What kind of amp do I need

I bought a new TV and like most now, they don't have a line level output. I bought a digital to analog adapter to drive my remote
amplified speakers but the line level out of the converter is so low I need to run the amps at full volume and they are still marginal. I think a small pre amp would work but the "turn table" amps might be too much of a good thing and they don't seem to have a gain pot.
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On 08/12/2020 18:44, snipped-for-privacy@aol.com wrote:

You are not the first person to spot this.
I wonder if the digital to analog adaptor is hackable? Could be a resistor change be all that is required in the ADC setup?
What's the chip in there?
BTW, you may get a better response posting elsewhere TV hardware related. Yeah, I know your TV runs on electricity, but ...
--
Adrian C

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???? 8/12/2020 8:44 ?.?., ?/? snipped-for-privacy@aol.com ??????:

you're right a turntable preamp is no good because these have had and have what is called a RIAA curve de-emphasis because the records used to (and are) being compressed in the bass, I think. basically what you need is an op amp to boost your signal, surely there are pres or even kits that fulfill your needs? when I did for my thesis (in EE) an AM transmitter I needed an 60 W audio amp so I picked a ready PCB, it just needed a PSU and box.HTH.
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On 19/12/2020 14:58, Dimitris Tzortzakakis wrote:

The (apparent, only) compression of the basis was an attribute of magnetic pick-ups but not of crystal pickups.
Simple electromagnetics, the faster the movement between conductor and magnet, the higher the induced voltage.
High frequencies entail faster movements than low frequencies!
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???? 19/12/2020 8:22 ?.?., ?/? gareth evans ??????:

right, I never thought of that. likewise dolby was also an analogue mode of compression, I still have a working tape deck!that can do dolby b and c. short before analogue tape became obsolete there was also dolby s. the best tape decks were the 3 headed ones, where you could listen to your recording on the fly, while it was recorded! they could fit a record/play head on one piece, mine is a regular auto reverse, twin deck. one of the last good quality to be made.
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On Tuesday, 8 December 2020 at 13:44:58 UTC-5, snipped-for-privacy@aol.com wrote:

Do they have a useable earphone jack?
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On Wed, 30 Dec 2020 06:55:47 -0800 (PST), Anthony Stewart

No. The only out is digital/fiber.
When I get little time I will get back to it. I am looking at LM324 circuits and I have a few chips already. I am not looking for audiophool quality, just reasonable sound I can hear. A couple I saw look reasonable and I am just looking for line level inputs to an amp. I think a 324 can do it. Since I have 4, I might double them up. I saw that trick too.
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On Wednesday, 30 December 2020 at 22:46:28 UTC-5, snipped-for-privacy@aol.com wrote:

It is possible new TV's do not have an isolated DC supply, so you might be best to use a transformer off the audio.
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On Thu, 31 Dec 2020 09:40:15 -0800 (PST), Anthony Stewart

Since the audio output is optical, it is not much of an issue but I did need to put an isolation transformer on the output of the DAC. That may be part of my low level problem .
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On Tuesday, December 8, 2020 at 1:44:58 PM UTC-5, snipped-for-privacy@aol.com wrote:

What kind of audio connectors are used? A set of computer speakers with an earphone jack would work, if your adapter uses 1/8" stereo headphone connec tors. Turn the volume way down, before turning it on.
Those mag phono preamps had the gain set to match the expected level of a c heaper cartridge. Some cheap cartridges put out up to 2V P-P. I used one ov er 45 years ago to bring the level up on the Network feed at a Military rad io station. That allowed a simple switch from local to network without adju sting the gain at every switchover.
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On Wed, 13 Jan 2021 07:58:33 -0800 (PST), Michael Terrell

Easy enough to try. Thanks.
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On Wed, 13 Jan 2021 07:58:33 -0800 (PST), Michael Terrell

It is not elegant but it works. It turns out the earphone jack must be attenuated because I had to turn the volume way up but it fixed my problem.
Thanks.
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