[Kozwoz]

A good 12 inch sub can usually go down to 20hz. You feel those frequencies, you don't hear them. Using a sine wave generator I can certainly feel pressure on my ears at 20hz using some headphones. If this is the limit of the A90's capabilities it is plenty low.

 

[Arniesb]

A good 12 inch sub can usually go down to 20hz. You feel those frequencies, you don't hear them. Using a sine wave generator I can certainly feel pressure on my ears at 20hz using some headphones. If this is the limit of the A90's capabilities it is plenty low.

How is amp responsible for headphones capabilities to reach low?

 

[nigel801]

After using and experimenting Topping A90 and D90 and swapping between Hugo 2 and D90 for several weeks, I regret to say Topping QC is very poor. Topping A90 RCA has lot of noise compared to XLR even the 4.4mm output compared to 4 Pin XLR is distorted. I guess I should look for some Burson stuff.

 

[Kozwoz]

How is amp responsible for headphones capabilities to reach low?

If my Shure 846 go down to 10hz but the amp goes down 20hz then the amp will not reproduce 10hz, this is regardless of whether you can hear it or feel it. There are ribbon tweeters that go up 50khz - this is not because you can hear past 20khz but because the harmonics reproduced above 20khz affect what you hear below 20khz.

 

[Voxata]

After using and experimenting Topping A90 and D90 and swapping between Hugo 2 and D90 for several weeks, I regret to say Topping QC is very poor. Topping A90 RCA has lot of noise compared to XLR even the 4.4mm output compared to 4 Pin XLR is distorted. I guess I should look for some Burson stuff.

Unfortunately this is well known - but most users won't have issues. I didn't, thankfully when I owned the A90. Considering balanced only, it's a very well-performing measurement first amp. Topping as of late has been sacrificing capability for measurement improvements and it's starting to rear an ugly head. Their new Pre90 comes to mind.

 

[wishbon3]

You can't hear above or below that range, so does it really matter?

How do you know he isn't a bat or dog?

 

[PhazeCrive]

I ain't special yet my ear bones are capable vibrating at 25khz. This is why I asked, cuz it may apply for others. But not that music is mixed with those extreme frequencies anyway.

 

[kingoftown1]

 

[Lolito]

After using and experimenting Topping A90 and D90 and swapping between Hugo 2 and D90 for several weeks, I regret to say Topping QC is very poor. Topping A90 RCA has lot of noise compared to XLR even the 4.4mm output compared to 4 Pin XLR is distorted. I guess I should look for some Burson stuff.

That's the main concern with this kind of products... when you look inside of them, the potentiometer used is tiny, it's a joke really. Schitt magnius or schiit jotenheim use a much much larger pot, and then the knob is easily swapable... lot of issues with the digital knob of the topping dx7 pro too apparently, check any thread about them... Maybe topping should be called schiit, if it wants because at least the got the sound right, while schiit not that good sounding... maybe jot 2?

not very expensive the topping, but not really nice either considering the price and not that hi quality inside... 399$ is it's price I think. Rather spend 600$ to get something properly finished, but then again, nothing in the market balanced at that price, right? smsl same crap.

 

[479235]

I have a Soekris 1421 and was thinking about getting an A90. Would A90 + Soekris 1421 be too analytical and not enjoyable?

 

[DeafAudiophile]

After using and experimenting Topping A90 and D90 and swapping between Hugo 2 and D90 for several weeks, I regret to say Topping QC is very poor. Topping A90 RCA has lot of noise compared to XLR even the 4.4mm output compared to 4 Pin XLR is distorted. I guess I should look for some Burson stuff.

I was about to say somehow the XLR in is definitely better than the RCA in the A90. This morning I wanted to see if there was a difference between the Schiit Modi and my Asus essence DAC and at first I thought there definitely was a noticeable difference and the music wasn't scratching the itch my Asus did. Being too lazy I just plugged the RCA from the modi back to the Asus and the itch still wasn't scratched. I was doing this test with both the HD660S and the HE6SEV2. I reconnected with the XLR in and viola, the itch was finally scratched.

This really does make me pretty disappointed that if I wanted the best out of my $500 purchase I'd always have to consider XLR and discourages me from considering the D90. I was pretty hyped about the A90 but now after a disappointing pairing with the He6sev2 and this RCA nonsense Schiit is looking real tempting right now.

 

[DeafAudiophile]

I placed 2 orders in the last 2 days. One was with APOS Audio and the other was with Shenzehaudio. It seems to me that these 2 companies are run by the same people. Is that something that is commonly known?

I did the same exact thing and purchased 2, one from apos and the other from shenzen. I'm pretty sure you've figured by now but they're essentially the same considering their shipping packaging are identical and it's likely Shenzen Audio is just the front they use for Amazon.

That being said I DO NOT recommend buying from Apos if you can help it. If you read their fine print on returns it's severely detrimental compared to if you went through Amazon:

• Orders that were price-matched against a final sale promotion are not eligible for return.
• Return requests made between 8 and 45 days after the order is marked as delivered will be subject to a 20% Processing Fee*.

I'm not sure if some of it is just a bad wording but from what I inferred if you price match an order you forfeit returning the item. I'm not too clear on what "final sale promotion" refers to though. This is especially bad considering they've raised prices for 2021 roughly ~10% on most items in their store. The 20% processing fee on top of return shipping(to their Oakland HQ hopefully) is quite absurd as well considering you're given only a week after delivery to decide if it's for you. Personally 20% is the highest fee I've seen for returning something within a normal 30 day window assuming you return everything properly. There are more restrictions to returns but I only picked out the ones that stood out to me as out of the ordinary.

Unless you're adamant on not giving Bezos your money, I wouldn't consider Apos Audio my place to purchase audio gear under most circumstances.

 

[acs236]

I'm a little confused by this. You're disappointed that you can perceive a difference between the RCA and balanced (XLR) outputs?

I would think one would be disappointed were this not the case.

I was about to say somehow the XLR in is definitely better than the RCA in the A90. This morning I wanted to see if there was a difference between the Schiit Modi and my Asus essence DAC and at first I thought there definitely was a noticeable difference and the music wasn't scratching the itch my Asus did. Being too lazy I just plugged the RCA from the modi back to the Asus and the itch still wasn't scratched. I was doing this test with both the HD660S and the HE6SEV2. I reconnected with the XLR in and viola, the itch was finally scratched.

This really does make me pretty disappointed that if I wanted the best out of my $500 purchase I'd always have to consider XLR and discourages me from considering the D90. I was pretty hyped about the A90 but now after a disappointing pairing with the He6sev2 and this RCA nonsense Schiit is looking real tempting right now.

 

[DeafAudiophile]

I'm a little confused by this. You're disappointed that you can perceive a difference between the RCA and balanced (XLR) outputs?

I would think one would be disappointed were this not the case.

If they were both ideally implemented should there be a difference? I understand XLR can pass more power and has lower noise at longer lengths or in general, but I was not expecting it to sound noticeably different. I even swapped out the cable for a "premium" one from monoprice but no difference. This was done in Tidal and I did remember to change the settings after switching DACs.

When I was testing the He6se through the RCA it sounded pretty close to when I tested it with the BasX(RCA in only) but XLR in is still something else. It wasn't just the volume increase as expected from the additional power but the actual audio improvements. I'm just under the impression that if both the XLR and RCA were optimally implemented, one wouldn't be better than the other in terms of sound. So my thought is either Topping gave RCA in a second thought or all those claims from random strangers on the internet that XLR sounding better wasn't just a placebo effect.

 

[LightBlue77]

Do you have any measurements or other evidence for us to support this? Not doubting what you're saying but I think I had the same impression while listening from a Fiio m15, sending the signal from fiio's line out to RCA input of a90 and thought that the sound was muddy. At that time a90 was new, also the iems were new, final audio a8000 and I was waiting for burn in, but I was also considering that a90 might be too powerful for these iems. Since then I only used Aune s8 dac connected with xlr cables to a90.