I have an older satellite/DTV receiver set top box, an RCA DirecTV one. I found that the analog audio line output is significantly lower than my other sources (FM tuner, CD player and such) and it was annoying having to turn up the amp's volume, and more annoying if I forget to turn it down when I switch away from the set top box. So I built 2 copies of this simple transistor voltage amplifier, mounted it inside, and I found inside the set top box a source of 24VDC. Also intercepted the analog output of the set top box at a ferrite bead on the main board of the set top box, patching this amp in. Oh, I checked that the set top box didn't have a volume control function on the audio, and could not find any, either by fooling around with the remote, or even RTFM... Thus the line level was around 1/2 volt, and my other sources more like 4V. This stage's gain, approx 6x, or 16dB, made this box's line level match my other sources.
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errata: R2 should be 10K
The value of R2 is wrong! Should be 10K, not 22K. And where is the "edit post" button? 😕
The value of R2 is wrong! Should be 10K, not 22K. And where is the "edit post" button? 😕- Status
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