right. So these are two stereo pots working in reverse from side to side. This somewhat steals the middle of the wave. It works, but I would say it's Lo-Fi
- one more simple thing is in my mind, as this is a 2x10W amp already, which would be enough for mid-high, so I can use 2 better outside speakers for that through a 22uF, and for the subwoofer input of the 2.1 speaker (actually it has a stereo RCA and a 5.1 RCA input) use 2 highfreq-filters from an old speaker's "divider", put it through a small transformer, 110+110V primary and 12V secondary, or can be smaller, 5V for a /20 divide. Like this: L+__/\/\/\__110Vprimary__L- and same for the right. How about that? 10kA trimmer on the secondary of course.
- no, no headphone outs. (these TVs are so smart and modern, you can't shrink your brain enough to understand)
- maybe I can use another DA chip. The problem is the digi input: this IC is so universal on input, and there is no info about ANYTHING inside this TV.
- the transformer sounds good, not too expensive, and maybe I can build it too... One problem resides: There is a substantial high siss and 50Hz noise.
Now I use it like this, with both the TV and the 2.1 speaker ungrounded:
Dots are spacings.
L+____5kA____________R5k__L-
...............|__R5k__Lout
L-____5kA____________R5k__L+
...............|__R5k__GNDmy
And the same for the right. So these are two stereo pots working in reverse from side to side. This somewhat steals the middle of the wave. It works, but I would say it's Lo-Fi
- one more simple thing is in my mind, as this is a 2x10W amp already, which would be enough for mid-high, so I can use 2 better outside speakers for that through a 22uF, and for the subwoofer input of the 2.1 speaker (actually it has a stereo RCA and a 5.1 RCA input) use 2 highfreq-filters from an old speaker's "divider", put it through a small transformer, 110+110V primary and 12V secondary, or can be smaller, 5V for a /20 divide. Like this: L+__/\/\/\__110Vprimary__L- and same for the right. How about that? 10kA trimmer on the secondary of course.
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That would help, but none of the HDMI ports work. (If it did, I would use it as a PC monitor and I would never need the audio out. OFF: This is a type-problem with this Ss TV-s, not being grounded and was connected to a grounded PC, a ground hook killed it. I'm not very far from changing the processor, I just need a similar model with a broken screen or stg)