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Review and Measurements of Topping A30 and Schiit Magni 3 Headphone Amps

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So I guess I'm still waiting for a Topping ' A50' and a 'PA5'. That would be a true budget stack that should sound great. I see that you too found the headphone output to have a 'brightness / brassy' tone. Too bad you couldn't test it as a preamp.
I will wait for a better performing preamp/ headphone amp.
 

restorer-john

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I've seen some people change the opamp on the A30 with some of the ones that Burson sells. Wonder what changes that could make.

With the absolute dearth of objective reviews on anything Burson, I would not be breaking out my soldering iron if I were you.
 

Grave

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Yay, thank you for reviewing the Topping A30.

Wow, a Schiit product which does not have terrible performance. I would still not buy it. Topping seems to be the way to go at the moment. Otherwise I would buy a JDS Labs OL DAC + O2, but this has less power.

The Topping A30 has all the power I will ever need. I calculated it would drive the HD 650's to >130 dB. My headphones are 300 ohms and 150 ohms. This is 30x or 15x the 10 ohm output impedance, so the 10 ohm output impedance is not an issue for me.
 
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Mad_Economist

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The higher output impedance of Topping A30 can modify the frequency response of your headphone (for good or bad).

I think it's just bad. If users can change output impedance, it will be a good option to change sound signature. But Just high output impedance is the limit to choosing headphones. there are many headphones which have low impedance and erratic impedance graph.
 
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amirm

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I think it's just bad. If users can change output impedance, it will be good option to change sound signature. But Just high output impedance is the limit to choosing headphones. there are many headphones which have low impedance and erratic impedance graph.
What I meant was that the change in frequency response of a specific headphone may be positive, or negative subjectively. Not that having high impedance can be good per se.
 

Bhargu

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What I meant was that the change in frequency response of a specific headphone may be positive, or negative subjectively. Not that having high impedance can be good per se.

True, it is like adding distortion could make or break some types of music. My guess is the listener can go for it if he likes only certain types of music or if he uses different amps for different music. I just think it is a bit of PITA. Zout is not going to matter with planars anyway.
 

Bhargu

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@amirm BTW, what was the volume level with 4V with the 400i? Or was that the headphone rattling level that you mentioned?
 

Wombat

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Jacona

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Has anyone sent Amir a FiiO K5?
Would love to see a comparison between these two and the K5 since it's in the same price range.

FiiO's E10K did alright for what it cost.
 
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amirm

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@amirm BTW, what was the volume level with 4V with the 400i? Or was that the headphone rattling level that you mentioned?
It was. I preset it to that level and the attenuated as needed for what was I was playing using the Topping DX7s volume control.
 

sssn

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It's a shame that TPA6120 and its stupid 10 ohm zout just won't die. NwAvGuy was reviewing the Fiio E9 with that chip 7 years ago. The A30 is cleaner, but still, 10 ohms zout...

Chinese manufacturers adore the TPA6120. Like 90% of Chinese desktop headphone amps feature this chip.
 

xxie

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Why would that be?
one reason: price.

From TI website (1K unit price):
TPA6120: $1.56
OPA1622: $2.9
BUF634: $5.68

I read somewhere TPA6120 is actually re-branded ADSL modem transformer driver, that is why we see such crazy slew rate at 1300v/us. If read the data sheet really carefully, I have a feeling that even data sheet writer think it is a bad choice for audio: it is a current-feedback opamp which is very hard to avoid oscillation.

I don't think BUF634 is good choice either. You need add another opamp for voltage amplifying and insert the BUF634 into the feedback loop.

OPA1622 might be the only opamp designed from ground-up for headphone amplifier, It get really good spec in noise, idle current, slew rate, short-circuit protection etc. (another one might be NJM4556 as used in O2, but the idle current bit high at 9mA, no short-circuit protection). It is just hard to DIY for the VSON-10 package and do proper layout. I really hope Topping can come up a design with OPA1622, it is not too expensive.
 
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Jimster480

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Nice review and measurements as always.

I've seen some people change the opamp on the A30 with some of the ones that Burson sells. Wonder what changes that could make.
Probably reduced performance and oscillation.
I changed my A30's OpAmp with the LM4562 and there were a couple specific test scenarios where certain parts of certain complex tracks sounded clearer.

I have a D30 / Magni 3 stack, and it's fine. Not the prettiest thing in the world (the Magni is ever so slightly wider than the D30, and the D30 is "deeper" than the Magni) but it works, and the feet of the Magni sit securely enough on the D30. This is the combo I recommend to pretty much everyone (either that or the D10 / Magni 3 stack if you don't care about aesthetics or having a DAC w/ external power).
I tried that but the Magni3 sounded bright to me, and it has so much power even on low gain that any low impedance headphone literally has no volume control.
 

Jimster480

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one reason: price.

From TI website (1K unit price):
TPA6120: $1.56
OPA1622: $2.9
BUF634: $5.68

I read somewhere TPA6120 is actually re-branded ADSL modem transformer driver, that is why we see such crazy slew rate at 1300v/us. If read the data sheet really carefully, I have a feeling that even data sheet writer think it is a bad choice for audio: it is a current-feedback opamp which is very hard to avoid oscillation.

I don't think BUF634 is good choice either. You need add another opamp for voltage amplifying and insert the BUF634 into the feedback loop.

OPA1622 might be the only opamp designed from ground-up for headphone amplifier, It get really good spec in noise, idle current, slew rate, short-circuit protection etc. (another one might be NJM4556 as used in O2, but the idle current bit high at 9mA, no short-circuit protection). It is just hard to DIY for the VSON-10 package and do proper layout. I really hope Topping can come up a design with OPA1622, it is not too expensive.
The TPA6120 requires you to have a high output impedance (atleast 10 ohm) to prevent oscillation.
But the distortion and power characteristics are stellar for the price especially.

It is funny that you mention current-feedback designs being difficult, when Schiit talks about the "exotic" current-feedback design of the Magni3 and how this "exotic technology is only featured in amps that are multiple times its price", yet most of the cheap amps on the market are using the same design due ot the TPA6120....
 
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