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Topping A90 Headphone Amplifier Review
- Thread starter amirm
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Veri
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- Feb 6, 2018
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Probably by blocking power connection to PC
good that it's gone now.Probably by blocking power connection to PC
Yeah, it bypasses the PC power and instead lets you inject power from a different source. Most 5V USB power adapters don't have a ground lug... so no ground issues
AUDIO MYTH - "SWITCHING POWER SUPPLIES ARE NOISY"
https://benchmarkmedia.com/blogs/ap...audio-myth-switching-power-supplies-are-noisy
Is this true？
Half. What was on the page is mostly right. But the issue is that only half of the story is told.
Just an update of my A90's intermittent relay issue. The distributor said the decision is up to Topping now, what to do with my unit.
Since the issue is intermittent and occurred while turning on, the distributor could not replicate the issue so far (afraid of damaging the power switch).
Since the issue is intermittent and occurred while turning on, the distributor could not replicate the issue so far (afraid of damaging the power switch).
@JohnYang1997 Any plan to use Gallium nitride (GaN) MOSFET in a headphone amplifer ?
No.
If you are sure you are hearing a pop that wasn't there. And if you are sure the relay is not doing its job. You have my permission to ask for a replacement. So now it's up to you.
Thanks, really appreciate it. Now I explicitly asked for unit replacement. Since it's still on warranty.
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Hi, I am bit confused with gain matching / figuring if A90 is suitable as a preamp to my power amp (NAD c356, preamps bypassed).
It has an input sensitivity of 950mV (impedance 20kOhms + 1nF). If I set gain to medium (0dB) does that correspond to 1V to amp, so if the potentiometer opened fully, gives max power of the amp (or clipping a little bit)?
It has an input sensitivity of 950mV (impedance 20kOhms + 1nF). If I set gain to medium (0dB) does that correspond to 1V to amp, so if the potentiometer opened fully, gives max power of the amp (or clipping a little bit)?
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Update: Got the A90 today, works great as a preamp on the low (L) setting for normal listening volumes in this setup. Got a little ground loop hum if I put my ear to the speaker, should try getting a shorter RCA cable (got 1,5m now when the need is for maybe 20cm...)
Could you try using a RCA to XLR cable with XLR pin 1 connected to RCA shield? Or is this of any benefit in ground loop situations?
I just wanted to report that I've also had this issue happen to me three times in the 2 weeks that I've had this amp. Using the front panel power switch, the relay clicked when I turned the amp off but when I turned it on a little while later it produced a staticky thump with no relay click. This is maybe three out of a few dozen times of turning the amp on. Perhaps this isn't just a one-off issue? I'll see if the distributor will allow a replacement.
It will be tricky if they need to replicate the issue before allowing replacement. Hope it will going well.
I know smsl has lots of quality control issues.
I assume topping are better, but by how much.
being a new product, people haven’t had it long enough to have enough data on things going wrong.
shame if it just happened outside the warranty period.
I assume topping are better, but by how much.
being a new product, people haven’t had it long enough to have enough data on things going wrong.
shame if it just happened outside the warranty period.
I forgot to add that when I got the burst of static and the relay didn't click, if I began playing music it played through the headphones like normal. It seems like the relay was already "on" when the amp turned on, even though I heard a relay click when I turned off the amp, and thus didn't protect the headphones from the turn-on transient. Either that, or the relay turned on immediately (with the relay click masked by the sound of the switch) without the usual delay.
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That is exactly what happened to mine.
Mine died yesterday after only a couple months of use. Sat down to my computer to relax and my right channel had either very low or no sound. checked the headphone connections and they were fine, went to unplug and replug in the 1/4" and the right channel had a incredibly loud "POP!" as the jack went in (hoping it did not damage my Focal Elex). I also grabbed a pair of cheap IEMs and had the same experience. Left it turned off and unplugged overnight, same issue today. Happened with both the 1/4" and XLR cable. I've reached out to Apos and am hoping they can get me sorted
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nerdoldnerdith
Senior Member
I am getting a pair of speakers that require biamping with an external crossover. They have a minimum impedence of 6 ohms. I have an extra Topping A90. I thought that maybe it would be possible to amp the tweeters with the Topping since they don't require that much power. Based on what I have read it is generally recommended not to drive speakers with a headphone amp, but what I am doing is a bit more specific. I have also read of people driving speakers with the Chord Hugo.
Would it be possible to drive the tweeters with the Topping A90 without damaging something?
Would it be possible to drive the tweeters with the Topping A90 without damaging something?
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