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Topping A90 Discrete Review (Headphone Amp & Preamp)

Rate this Headphone Amp/Pre-amp

  • 1. Poor (headless panther)

    Votes: 12 3.5%
  • 2. Not terrible (postman panther)

    Votes: 12 3.5%
  • 3. Fine (happy panther)

    Votes: 58 16.8%
  • 4. Great (golfing panther)

    Votes: 263 76.2%

  • Total voters
    345

Bow_Wazoo

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Thanks to my Chinese friends from AliExpress for this beautiful plug

20220910_070956.jpg
 

Cidious

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Ok after a decent amount of testin the A90D vs my A30Pro I'm pretty conclusive about my findings.

A90D hands down beats the A30Pro in sound quality in about every genre I tried. Main difference being a smoother more balanced sound with better instrument separation and positioning. Faster tracks tend to get a bit messy on the A30Pro where the A90D undoubtedly handles this better and with more grace.

What else is that the A30Pro sounds quite hot and in my face compared to the more relaxed and smooth A90D. My HD660s is known for having a bit hot upperbass and vocals. The A30Pro makes this worse, where the A90D has a less aggressive approach to these areas of the frequency range. Also tried the Mad Dogs (Fostex T50RP Mod) and same results.

All in all I really LOVE the A90D for it's sound. It's just a better amp for all the cans I tried on it with the D30Pro. Hands down a better listening experience all round without endlessly sharing my subjective opinion here. That said I send it back. Why? Because function wise it doesn't suite me for it's price. It doesn't have physical buttons on the front other than the knob which is very limited in usage. For the rest of it's function Toppings sends you their flimsy plastic remote that just doesn't work very intuitively and just feels like a cheap piece of plastic, squeeking, having gaps and just built poorly. As the main tool for controlling the amp I expect more at this price point. Also my A30Pro has a nice pass-through option to let my D30Pro directly send the signal to my speakers when the amp is off. Thus saving power and one less step in the chain to disrupt the sound. I don't need the pre-amp function of the A90D. The D30Pro is perfect as it is for this. And then the final nail in it's coffing which isn't it's fault, I just don't use the amp enough these days for listening to music to make it worth the swap. I mostly use my ADAM T5Vs and they are doign really well on the D30Pro by passthrough and sound better directly to the D30Pro than through the A90D. So all in all not the right pick for me.

Sounds better than A30Pro by quite a bit (hard to argue even subjectively.. Not just taste. Technically). Function wise lacking for my use case. Flimsy remote is embarrassing at this price point. Give us back the A90 switches instead of that LED volume thing..

WeChat Image_20220915215712.jpg
 

Music1969

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Joined
Feb 19, 2018
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From the measurement results, it's not clear to me if 12 ohms impedance cans (MrSpeakers AEON) is a problem or not for this amp?

Its ok up to 10Vrms @ 12 ohms = 0.8A?

So as long as your cans dont need 0.8A then it can drive 12 ohms cans fine ? That's also 8W

And limited to 0.6A for 16 ohm cans ? 6W

Have I interpreted this result correctly ?

@JohnYang1997 @solderdude

index.php
 
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tomelex

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I guess I might as well lodge my primary complaint about this unit and it is the REMOTE volume "ring" is too small a surface area, the main thing you do with the remote is change volume and turn the unit off and on, the on off button is fine, but the other most used function is volume, and it is too small IMO.
 

Cidious

Active Member
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Jan 18, 2019
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I guess I might as well lodge my primary complaint about this unit and it is the REMOTE volume "ring" is too small a surface area, the main thing you do with the remote is change volume and turn the unit off and on, the on off button is fine, but the other most used function is volume, and it is too small IMO.
It's just shit haha. A device in this price class deserves better. An aluminum housing and bigger controls don't cost a ton. They sell an aluminum remote replacement for the DACs for 120 RMB here which is about $17. Should have been included for the AMP if they decided to remove all essential controls on the unit and still then. I want controls on the unit. It's a desktop amp intended to use like that..
 

tomelex

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It's just shit haha. A device in this price class deserves better. An aluminum housing and bigger controls don't cost a ton. They sell an aluminum remote replacement for the DACs for 120 RMB here which is about $17. Should have been included for the AMP if they decided to remove all essential controls on the unit and still then. I want controls on the unit. It's a desktop amp intended to use like that..

There are many that want controls on the unit as well if you are using it as a desk top unit, and in fact that is how I use it too. I would suppose that the actual total cost to manufacture the A90D at scale is about $60 in China, so a better remote should not be a problem.
 
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JimmyMac

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Nov 9, 2020
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Just got my A90D delivered. It came with Firmware 2.3 already and after connecting it to my Mac Studio with a USB-C to USB-A cable, the firmware drive came up on my desktop immediately. Sound is as good as my A90. Can't really hear any difference with my Sennheiser 660s or with my Sundaras. I have it set it up in High gain and volume at 65 is plenty loud for me. This is really the perfect companion for my Matrix Audio X-SABRE 3 ;)

View attachment 222324
What stand is the Matrix sitting on? Where did you get it? Thanks, Jim
 

bauerctu

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Jul 23, 2021
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Please note that the noise performance of the XLR output is always gonna be slightly worse than the 6.35mm output same for the A90.
The 6.35mm output performance is essentially the same as A90.
I have ordered A90 discrete and waiting delivery, will use it with HD800S and Arya V2 (non stealth). Problem is that I just have stock 6.35mm and 4.4mm cable for HD800S, 6.35mm stock and 4.4mm custom cable for Arya.
Q1) For better perfomance, do I need to buy XLR headphone cables?
Q2) If not buying XLR, at same volume level, which one sounds better, 6.35 and 4.4?
Thanks a lot for your further reply.
 

EvaGrin

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Noob here, please help!

I need to buy new a DAC, AMP stack.

I made some combos.

1.SP400+M400
2.SP400+ VMV D1SE
3.SH-9+SU-9N (save some money)
4.A90+D90LE
5.A90D+D90LE

Hope someone can solve this riddle.

I will use it with HD800S, LCD2 CB, Empyrean.

Thanks!

PS. Did topping solved the issue of A90D SE?
 

Veri

Master Contributor
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I have ordered A90 discrete and waiting delivery, will use it with HD800S and Arya V2 (non stealth). Problem is that I just have stock 6.35mm and 4.4mm cable for HD800S, 6.35mm stock and 4.4mm custom cable for Arya.
Q1) For better perfomance, do I need to buy XLR headphone cables?
Q2) If not buying XLR, at same volume level, which one sounds better, 6.35 and 4.4?
Thanks a lot for your further reply.
4.4mm uses exact same output as the XLR you know. So you can just try it all out.
 

enricoclaudio

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bearcatsandor

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Ok after a decent amount of testin the A90D vs my A30Pro I'm pretty conclusive about my findings.

A90D hands down beats the A30Pro in sound quality in about every genre I tried. Main difference being a smoother more balanced sound with better instrument separation and positioning. Faster tracks tend to get a bit messy on the A30Pro where the A90D undoubtedly handles this better and with more grace.

What else is that the A30Pro sounds quite hot and in my face compared to the more relaxed and smooth A90D. My HD660s is known for having a bit hot upperbass and vocals. The A30Pro makes this worse, where the A90D has a less aggressive approach to these areas of the frequency range. Also tried the Mad Dogs (Fostex T50RP Mod) and same results.

All in all I really LOVE the A90D for it's sound. It's just a better amp for all the cans I tried on it with the D30Pro. Hands down a better listening experience all round without endlessly sharing my subjective opinion here. That said I send it back. Why? Because function wise it doesn't suite me for it's price. It doesn't have physical buttons on the front other than the knob which is very limited in usage. For the rest of it's function Toppings sends you their flimsy plastic remote that just doesn't work very intuitively and just feels like a cheap piece of plastic, squeeking, having gaps and just built poorly. As the main tool for controlling the amp I expect more at this price point. Also my A30Pro has a nice pass-through option to let my D30Pro directly send the signal to my speakers when the amp is off. Thus saving power and one less step in the chain to disrupt the sound. I don't need the pre-amp function of the A90D. The D30Pro is perfect as it is for this. And then the final nail in it's coffing which isn't it's fault, I just don't use the amp enough these days for listening to music to make it worth the swap. I mostly use my ADAM T5Vs and they are doign really well on the D30Pro by passthrough and sound better directly to the D30Pro than through the A90D. So all in all not the right pick for me.

Sounds better than A30Pro by quite a bit (hard to argue even subjectively.. Not just taste. Technically). Function wise lacking for my use case. Flimsy remote is embarrassing at this price point. Give us back the A90 switches instead of that LED volume thing..

View attachment 231104
Are the numbers on the A90D white or blue LEDs? They look one or the other in every picture I've seen (would be nice to be able to set the color ourselves).
 

tomelex

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Are the numbers on the A90D white or blue LEDs? They look one or the other in every picture I've seen (would be nice to be able to set the color ourselves).
Well, they are not dark blue or even medium blue, they are not white, they are what I would describe as a very very light and bright blue color, but they are not white for sure. They are like the lightest blue sky you have ever seen on a bright day mid summer. They are the most sophisticated color I have ever seen and IMO are the best out there.

Once the warranty is over I will be taking a look to see how they pulled it off, maybe something to do with polished holes in the metal or something but I think you will like them.

There is a mode where the numerals turn off after 10 seconds or so of not touching the volume knob and that's the way I roll.
 
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bearcatsandor

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Well, they are not dark blue or even medium blue, they are not white, they are what I would describe as a very light blue color, I almost would not even describe them as blue but they are not white for sure.
oooo! That's perfect. I'm considering gettting a black one, and ordering the volume knob that comes with the white one for some contrast.
 

Tonza

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I got this amp a few days ago. One thing I noticed that when headphones are connected through XLR or 4.4mm (haven't tried SE), I can hear a quiet pop when switching gain level or when switching on the amp from standby. It happens even without any source connected. Anyone with the amp experiencing the same? The pop is quite quiet so its best heard in silence. The amp is on the latest 2.4 FW. I wonder if it can be dangerous for the headphones.
 

RosalieTheDog

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I am looking for a way to add a headphone amp to my living room / TV set-up, between the balanced out of my D70s and the balanced in of my power amp. Does anyone care to give his / her 2 cents about the options?

- On Audiophonics there are only two options under €1000 (preamp and HP amp with XLR in/out and remote): Gustard H16 at €400 and Topping A90 Discrete at €600. What advantage does the Topping have over the Gustard?

Edit: I read the Gustard XLR-output is always active. That's inconvenient!

- A cheaper alternative would be to use the RCA out of the Topping D70s, and buy a dedicated HP amp with RCA in, separate from the chain, and switch the Topping D70s XLR/RCA out and preamp/DAC mode whenever I'd want to use headphones. It'd be slightly more of a hassle, but several €100s cheaper.

There is a mode where the numerals turn off after 10 seconds or so of not touching the volume knob and that's the way I roll.
That is great to know. I regret that most reviews (or indeed product websites) neglect to include such crucial info. However beautiful or elegant the lights are, I do prefer them turn off while I'm watching something ...

It's just shit haha. A device in this price class deserves better. An aluminum housing and bigger controls don't cost a ton.
I agree, though many manufacturers skimp on this, even Denon for instance (the PMA integrateds come with a RC-1234 enormous plastic remote with 90% useless buttons unless you use CD players and the like, and a placement for volume control buttons that gives you arthritis). The best remote I've had came with a very cheap all-in-one German Teufel: heavy, aluminum, responsive at a distance, ... Anyone know how to or if it's even possible to configure the Nvidia Shield remote to do the volume control of Topping products?
 
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chaturanga

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This is a review and detailed measurements of the new Topping A90 Discrete balanced preamplifier and headphone amplifier. It was sent to me by the company and costs US $599.

View attachment 213870
Announcement was supposed to be a few hours from now but one of the distributor already released it so here we go. As you can tell, there is a new design in the form of those pin-hole LEDs which I find quite elegant. Inside there is stepped relay for volume control. Of course as the name indicates, this design uses discrete transistors rather than op-amps. 39 transistors are used to accomplish that task in each module. Will performance be as good as op-amps? And is there an advantage? We will find out in the measurement section. Here is the back panel:

View attachment 213871

I was pleasantly surprised to see the same extension connector to connect to Topping EXT90 to provide more inputs. In addition there is 12 volt trigger which many have been asking for. And even a ground lift switch.

In use, I found minor ticks during quiet parts of the music when changing the volume quickly. This is quite common in stepped relay implementations.

Topping A90 Discrete Measurements
In order to save time, all measurements are with balanced XLR input and balanced 4 pin XLR headphone output. Unbalanced has quarter of the power. Here is our dashboard:

View attachment 213872

While SINAD of 119 dB is superb and assures transparency in all conditions, it is a hair worse than A90:
View attachment 213873

This is incredible performance as every other discrete headphone amplifier I have tested has given a lot of performance (in the form of noise and distortion) to get there. Dynamic range is a bit lower which is responsible for that:
View attachment 213874

We see that penalty in the 50 mv test:
View attachment 213875

Multitone test shows how low the distortion products are:
View attachment 213876

Frequency response is of course extended and flat:

View attachment 213877

THD vs frequency shows a slight rise at the top end:
View attachment 213878

I measured power at three impedances: 300, 50 and 32:

View attachment 213879

View attachment 213880


View attachment 213881

The advantage of discrete implementation seems to be in current delivery into low impedances:
View attachment 213882

Usually I see a pull back at 32 ohm but here, that load doesn't impact the amp at all. It is not until we get to 20 ohm that the output voltage starts to drop a bit. This is a first since I started to make this measurement.

When pushed into protection with loads < 32 ohm, the unit shut off. Powering on everything was fine so it passed this stress test.

The beauty of stepped relay volume control is perfect channel matching which we see here:
View attachment 213883

I am amazed how well this works. Some stepped relay implementations lose their grip at low volumes but there we go past our limits of hearing before the mismatch even registers!

Topping A90 Discrete Listening Tests
I have been using my everyday Dan Clark Stealth headphone as a "it won't drive it but let's see what it does" test for headphone amps. This is the first time I have seen an amplifier have such an upper hand over these headphones. The sound is incredibly dynamic and beautiful. "Loud" listening is at volume level 80 in high gain. I cranked it up to 95 before I got scared for my hearing without any hint of distortion. I had not heard these headphones come to life so well.

Needless to say, driving Sennheiser HD650 and Drop Ether CX was in a walk in the park. I am talking incredible bass, detail and fidelity with volume indicator in 60s.

What a joy....

Conclusions
I must confess that I got a bit worried when Topping told me about the A90 Discrete. I worried that they were making a discrete version just to appease audiophiles but with much loss in noise and distortion metrics. Happily Topping approaches everything with extreme focus on performance and they managed to get the A90 discrete within a split hair of the op-amp version. But then innovated with stepped ladder volume control, trigger support and major step up in class/look of the unit. I happily take these as a trade off for that 1 dB of SINAD.

From design point of view, this is another watershed audio/engineering event brought to us by Topping. Who would have thought that this company would keep breaking new ground instead of all the major/usual names we know in hi-fi.

It is my pleasure to add Topping A90 Discrete headphone amplifier/pre-amplifier to my recommended list. My challenge is to figure out if it goes in my main system or desktop! :)

------------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

Thank you for that measurements and review, I have Soncoz SGA-1, is there a big difference on listening and any audible reason to sell Soncoz and to buy this one?
 
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