[MatW]

Could somebody comment about the options of replacing the volume knob by something more substantial? like, has somebody tried this already? is it a standard diameter size, like a round number, what is the exact diameter actually? Does ti has a bolt to be disassembled?

It's the only flaw I find on this device. In my JDS atom I can change the knob for an aluminium one better than the original which is very flat like this one. Maybe a green anodized one would be cool, or red... or silver, or pink, or purple!!! all anodized aluminium color look awesome.

Thanks a lot in advance!!

I agree, I would be in favor of a better, more substantial volume knob. I have to be careful how I word this now.. (I said volume knob!)

 

[Lolito]

Do you have some close-up pics of the knob? Like typical volume knobs, there may be a small screw at the knob.

no, I have no photos because I have no a90 unfortunately, I am interested on knowing more about knob options before ordering one. For the JDS Atom I have a really nice custom aluminium knob...

 

[jshaevitz]

Also, I had an iPhone on a wireless charger, audible interference was coming through. Removed the phone and it went away. Charger was about 1 foot away from stack. Just for reference if anyone notices interference and is wondering what may be causing it.

I had exactly this with my L30 and it was driving me nuts. I couldn't understand why I had this annoying interference (something like a 5 Hz low freq pulsing) only in the evenings. Finally realized that's when I put my phone on the wireless charger which was ~8 inches away. To test, I put the charger right on top of the amp and the interference was quite loud and only when I put the phone on the charger. Moved the charger to the other side of my desk and all is well. Wish I would have found this post earlier

 

[Lolito]

nobody can talk about the knob options? does it have a hole for a screw head in the opposite side of the volume indication mark/line? thanks a lot in advance!! If I can swap the knob, I buy me one of these.

 

[MatW]

nobody can talk about the knob options? does it have a hole for a screw head in the opposite side of the volume indication mark/line? thanks a lot in advance!! If I can swap the knob, I buy me one of these.

No hole, as far as I can see.

 

[Lolito]

Great, no hole, then it must be just pressed in, like with JDS Labs ATOM. Can you remove the knob?can you pull it out slowly, should be no problem, all knobs are removable by pulling if there is no screw hole. Hopefully we can confirm it, then measure the diameter and the stem, and order a substantial knob.

 

[sebiambrus]

Hi i am reccently purchased an A90
Can you tell me how to switch on and off the A90, First the backside where is the power cord, and after the faceplate to turn on?
And to switch off first turn off the faceplate then after the backside ?

 

[the machine]

Hi i am reccently purchased an A90
Can you tell me how to switch on and off the A90, First the backside where is the power cord, and after the faceplate to turn on?
And to switch off first turn off the faceplate then after the backside ?

You don't need to turn the power on the back off. To turn the back switch on, the highest part of the switch should be flat. Then push the switch on the front up. If you're having issues turning the unit on, you may have a defective unit, although, it seems unlikely they would ship out a unit that didn't power on.

 

[Gorillaphant]

I’ve seen some comments saying the A90 is a little warmer than the AAA 789 but is it actually a noticeable difference? Any other performance differences between the two that are immediately apparent?

Considering selling my 789 and buying one of these but not really sure if it would be worth it.

 

[zeromacro]

I’ve seen some comments saying the A90 is a little warmer than the AAA 789 but is it actually a noticeable difference? Any other performance differences between the two that are immediately apparent?

Considering selling my 789 and buying one of these but not really sure if it would be worth it.

I haven't heard the 789 so take this for what it's worth but the general consensus seems to be that the difference is not significant enough to warrant an upgrade.

 

[carlosgab]

I haven't heard the 789 so take this for what it's worth but the general consensus seems to be that the difference is not significant enough to warrant an upgrade.

I second this. I currently have both. My only problem with the 789 is that it sounds best on Medium Gain. The High gain tends to sound somewhat shouty, less smooth whereas the A90 does not have that problem.

 

[NickT23]

Am getting the HPA-4 one day so I no longer considering the A90. But i would like to compare them though and some people view about the A90

 

[elricofchaos72]

Am getting the HPA-4 one day so I no longer considering the A90. But i would like to compare them though and some people view about the A90

The HPA4 did not have enough power for my Abyss headphones unfortunately. The A90 does on medium and high gain. Really too bad as I had the DAC3 HGC. It too didnt have enough power for the Abyss.

 

[NickT23]

The HPA4 did not have enough power for my Abyss headphones unfortunately. The A90 does on medium and high gain. Really too bad as I had the DAC3 HGC. It too didnt have enough power for the Abyss.

Now, that is a disappointment since the Abyss is not push to its potential in terms of power. Always thought the HPA-4 is also a beast when it comes to power and transparency. Does the A90 on medium and high gain provide sufficient power for the Abyss than HPA-4.

 

[LightBlue77]

Hey everyone, I have some questions, apologies if they were already discussed:
- turning the volume knob to minimum doesn't completely turn off the volume, i still hear the music, very low level but audible. I've seen it mentioned already somewhere on page 15 or so but didn't read any answers. I would say it is a flaw, a small one but still. Is it happening to anyone else and can it be fixed? Not by sending it to China, but maybe with a firmware update?
- second is more of a technical issue: until getting a better balanced dac, i feed A90 from single ended line out of fiio m15 to RCA input but the headphones are connected to 4.4mm balanced output. The sound is very good, but is it a problem doing this? I assume not since it works and guess the sound is not truly balanced but just curious.
Thanks in advance.