Absolutely âgood enoughâ for my standards too â I have the D70 DAC and love it. But a slightly wiggly toggle would be ok with me too. Would never find that on something made by Benchmark, for example.
I am not criticizing Topping â only saying their price points require an acceptance of some compromise.
Hi. I just want to share an experience with you all 
I have recently bought an Topping A90, and have struggled a little with noise through my USB with an D10s dac.
So i finally connected my Interface that is a SSL 2+, with balanced connections to my A90.
And really liked what i discovered. The noise was all gone, with music on pause, and volume at max on high gain. With sensitive iems connected on balanced output. No noise at all
Also a little bonus as i see it, this inteface has a little bit warmer sound to it. And this proves that the A90 just puts through what it reveives from the source. Even the sound on pre-amp setting from A90 to my Adam Audio T7V, is more controlled with this setup
How does the A90 compare to the Rebel Amp?
Does anyone using the smsl su-9 with a90? I dont wanna spent more than $500 on a dac for now and it seem that su-9 is perfect for the job
Iâve been very happy with my SU-9 with several other speaker and headphone amps. My A90 is coming in on Thursday and will report back once I get some listening time in with that combo.
Just came across this review today - he talks about the differences between the Rebel and the A90 as well as comparing it to the Asgard:
Rebel Audio Rebel Amp Review | The $500 Benchmark - YouTube
Okay, so the headphone amp portion of the A90 sounds fantastic, but Iâm having issues with the preamp portion.
My configuration is USB from my PC, to an SMSL SU-9 DAC, then XLR to the A90. I have then tried both RCA and XLR to an SMSL DA-8S speaker amp driving Jamo s803âs.
When using RCA, I get loud static from the right speaker when the A90 is set to off or HPA mode. When I set the A90 to Preamp mode, I just get audio from the right speaker and it has a very high noise floor.
When I switch the connection between the A90 and DA-8S to XLR, I no longer have the loud static when the A90 is set to off or HPA mode. Instead, I have a very high, audible noise floor and mono audio.
If I try connecting the DA-8S directly to the SU-9 with either the RCA or XLR connection, using the exact same cables (taking the A90 completely out of the equation), I get perfect, stereo sound and an inaudible noise floor.
For the XLR cables, Iâm using 6" Worldâs Best Cables that utilize Canare wire and Amphenol XLR connectors. For the RCA cables, Iâm using 6" Schiit Pyst RCA cables.
Is there anything else anyone can suggest to troubleshoot the issue or do I need to start the RMA process with Apos?
Thank you so much!!!
Update: Apos is starting an RMA on my A90 and sending me a new one due to the issues with the preamp stage.
Just wanted to provide a quick update. Received a replacement A90 this morning, hooked it up exactly as I had the other one, and had zero issues. Switched back over to the Adam T5Vâs and also had zero issues.
Additionally, while I didnât think there was anything wrong with the headphone amp functionality, I didnât think it really outperformed my Monolith THX 887. Upon listening to a set of headphones on the replacement A90 and it was immediately clear that there was something wrong with the headphone amp portion of the original A90 in addition to the issues with the preamp portion. This new A90 actually kind of shocked me at how good it made my Aeolus sound compared to the THX 887 as I really wasnât expecting much difference.
Anyway, just wanted to follow up with my experience with the replacement A90.
Thank yâall again for the help!
After only a year my 789 is already getting bad volume pot scratch. I was thinking of upgrading my 789 to the Topping A90. I think the black color version will pair nicely with my RME adi-2dac all hooked up balanced. 
A90 kind of has a similar shitty pot. Just unscrew the backplate of the 789 (it is already out of warranty anyways), push out the pcb to gain access to the 789âs volume pot, and work in some liquid deoxit there. Spending $10-20 is preferable to spending a couple hundred dollars. Measurements-wise, I donât know how much of an upgrade the A90 would be since any measurable performance gains is inaudible already.
Noob question. Iâm thinking about upgrading to this from 789. Along with using this with my DAC (RME adi-2) I hear you can use the xlr output for studio monitors? Is this really true and what controls the volume for the speakerâs and can I seamlessly switch from headphones to the studio monitorâs? Is there any drawbacks ect. Thank you for your time.
The performance gains from a 789 to an a90 is not inaudible like @mbvjmc thinks. All around smoother on the a90 without coming across as âcoloringâ the sound whatsoever. Noticeably less grain and the power when you need it is actually really nice to have.
It is not what I think, it is what the measurements show. Read my post again, I emphasized measurements since those metrics are what people tend to use when evaluating these two amps. These amps are supposed to be âwire-with-gain,â so any colorations between the two, according to ASR acolytes, should show up on the measurement rig as audible distortion. That isnât the case based on the published measurements from ASR.
Also, to parrot an oft-used retort from ASR to subjective impressions, did you adequately perform a volume-matched double-blind test with these two amps?
PS. I really donât care for either of these two amps. Use whatever makes you and your wallet happy. I was just mocking how discussions on ASR are typically conducted.
Yeah but their graphs are smoothed a lot and grain would show if they werenât.
THX 789 has a hum that is audible and measurable. I think Joshua Valour mentioned that, too. ASR also stated that. Link: https://www.audiosciencereview.com/forum/index.php?threads/apparently-the-thx-789-is-a-noisy-amp-i-call-bs.13392/
The hum only comes if youâre using it unbalanced, though.
That Topping guy (JohnYang1997) is being ehm⌠the A90 uses a pair of these integrated AC-DC power supplies. The extremely wide supply range of those means Switch Mode Power Supply.
Also: The voltage ripple (lower is better):
That said, two things:
Why are we talking about this in the A90 thread?
100mV peak-to-peak ripple on the power is definitely not great, I would say. AFAIK there is nothing in terms of power filtering in any of the THX amps, so to some degree that ripple will definitely make its way to the output.
You couldâve read the previous posts. It was about A90 vs 789. The hum in 789 is audible. Hum is never desired and harmonic.
I didnât say anything about A90âs power supply or JohnYang1997.
