Portable Amp Power: Alkaline or Lithium?
Nov 15, 2008 at 2:12 AM Thread Starter Post #1 of 6

ROCKOQATSI

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My new Meier-Audio Corda2Move arrived a couple of weeks ago and I've been all smiles since. (Thank you so, so much Jan!) Only, something soon occurred to me that I didn't account for. The first battery I chose was essentially the closest one to me at the time---in this case, an alkaline battery. When that eventually wore out (and the amp signaled this by starting to clip; this came on quicker than I thought it would, possibly because of the way the power output of alkaline batteries decreases steadily over their lifespan) I proceeded to replace it with a lithium battery, of course because not only would it last much longer, but the power output would be solid and constant---so it would sound better.

Or so I thought...

It came as a surprise to me that the low end didn't sound as smooth and deep with the lithium battery, and I immediately thought that the stronger power source might be making the amp overload... But I'm just speculating as to what could be the problem (or even if I am in fact imagining this issue!) I went back to the store and got an alkaline battery so I could hold a side-by-side (as best I could manage) test. It seems my suspicions are correct, but the difference isn't exactly night and day. Nevertheless, this is driving me nuts! Has anyone with a portable amp tried different kinds of batteries to find out which sounds best? (Or if there is any difference in sound quality between them at all? Alkaline vs. Lithium? vs. NiCd? vs. NiMH? Rechargeable Lithium-ion?

Any feedback and tips would be appreciated!

---Matt
 
Nov 15, 2008 at 4:13 AM Post #2 of 6
Like you said, alkalines will typically start at around 1.5-1.7v, and will drop down to around 0.9v at the end of it's life.
NiMH and lithium batteries are much better in this regard;
NiMH maintains a constant voltage of around 1.2v, as will Lithium batteries. There are some brands that offer as high as 1.4v, and they typically drop about 0.1v throughout it's lifetime.
Lithium batteries tend to last a lot longer than NiMH, but are not rechargeable.
afaik, none of those batteries should have any trouble outputting the current required, and they should all offer clean dc power.
I think the difference you're seeing may be due to the initial higher output voltage of the alkaline.. but maybe not.

NiCd is similar to NiMH, but holds less capacity. Lithium-ion is not offered in AA sizes.

edit- nvm to most I said. I forgot it uses 9v batteries. Most NiMH and Lithium batteries have a nominal voltage of ~8.5-9v.
 
Nov 15, 2008 at 5:23 AM Post #3 of 6
I am not an expert on anything.. but I can always find someone who knows more than I do.
For anything regarding how electrons behave, I go directly
to Phil Larocco. When designing "portable" amps with the intension that they
preform like home amps he begins with POWER.. Hence, The Lisa III is powered
BY 18 VOLTS !! the std. has 2 X 9 volt NiMH in series ! XP has 12 AA NiMH !!!!
!!!!!!!!!!!>>>NOW THAT IS POWER <<<!!!!!!!!!!!
atsmile.gif
 
Nov 15, 2008 at 9:41 AM Post #4 of 6
Notice the same thing on my 3MOVE. Battery choice definitely affects the SQ (though not by a big degree). I compared NiMH and alkaline and find out the although my (used) alkaline is lower in voltage (~8V), it still makes 3MOVE sounds better and louder than the rechargeable (8.6V). Maybe there is something different in the current but I don't have anything to measure them...
 
Nov 15, 2008 at 8:32 PM Post #5 of 6
Within NiMH rechargeables, the Low Self-Discharge batteries allow portable audio units to sound their best, to my ears. The technology they employ reduces their internal resistance, resulting in the ability to deliver current more quickly on demand with less voltage ripple (resulting from varying current demand). I use Low Self-Discharge NiMH "AA", "AAA" (Sanyo Eneloop), and "9V" (Tysonic) batteries. In every case, they deliver power to allow a portable audio unit to sound better than their "non Low Self-Discharge" NiMH counterparts.
 
Nov 17, 2008 at 3:37 AM Post #6 of 6
This is interesting stuff. (I seriously thought I was alone in the dark about this issue.) Thanks all for your replies so far.

So, at least one more person has confirmed that alkaline batteries (for whatever reason) sound better. (Although I would like to look deeper into these "low self-discharge" NiMH's.) Question now is, what is it about the alkalines that makes them sound better? What characteristics of their power output can we attribute to better sound quality?

And how do I get in contact with Phil Larocco?
 

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