Topping A90 Headphone Amplifier Review

[dpippel]

Playin' around today. Once again, I've gotta give a shout-out to Apos Audio. Ordered the A90 late Monday afternoon, it shipped from mainland China on Tuesday, and it was at my door in Arizona today. DHL Express shipping was free and I paid no sales tax. Sweet!

 

[A.Cristea]

Are there any DAC match reccomendations for the Topping A90 (preferably not exceeding 500€)?

I was thinking of:
Topping D70 DAC: 500€
Soncoz LA-QXD1 DAC: 250€

The Topping D90 with 700€ would be probably a bit too pricey as i wouldn't use all of its features. I would basically want to link the Amp to the DAC (trough xlr ), the DAC to the my focusrite 8i6 soundcard (through coax or optical cable) and the soundcard to the iMac (i was reccomended the
halide bridge converters but i'll look into at a later stage).
Btw i'm using Audeze LCD-3 headphones.

 

[mt196]

Both SONCOZ seems to be a good choice for A90 pairing, I think they have both extremely good value for what they cost, especially if you need xlrs

 

[DavidBloch406]

Are there any DAC match reccomendations for the Topping A90 (preferably not exceeding 500€)?

I was thinking of:
Topping D70 DAC: 500€
Soncoz LA-QXD1 DAC: 250€

The Topping D90 with 700€ would be probably a bit too pricey as i wouldn't use all of its features. I would basically want to link the Amp to the DAC (trough xlr ), the DAC to the my focusrite 8i6 soundcard (through coax or optical cable) and the soundcard to the iMac (i was reccomended the
halide bridge converters but i'll look into at a later stage).
Btw i'm using Audeze LCD-3 headphones.

I link the D70 and the A90 and I’m very pleased: I really like the AK4997 implementation in the D70 and it seems very well sorted - I’m a little put off by the tech issues with the D90. At $399 I think the D70 is great value - and of course the A90 is a very fine amplifier, just as reported.

 

[EdW]

Are there any DAC match reccomendations for the Topping A90 (preferably not exceeding 500€)?

I was thinking of:
Topping D70 DAC: 500€
Soncoz LA-QXD1 DAC: 250€

As already pointed out the Soncoz SGD1 would be just inside your budget. To differentiate it from the very good LA-QXD1 it has a built in power supply, a remote control and improved performance. Probably nearer the quality of the A90? I see that you are quoting prices in Euros - if you are based in Europe you might consider a purchase from Purite Audio in the UK

https://www.puriteaudio.co.uk/

Keith‘s prices are competitive on Soncoz. Plus he frequently contributes his expertise to ASR

 

[A.Cristea]

Thanks for the tip, with 185GBP it lands in my bucket list #1 - I will also dig more into the SGD1 (around 400GBP -> 450€) which has a sick design (however with that Price tag i'd be probably more tempted to get then the D70).

Also thanks to @DavidBloch406 and @mt196 for the contribution. I ordered today my A90 and i can't wait for the delivery - Meanwhile i'll look into which DAC to get.

 

[EdW]

Thanks for the tip, with 185GBP it lands in my bucket list #1 - I will also dig more into the SGD1 (around 400GBP -> 450€) which has a sick design (however with that Price tag i'd be probably more tempted to get then the D70).

Also thanks to @DavidBloch406 and @mt196 for the contribution. I ordered today my A90 and i can't wait for the delivery - Meanwhile i'll look into which DAC to get.

Sorry about my formatting of the first post - my careless typing!
For the avoidance of any doubt both Soncoz DACs have now conquered the irritating IMD hump, a feature of all so many ESS9038 implementations

 

[Harmonie]

I link the D70 and the A90 and I’m very pleased: I really like the AK4997 implementation in the D70 and it seems very well sorted - I’m a little put off by the tech issues with the D90. At $399 I think the D70 is great value - and of course the A90 is a very fine amplifier, just as reported.

What are the tech issues of the D90 you mention ?

 

[Harmonie]

I link the D70 and the A90 and I’m very pleased: I really like the AK4997 implementation in the D70 and it seems very well sorted - I’m a little put off by the tech issues with the D90. At $399 I think the D70 is great value - and of course the A90 is a very fine amplifier, just as reported.

BTW, can you show me where you get the D70 at 399$ ???

 

[DavidBloch406]

What are the tech issues of the D90 you mention ?

Please read the D90 thread, I don’t have the expertise to summarise the several points that are explored there

 

[DavidBloch406]

BTW, can you show me where you get the D70 at 399$ ???

My mistake! - that’s $499 at Shenzhen Audio. I apologise... thank G-d my wife doesn’t read the CC bills...

 

[JohnYang1997]

Please read the D90 thread, I don’t have the expertise to summarise the several points that are explored there

There's no issue with regular version of D90. And only known issue/non issue of MQA version is pop switching from dsd to pcm on linux(-80db pop).

 

[A.Cristea]

Sorry about my formatting of the first post - my careless typing!
For the avoidance of any doubt both Soncoz DACs have now conquered the irritating IMD hump, a feature of all so many ESS9038 implementations

It's probably going to be the Soncoz LA-QXD1 or the SMSL SU-8 (210€ on amazon), unless I find an offer on the D70/90.

Also would there be soundwise any differences by following cable linkings?
1) USB Type B (DAC) -> USB-C (Macbook pro 2020)
2) USB Type B (DAC) -> Usb Hub Adapter of Macbook Pro
3) Coax IN (DAC) -> SPDIF OUT (Focusrite 8i6) // Would use it 80% like this

 

[Harmonie]

Not that I defend particularly the D90, I never heard it, just read so much about it. I'm listening quite pleasantly the Gustard A22 since a week. No issues but I only spindled CD's so far.

 

[survivingscout]

@JohnYang1997 This might be a very dumb question, but do you anticipate any differences for the A90 in using the balanced XLR headphone output vs the SE quarter inch headphone output, or should they be the same (besides the balanced output having 2x the power)? I never owned the THX 789, but have read that even though the unit has both outputs, the design intention leaned towards the xlr balanced output.

 

[JohnYang1997]

@JohnYang1997 This might be a very dumb question, but do you anticipate any differences for the A90 in using the balanced XLR headphone output vs the SE quarter inch headphone output, or should they be the same (besides the balanced output having 2x the power)? I never owned the THX 789, but have read that even though the unit has both outputs, the design intention leaned towards the xlr balanced output.

BAL should have about 4 times the power than SE for high impedance load.
Noise on BAL output is higher than SE.
At the end of the day, if you hear a difference then choose the one that suits you. If you don't then use either for convenience.

 

[burma]

BAL should have about 4 times the power than SE for high impedance load.
Noise on BAL output is higher than SE.
At the end of the day, if you hear a difference then choose the one that suits you. If you don't then use either for convenience.

Even on low gain XLR vs middle gain SE? Hmm. That would be strange to hear that it's more noisy by design.

 

[Veri]

Even on low gain XLR vs middle gain SE? Hmm. That would be strange to hear that it's more noisy by design.

BAL cannot be less noisy than SE in an equivalent design, simply because it needs double the amplifiers = double the noise. The noise level John is talking about is already very low though, it's just a nitpick: a balanced amplifier has inherently more noise. Not like it's a "problem".
Especially of you need the increased voltage for something like a demanding Hifiman planar, making use of the XLR/4.4mm output makes perfect sense!

 

[Vini darko]

Even on low gain XLR vs middle gain SE? Hmm. That would be strange to hear that it's more noisy by design.

If for given input voltage. You make 4x power XLR compared to SE thats a whole lot of extra gain being added so noise floor is gonna higher.

 

[JohnYang1997]

Even on low gain XLR vs middle gain SE? Hmm. That would be strange to hear that it's more noisy by design.

That's not really fair to say that. However it's understandable that regular people don't understand.

Firstly, you can go to Massdrop 789's page, check the specifications of that. You will see that balanced output is twice as noisy. So by showing this, it's not just A90 that has this property.

Now, if you have access to Douglas Self's small signal book(or doesn't matter if you don't), it's said that balance connection is inherently more noisy than single-ended. While this is not intuitive, it's actually true. If you have balanced to single ended or single ended to balanced conversion, you get even more noise(relatively). Balanced connection however have better rejection to interference.

At this moment, we established that this is common and not a strange phenomenon.

Then, in comparison, A90's balanced output, even though is relatively more noisy than single-ended output, has much less noise of single ended output on many amplifiers even compared with 789. 0.6uV vs 1.2uV. Single ended output of A90 is just lower at 0.2uV. Probably the lowest on the market, at least to my knowledge.

Lastly, does it matter. Maybe yes maybe no. Most of the headphones aren't noisy with over 4uV noise. Most sensitive IEMs can produce audible noise with 0.8uV noise. So it really depends. For the user, just try it. Pretty simple.