PowerPad and the ultra extreme headphone amp TPA

[carlosfm]

P-A, I received a very nice message on my PM some days ago telling me that TI sells the PCB of the appnote.
In the States it's $49.
That guy bought it, built and reported me the results.
That's why I said I have "news" that this chip is worth a try.

 

[peranders]

I like it but its not quite powerful enough for my needs.

How do you mean? What type of headphones do you have?

 

[thomas997]

How do you mean? What type of headphones do you have?

Some crappy Sony MDR or something. Not very good.

Its just that the output I have is very low, so I will try increasing the gain and see how it does.


Soldering is a little challenging. If you can find some sort of socket for it, that would help a lot.


Carlos: I tried with 12V as well, seemed to help a little. and yes i need to increase the gain. Just wanted to build it identical to the datasheet first.

 

[00940]

There must be something wrong with your amp. There are a few TPA6120a2 running and nothing like this lack of power was reported. Check for example this thread : http://www4.head-fi.org/forums/showthread.php?t=74525&highlight=tpa*

 

[peranders]

Thomas, I vote for something isn't otpimized. Weak input signal? Altough with only gain of 2 your ears will hurt and 5-7 Vrms will make your headphones to glow.

An oscilloscope may do some good. Can you drive the amp to clipping for instance.

 

[carlosfm]

Altough with only gain of 2 your ears will hurt and 5-7 Vrms will make your headphones to glow.

Nah...
With a portable device?
I can bet that the mp3 player doesn't even get to 1V output.
500mv~750mv is common for portables.
You can't ask much more for a thing that runs with one or two 1.5v batteries...

 

[Upupa Epops]

Hello again, guys . What do you think about this idea : ten of these chips connected in parallel will can easy drive an speaker box and I mean, that it will be more better than any Aleph or Hiraga . Any comments ?

 

[Upupa Epops]

Mea culpa - not Aleph, Zen .

 

[carlosfm]

Hello again, guys . What do you think about this idea : ten of these chips connected in parallel will can easy drive an speaker box and I mean, that it will be more better than any Aleph or Hiraga . Any comments ?

Mmmmm...
Well... if you parallel another 10 and bridge 10+10, we may be talking more serious business.

 

[peranders]

Carlos, I ment of course that the gain must be adjust for the application. If thomas has a weak signal he must increase the gain which is done very easily.

 

[carlosfm]

Carlos, I ment of course that the gain must be adjust for the application. If thomas has a weak signal he must increase the gain which is done very easily.

That's what I meant on a previous post.
2x gain is low, as he is testing with an mp3 player.
If the intention is to make a headamp for portables, gain should be much higher.
But the feedback resistor must remain as per the manufacturer's recommendation.

 

[peranders]

But the feedback resistor must remain as per the manufacturer's recommendation.

Indeed, becasue this is a current feedback amp where you also control the speed with the feedback resistor.

 

[ericallan]

Tip for soldering pad

I cut a small rectangle of copper out - the width of the chip - heated a blob of solder on the centre with a gas torch, then quickly stuck the chip on the molten solder. I then hard wired leads to the active legs of the chip and made up the circuit as per the basic evaluation model.
It sounds very good - my friend has a Chiarra Single Ended Class A Headphone Amp - and he was a bit sickened to hear this almost free amp.

 

[carlosfm]

Re: Tip for soldering pad

It sounds very good - my friend has a Chiarra Single Ended Class A Headphone Amp - and he was a bit sickened to hear this almost free amp.

Wednsday I'm going on holidays for a week.
Don't make me take the soldering iron to the beach, please.

 

[Upupa Epops]

How you can endure it - you must have realy big other inspirations, probably with nice t... !

 

[carlosfm]

How you can endure it - you must have realy big other inspirations, probably with nice t... !

Ah yes... forget the soldering iron...

 

[Devil_H@ck]

So, how would one solder this chip to a PCB? Would applying solder to the copper, then putting the chip on & then warming up the opposite side of the PCB work?

 

[peranders]

Today I have started to convert my QRV04 headphone amp to AD8620 and TPA6120. I have great expectations in this IC.

The pcb will be easy to solder, even the "PowerPAD".

I haven't desided yet if the TPA6120 should run in inverting mode or not.

 

[matjans]

haven't checked the datasheet yet but it should be doable to solder.
here's a guide to soldering smd parts .

 

[Upupa Epops]

Matjans, problem is soldering of POWERPAD, which is something quite different .