In terms of the noise, I guess that you are using RCA input. Noise while moving mouse is classic ground loop issue related to usb power. Idefender would work better in this case. Also using short RCA cable would help on this matter also.
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Topping A90 Headphone Amplifier Review
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Berdugo
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Ok so it's not normal ? I mean once I've found the good position, if I don't touch it and leave it like that it won't move. Maybe other people noticed the same thing but didn't care, plugged it once and done ? If it's not normal, fortunately I still can return it to Audiophonics, I contacted them, but I fear all units are like this.
Yes I'm using RCA. The iUSB3.0 already has a ground-correcting function, 'Isoearth', which is present in the iDefender, I remember iFi saying in a forum that they were redundant. When I switch off the Isoearth function, the noise is horrendous, and when it's on, well it's much better but it's still there.
Just as a comparrison. I have not had any issue with my A90 and any power cord including the one provided. I have tried three just to check (I do not have any of the large expensive power cables) All of the power cables push all the way on and make good connection with the normal ~1-2mm gap between the shoulder and socket.
I have used only short 25cm rca cables. My normal setup is 25cm xlr dac to A90 50cm xlr to hypex et400a in stereo. No hiss in any orientation.
Hope you are able to resolve these issues with as little effort as possible. I would try other powercords, shorter rca`s xlr if can.
In my A90 I do not have electrical contact problems with any cable of a different brand or quality even if I move the cable from side to side with force. I only lose electrical contact obviously when I remove it.
That it moves a little laterally is normal, in this amplifier and in many other devices as long as it is firmly held when we pull it and makes good electrical contact. It shouldn't be easy to remove if that's the case.
But in your case I think that it moves too much and it is not normal that it has to be in a position for it to work. The internal pins of the IEC are riveted
¿Have you tried more cables and the same thing happens with all of them?
That it moves a little laterally is normal, in this amplifier and in many other devices as long as it is firmly held when we pull it and makes good electrical contact. It shouldn't be easy to remove if that's the case.
But in your case I think that it moves too much and it is not normal that it has to be in a position for it to work. The internal pins of the IEC are riveted
¿Have you tried more cables and the same thing happens with all of them?
Tks
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Makers producing locking XLR's when in reality we need locking power plugs. RME did this right with a slight turn of a barrel power connector, you basically secure the thing for good.
These square-ish style connectors are only good if you can get the power cable completely seated deep to where the wall of the device is touching the thickened part where you hold onto the cord. These that don't go in all the way make no sense to me.
robertozappala
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I noticed it too. the power plug of the D90 is more stable
The issue being raised here, i.e., of power cords that get loose, because they are cheap ones, has cost me several thousand dollars. I bought a Topping D90 in mid-January and, during using it, the power cord went loose, connecting intermittently (read: not switching off instantly) and ruining my expensive audio system -- KEF Q950 speakers, Sennheiser HD800, Massdrop AAA THX amplifier, Benchmark AHB2. Common sense should have dictated the designers of Topping D90 to provide it with multiple protection against such events. Perhaps A90 does not feature any protection of the kind either. It should have shut down immediately, the way computer switching PSUs do, etc. This accident would also not happen if the ordinary power cord that Topping D90 sells with had been a locking one, such as the one Benchmark sells its AHB2 amplifier with and specifically asks to be used. Besides, AHB2 features protection against clipping, accidental strong signals, and shuts down instantly in case of any incidents, which is not the case of Topping D90. Think about using with Topping audio equipment of the kind very expensive and sensitive equipment that may get ruined forever! I also observed the silly AC voltage switch that Topping D90 has, which could easily be erroneously switched from 220 to 110 V and can destroy it! In Europe that would mean feeding Topping D90 with 440 V. I guess that safety is more important than performance only! I am also intrigued by the fact that the XLR output crosstalk of Topping A90 is not on a par with that of Massdrop's AAA THX, which costs less!!! There is no excuse for that, whatsover!
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Tachyon88
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I just hooked up my recently acquired a90 and my only gripe is I wish the volume knob was longer and not tapered.
I will miss the thx 789 knob.
I'm fully balanced and everything sounds great. The preamp function is why I bought it and its so convenient.
Now topping just needs to make an all in one D90/A90 with remote and preamp function.
I will miss the thx 789 knob.
I'm fully balanced and everything sounds great. The preamp function is why I bought it and its so convenient.
Now topping just needs to make an all in one D90/A90 with remote and preamp function.
You are not making any sense here, if your AHB2 is so great with so many build in protection, how did it, and other gears down the chain got ruined when your D90 had issue?
Please also let me know how to do you reaching under D90 to switch the voltage without trying to do it, the gap isn't enough for your finger unless you lift the unit up in the first place. Lastly, if A90 has no excuse for being a much higher performance unit overall with only 1 area being not as good as 887 because it cost 20% more, by that same logic, HPA4 would be an epic fail since it cost 6x the amount of A90 but has worse performance overall.
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JohnYang1997,
What is the balanced input impedance of the A90 for the XLR?
I am asking because the rated output impedance of the Musician Pegasus DAC I just got is 1250 ohm for balanced. And I am wondering that is the reason why the Pegasus (rated 4.4 vmrs) output volume is quite massively -4.5db lower than my D90 (rated 4.0 vmrs), looking at vmrs rating I would expect it the Pegasus to be be louder. Sandu from Soundnews suggested/hypothesized that this might also be caused by the input impedance of the A90.
What is the balanced input impedance of the A90 for the XLR?
I am asking because the rated output impedance of the Musician Pegasus DAC I just got is 1250 ohm for balanced. And I am wondering that is the reason why the Pegasus (rated 4.4 vmrs) output volume is quite massively -4.5db lower than my D90 (rated 4.0 vmrs), looking at vmrs rating I would expect it the Pegasus to be be louder. Sandu from Soundnews suggested/hypothesized that this might also be caused by the input impedance of the A90.
Simply. F off. All assumptions no evidence. For the past few months. There were several times of power shortages. None of the devices are broken. There are all the protections.
2kOhm. That's why you lose volume.
NDC
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Hi. What's your country or the plug of the cord? We just checked all the current A90 units. All have tight fit. So you should be alright if you get a new unit.
Awesome, thanks! This explains a lot.
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I am wondering why the A50 uses a digitized volume adjustment while the higher priced A90 apparently does not? http://www.tpdz.net/productinfo/398152.html
Perfect channel balance while adjusting volume would be a wonderful thing to have in a flagship amp like the A90, I just find it strange it is on a lower end model and not their top of the line model. The only other manufacturer that does this in headphone amplifiers is FiiO, not including DAC/Amp combos from other companies.
Perfect channel balance while adjusting volume would be a wonderful thing to have in a flagship amp like the A90, I just find it strange it is on a lower end model and not their top of the line model. The only other manufacturer that does this in headphone amplifiers is FiiO, not including DAC/Amp combos from other companies.
Noisy and high distortion. And a90's volume control is very nice balance to very low volume.
Veri
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I have perfect channel balance on my A90 just the same. Digital volume may have benefits but there are also penalties in terms of noise.
hi, finally my topping a90+d90 mqa arrived, i have a little question,
which one the best setting for using on headphone?
For A90
1. A90: HPA > XLR > H ?
2. i use hd800s with 4.4 balance jack plug, what different between jackplug 4,4 vs xlr plug ?View attachment 79106
3. Volume Knob, how much volume should i use on A90?
View attachment 79107
For D90
1. how to setting d90? just turn on and forget it ?
2. how to use bluetooth on d90?
3. for play mqa music , this is automatically or should have a specific setting?
which one the best setting for using on headphone?
For A90
1. A90: HPA > XLR > H ?
2. i use hd800s with 4.4 balance jack plug, what different between jackplug 4,4 vs xlr plug ?View attachment 79106
3. Volume Knob, how much volume should i use on A90?
View attachment 79107
For D90
1. how to setting d90? just turn on and forget it ?
2. how to use bluetooth on d90?
3. for play mqa music , this is automatically or should have a specific setting?
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