DSP + TDA7492 + TPA3118 or?

Thanks guys

Its academic for a month now.

I repaired a faulty tda7492 to try syncing the two units and it worked for a bit then they both died. I feel like never attempting anything like this again. So annoyed with myself.

I've ordered two more boards. Pffffff.


Hi

:D
never mind...during my TPA3255 mods i made a lot of mistakes:p:rolleyes::p
some burning things are part of DIY...;):D...should be calculated in the budget:p



chris
 
Hi

:D
never mind...during my TPA3255 mods i made a lot of mistakes:p:rolleyes::p
some burning things are part of DIY...;):D...should be calculated in the budget:p



chris

Your are very very right. I should have planned to fail! I was in such a foul mood when that happened, I've been wanting to finish this project for my friend (a pair of floorstanders as a present for being my best man and organising stuff) for ages!

I'll carry on, I'll get there in the end, thanks for all your input chaps!
 
diff dist -6.jpg

non diff dist.jpg
Your are very very right. I should have planned to fail! I was in such a foul mood when that happened, I've been wanting to finish this project for my friend (a pair of floorstanders as a present for being my best man and organising stuff) for ages!

I'll carry on, I'll get there in the end, thanks for all your input chaps!

Yeah, don't beat yourself up, been there and got the book.

Re the differential sure adau1701 and pcm5102, I took a couple off rough and ready measurements, the first pic is set up with differential in and out, the other with one channel disconnected and run SE into sound card.
 
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View attachment 788537

View attachment 788538

Yeah, don't beat yourself up, been there and got the book.

Re the differential sure adau1701 and pcm5102, I took a couple off rough and ready measurements, the first pic is set up with differential in and out, the other with one channel disconnected and run SE into sound card.

Looks super clean! It's fairly simple as I remember you saying?
 
Morning all.


New boards have arrived.


So, as Turbo suggested, I should do this bit by bit to chase down problems as they arise.


First off I checked both amps and they function properly. I set one to slave and connected them via the sync pin. BOOM. They work together absolutely fine as they are shown in the diagram.

However, they don't like having the same source, ie. an audio signal split going to each boards inputs. There is again, a high pitching whining. I tried disconnecting the ground from one signal input, no change. It seems to be when both boards share those positive signal lines.

Next I will make an isolated 5v power line and connect the DSP to ONE amp. If this is noise free I will see if the two boards run better from dedicated outputs from the DSP.
 

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How do you power your audio source? is there noise when only one source is connected to the amp?

Maybe you have not understood the cause of a ground loop. Any loop you close makes noise.
The power may be a ground line too, so if you use two power supplies, problems start.

If you use a laptop as source, while it runs on the battery, how is that? So no charger connected to the laptop.
 
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How do you power your audio source? is there noise when only one source is connected to the amp?

Maybe you have not understood the cause of a ground loop. Any loop you close makes noise.
The power may be a ground line too, so if you use two power supplies, problems start.

If you use a laptop as source, while it runs on the battery, how is that? So no charger connected to the laptop.

Source used was two mobile phones. The amps DO NOT make nasty noise when there is either one phone connected to one or two phones connected to both separately; only when one phone is connected to both it makes nasty noise. The phones were running on battery, I did this specifically to not create what you just described.

Do you only use two speaker for two amps? Don´t you know you blow them up without load? Has been written here about 100 times.

Whoops!
 
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Please use both outputs at each amp.

If not, short the input to ground
and
put a 4-16 Ohm resistor from output + to -

There is this problem with the cheap amps that no one can explain so far, always trouble with an open output. The amp will put energy into the output stage which, in some cases, destroys the D-chip.

If it oscillates, this might be the sound you hear, as it is transmitted to the other channel over the + power supply.

Maybe that killed your other amp, too.
 
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So... I'm a little confused over the consensus about these power supplies fr. The Window (formerly Sure).store. I've been buying my sure power supplies and amp modules from them for over 15 years.

Have inbeenakimg a grave error?

I design and fabricate my own speakers, and often use sure /.Window amps and power supplies to push them, and have been happy with results.

I've even tested the audio. Everything seems to be gravy. I'm no audiophile, and very well could beissing something.

Anyone wanna clue me in?

Pete, In
Rochester, NY