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Topping A90 Headphone Amplifier Review

maxxevv

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I have the smsl sp200 which should be quite close from the 887 as well as the A90. I can confirm most of PCZ_97 impressions. A90 is slightly warmer (bass and low medium). the thx feels a bit more energetic though. Both units are really good. I was not expecting such quality for moderately priced units coming out from a Spl phonitor which just died.

The HD800 can sound different from playing at different at volume levels. The 2 amps have different gain levels and thus different output values even if they "sound" the same or the volume pots are the same.

Chances are, you are listening to the A90 at a few dB louder without realising it.
At higher dB's, the HD800's perceived bass gets more prominent, and its probably why you guys think one amp sounds warmer than the other when both are measurably transparent.

Try using some handphone apps that can help to measure the actual sound levels output from the headphone (if you do not already have a calibrated microphone lying around). Equal the volume values at the headphone from both amps to within 0.1 dB if possible and then do a blind test.

I'll be extremely surprised if you can pick them apart with confidence in a greater 10 try blind trial.
 

w1000i

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I have no issue with the Element X internal amp, very detailed linear and good resolution but sometimes I just miss the extra bass/punch/rumble on some of the content I play on Element X. Will the A90 give me some punch/bass or warmth when paired with Element X? The A90 is just a simple plug and play on the element X balanced out if needed.

what is your headphone ?
 

auronthas

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It's not the only way to go. There are many cases there's no issue. People report only when there's an issue. You don't know the cases where it's fine.
Since quite a few people complaining about noise on RCA, I would like to clarify here.

I have D90MQA and A90 paired with RCA (1 meter Van den hul the Source) , I did not hear any noise from my HD650 and HE4XX with low and medium gain tested. No test on high gain though as not required as of now.

Electrical system here is single phase (two-wire L & N and earth), power supply to D90 MQA/A90 is from wall wart with proper earthing
 
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EdW

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I had absolutely no issue with RCA going from Qutest to A90. I used very short RCA cables and couldn't detect even a hint of noise on max gain and volume.
As John Yang points out it can be pretty much a case of hit or miss whether you get hum loop problems. But with the Qutest the power supply is from a wall wart - so no ground connection. You would have been unlucky to get any ground loop issues
 

raif71

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Is there anything that Topping can do to rectify rca noise etc in future production batches ?
 

Beppe

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I had absolutely no issue with RCA going from Qutest to A90. I used very short RCA cables and couldn't detect even a hint of noise on max gain and volume.
I also have the Qutest connected to the shiit Jounheim and that's fine. How's it going with the A90? is the sound better perceived? is it worth upgrading to the A90 in your opinion?
 

Rigel

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Hey guys!

I am having a noise problem with my Topping A90 at medium and high gain w/ my DT 1990s. There is a very noticeable buzz even when the gain nob is at the halfway point on medium gain. I am using RCA inputs from my motherboard dac (SABRE 9118 DAC ) (don't have an external DAC yet, need to decide on which on to get) and the 6.5mm headphone out.

The thing is I don't get nearly any noise when I use my THX 887 with the same outputs/inputs. Would this huge difference be caused by the internal computer noise and the A90 being much more powerful? It seems weird that there would be huge difference between the A90 and my THX 887. If I can't figure this out I am going to have to return the A90 unfortunately as the noise is too problematic.

Do you guys have any thoughts?

Hi Monteh

The A90 has good sound. If you plan to purchase a DAC in the near future, you could wait to test it with the new DAC before returning it.

In my case I have the D90 and there is hardly any noise with HD800 headphones at maximum gain and volume when I connect it to the A90 through RCA. And when I connect an idefender to the PC, the silence is already absolute by RCA.
At least in my case and I suppose that in all the most common PCs, the leakage current of the PC and that can be transmitted through the wiring, is much higher than that of the rest of the equipment. DAC and amplifier.

It is also easier to minimize noise on a USB connection than an RCA if the noise source is the PC as I mentioned before.

Do you only have connected to the system, the PC and the amplifier?
If the noise source is the PC, I think that more than a buzz, a noise similar to that of old modems or similar to sound would be heard when the radio frequency of a mobile phone is coupled to active speakers. Typically, noise increases with PC processing.
 

nyj585

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It's not the only way to go. There are many cases there's no issue. People report only when there's an issue. You don't know the cases where it's fine.

Yes, I think with all things it's down the individuals system/situation. But I've read RCA issues on here, head-fi, as well as a youtube video so I figured it wasn't just one or two units being defective (which wouldn't worry me at all as it happens to all products), but rather a certain common factor across these systems that seem to cause issues with the amp. The youtube video by Maximilian Power especially worried me because I do plan on using the amp with my computer system.

I kind of get the people only report when there are issues though as I'm currently using an EVGA Nu Audio Card and I never had issues with installing the drivers like many people have; But it seems pretty common for the amount of people to complain that it has software issues in similar ways. I do think while I got lucky, that there must've been a legitimate issue despite it never occurring to me really. Now whether it's a user-end issue or software engineer-end issue, I have no idea. Coming back to the Topping A90, just the frequency and common factor of using RCA among a number of people who bought the amp is what concerned me is all. This is also my first step into getting a dedicated DAC/Amp stack so I am also trying to make sure I make a good purchase.

The nice part seems to be that XLR seems to alleviate the possibility of any issue in all of these cases, which mean I will likely get XLRs if I decide to go the LAQXD-1/A90 route instead of the E30/L30. However, I hope whatever the issue is doesn't effect me as it would be nice to have the flexibility to wire it with RCAs if I need or want to. I guess I'll finally have to make my decision once the L30 comes out.

I am guessing though that the RCA outputs to a speaker power amp would be fine then if I connect the DAC to the Amp via XLR as the ground loop issue is happening before then.

Also thank you for being around to answer people's questions and address issues though. It's not often a product has someone who actually helped design it around to talk about it/address concerns.
 
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Monteh

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Hi Monteh

The A90 has good sound. If you plan to purchase a DAC in the near future, you could wait to test it with the new DAC before returning it.

In my case I have the D90 and there is hardly any noise with HD800 headphones at maximum gain and volume when I connect it to the A90 through RCA. And when I connect an idefender to the PC, the silence is already absolute by RCA.
At least in my case and I suppose that in all the most common PCs, the leakage current of the PC and that can be transmitted through the wiring, is much higher than that of the rest of the equipment. DAC and amplifier.

It is also easier to minimize noise on a USB connection than an RCA if the noise source is the PC as I mentioned before.

Do you only have connected to the system, the PC and the amplifier?
If the noise source is the PC, I think that more than a buzz, a noise similar to that of old modems or similar to sound would be heard when the radio frequency of a mobile phone is coupled to active speakers. Typically, noise increases with PC processing.

Hi! Thanks for the response. What worried me is that I don't get this noise with my THX 887. I think it may be a problem with my unit as others have not had this problem. I want to try it with an external DAC but I am currently indecisive about which one to get haha.
 
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Martin

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I have Audeze LCD-3 (101 dB/1mW at 110 ohms) and Focal Clear (104 dB/mW at 55 ohms) headphones and am currently using a Topping DX7 Pro. Is there a compelling reason to buy an A90 to run off the DX7 Pro DAC, or buy the A90/D90 stack to replace the DX7 Pro?

Thanks,
Martin
 

Hemi-Demon

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To be fair, if Schiit gets ripped for all the past mistakes, then Topping deserves some heat for releasing a product that appears to have some basic issues with RCA outputs. What is the point in having a great measuring device, that you get noise from a basic single ended standard. Telling people to just return it (at the cost to the buyer), and then hope the L30 is better is pretty poor discourse, imo.

I have owned quite a few Topping devices, but at $500 the RCA issues documented by quite a few members, certainly makes me pause on buying this one in particular.
 

bboris77

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As for the RCA being sensitive to ground loop noises with 3-prong devices, I have had the same issue with all the headphone amps that do not use an external 2-prong power adapter.

If this is the only problem with the A90’s RCA inputs, it is a non-issue as it is endemic to any fully grounded amp (The Asgard, Burson Soloist etc.).

There are 2 ways to work around this problem without affecting the fidelity of the signal: get the EB Tech Hum X for $79 or get an USB isolator.
 
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JohnYang1997

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To be fair, if Schiit gets ripped for all the past mistakes, then Topping deserves some heat for releasing a product that appears to have some basic issues with RCA outputs. What is the point in having a great measuring device, that you get noise from a basic single ended standard. Telling people to just return it (at the cost to the buyer), and then hope the L30 is better is pretty poor discourse, imo.

I have owned quite a few Topping devices, but at $500 the RCA issues documented by quite a few members, certainly makes me pause on buying this one in particular.
It's basic understanding of electronics that earthed single ended systems are much more prone to ground related issues.
 

Audimon

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@JohnYang1997 why not make an external adaptor for sensitive audio equipment? My RME ADI-2 has an external adaptor. It's dead silent after I got rid of the usb ground. And the best thing is that I don't have huge plugs and thick cable on my desk. So why not do the same?
I am waiting with slight horror for my A90 thinking how I will be rewiring my desk to fit yet another huge cable cause I already got custom length Supra for it.
 
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JohnYang1997

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@JohnYang1997 why not make an external adaptor for sensitive audio equipment? My RME ADI-2 has an external adaptor. It's dead silent after I got rid of the usb ground. And the best thing is that I don't have huge plugs and thick cable on my desk. So why not do the same?
Because people don't like external supply....
 

gvl

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Some manufacturers seem to be able to do away with ungrounded chassis and mains connection. Is this perhaps one approach to consider?
 
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