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oneway
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21/04/2020 8:29 pm  

Last year I bought my brother a pioneer sx10ae (I believe is the correct model number not that it matters too much) which is a pretty bare bones 2 channel receiver with Bluetooth and a sub out.

He primarily uses it while watching tv occasionally dvd and music through Bluetooth  He recently purchased a new tv. As with most new TVs it has no analog outputs so he bought a optical to rca convert. The problem with it is that he’s lost a noticeable amount of output. Luckily his DVD player has analog outs so I was able to hook it up to the stereo. 
So I’m looking for suggestions on what can be done to solve the problem with the weak signal with the converter. I found nothing in the audio settings on the tv to help with the issue either. 


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DIYAudiphileElliottBridge
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22/04/2020 3:06 am  

It sounds like a problem with the converter to me, get one that is powered separately from the digital input and make sure its output is "line-out" as that is a specific voltage that receivers are made to receive. I hope that helped.

Edit: Most DACs have their own volume control so make sure that this is turned up also.


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oneway
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22/04/2020 5:31 am  

I’m pretty sure there’s no volume/gain. It’s working and the lights on. I would estimate around a -3 to -6 dB response. I’ve never personally needed a dac so my experience with one is 0. 
I will double check it and make sure there’s no volume knob next time I’m up there. If I’m right I’ll suggest getting one with volume control. I’m sure he got the cheapest one he could find.
Makes since and thanks for the response 


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TVOR-Ceasar
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25/04/2020 5:08 pm  

Sounds like he has the same type of problem I have with the HDMI audio from the cable box. The TV I bought years ago had the most powerful amp out of the lot (in my price range), yet when I use the cable box to watch shows or movies, it gets cranked to 100 and is still very quiet. Then comes the commercials and the scramble for the mute button. When using any other input, including other HDMI devices (i.e. Firestick), 30 is about as loud as we need.

I haven't done it yet, but I have things fed into the surround system and I really want to make up a small, simple "booster amp" for the times when it's just the cable box in use. I have a very clean and simple 9V unit that will overpower the inputs on most consumer equipment if not attenuated down a bit. If you or your brother are comfortable enough to build a circuit from scratch, I'd be willing to share.

Actually, since he probably has a USB port available, I can mock one up for 5V use.

-Charlie


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oneway
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25/04/2020 5:47 pm  

@tvor-ceasar 

if I did anything like that it would be my first attempt. So not sure about that. 
I’m trying to talk him into buying a ht receiver. He should all the equipment i donated (except the dac)so it wouldn’t hurt for him spend a little money on it.  Would give some room to grow and me a reason to build some speakers. 
I wouldn’t mind seeing what you’re doing with that though . See what it takes see if I might be interested in doing stuff like that. Thank you 


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TVOR-Ceasar
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25/04/2020 5:55 pm  

@oneway

I might need a slight bit of time to bring it round, as I am still busy with some work and tomorrow is a heavy day with my wife's company. I'll give it the old college try tonight.

-Charlie


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oneway
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25/04/2020 6:25 pm  

@tvor-ceasar no worries I should be at the bottom of your list of things to do lol. I’m more curious about it more than anything. My electronic skills consist of curiosity at this point as far building anything 


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oneway
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25/04/2020 6:38 pm  

@tvor-ceasar your response made me think of something else.I have a question you may or may not be able to help with. 
i have the Dayton 250 watt plate amp that has been sitting on a shelf for a while. Powers on and works like it should but then will make kind of a feedback noise and throws the sub to full excursion and will hold it there until I can frantically turn it off. Turn it back on and it usually will work. 
just wondering if you might have an idea of what might be the problem?  


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TVOR-Ceasar
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25/04/2020 9:57 pm  

@oneway

Sounds like the squeal is a component heating up and causing oscillation which saturates the output section. When you turn it off and back on, it changes it just enough to dampen the oscillation.

What causes it? Could be any single thing or combination. I'm leaning toward 3 possible scenarios.

A failing capacitor

Bad solder joint

Micro crack in the board

When you first turn it on, components heat up and expand. Capacitors have to charge up. If the cap is electrically leaky, it can cause oscillation. The shock of turning it off and on actually helps stabilize the charge for a time.

Bad solder joints can really wreak havoc in many different ways - too many to list here. Basically it is the same thermal heating and cooling that affects the connection of the joint.

Micro crack - well, you get the idea of the thermal problems listed above.

About all you can do is close inspection with good magnification to hopefully narrow it down to a certain area.

-Charlie


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oneway
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26/04/2020 2:27 am  

@tvor-ceasar 👍 thanks I’ll give it a look over soon. It’s only a little over a year old but since it’s refurbished the warranty already up. 


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123Toid
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26/04/2020 2:37 am  

@oneway

Check to see if the tv has a variable out.  The easiest way to do this is to turn up the volume on the television remote.  If that turns up the volume of the pioneer, it is set to variable.  Most televisions now a days have a way to set it as either a variable or fixed in the settings.  Either way, he should check the setting and put it on fixed and disable his television speaker.  There should be a way to disable those.


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oneway
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26/04/2020 4:06 am  

@123toid I set the tv to pcm and optical out which turns the tv speaker off. When you adjust the volume on the remote an icon appears on the screen that says optical audio out if I remember right. So assuming it’s not variable.There’s no adjustment in the settings. 65” Samsung idk the model # but it’s last years or perhaps year before model from sams club. 
idk I’m almost done with his mids and highs so when I take them to him I’ll get the model # and look up the manual if he doesn’t have a paper copy and see if I can find one and see if maybe I over looked anything. 
I might keep it a secret though. I think he’d enjoy a ht receiver if I can convince him to get one. 


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123Toid
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27/04/2020 1:56 am  

sounds like it is set right.  That is weird.


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TVOR-Ceasar
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30/04/2020 12:47 am  

Did a bit of sleuthing. I think this one is his DAC. If you look here, it says 0.3v output electrical level. Now, this is what all home components used to be set to. I don't know about today's components, but I hear they all need a higher level signal.

-Charlie


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oneway
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30/04/2020 1:50 am  

It’s this one  I see it in the link  .3v isn’t much compared to other dacs. We improved his mids and highs with some better higher sensitivity speakers, he had a set of acoustimass Bose, so that helped but I think he’ll end up with a new receiver before too long.
He’s never had anything really worth a darn. The Bose are mine I’ve had since

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the early 90s. I can’t stand them but they’re easy to store and work in a pinch. I don’t think he realizes how much of an  improvement he would get with a ht receiver. It’ll just come down to how bad he wants his tv to sound as good as his other sources. I’m sure something like the schiit modi would get it there but for double the $ a 5.2 receiver could be even more of an improvement on the whole system. 

thanks for looking that up. It’s definitely the weak link in the chain. 


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