The Sub-$100 Portable Amps Shootout – 11(+1) amps compared
Feb 25, 2012 at 3:52 AM Post #61 of 399
Oh cool :D!
Yea I asked, because that's all I've seen you recommend.
ie. You didn't like the ZO2 for example?

Btw, what version of it do u have again?


I do like the ZO2.3 I have and actually use it for bass boost more than I use E11 as amp. The problem is it hisses with some of my low impedance, high sensitivity IEM so I can't use all of them with ZO2.3. As an amp, it isn't the best around; but as a bass booster, it is great. That's why I only recommend ZO2.3 for those who want a bass boost first and an amp second.


ClieOS, I know this is a sub $100 thread, but I'm just curious what are your thoughts between the FiiO E17 and the iBasso D7. I'm only asking about SQ and amplification wise.


Haven't heard the D7, and likely won't as I have little use for another USB DAC for now. When it comes to iBasso, my attention is on their ultra-portable amps.

What about for the Beyerdynamics DT 770 Pro 80  ?


Do note, capable of driving a headphone and driving it well are two different things, especially if you put synergy into the mix.
 
Feb 25, 2012 at 8:17 AM Post #62 of 399


Quote:
I do like the ZO2.3 I have and actually use it for bass boost more than I use E11 as amp. The problem is it hisses with some of my low impedance, high sensitivity IEM so I can't use all of them with ZO2.3. As an amp, it isn't the best around; but as a bass booster, it is great. That's why I only recommend ZO2.3 for those who want a bass boost first and an amp second.
Haven't heard the D7, and likely won't as I have little use for another USB DAC for now. When it comes to iBasso, my attention is on their ultra-portable amps.
Do note, capable of driving a headphone and driving it well are two different things, especially if you put synergy into the mix.


ah yes, its not really an amp - but it does bring a different sound signature :)
I had loads of hissing with the E11 - 0 with the ZO2
 
 
 
Mar 2, 2012 at 9:08 PM Post #63 of 399
?
 
Mar 3, 2012 at 1:00 PM Post #64 of 399
Hi All,
 
Was doing a little research on the PA2V2 and was asking Gary about the overcharging issue...his response was as follows:
 
"RECHARGING THE BATTERIES

Once the batteries are installed inside Pocket Amp 2, you will not have to open the amp up for about 500 to
1000 recharging cycles, which should easily amount to three or four years of normal use. Pocket Amp 2 has
a built in recharging circuit. When the AC adpater is plugged in, the batteries will automaticaly begin to
recharge, whether the amplifier is in the ON or OFF position. If the AC adapter is connected, and the amp is
ON and being used, the batteries will not be overcharged. However, if the amplifier is OFF, the AC adapter
should not be plugged in for periods longer than eight hours to avoid overcharging
.
"
 
You can also now adjust the gain using two screws in the unit.
 
He is also putting them out using clear plastic at the moment as the red plastic he was using has gone off the market:
 
www.electric-avenues.com/pa2v2_clear.jpg
 
 
Mar 3, 2012 at 1:08 PM Post #65 of 399
That's pretty much the same stuffs I have mentioned in the review, and of course the issues associated with them.
 
Mar 3, 2012 at 8:01 PM Post #66 of 399
Hi ClieOS,
 
Sorry about that...I copied and pasted the wrong post contents :)...silly me...below is his response regarding the issues with charging...
 
"The information on the Opertation Instructions page is a little outdated. The website is currently being remade and will be ready in one more month.

The good thing with the amps today is that when the batteries inside get full, the charging rate slows down to a point where it is just keeping them topped up (no matter if the amp is on or off). So it is not possible to overcharge the batteries."

 
So he has updated the units to actually never overcharge, thus eliminating the need to watch the unit if it isn't on and being used while charging.
 
Mar 3, 2012 at 8:49 PM Post #67 of 399
Hi ClieOS,

Sorry about that...I copied and pasted the wrong post contents :)...silly me...below is his response regarding the issues with charging...

"The information on the Opertation Instructions page is a little outdated. The website is currently being remade and will be ready in one more month.




The good thing with the amps today is that when the batteries inside get full, the charging rate slows down to a point where it is just keeping them topped up (no matter if the amp is on or off). So it is not possible to overcharge the batteries."


So he has updated the units to actually never overcharge, thus eliminating the need to watch the unit if it isn't on and being used while charging.


My PA2V2 was made June last year, so unless the update is between then and now (which I doubt as there is no mention of it), the same issue persists. I think he is just referring to how generic NiMH behaves when charged. When given a small enough current on a slightly higher voltage, you can indeed charge the battery indefinitely as the battery creates a certain resistance to the charging once it is getting closer to full. But the point is, it only works in certain condition (voltage vs current) and you could get into trouble if the condition change. It is still a hidden risk if you don't unplug the charger yourself after a certain period of time especially if you have used the battery for a while and it doesn't hold as much charge or voltage. This is no specific to PA2V2, as any rechargeable amp that doesn't has a charging circuit will be more or less run the same risk. It is some thing the user must be know to look for, even though it could very well be safe to use in years.
 
Mar 3, 2012 at 8:56 PM Post #68 of 399
While there isn't specific info on hardware updates, Gary has made a few changes to PA2V2, like how all amps with serial numbers #8000 and beyond have better EMI shielding, and from #5000 there were a few parts updated, but I'm not in on that specific update.
 
Mar 3, 2012 at 9:13 PM Post #69 of 399
Mine is #8000 and up, but EMI is still really bad. Only AirHead / BitHead is worst in all pf my amps.

I have looked into some old picture of PA2V2 (as early as 2007) and doesn't notice much change, at least not on the circuit design level. There are 1) the gain switches that replaced the fixed resistors, 2) using SMD instead of DIP8 and 3) caps upgrade. Don't really how those change can improve EMI in a significant way, unless the previous version has much worst EMI than what I already consider to be really bad EMI.
 
Mar 3, 2012 at 9:34 PM Post #70 of 399
I have two PA2V2 amps, both previous to #8000 but already having gain switches, and curiously while my first amp did have rather noticeable EMI, my second one (almost near #8000) did have less EMI, while still having it though.
 
Does your casing have markings or is it all black?
 
Mar 3, 2012 at 10:03 PM Post #73 of 399
Add the zo2 to the ranking! xD


ZO2 is originally in the ranking. It was $99 when I posted the review, but the price goes up to $120 a few days later.
 
Mar 3, 2012 at 10:27 PM Post #74 of 399


Quote:
All black.



All the casings with markings have better EMI shielding, while the all black ones are supposed to have the same shielding, but I can't confirm that all do.
 
How severe is EMI with yours?
 
Mar 3, 2012 at 10:54 PM Post #75 of 399
If AirHead / BitHead is a 1/10, I'll put PA2V2 around a 2/10 or 3/10
 

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