Topping A90 Discrete aka A90D

Jan 1, 2025 at 7:32 AM Post #826 of 844
How to disable the volume control on the A90D? Since I am using an external preamp, I enable the HPA mode, but somehow the volume control is still active. Is there a way to bypass it

I would turn the volume on the A90D all the way up, and use the volume control on the other preamp. Obviously this will not disable the volume control on the A90D, which is something that cannot be done, but I am doing this with my A90D, which I'm now using as a 'secondary' amp being fed by a ifi iCan Signature.
 
Jan 1, 2025 at 9:21 AM Post #827 of 844
How to disable the volume control on the A90D? Since I am using an external preamp, I enable the HPA mode, but somehow the volume control is still active. Is there a way to bypass it?
In order to avoid connecting two preamplifiers in series (A90D > line out > External preamplifier) you need either a way to connect your line out sources directly to the external preamplifier or a HP amplifier with the line in line out passthrough feature, like thr Topping A30 Pro
 
Jan 1, 2025 at 4:23 PM Post #828 of 844
I'm getting one of these used tomorrow. Would the A90D pair well with the Schiit Gungnir MB or the Denafrips Ares II? I have the Gungnir but looking at getting the Ares II.
 
Jan 2, 2025 at 5:04 PM Post #829 of 844
Okay so I just got this amp and I'm listening to it right now. I'm using my Focal Hadenys at the moment but also tried the amp with my HD600 and Bokeh Closed. Like reviews have stated this must be a very linear amp. It does not have any "warmth" to it so I'm left wanting more bass even though I'm not a bass head. Clarity is certainly there so I do hear somethings in the mix I don't think I have heard before. I'm also needing to be on high gain even with my Focal Hadenys. With my HD600 I was maxed on low gain and it was not too loud. I don't have that with the Schiit Midgard and that's not even a balanced amp. It just has the XLR in and out for convenience. Low gain on the Midgard is more than fine and the A90D is supposed to have up to 10 watts. So far I'm not overly wowed by this amp. I'm pairing it with my Gungnir MB DAC.
 
Jan 2, 2025 at 5:27 PM Post #830 of 844
Okay so I just got this amp and I'm listening to it right now. I'm using my Focal Hadenys at the moment but also tried the amp with my HD600 and Bokeh Closed. Like reviews have stated this must be a very linear amp. It does not have any "warmth" to it so I'm left wanting more bass even though I'm not a bass head. Clarity is certainly there so I do hear somethings in the mix I don't think I have heard before. I'm also needing to be on high gain even with my Focal Hadenys. With my HD600 I was maxed on low gain and it was not too loud. I don't have that with the Schiit Midgard and that's not even a balanced amp. It just has the XLR in and out for convenience. Low gain on the Midgard is more than fine and the A90D is supposed to have up to 10 watts. So far I'm not overly wowed by this amp. I'm pairing it with my Gungnir MB DAC.
Not sure if you know this already and how relevant it might be in your case, but the volume curve setting has a big impact on how the volume control behaves.
 
Jan 2, 2025 at 5:30 PM Post #831 of 844
Not sure if you know this already and how relevant it might be in your case, but the volume curve setting has a big impact on how the volume control behaves.

I went through the manual. But I did not see that setting option. But either way how would that affect the sound signature of the amp? It's still a linear amp.
 
Jan 2, 2025 at 6:28 PM Post #832 of 844
I went through the manual. But I did not see that setting option. But either way how would that affect the sound signature of the amp? It's still a linear amp.
This amp puts out max power into 16ohm. Any headphone much over 32ohm would be better served by a different amp. Plays wonderfully and loud with the 15ohm Moondrop Cosmo. Impactful bass, clarity, and correct tone. Many of the Hifiman planars pair well with it also.

HD600 and Bokeh wouldn't be the best choice for this amp.
 
Jan 2, 2025 at 8:50 PM Post #833 of 844
This amp puts out max power into 16ohm. Any headphone much over 32ohm would be better served by a different amp. Plays wonderfully and loud with the 15ohm Moondrop Cosmo. Impactful bass, clarity, and correct tone. Many of the Hifiman planars pair well with it also.

HD600 and Bokeh wouldn't be the best choice for this amp.

The Topping A90D puts out 1000mW into 300ohms. My Schiit Midgard puts out 750mW into 300ohms. How is the A90D not powerful enough for my headphones?

What amp would you recommend?
 
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Jan 2, 2025 at 9:15 PM Post #834 of 844
It's a current driven amp though. It's not going to provide the voltage swing the HD600 and Boleh crave. Trust me, I have a dumb amount of amps all hooked up through switchers.
 
Jan 2, 2025 at 9:21 PM Post #835 of 844
As for recommendations, Violectric 202 or 222 will put you in a state of bliss.
 
Jan 2, 2025 at 9:23 PM Post #836 of 844
The Topping A90D puts out 1000mW into 300ohms. My Schiit Midgard puts out 750mW into 300ohms. How is the A90D not powerful enough for my headphones?
~ A90D has enough power but it has a low [0.1 ohm] output impedance. With 300-ohm headphones, this is a monstrously high 'damping factor' of 3000 (@ 1kHz). The earspeaker drivers are overdamped, overly controlled -- sound loses blossom, becomes lifeless.
~
In short, the issue is not power but suitability. A90D is a better candidate for driving higher-current need, constant & lower impedance planar/magnetic headphones.
~ I will PM with recommendations.
 
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May 23, 2025 at 12:16 PM Post #839 of 844
Got the A90 Discrete, can someone link to some feet for it to be lifted a bit off the desk? Want it to be higher than the rubber nibs to allow better cooling
YES! You can buy rubber "spacers" off Amazon that are cheap and excellent. https://www.amazon.com/s?k=rubber+spacers&crid=2QRJX5XJPLTP8&sprefix=rubber+spacers,aps,182&ref=nb_sb_noss_1
You just set them under your existing feet. You don't need to screw them in.

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https://www.amazon.com/OURUI-Thickn...efix=rubber+spacers+ourui,aps,143&sr=8-1&th=1
 

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