Chinese TPA6120 eBay module warning!

[ivanlukic]

I just received information from Serbian forum that left electrolytic on the picture is incorrectly polarized, it should be rotated for 180 degrees.

1PCS TPA6120 Hi-Fi Stereo Headphone Amplifier AMP Audio Amplifier +-5V to +-15V S | eBay

 

[ivanlukic]

More info. It seems that on some of the modules everything works fine. So some modules are good.

 

[weissi]

Well, I have about ten of these modules from two batches. Even the silkscreen is wrong. Surprisingly it only was about the fourth module or so that started up in Badaboom 😉
All in all not a big thing, its easy to change the 'lytics and the price is still awesome.

 

[ivanlukic]

I bought mine for output stage of low distortion oscillator where both channels will be used in parallel to provide high current for the load as low as 50R. Have you tried it as headphones amp? Is it good?

 

[weissi]

Yes, I use them as headphone amps. For my K702 and T50RP I needed something with a little bit more oomp. I'd say it is very good, even better if you mod the board for balanced input which can be done but one needs 0603 resistors. The PCB layout is prepared for balanced in.

 

[xrk971]

I have tried this recently and it sounds quite decent - has 0dB gain though so just a current buffer. Nice built in linear PSU with dual voltage regulators and bridge and smoothing caps.

TPA6120 Headphone Amplifier Board HiFi TPA6120A2 Dual Channel Headphone Amp | eBay

Caps all appear to be in correct orientation. Plus, the resistors are all metal thin film and film bypass caps are used. Metal thin film has lower distortion than metal thick film SMD's when used on feedback circuit path.

 

[phase]

Wow, that looks much better than the usual stuff. Great find.

 

[bwolf]

More info pls (reg Cap ) i just ordered one for my CSR8645

 

[abraxalito]

I just got one of these TPA6120 boards from Taobao - very cheap - and it gets my award as the worst sounding amp I've ever heard. There must be something wrong with the circuit. The pot is 50k and that goes direct to the input of the TPA, where the typical bias current is 4uA. The result is the pot sounds 'scratchy' as its turned but this is the least of this amp's problems.

 

[abraxalito]

Ignore my last post, finger trouble! I hadn't twigged that this amp was entirely DC-coupled when I fired it up and I'd connected it to a prototype DAC that had very significant DC offset on its outputs. Putting some series capacitors in-line has fixed it from sounding so awful, its now not bad at all for the money although clearly adding its own veiling when compared to a direct feed.

 

[kstlfido]

Hi folks-

Im making a little phono preamp for a friend, repurposing an old surplus military box. Pics attached.

I was going to use the Electronics Salon RIAA preamp-
Stereo Phono RIAA Preamplifier Module Board, Preamp, MD-A310. | eBay
-and thought it would be cool to add a headphone amp inside.

I'd like to use a kit or get a decent headphone amp board off ebay. There are numerous choices out there. There are some great builds/projects here on diyaudio-

"WHAMMY" Pass DIY headphone amp guide

The Objective2 (O2) Headphone Amp DIY Project

The Wire - All Boards and Kits Explained Here!

The Objective2 (O2) Headphone Amp DIY Project

But it needs to fit in this little box. 80x50 mm.

TPA6120 Hi-Fi Stereo Headphone Amplifiers mentioned here, but what about these?

https://www.ebay.com/itm/RA1-clone-...h=item41f33fb549:g:tB4AAOSwkNZUlYOy:rk:1:pf:0

https://www.ebay.com/itm/HV-10-RA1-...=item33f10a574d:g:WkEAAOSwKLxbYvI8:rk:89:pf:0

https://www.ebay.com/itm/47-Amp-Hea...=item5467e8f67b:g:n4MAAOSw8R9cJttG:rk:57:pf:0

Any good feedback out there on the above headphone amps?

Thanks! -Kent

 

[ivanlukic]

Grado RA1 clones from your list are very good but these can not fit in your little box.

 

[Andersonix]

Hi Kent!
I just ordered two of the pink TPA6120 pcbs at under $5 each, so I'll let you know how it sounds when it arrives (in 3-4 weeks!)
It's quite flexible about the ps: +/-5V to 15V.
Stay tuned.

 

[Andersonix]

A composite pic w schematic by Pavouk attached.

 

[kstlfido]

Thanks, I look forward to your listening impressions!

 

[Spacehead]

I was thinking about testing this one. It looks interesting. I have tried TPA6120 before, nothing special about. How is the DC offset?

 

[impuls60]

Anyone tried building these in parallel or to mono amps? I wonder if the 10 ohms output resistor could be swapped for 300nH air coil like another member here did? I need more current for my 25ohms HE400SE Hifiman. On Ali these amps can be had for 2.65usd a pop.

 

[weissi]

Use one module for each channel, keep the 10Ohm resistor - you might want to put the inductor in parallel to the resistor, effectively shorting the resistor out for lower frequencies.

 

[impuls60]

Thats probably a good idea. I looked at the composite amp schematic and I got the feeling the custom feedback loop makes the inductor idea possible. So I might instead try 3 chips in parallel to get the output impedance down.