[jlemaster1957]

Finally I have got A90 discrete set up and did an extensive listening session using D90SE (set to 00 Db output, BT=off, output V =5, connected to A90D via Mogami Studio Gold XLR 3’ cables. HPs are HIFIMAN Arya via 4.4 mm A90D output, gain is M). I used stock power and USB cables and no power conditioning, listening on a dedicated power line. Burn in was only 24 hours. Comparison is to Hiby R8, Turbo = on —> Cayin C9 (4.4 mm balanced input on SS Class AB with no tubes).
Tracks were Fruhlingsgefuhle by Melokind, Magnetar by Mark Lettieri, Beldiya by Triplego, Twice by Ludovici Einaudi (Reimagined by Mercan Dede) Lifted by Love by KD Lang, Drover by Bill Callahan. I listened through all tracks twice.

Disclosure- this is my first desktop stack other than the IFi Zen stack (DAC V2 and CAN). I have the IFI micro I DSD Signature also. But I am mostly a DAP man, so that’s why I am comparing the Stack to a DAP, albeit a TOTL one. Cayin C9 is of course a stand alone portable analogue amp.

I was immediately struck by the difference in the overall smoothness and detail retrieval especially in the treble region. There are details not discernible on tbe R8-C9 combo that can I can hear, way high, ie snare brush strokes but also breathy vocalizations or wind-like sounds that are elevated by the D90SE-A90D combo. Some softer instruments that had been hidden in the mix with R8-C9 were now more distinguishable on the Topping stack. Treble was also more forward, I was noticing a lot more snappy, crispy, sparkly details up top, especially on percussion instruments- transients were perfectly timed. OTOH as noted treble is smooth, I heard no harshness or sibilance, nor is it shouty or shrill - lower treble in the vocal range is clear, breathy, consonants are forward but really just right.

This all continues down into the mids, which are very real and present. Voices are forward- intimate even, but not ‘in the head’ and when soft it’s like they are whispering in my ear or just behind it- more of this under imaging. No issues here of concern, balance with bass and treble is perfect

Bass- on R8-C9 bass quantity was always strong, but with The Stack I am hearing a lot more bass detail, as well as loads of rumble and slam (read: lots), I think sub-bass rumble is in fact more - but with an important caveat. Roon DSP allows me to dial up a bass shelf, and the Topping Stack scales up on this impressively- I encourage you to try it. The bass control I had wanted, hoped for is -THERE- . This is really noticeable on Bill Callahan's Drover- kind of a test track for physical drums. With the Roon bass shelf ( below 60 Hz m, + 4 DB) those drums are right in the room with me. Mid-bass (especially bass guitar) vibration is palpable. Bass remains forward but there is zero bleed or suppression of lower mids now. Micro-dynamics (max bass to max blackness in between bass drops) is excellent, decay seems a bit faster than with R8-C9. This is particularly impressive given that the Aryas are not a particularly bass-y set.

In terms of staging and separation overall, as I've already I think made clear, the Stack has it in spades- instrument separation and space between instruments across the FR is crystal clear. Stage width was a BIT narrower for the Stack vs R8-C9 —about as deep as it is wide- literally like a small performance stage, and I am sitting in the front row. The preciseness of instrument or vocals location on that stage was crystal clear, with greater instrument separation than I noticed with R8-C9. Having said that,instrument separation was still great with R8-C9- the Stack just dials it up - again the difference to me is in the details I can hear coming from A90D. Having said all that, the smoothness, a musicality, and coherence I have always loved from R8-C9 is still present on A90D.

One final thing - this Stack is so smooth that is tempting to listen to it very loud- as there is no distortion or pain when doing so. I was getting up to over 80 on the Volume dial and it sounded = great! Be careful out there.

Conclusion- the A90D pairs wonderfully with D90SE across the FR, and can transmit detail and (with a bit of EQ) impressive impact and dynamism, and serve it up smooth as silk. I can’t say how it will pair with other DACs - I will check it directly vs C9 using the IFI micro iDSD Signature connected to both A90D and C9 via RCA dual-> single 3.5 mm cable . More soon..

 

[Currawong]

Finally I have got A90 discrete set up and did an extensive listening session using D90SE (set to 00 Db output, BT=off, output V =5, connected to A90D via Mogami Studio Gold XLR 3’ cables. HPs are HIFIMAN Arya via 4.4 mm A90D output, gain is M). I used stock power and USB cables and no power conditioning, listening on a dedicated power line. Burn in was only 24 hours. Comparison is to Hiby R8, Turbo = on —> Cayin C9 (4.4 mm balanced input on SS Class AB with no tubes).
Tracks were Fruhlingsgefuhle by Melokind, Magnetar by Mark Lettieri, Beldiya by Triplego, Twice by Ludovici Einaudi (Reimagined by Mercan Dede) Lifted by Love by KD Lang, Drover by Bill Callahan. I listened through all tracks twice.

Disclosure- this is my first desktop stack other than the IFi Zen stack (DAC V2 and CAN). I have the IFI micro I DSD Signature also. But I am mostly a DAP man, so that’s why I am comparing the Stack to a DAP, albeit a TOTL one. Cayin C9 is of course a stand alone portable analogue amp.

I was immediately struck by the difference in the overall smoothness and detail retrieval especially in the treble region. There are details not discernible on tbe R8-C9 combo that can I can hear, way high, ie snare brush strokes but also breathy vocalizations or wind-like sounds that are elevated by the D90SE-A90D combo. Some softer instruments that had been hidden in the mix with R8-C9 were now more distinguishable on the Topping stack. Treble was also more forward, I was noticing a lot more snappy, crispy, sparkly details up top, especially on percussion instruments- transients were perfectly timed. OTOH as noted treble is smooth, I heard no harshness or sibilance, nor is it shouty or shrill - lower treble in the vocal range is clear, breathy, consonants are forward but really just right.

This all continues down into the mids, which are very real and present. Voices are forward- intimate even, but not ‘in the head’ and when soft it’s like they are whispering in my ear or just behind it- more of this under imaging. No issues here of concern, balance with bass and treble is perfect

Bass- on R8-C9 bass quantity was always strong, but with The Stack I am hearing a lot more bass detail, as well as loads of rumble and slam (read: lots), I think sub-bass rumble is in fact more - but with an important caveat. Roon DSP allows me to dial up a bass shelf, and the Topping Stack scales up on this impressively- I encourage you to try it. The bass control I had wanted, hoped for is -THERE- . This is really noticeable on Bill Callahan's Drover- kind of a test track for physical drums. With the Roon bass shelf ( below 60 Hz m, + 4 DB) those drums are right in the room with me. Mid-bass (especially bass guitar) vibration is palpable. Bass remains forward but there is zero bleed or suppression of lower mids now. Micro-dynamics (max bass to max blackness in between bass drops) is excellent, decay seems a bit faster than with R8-C9. This is particularly impressive given that the Aryas are not a particularly bass-y set.

In terms of staging and separation overall, as I've already I think made clear, the Stack has it in spades- instrument separation and space between instruments across the FR is crystal clear. Stage width was a BIT narrower for the Stack vs R8-C9 —about as deep as it is wide- literally like a small performance stage, and I am sitting in the front row. The preciseness of instrument or vocals location on that stage was crystal clear, with greater instrument separation than I noticed with R8-C9. Having said that,instrument separation was still great with R8-C9- the Stack just dials it up - again the difference to me is in the details I can hear coming from A90D. Having said all that, the smoothness, a musicality, and coherence I have always loved from R8-C9 is still present on A90D.

One final thing - this Stack is so smooth that is tempting to listen to it very loud- as there is no distortion or pain when doing so. I was getting up to over 80 on the Volume dial and it sounded = great! Be careful out there.

Conclusion- the A90D pairs wonderfully with D90SE across the FR, and can transmit detail and (with a bit of EQ) impressive impact and dynamism, and serve it up smooth as silk. I can’t say how it will pair with other DACs - I will check it directly vs C9 using the IFI micro iDSD Signature connected to both A90D and C9 via RCA dual-> single 3.5 mm cable . More soon..

What was your USB source? The R8?

 

[jlemaster1957]

What was your USB source? The R8?

For A90D it was Roon streaming USB from a Sonore MicroRendu connected to a Google Wifi extender. For R8 music was streaming directly (to R8 no USB) via wifi signal on the same network. So different streaming method though analogous signal. I guess to be as equal as possible I should connect R8 to the Sonore via USB to make the comparison. I will try that to see if any thing changes in the impression. Thanks for mentioning.

Btw not making claims for technical equivalence or scientific measurements here- just trying to provide a user impression that is as methodical as I knew how to do. I am still learning and thankful for any guidance provided.

Maybe the main finding i had that I haven’t read before is that A90D is channeling DSP/Eq well, while retaining its own technicalities particulars (as expected).

 

[jlemaster1957]

New review by Soundnews including YT vid
https://soundnews.net/amplifiers/headphone-amps/topping-a90-discrete-review-forging-ahead/

 

[Blackrao]

I hope to see more impressions concerning the use of the Discrete versus other solid state amps with HE6 and HE6SE.

Hi reviewed the Topping A90D with Topping D90se Dac with the He6sev2 and quite frankly its an amazing combo. The A90D has much better bass response than previous version

 

[Mista Lova Lova]

So I got my friends a90D today, along with his gustard x26 pro because he said its very impressive for a d/s dac.

Something strange with the A90D, the X26 and my Holo May sound almost indistinguishable from each other on this amp. But on my Soloist GT, theres a very audible difference between the two. This also happens when upsampling on the May. With the GT theres an audible difference between 44.1 vs upsampling to 1.5mhz. On the A90D I can barely tell any difference. Going to need some more time with it as these are just early impressions.

This is very interesting because in my "review" many pages ago I was comparing the OG A90 with the A90 Discrete, I actually also own a Gustard X26 Pro and was switching between it and a D90 (AKM). On the original A90 the differences between the DACs were more immediately apparent than on the A90 Discrete. Having read/watched some more reviews now with some people claiming that the A90D (Soundnews) is Topping's attempt not to sound so "flat" - it makes me think that this amp is slightly coloured, hence not as transparent as the OG which would explain why it was harder to hear the differences between DACs. If I had an issue with my DAC then I might have preferred the Discrete version but since the Gustard, especially with external upsampling, is wonderful - I ended up enjoying the OG A90 more and sending the DIscrete back.

 

[ToneDeafMonk]

Just got mine in today and first listen with the Geshelli JNOG J2 AKM I love it wicked synergy, smooth with authority and more bottom end.

 

[KPzypher]

Just ordered A90d thru APOS. Although I am perfectly happy with my OG A90, I don't get enough volume control with many of my studio monitoring HPs that are low impedance/high sensitivity, as I am a very low volume listener. Not expecting any meaningful changes in SQ. One thing I'll miss though is the toggle switches.

PM me if anyone wants an excellent deal on the OG A90 (black). I plan on adding it to the classified once the discrete model arrives.

 

[Povell42]

Question: I have had my A90 D for a week or so. Specs show some massive power through balanced headphone amp (9800 mW @ 16 ohm). However, I seem to need the volume level to be at in the 50's for a decent listening level, while my "less mW rated amps" are only @ like 9 or 10 O'clock (like at 25%-35%) knob position. ??

If I put my the THX AAA 789 or Aune X7S headphone amp to "50%" or 12 0'Clock they are at very, very loud volume levels. This leaves me with the feeling that the Topping A90D is weaker or has less headroom in comparison. From what I have seen it isn't uncommon to see people putting the volume level @ 50 - 80 (equivalent of 50% - 80%) on balanced headphone output.

Any thoughts, as I bought this with several reviews saying it has beastly power and can drive any headphone with ease?

And to confirm... I am on volume curve 1, on High gain on the A90 D

 

[uckexk]

Question: I have had my A90 D for a week or so. Specs show some massive power through balanced headphone amp (9800 mW @ 16 ohm). However, I seem to need the volume level to be at in the 50's for a decent listening level, while my "less mW rated amps" are only @ like 9 or 10 O'clock (like at 25%-35%) knob position. ??

If I put my the THX AAA 789 or Aune X7S headphone amp to "50%" or 12 0'Clock they are at very, very loud volume levels. This leaves me with the feeling that the Topping A90D is weaker or has less headroom in comparison. From what I have seen it isn't uncommon to see people putting the volume level @ 50 - 80 (equivalent of 50% - 80%) on balanced headphone output.

Any thoughts, as I bought this with several reviews saying it has beastly power and can drive any headphone with ease?

Pot position isn't a good indicator of amp power output percentage. Pots on different amps behave differently.

A90D has a logarithmic pot. A volume increase of 10 in most cases would translate to a 10dB or 10x multiplication in power output. At 50 volume it has an attenuation of -40dB, which means it only outputs 0.01% of its max potential. That's the nature of logarithmic volume control.

 

[BowWazoo]

Thanks to my Chinese friends from AliExpress for this beautiful plug.

 

[jlemaster1957]

This is very interesting because in my "review" many pages ago I was comparing the OG A90 with the A90 Discrete, I actually also own a Gustard X26 Pro and was switching between it and a D90 (AKM). On the original A90 the differences between the DACs were more immediately apparent than on the A90 Discrete. Having read/watched some more reviews now with some people claiming that the A90D (Soundnews) is Topping's attempt not to sound so "flat" - it makes me think that this amp is slightly coloured, hence not as transparent as the OG which would explain why it was harder to hear the differences between DACs. If I had an issue with my DAC then I might have preferred the Discrete version but since the Gustard, especially with external upsampling, is wonderful - I ended up enjoying the OG A90 more and sending the DIscrete back.

Question ; for either A90D or A90, did the wide/deep sound stage of which X26 is famous project via these amps? If yes, pls describe here about imaging and stage using either of them.

 

[jlemaster1957]

Question: I have had my A90 D for a week or so. Specs show some massive power through balanced headphone amp (9800 mW @ 16 ohm). However, I seem to need the volume level to be at in the 50's for a decent listening level, while my "less mW rated amps" are only @ like 9 or 10 O'clock (like at 25%-35%) knob position. ??

If I put my the THX AAA 789 or Aune X7S headphone amp to "50%" or 12 0'Clock they are at very, very loud volume levels. This leaves me with the feeling that the Topping A90D is weaker or has less headroom in comparison. From what I have seen it isn't uncommon to see people putting the volume level @ 50 - 80 (equivalent of 50% - 80%) on balanced headphone output.

Any thoughts, as I bought this with several reviews saying it has beastly power and can drive any headphone with ease?

And to confirm... I am on volume curve 1, on High gain on the A90 D

What DAC are you using? Remember the Rule of 8s - the input impedance of your amplifier must be at least 8 x higher than the output impedance of your DAC. A90D has input impedance of only 2k ohms for balanced. So if your DAC has an output impedance of anything greater than 250 ohms via balanced output, you’re going to need a pre-amp.

 

[BowWazoo]

@Povell42

The position of the volume control says nothing about the max. power of an amplifier. It also does not allow direct comparisons, as you have done.
The volume control of the A90D, can also be adjusted in five steps with respect to its sensitivity.

 

[Povell42]

What DAC are you using? Remember the Rule of 8s - the input impedance of your amplifier must be at least 8 x higher than the output impedance of your DAC. A90D has input impedance of only 2k ohms for balanced. So if your DAC has an output impedance of anything greater than 250 ohms via balanced output, you’re going to need a pre-amp.

Currently using my Geshelli Labs ENOG 2 Pro DAC in the highest output voltage. I have been interested in the Denafrips Ares ii.