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3e Audio SY-DAPx002 TPA3250/TPA3255 DSP Amplifier

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It is not normal. Mine has hiss but sounds good when the music covers it.
So, mine does too, I think I made it seem like it was ALL noise when volume is turned up, but that's not the case, you can hear it at lower volumes for sure though.

The distortion, however, you can hear at medium to moderate levels. I'm going to be putting it on my oscilloscope today with some tones to see what it's actually doing.
 

Ralferator

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And sure enough, I got mine, definitely a hiss in the audio...now normally I'm not one to complain about something so little, but the S/N is just crap. Also, whether using external (RCA) audio or BT...it distorts pretty heavily. I was watching a show and wow...the speech was distorting pretty heavily. (Capt. Janeway's voice).

I'm not sure if this is normal or not, but coming from the mobile audio world, if you guys are hearing the same thing I am...and still consider it to be great sound....I'm going to have to question this forum's ability to discern good from bad audio. Hell, even my sister (who is dumber than a bag of hammers when it comes to sound/audio) noticed it.
With RCA it could be that your input gain is too high but with BT it's really strange. Maybe fake op amps again messing up what could be a really good amp?
 
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So, mine does too, I think I made it seem like it was ALL noise when volume is turned up, but that's not the case, you can hear it at lower volumes for sure though.

The distortion, however, you can hear at medium to moderate levels. I'm going to be putting it on my oscilloscope today with some tones to see what it's actually doing.

Yes as Ralferator said your rca input gain may be too high(make sure your input is 1vrms) if using a chromecast audio like I do, you'll have to disable full dynamic range option else it's 2vrms and will be overloading the amp 1vrms limit) as for bluetooth the only thing I can think of is that in the past it happened to me with another similar amp and I had forgotten to screw in the bt antenna...
 
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RCA input was a BT-B19 Bluetooth adapter, with the volume set to output 1vrms @ 1kHz 0db tone with out processing of any sort (no EQ'ing, etc), using my android tablet. So in essence both connections were Bluetooth.

The other thing I noticed, using my V30 phone (haven't tested my iPhone 11 Pro)...is that the V30 doesn't see the device as an AptX device...while it does see the BT-B19 adapter as one, and the SMSL DA-8S as one also....

There is definitely a discernible "fuzzyness" in the dialogue...oddly, even at lower volume. It's just not clean. I'm ordering NE5532's from Mouser, along with a few others 1602, 1612, etc. to try "rolling" (though I know they don't actually "color" the sound...).
 
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Jan 7, 2021
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Hello Sir,

I may buy this amp but will factor in replacing the Opamp from the go. Which version of the NE5532 would you choose? There a number of variants suitable for Dip8
 
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Aug 16, 2020
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Yes as Ralferator said your rca input gain may be too high(make sure your input is 1vrms) if using a chromecast audio like I do, you'll have to disable full dynamic range option else it's 2vrms and will be overloading the amp 1vrms limit) as for bluetooth the only thing I can think of is that in the past it happened to me with another similar amp and I had forgotten to screw in the bt antenna...
Where does it say the Amp has only a 1V limit? I thought 2V was the standard.
 
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Holy crap...I put it on the scope today noting connected... No speakers, no Bluetooth, no RCA's...(see third)

First thing I noticed, there is an audible hum/coming from the power supply while in standby mode.

Second, while turning on and the LEDs are circling around, you hear a very very faint click coming from the power supply until it's fully on... I'm assuming it's the relay.

Third, as I mentioned above... When I connected the scope's leads, there was a ~450kHz 1.5v peak to peak signal.

This signal seems to be evident during playback as I had the amp turned up to the 4th LED, my phone (iPhone 11 pro this time) was at 48% volume using a tone generator at 1kHz. The signal looked like complete trash. Now this could've been my fault, I'm still getting used to this scope and I was in a rush to leave. I will post screen grabs from the scope to show you guys... Maybe you'll have some insight.

The distortion is audible in music, Netflix audio (while watching shows), and everything in between..... At low volumes.

I'll update the thread with more, right now I'm not completely disappointed with the amp... But for the price? Come on.
 
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View attachment 104481

This sound from the capacitor in a snubber. Sound intensity varies with temperature. As the amplifier (the capacitor) warms up, the sound decreases. This sound also disappears when the power supply goes from active burst mode to normal mode.
Thanks for the explanation! I never knew and am still learning... Particularly about power supplies. Thanks again.
 

Ralferator

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@AfterThought you may only see below not audio signal?

View attachment 104471
I have a question. Do all delivered amps now have the strong hiss problem or will 3eAudio make a quality control check before delivery and make sure to build in op amps without that strong hiss?
I am thinking about ordering one, but how do i know if the amp will have this hissing problem and if i should from the start order better working op amps for it?
 

3eaudio

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Nov 8, 2018
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I have a question. Do all delivered amps now have the strong hiss problem or will 3eAudio make a quality control check before delivery and make sure to build in op amps without that strong hiss?
I am thinking about ordering one, but how do i know if the amp will have this hissing problem and if i should from the start order better working op amps for it?
confirm both integrated amp(3250/3255) start from mid of Dec had add these cap as our final solution. and the test data showed in product description page are base on that.
thanks for all these amigos's great feedback(almost this forum) and we will keep improve to make good product.
 

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