Topping A90 Discrete aka A90D
Aug 6, 2022 at 12:42 PM Post #106 of 560

De7mi

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Okay, so granted I am an admitted Topping fanboy, but I am so pleased with this amp!!

My only very minor criticism is that the LED color doesn't really match the rest of the X90 product line. No big deal though...

My main motivation for upgrading was because I had to run the A90 on low gain and with the volume knob way down at like 9 o'clock. There was a little bit of channel imbalance with the volume really low, and the volume was super sensitive.

I was hoping with the A90D I could run it at very low volumes without any channel imbalance. And I figured if I didn't have fine enough control over the volume level, I could adjust the volume on the DAC a touch.

I was pleased to discover that the A90D has extremely fine volume control, even on low gain. And, by virtue of the resistor ladder volume control, the channel balance is always perfect.

I sold my A90 before the A90D arrived so I couldn't do an A/B comparison, but I am so SO pleased with the function and performance of this unit.
From memory can you elaborate a little bit on the difference between the A90 and A90 D ?
I never heard the original A90 but my impression of the A90 D is that it is a very natural neutral with a touch of warmth.
 
Aug 6, 2022 at 1:28 PM Post #107 of 560

hsg120

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From memory can you elaborate a little bit on the difference between the A90 and A90 D ?
I never heard the original A90 but my impression of the A90 D is that it is a very natural neutral with a touch of warmth.
Well, please take the following with a grain of salt. There was like a 1 month span between the time I sold my A90 and got the A90D...

I had my A90 for two years and I personally never detected any added warmth (note--I only have a single set of cans). I did A/B comparisons with other amps I've had over the years and I always thought the A90 was absolutely faithful to original recordings, sometimes to a fault. That is to say, extremely resolving, and very neutral and natural sounding. Which is not coincidentally, my personal preference.

And frankly to my ears, I feel the A90D sounds more or less the same. I don't think it adds or takes anything away from the track. You just get incredibly clean reproduction, basically as loud as you'd like =D
 
Aug 7, 2022 at 3:13 PM Post #108 of 560

jclyle

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Is there a review embargo?
I thought we'd have more insight on this amp by now from the 'pro' reviewers.
 
Aug 7, 2022 at 7:08 PM Post #109 of 560

carlcamper

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Is there a review embargo?
I thought we'd have more insight on this amp by now from the 'pro' reviewers.
Joshua Valour should have his review out this week, stay tuned
 
Aug 7, 2022 at 7:32 PM Post #110 of 560
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Is there a review embargo?
I thought we'd have more insight on this amp by now from the 'pro' reviewers.
I had one arrive a couple of days ago. Seems to be a fairly solid design. The fantasy that low THD/SINAD numbers translates into actual resolution is just that though. For what you get for $600 it's pretty good though.
 
Aug 8, 2022 at 1:09 AM Post #111 of 560

Arniesb

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I had one arrive a couple of days ago. Seems to be a fairly solid design. The fantasy that low THD/SINAD numbers translates into actual resolution is just that though. For what you get for $600 it's pretty good though.
Plenty of times this ''resolution'' is just the result of distortion and noise acting as a fake detail.
Personally i never find anything that measure bad to sound impressive for good and dynamic recordings.
Maybe for old recording with low dynamic range i would find low sinad stuff impressive.
 
Aug 8, 2022 at 8:58 AM Post #112 of 560
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Plenty of times this ''resolution'' is just the result of distortion and noise acting as a fake detail.
Personally i never find anything that measure bad to sound impressive for good and dynamic recordings.
Maybe for old recording with low dynamic range i would find low sinad stuff impressive.
In those cases, it's usually harshness/brightness that is mistaken for detail. When I refer to detail, it is things such as being able to hear the reverberations in strings during note decay, or the reflections of sound inside the recording venue. The ability to resolve these things isn't related to SINAD, which is just a measure of a single sine wave when the amp (or device) is just driving the analyser, and not headphones. You can, for example, have high harmonic distortion and still hear micro details in the music.

What's arguably more important is the crosstalk graph and IMD (unpleasant-sounding distortion) graphs. Note that they are often missing! The IMD of amps in this range is most often much higher than the THD from what I've seen.

I'll get into the specifics of what I hear with music from the A90 Discrete in the review. For $600 it seems to be good value.
 
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Aug 8, 2022 at 10:21 AM Post #113 of 560

jclyle

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How Is the clicking sound when adjusting the volume? I know it's typical for relay volume controls to make the sound.

This video makes it sound loud.
Mine will be here Wednesday :)

 
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Aug 8, 2022 at 11:10 AM Post #114 of 560

TheMiddleSky

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You first have to upgrade the firmware to V2.3 then you can use the volume knob to change the gain setting.

https://www.topping.audio/newsinfo/663543.html

Thanks for the info man.

------------------

What a clever and genius way to make their flagship amp need firmware update to able to change the gain. Everyone should have think about that.

*Do they really forgot to add gain control for their amp or something above human knowledge was happening and prevent them to do it?*
 
Aug 8, 2022 at 3:55 PM Post #115 of 560

hsg120

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How Is the clicking sound when adjusting the volume? I know it's typical for relay volume controls to make the sound.

This video makes it sound loud.
Mine will be here Wednesday :)



The clicking noise from my amp is comparable in volume to other relay-stepped volume controls I've had. I don't think this amp is particularly noisy in that regard.

Thanks for the info man.

------------------

What a clever and genius way to make their flagship amp need firmware update to able to change the gain. Everyone should have think about that.

*Do they really forgot to add gain control for their amp or something above human knowledge was happening and prevent them to do it?*

You could always change the gain using the remote. They added the ability to change the gain using the volume knob via a firmware update.
 
Aug 8, 2022 at 4:01 PM Post #116 of 560

wazzupi

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In those cases, it's usually harshness/brightness that is mistaken for detail. When I refer to detail, it is things such as being able to hear the reverberations in strings during note decay, or the reflections of sound inside the recording venue. The ability to resolve these things isn't related to SINAD, which is just a measure of a single sine wave when the amp (or device) is just driving the analyser, and not headphones. You can, for example, have high harmonic distortion and still hear micro details in the music.

What's arguably more important is the crosstalk graph and IMD (unpleasant-sounding distortion) graphs. Note that they are often missing! The IMD of amps in this range is most often much higher than the THD from what I've seen.

I'll get into the specifics of what I hear with music from the A90 Discrete in the review. For $600 it seems to be good value.
I think a comparison with the singxer would be fantastic as I’m in the market for a SS amp for my Kennerton rognir planar and iems.
 
Aug 8, 2022 at 5:06 PM Post #117 of 560

ericx85

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If the D sounds exactly like the original A90, then I would go check the SA-1 thread and see peoples comparisons with the original. People who had gripes with the A90 generally much preferred the Singxer. There's also the whole thing of the jumper mod on the Singxer but people were preferring it before the mod was discovered if I remember correctly.
 
Aug 11, 2022 at 5:38 PM Post #118 of 560

Mista Lova Lova

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In those cases, it's usually harshness/brightness that is mistaken for detail. When I refer to detail, it is things such as being able to hear the reverberations in strings during note decay, or the reflections of sound inside the recording venue. The ability to resolve these things isn't related to SINAD, which is just a measure of a single sine wave when the amp (or device) is just driving the analyser, and not headphones. You can, for example, have high harmonic distortion and still hear micro details in the music.

What's arguably more important is the crosstalk graph and IMD (unpleasant-sounding distortion) graphs. Note that they are often missing! The IMD of amps in this range is most often much higher than the THD from what I've seen.

I'll get into the specifics of what I hear with music from the A90 Discrete in the review. For $600 it seems to be good value.
If you've heard the original A90, I would be very interested to learn about the differences between the two, i.e. whether they are technically different but arrive at the same (or similar) sound, or whether the use of discrete components has changed the sound quality. I have recently upgraded to a fully discrete DAC - Gustard X26 Pro - which has exceeded my expectations (compared to the Topping D90 and Denafrips Ares II) and it would appear that at least one of the reasons for this DAC sounding so wonderfully holographic and "full" is the lack of any op-amps in the signal path. This has got me thinking if a similar effect has been achieved in the new A90 amp (although, compared to e.g. the THX 789, the original A90 already sounds quite full-bodied and holographic).
 
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Aug 11, 2022 at 6:09 PM Post #119 of 560
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I don't have the original, unfortunately. Discrete amps have the benefit that the designer can implement things as they wish, and they aren't beholden to someone else's design.
 
Aug 11, 2022 at 6:14 PM Post #120 of 560

Mista Lova Lova

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I don't have the original, unfortunately. Discrete amps have the benefit that the designer can implement things as they wish, and they aren't beholden to someone else's design.

Thank you for the explanation. If I've understood you correctly, this simply means that the discrete version of the A90 has the potential of sounding better, or at least different, from the original A90, but at the end of the day it depends on the further choices made by the engineers? In other words - it's not automatically better, simply due to the fact that discrete parts have been used?
 
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