Astell&Kern, or Astell and Kern, AK PA 10 portable headphone amplifier impressions, comments, or general discussion
Sep 18, 2023 at 1:50 PM Post #243 of 496
Yes, it is possible 5-6 hours on a balanced 4.4mm connection, +2 hours on 3.5mm.
The Class-A amplifier consumes power and in my opinion it is acceptable.
It is a balance between the size of the housing, portability and operating time.
 
Sep 19, 2023 at 5:31 AM Post #245 of 496
I have only used mine on a longer session with AuR Audio Neon Pro IEM.

Out of the 4.4mm on low gain, low current setting, cross feed off if that matters and the volume pot with the marker around the middle of the angled corner of the PA10 it went all day, 8 hours and it was still on the yellow light so something more than 30% battery still left.
 
Sep 19, 2023 at 6:46 AM Post #246 of 496
I have only used mine on a longer session with AuR Audio Neon Pro IEM.

Out of the 4.4mm on low gain, low current setting, cross feed off if that matters and the volume pot with the marker around the middle of the angled corner of the PA10 it went all day, 8 hours and it was still on the yellow light so something more than 30% battery still left.
I thought I read that only crossfeed selection is active while using the 4.4mm balanced connection and that the current and gain settings are disabled. Am I mistaken on that?
 
Sep 19, 2023 at 11:09 AM Post #248 of 496
Crossfeed, current and gain settings are all active with single-ended or balanced connection.
 
Sep 19, 2023 at 2:39 PM Post #249 of 496
I thought I read that only crossfeed selection is active while using the 4.4mm balanced connection and that the current and gain settings are disabled. Am I mistaken on that?

Yes you are mistaken.

The list of features at the start of this thread is poorly worded and the use of the term “support” sort of reads like the outputs support the features but that is not what is meant.

The gain control is certainly active on both 3.5mm and 4.4mm as is the cross feed. The effect of both is immediately obvious.

I can’t say that I have heard the effect of the current control because I have only messed with it very briefly and any change I thought I heard was very subtle and frankly I might have been imagining it. Nothing I have read says it only works on the 3.5mm however. That would make no sense, why would they implement a somewhat sophisticated feature on the less technically capable and less powerful single ended 3.5mm output ?
 
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Sep 19, 2023 at 5:04 PM Post #250 of 496
Yes you are mistaken.

The list of features at the start of this thread is poorly worded and the use of the term “support” sort of reads like the outputs support the features but that is not what is meant.

The gain control is certainly active on both 3.5mm and 4.4mm as is the cross feed. The effect of both is immediately obvious.

I can’t say that I have heard the effect of the current control because I have only messed with it very briefly and any change I thought I heard was very subtle and frankly I might have been imagining it. Nothing I have read says it only works on the 3.5mm however. That would make no sense, why would they implement a somewhat sophisticated feature on the less technically capable and less powerful single ended 3.5mm output ?
I've noticed higher current settings progressively make the sound thicker. I think more current adds more harmonics. Could be good or bad depending on the synergy. There's typically good synergy with planar transducers with higher current, have you tried any?
 
Sep 19, 2023 at 7:40 PM Post #251 of 496
One kind of fun experience I've had with my PA10 is discovering that it transformed the sound quality of my entry-level Sennheiser 400s closed-back headphones (priced at about $50).

I normally use my Sennheiser 660S2's, but a few years ago I bought the inexpensive, but reasonably good sounding 400s--for me they're great for traveling (throwing into a backpack or suitcase).

As I said they sound good and are satisfying (obviously they are not 600 series sound) but when plugged into the PA10, the sound quality difference really is night and day--they sound controlled, solid and expansive (especially when using the PA10's cross-feed circuit). Remarkably, I think I hear a bigger RELATIVE improvement plugging the Sennheiser 400s into the PA10 than I hear plugging the 660sv2 into the PA10 (which sounds great too).
 
Sep 19, 2023 at 9:16 PM Post #252 of 496
I've noticed higher current settings progressively make the sound thicker. I think more current adds more harmonics. Could be good or bad depending on the synergy. There's typically good synergy with planar transducers with higher current, have you tried any?

I have briefly tried my DCA Aeon Noire because as you said the very low impedance and somewhat insensitive planars should prefer more an amplifier capable of delivering current swing versus voltage swing. I thought I noticed a small change in the bass but it was subtle and may have been imagined because I sort of expected it.

Listening to HD600 at the moment and they sound very good and I hear no change with the current settings.

I would have thought that if the transducers didn't need more current it it would make no difference and that has sort of been my observation but, like I said, I am not entirely convinced I heard any change at all and it there was one it was not a real wow moment, not even close.

Very happy with the PA10 nevertheless.
 
Sep 20, 2023 at 12:23 AM Post #253 of 496
I spent another hour and a half with my DCA Aeon Noire off the PA10 4.4mm on high gain listening to a bit of bass heavy and very busy dub experimenting with the current control.

It is subtle but I do believe the higher current setting just tightens up the bass a touch, gives the bass a smidge more impact and as a result adds a little of extra clarity to busy bass heavy passages.

In a quick comparison the PA10 does very well against the iFi Diablo. It doesn't have the outright power but it has plenty and to my ear has a nicer warmer tonality with the Diablo being a touch colder. That is using the Diablo as an amplifier only like the PA10 with them both fed 4.4mm balanced from my FiiO M11 Plus LTD. The Diablo is awesome into 300 ohm Sennheiser HD600 were voltage swing is needed but struggles with the very low 13 ohm of the Aeons with very distinct distortion when the amplifier is pushed hard, no distortion at all into 300 ohm HD600.

I have been listening with the PA10 for 8.5 hours total, about 4 hours with IEM at modest volume pot setting, about 3 hours with HD600 and then 1.5 hours with the Aeon Noire on high gain and high current run pretty hard and the battery indicator is still yellow showing more than 30% charge remaining.

Once again, I am very happy with the PA10, my new favourite toy and like I said before probably my best head fi buy ....... outside the FiiO M11 Plus LTD.
 
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Sep 24, 2023 at 3:42 PM Post #254 of 496
Recently purchased a PA-10 and have an issue.

Here's the deal:

The unit has fine sound, I mean this is truly fine sound and powers everything I've got. I doubt that I would get a Class-A amp with this power and BAL LO [a main selling point for me] for this price, anywhere.

Vexing issue: The low volume balance. My hearing isn't perfect, some high frequency loss for sure but its sensitivity is pretty good, maybe very good. With LO set on either balanced or SE, using a pair of reasonably sensitive over-ear cans, I have to turn the volume knob, I would estimate, nearly 1/6 to 1/5 of MAX, to get the channels balanced. This is basically the same on low or high gain. It starts off with the right channel's volume coming in and gradually evens out (I think) with the left. I am well aware that analogue volume pots have this issue and I have a few with this but this seems to be maybe the worst I've experienced. I have read a few reports from folks on this thread that they have this too so it seems that the PA-10 may have this issue, at least with some units.

My DAP has a balance feature in audio controls that permits balance adjustment even with the LO (I just tested it) so with a little tweaking, I can listen to low volume music out of the amp and even out the balance. At the point of doing all of that however, I might as well listen right off the DAP.

This was bought from a reputable seller I've previously dealt with and was factory sealed. I have about another week or so that I can return. The seller does not permit refunds only exchanges and I knew this going in. If this were an easy refund return (like some sites offer) I would strongly just consider returning for a refund. I don't say any of this lightly. I really like the sound and am very impressed with the overall quality and solidity of the amp, but I wonder if the balance of these potentiometers may really vary from unit to unit and I got one at the farther end of the bell curve.

I estimate it would cost, with insurance and tracking, probably $50.00 to $100.00 bucks to return and then, of course the rub is, would I get another new unit with the exact same issue? At that point I'd have to stop the insanity but I'm out the postage and added stress of monitoring a return along with the possibility of a mailing issue, theft, damage, etc.

Should I live with this and just deal with it, enjoy the great sound and accept it or take the risk as stated above of an attempt at an exchange?

Thanks for any advice!
 
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Sep 24, 2023 at 4:06 PM Post #255 of 496
I can guess what you mean.
Channel imbalance at very low volume.
I wrote it in this thread at the beginning, I was worried before the purchase too.
From my observations, it does not occur on the 3.5mm connection, but on the balanced 4.4mm connection it is present, but only at a really low volume.
I have several pairs of headphones, with AKT9iE with 16Ω and an efficiency of 96dB, it can be said that it is not bothersome, at 32Ω it is no longer noticeable.
If the imbalance also occurs at higher volumes, I would think about replacing it.
 

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