Cheap ebay 6120A2 amps - any experience with these?
Dec 3, 2012 at 10:57 AM Thread Starter Post #1 of 9

Headzone

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HA INFO mini-ear Headphone Amplifier
 
http://www.ebay.com/itm/HA-INFO-mini-ear-Headphone-Amplifier-TI-TPA6120A2-for-HIFI-headphones-/380461843386
  1. [size=12pt]6.35mm headphone socket for 16-600Ω Hi-Fi headphones[/size]
  2. [size=12pt]Power output: 1000MW ( 32 ohms ), 300MW ( 120 Ω), 150MW ( 250 ohms )[/size]
 
 

SMSL sApII TPA6120A2 Headphone Amplifier

http://www.ebay.com/itm/261131930434
cheaper version: http://www.ebay.com/itm/SMSL-sApII-TPA6120A2-Big-Power-High-Fidelity-Stereo-Headphone-Amplifier-/271108319467?pt=US_Amplifier_Parts_Components&hash=item3f1f50a8eb
• Output power: 150mw / 250Ω, 300mW / 120Ω, 1000mw / 32Ω
 
 
 
They use the same opamp as Fiio E9 and some Asus mid-fi sound cards. Both seem quite powerful to run even 600Ω headphones. They are half the price of a new Fiio E9, just wondering where did they cut corners to get the price this low?
 
 
 
There's also one (small) review of the S.M.S.L amp here on head-fi: http://www.head-fi.org/products/smsl-sapii-tpa6120a2-big-power-high-fidelity-stereo-headphone-amplifier-golden/reviews
 
Dec 3, 2012 at 11:29 AM Post #2 of 9
It's probably some sort of 18v cmoy clone in a fancy case.
 
Dec 3, 2012 at 11:51 AM Post #3 of 9
In looking at the board for this one http://www.ebay.com/itm/261131930434 there does not seem to be any protection circuitry for your headphones. (I doubt it's on the back of the board but I could be wrong...)
 
It's my understanding that TI's TPA6120A2 chip can have high enough levels of DC on the output to destroy your headphones if anything goes wrong with that kind of minimal build.
 
Dec 3, 2012 at 5:11 PM Post #4 of 9
Some folks at DIY audio have used the mentioned amps, do a search there if you don't have luck.
 
Dec 4, 2012 at 1:29 AM Post #5 of 9
Quote:
They use the same opamp as Fiio E9 and some Asus mid-fi sound cards. Both seem quite powerful to run even 600Ω headphones. They are half the price of a new Fiio E9, just wondering where did they cut corners to get the price this low?
 

The fiio e9 uses opa2134 for the gain stage and tpa6120 as a buffer. This only has a tpa6120. They also used a different cheaper power supply scheme. This might be good for someone looking for something cheap to power demanding headphones.
 
Dec 4, 2012 at 2:54 AM Post #6 of 9
Quote:
HA INFO mini-ear Headphone Amplifier
 
http://www.ebay.com/itm/HA-INFO-mini-ear-Headphone-Amplifier-TI-TPA6120A2-for-HIFI-headphones-/380461843386
  1. [size=12pt]6.35mm headphone socket for 16-600Ω Hi-Fi headphones[/size]
  2. [size=12pt]Power output: 1000MW ( 32 ohms ), 300MW ( 120 Ω), 150MW ( 250 ohms )[/size]
 
SMSL sApII TPA6120A2 Headphone Amplifier
http://www.ebay.com/itm/261131930434
cheaper version: http://www.ebay.com/itm/SMSL-sApII-TPA6120A2-Big-Power-High-Fidelity-Stereo-Headphone-Amplifier-/271108319467?pt=US_Amplifier_Parts_Components&hash=item3f1f50a8eb
• Output power: 150mw / 250Ω, 300mW / 120Ω, 1000mw / 32Ω
 
They use the same opamp as Fiio E9 and some Asus mid-fi sound cards. Both seem quite powerful to run even 600Ω headphones. They are half the price of a new Fiio E9, just wondering where did they cut corners to get the price this low?
 
There's also one (small) review of the S.M.S.L amp here on head-fi: http://www.head-fi.org/products/smsl-sapii-tpa6120a2-big-power-high-fidelity-stereo-headphone-amplifier-golden/reviews

I have the sApII TPA6120A2 headphone amplifier, not that impressed.
I own 4 SMSL products 2 are not working
Advise spending the extra cash for the Fiio E9.
 
Dec 4, 2012 at 9:11 PM Post #7 of 9
Quote:
I have the sApII TPA6120A2 headphone amplifier, not that impressed.
I own 4 SMSL products 2 are not working
Advise spending the extra cash for the Fiio E9.

Ok, I think i'll pass and buy used O2 unless I find anything else cheap and good performing.
 
Would the sApII TPA6120A2 be worth the price even sound-wise, if we forget about the bad build quality and lack of DC protection trolldragon mentioned? ie. how did it sound when compared to your other amps, does it have huge background noise etc..? 
 
Dec 4, 2012 at 11:31 PM Post #8 of 9
Quote:
Ok, I think i'll pass and buy used O2 unless I find anything else cheap and good performing.
 
Would the sApII TPA6120A2 be worth the price even sound-wise, if we forget about the bad build quality and lack of DC protection trolldragon mentioned? ie. how did it sound when compared to your other amps, does it have huge background noise etc..? 

With my 250-Ohm headphone running at normal listing levels it's fairly good, but crank the volume and you can hear the noise.
But for $80 you can get a used Fiio E9.
 
Jul 8, 2013 at 3:46 AM Post #9 of 9
This is a my modification of this HPA, which I made​​. In the original diagram I had very high DC offset at the output TPA (+ - 180 mV). After adjusting circuit diagram the DC offset is now -4.9 mV and 0.7mV. 

 

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