Topping A90 Discrete Review (Headphone Amp & Preamp)

[staticV3]

So, why this protection limit will not engage if we have a 13 ohm headphone?

It will eventually, but not before the Noire reaches 124dB SPL Peak and potentially damages the headphones and your hearing.

What mean in the first post by amir “When pushed into protection with loads < 32 ohm, the unit shut off” and “Protection limited at 16 and 12 ohms”.

Exactly what it says. There's no hidden meaning.

A protection circuit exists, but in practive your ears and the Noire will call it quits before the A90D does.

And why noise would be “not even remotely udibile”, there shouldn’t be a significant reduction in thd+n at that impedance?

Correct. Noise and distortion is not meaningfully affected by a 13Ω load, and is so low in the first place as to be conpletely inaudible.

 

[Roland68]

May you explain me better?

So, why this protection limit will not engage if we have a 13 ohm headphone?

What mean in the first post by amir “When pushed into protection with loads < 32 ohm, the unit shut off” and “Protection limited at 16 and 12 ohms”.

And why noise would be “not even remotely udibile”, there shouldn’t be a significant reduction in thd+n at that impedance?

Thanks

You just have to make an effort to look at the tests on ASR; all the relevant information is there.
The A90D still delivers over 10 volts at 12 ohms before the protection circuit kicks in. At this voltage and 12 ohms, THD+N is approximately -113 or -114 dB, so definitely inaudible.

At 10 volts, you'll permanently damage your hearing with the Noire, or even damage it—which would be worse?

 

[maruko]

You just have to make an effort to look at the tests on ASR; all the relevant information is there.
The A90D still delivers over 10 volts at 12 ohms before the protection circuit kicks in. At this voltage and 12 ohms, THD+N is approximately -113 or -114 dB, so definitely inaudible.

At 10 volts, you'll permanently damage your hearing with the Noire, or even damage it—which would be worse?

I'm still learning and I'm still not able to read and interpreting every nuance in a review. But I was in a hurry to understand this because I'm considering buying the Noire.

My concerns come from this post here on ASR.

 

[staticV3]

I'm still learning and I'm still not able to read and interpreting every nuance in a review. But I was in a hurry to understand this because I'm considering buying the Noire.

My concerns come from this post here on ASR.

The A90D is rated for headphones down to 8Ω and shows no increase in noise whatsoever when load impedance drops from 300Ω to 16Ω and basically no increase in distortion either:


Source

This trend is unlikely to change when load impedance drops from 16Ω to 13Ω.

 

[JIW]

I'm still learning and I'm still not able to read and interpreting every nuance in a review. But I was in a hurry to understand this because I'm considering buying the Noire.

My concerns come from this post here on ASR.

This is how the A90D performs in Amir's test for different loads. SINAD is unaffected until protection or clipping.

The post in question makes sweeping claims with only a few anecdotes of poorly performing devices to back them up. Not convincing at all.

 

[maruko]

@JIW @staticV3 @Roland68
Thanks

 

[Luvchampagne]

I'm thinking of buying and using the A90D as a preamp instead of the Pre90. Seems to have all the same basic functionality and also has the 12v trigger. Specs look almost the same or at least whatever the difference is inaudible.
Anyone else gone down this path?
Only concern is reliability. Don't want a metal brick in 1 or 2 years.
Thoughts?

 

[Roland68]

I'm thinking of buying and using the A90D as a preamp instead of the Pre90. Seems to have all the same basic functionality and also has the 12v trigger. Specs look almost the same or at least whatever the difference is inaudible.
Anyone else gone down this path?
Only concern is reliability. Don't want a metal brick in 1 or 2 years.
Thoughts?

You could also use the L70, which is even cheaper. It includes a trigger and relay-based volume control. Some measurements are even better.

The only thing you can't do is connect the EXT90.

 

[Luvchampagne]

You could also use the L70, which is even cheaper. It includes a trigger and relay-based volume control. Some measurements are even better.

The only thing you can't do is connect the EXT90.

Thank you for your suggestion
I'm playing around with the A90D and it's a nice little piece. Unfortunately the comments about controlling the volume are spot on. So difficult to aim the remote, let alone trying to control it with my iphone Harmony app.
Any idea whether the L70 has the same IR problem? Is there a fix for it?

Thanks

 

[Roland68]

Thank you for your suggestion
I'm playing around with the A90D and it's a nice little piece. Unfortunately the comments about controlling the volume are spot on. So difficult to aim the remote, let alone trying to control it with my iphone Harmony app.
Any idea whether the L70 has the same IR problem? Is there a fix for it?

Thanks

No, the remote control on the L70 works perfectly even at a 30° angle from a distance of 3 meters.
The volume can also be adjusted quickly and precisely, and I haven't noticed any crackling noises so far.

 

[maruko]

Anyone else gone down this path?
Only concern is reliability. Don't want a metal brick in 1 or 2 years.
Thoughts?

I bought it about two weeks ago mainly as a pre-amplifier to pair with an Audiophonics HPAS400ET amplifier.

I share your concerns and asked if there were any units that have been working for more than two years. Apparently, there are.

Also, I was able to find many comments online about similar issues with the old A90, which I’ve had for 5 years now, without any problems.

If it happens, I’ll send it to Topping for repair.

 

[Luvchampagne]

I'm guessing that maybe the Pre90 is less susceptible to failure? Doesn't have the 2 wall wart SMPS inside like the A90d.
I wonder about the reliability of the L70?

Lastly, could someone please share the solution to the remote control issue? As one person put It, "sharpshooting" skills are necessary.
I try to run everything from my iPhone so it has to be able to be reliably operated by a Logitech harmony blaster. Currently I can do it through my RME ADI2 DAC FS. Just looking for additional flexibility without losing transparency.

Thank you in advance for all the helpful comments.

BTW, for the 2 days I had the A90d in my system, it was an excellent preamp. Other than the remote control issues, it was transparent and highly functional.
MacAir-> RME ADI2 DAC FS -> Preamp -> 2 subs (from RCA) and 2 amps through XLR.

 

[maruko]

I'm guessing that maybe the Pre90 is less susceptible to failure? Doesn't have the wall wart SMPS inside like the A90d.
I wonder about the reliability of the L70?

Lastly, could someone please share the solution to the remote control issue? As one person put It, "sharpshooting" skills are necessary.
I try to run everything from my iPhone so it has to be able to be reliably operated by a Logitech harmony blaster.
Thank you in advance for all the helpful comments.
BTW, for the 2 days I had the A90d in my system, it was an excellent preamp. Other than the remote control, it was transparent and highly functional.
MacAir-> RME ADI2 DAC FS -> Preamp -> 2 subs (from RCA) and 2 amps through XLR.

Since I would to add a subwoofer in the future, can you confirm that A90D con output both on RCA and XLR simultaneously?

 

[Luvchampagne]

Yes.
First I tried to run it off a Y splitter off another y splitter on the xlr. I have a an XLR low pass filter that I was using. Nothing.
Second
2 rca y splitters. Each running 2 cables to each of the 2 subs. Subs receiving both L and R inputs.
I'm doing this so that when I run REW, I can utilize both subs. If I connect each sub to 1 channel, I won't have both subs when testing L and R channel separately.
Success.

 

[Roland68]

I'm guessing that maybe the Pre90 is less susceptible to failure? Doesn't have the 2 wall wart SMPS inside like the A90d.

This is more of a disadvantage, as the +/- voltage has to be generated from a single voltage power supply using a switching frequency.

I wonder about the reliability of the L70?

I've had the L70 running for a year and a half now, and I haven't heard much about failures.

 

[Luvchampagne]

Spoke with the great folks at Synthax (RME USA folks).
Currently using my RME ADI2 DAC FS as my preamp as my Krell HTS 7.1 was introducing problems when REW testing.
Was trying to squeeze the Pre90 /A90D / L70 as my preamp.
Struggling with the remote control for volume and on/off and still need to use the RME to change inputs.
For now, decided I don't need a preamp as I can easily control the RME from my iPhone via Logitech Harmony Hub. Input/EQ presets/Variable Loudness/Volume control all work great.
Why introduce another piece of equipment into the signal chain other than some super exotic preamp or eye candy preamp like a Mcintosh C2300??
Funny thing is the 1 thing I'm missing is 12V trigger. Tried to use my Niles APC2 but for some reason it is not triggering with the RME. So, my Krell HTS 7.1 is a very expensive and big 12V trigger.
Open to ideas on how I can utilize on/off of RME to trigger a large Furman Power Conditioner to then power on/off my amps.

Thanks

 

[trog69]

Have any of you had the A90D for more than two years without ever having had a problem?

I got mine two weeks ago, as a preamplifier in my speaker system, and I feel very good.
Now I only use the A90 for headphones.

But I'm afraid it may present the problems that many of you have had.

I truly hope that's not the case. I, too plan on using the a90d as a preamp to either the NAD 208thx or an Adcom 555 power amps to my beloved aDs 910 loudspeakers. So far this HP amp is just what I like in sound quality but I've only used it as a HP amp. I think it'll be awesome as a preamp.

 

[trog69]

I recently and accidentally set the A90D's screen to turn off after a few seconds. How can I turn the screen back on? The instructions are very hard for this dumbell to figure them out.

 

[JIW]

I recently and accidentally set the A90D's screen to turn off after a few seconds. How can I turn the screen back on? The instructions are very hard for this dumbell to figure them out.

This should do it.

 

[mediocrebutarrogant]

Can anyone tell me the weight of the Topping A90D please? On my body weighing scale inside the box it is 1.55 Kg