Sabaj A20h Balanced Headphone Amp Review

[IAtaman]

Weird that theres no output in the front where the dial control is, you need to plug in from the back.

That is indeed a bit irritating but not the main problem with this amp in my view. You can plug in a short XLR to whatever you need connector cable and problem solved.

The main issue I had with this amp was that it was very prone to creating noise from nearby mobile devices - that made it unusable on the desk for me. It's waiting for the day that I will find the time to disassemble it and convert it into an DAC/AMP combo with built-in CamillaDSP.

Sabaj A20h Balanced Headphone Amplifier Owner's Thread

Today the remote control stopped responding even when I changed its batteries. That's a shame since I find it easy to change the gain when switching between headphones and IEMs. However, when I search for a replacement I find this description: 'Sabaj Audio Amplifier Remote Control, suit for...

audiosciencereview.com

 

[OK1]

They are testing at 5 volts while I have standardized on 4 volts in/4 volts out. 5 volts improves SNR which in turn improves SINAD since we are noise limited.

Thanks Amir, now I understand better. Do SMSL, Topping and Schiit, also "improve" their results using this kind of variation in their test results?.

I'm fully committed now to take decisions based on measurements, and I have fair confidence, that because you are keeping these manufacturers honest and on their toes - after all they now send you gear for your independent evaluations, that it would be foolish for them to deliberately fudge their published specs, beyond reasonableness.

So even where you have not tested, or reviewed a item, I have some confidence in the published manufacturer specs, at least some confidence. Therefore I can buy (at least from the manufacturers who publish specs well like Schiit, SMSL and Topping) based on spec and features, user reviews of durability and issues, and price. Paying no more attention to subjective reviews, none of them are double blind tests. None.

Combining this objective information, with a good knowledge of the audibility thresholds, one can make a most informed buying decision.

I appreciate all that you do. Just a few of you have changed this whole industry. Thank you.

 

[anphex]

Looking at videos if the recent High End Audio Fair in Germany I am again and again grateful on how we have the option to get reference gear for a fraction of the costs of the stuff that usually gets displayed at those fairs (and performs better). I kind of feel sorry for people who save up years to get a setup with dozens of devices and huge speakers when they could have gotten the same or better performance for a 1/50 of the cost.

Always remember guys, knowledge is money.

 

[Lambda]

am going to shorten the review a bit by focusing on balanced input and outputs. Unbalanced would be close.

Are the Outputs truly balanced? (and Symmetrical Differential? )
if so I would assume the Max. output lower if used with Non balanced headphones.

 

[carlcamper]

My unit A20h also has slight crosstalk, but it is less then my Asgard 2 and way less then Zen Can.
Actually when balanced to balanced it gives more crosstalk, then balanced to 6.3mm.
Funny Little Dot mark 2 has zero audible crosstalk also Creative AE-5 headphone amp has no crosstalk at all.

Thanks for confirming this. My other balanced amps also have zero crosstalk, like my Topping A90D, Qudelix 5k, and Moondrop Dawn, so this makes me suspicious that the A20h isn’t fully balanced. Still a great buy for the relay volume control with remote, and the max output!

 

[Roland68]

Thanks for confirming this. My other balanced amps also have zero crosstalk, like my Topping A90D, Qudelix 5k, and Moondrop Dawn, so this makes me suspicious that the A20h isn’t fully balanced. Still a great buy for the relay volume control with remote, and the max output!

The Topping A90D is not completely symmetrical, like the A20h. You can always tell this by looking at the volume controls or the number of relays. In this case, both devices are only stereo, so 2 channels, not 4, for volume control.

 

[vins555]

I think A20h is fully balanced it has four TPA6120. Topping L70 has the same number of volume relay(as I see). On A20h if you plug the phones in 6.3mm and plug in the dac in XLR and RCA, then you will hear the sound from XLR input is louder even on 6.3mm output.

 

[carlcamper]

I see, thanks for the clarification. Being balanced isn’t a guarantee of zero crosstalk then. Somewhere in the circuitry there must be bleeding into the other channel going on.

 

[vins555]

But anyway, crosstalk is less audible then even on Schiit Asgard 2

 

[uwotm8]

The question is if it's actually good to have zero crosstalk with headphones. The more crosstalk the more binaural it goes

 

[carlcamper]

The question is if it's actually good to have zero crosstalk with headphones. The more crosstalk the more binaural it goes

True. The music may have been mastered to have left and right channel isolation, but playing it back in speakers or listening to a live performance will always have sound coming to both ears!

 

[Roland68]

I think A20h is fully balanced it has four TPA6120. Topping L70 has the same number of volume relay(as I see). On A20h if you plug the phones in 6.3mm and plug in the dac in XLR and RCA, then you will hear the sound from XLR input is louder even on 6.3mm output.

Inputs and outputs are balanced, but before the volume control it is debalanced and then balanced again. This is normal and can also be found in very expensive devices. It is not a disadvantage.
This applies to A90D, A20h, L70 and most devices. One of the few exceptions is the Singxer SA-1

The question is if it's actually good to have zero crosstalk with headphones. The more crosstalk the more binaural it goes

The controlled version of this is called crossfeed. There are a few headphone amplifiers that have it built in, e.g. Meier Audio Crossfeed.

 

[vins555]

SMSL SP400 only has 8 relays, and even Flux labs FA-12s also has 8 . But original Topping a90 had quad potentiometer.

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[Jimster480]

I am kind of amazed at (apparently) how many members use headphones. I did not realize they were so popular. My father had the original Koss Pro 4AA in the 80's. They were so uncomfortable I think they scarred me for life.

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I would say that a large portion of this forum is headphones, and this is why we appreciate headphone amplifier reviews such as this one. I mean, honestly, in the modern day world, headphones are more popular just due to the prices of living space in general.

 

[Veri]

My unit A20h also has slight crosstalk, but it is less then my Asgard 2 and way less then Zen Can.
Actually when balanced to balanced it gives more crosstalk, then balanced to 6.3mm.

Interesting. Thanks for reporting. I've mostly used it BAL in SE out, so no complaints from me....

For the low price, I can't say there's been a single competitor that does as much for the $'s I've paid. So good job Sabaj

 

[ampguy]

Thank you for reviewing it @amirm even if a bit late.
As an axtremely pleased owner of an A10h i was on the verge of buying it since it was at 90€ at Amazon for a long time, never done because I mostly use iem and the lack of negative gain was a concern. The 50mv measurement confirmed that it would not be a perfect choice for my scenario, otherways very very nice for less sensitive phones.

I also considered both and went with the a10h for the preamp mode, but ultimately looking for a small all in one to replace this small desk top hp amp with sys switcher, and Fosi v3 down to 1 or 2 devices w same functionality.

 

[Roland68]

SMSL SP400 only has 8 relays, and even Flux labs FA-12s also has 8 . But original Topping a90 had quad potentiometer.

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Exactly, and with 8 relays you can only control 2 channels = stereo, because with balanced you would only have 16 levels of volume control with 8 relays.
Normal quad potentiometers are not a good idea either. All potentiometers, but especially these small green ones like in the A90, have fluctuations in relation to each other on all 4 levels. In addition to the fluctuations from right to left, they also have fluctuations from + to - in the same channel. One reason why my Singxer SA-1 is currently mothballed.

 

[mc.god]

Manufacturer Specifications:

View attachment 372296

Just now I noted a discrepancy in the medium gain spec, on the same page where you can read those data (+9db) you can also see this gigantic info

Could this be simply an error or maybe it has different gain for SE and balanced outputs (something like Topping A50III from it's specs)?

 

[AdamG]

Just now I noted a discrepancy in the medium gain spec, on the same page where you can read those data (+9db) you can also see this gigantic info

View attachment 372766

Could this be simply an error or maybe it has different gain for SE and balanced outputs (something like Topping A50III from it's specs)?

I don’t know specifically. I just copy & pasted the Manufacturer Specs listed on their site. You might be able to sus out the answer in the Owner’s manual (linked below)

SABAJ-A20h-Manual.pdf

drive.google.com

 

[mc.god]

I don’t know specifically. I just copy & pasted the Manufacturer Specs listed on their site. You might be able to sus out the answer in the Owner’s manual (linked below)

SABAJ-A20h-Manual.pdf

drive.google.com

Thank you, I lazily didn't think about the manual.
And ok, it is variable indeed but what changes is the high setting, so the specs pictures on their site is at error: