[krismusic]

"9 V" batteries have quite a range of starting and ending V, the difference between chemistries give different V per cell - and "9 V" batteries have been made with different # of cells per battery

the different chemistries V apples to single cells too  of course

Hmmm. I may well be wrong on this but I really don't think that minute, theoretical differences like these have any bearing on listening pleasure. As I say, I may be wrong.

 

[davidsh]

My dap surely sounds best when receiving between 8.1-8.4 volts, but all batteries are ~9 volts when charged. Most batteries I try surely start to sound grainy too when they are discharged to the sweet spot. What a pain!  

 

 

[analogsurviver]

  My dap surely sounds best when receiving between 8.1-8.4 volts, but all batteries are ~9 volts when charged. Most batteries I try surely start to sound grainy too when they are discharged to the sweet spot. What a pain!  

 

Here the solution to your problem :
 http://www.ebay.com/itm/1pc-Soshine-9V-650mAh-8-4V-Li-ion-Rechargeable-Battery-cell-/311418289313
 
Soshine also produces 8.4V 600 mAh LiIon and 9V 350 mAh NiMH cells in 6F22 ( "9V " ) size. The only problem is that LiIon version is slightly larger dimension - and with very square edges, meaning sometimes it will just not fit in some tight places. Both versions are VERY low self-discharge; not on a par with Sanyo Eneloop ( which BTW does not produce 6F22 9V rechargeables ), but close.  You can have a peace of mind if the batteries were charged a month or two before the use; the capacity will be only slightly less than freshly charged cell.
 
And yes, some equipment definitely does work better with 8.4 V instead of 9 V ; some does require higher voltage for proper operation. There are dedicated chargers for LiIon and NiMH from Soshine, as well as "universal" one ( which is a bit harder to obtain ). 
 
So far, reliability has been excellent; only time I did fry LiIon ( discharge below cutoff voltage is terminal failure for LiIon cells ) was due to running some in series, and under these adverse conditions it is easy and possible to destroy them. In normal operation, everything flying colours.

 

[jcx]

the battery chemistry and cell count variation give 7.2 V to 9.6 V range for fully charged/new "9 V" battery - not "minute" - with the 7.2 V "9 V" battery the circuit may need to work to  <6V if you want to use most of its charge
 
especially with LiIon rechargeables the discharge curve is very sloped over the whole life and many just put 2 cells in the "9 V" package
 
with some common cmoy or a47 candidate op amps dropping another ~1.5 V from each rail you could have 2x output V swing difference in a single "9 V" battery amp depending on type and charge condition

 

[Audioholic123]

The reason for the noise is most likely due to the higher quality audio files your listening to combined with the quieter atmosphere. Once you reach higher bitrates then under certain circumstances and depending on your level of concentration/awareness, you often can hear really subtle details in music, not forgetting quality of kit! a good audio setup can make such subtle nuances rather obvious.
I own modded Fostex t50rp's and this is one thing they excel at because of their drivers.
If the hiss only begins when you select a track and press play, then you may well be hearing the recording equipment that the artist used during the recorded passage.
( which you can hear in the background). This would explain why you only hear it in some tracks and not all, as digital recorders are quiete compared to analog ones, also in this day and age studio's record directly onto computers.

 

[sonitus mirus]

  The reason for the noise is most likely due to the higher quality audio files your listening to combined with the quieter atmosphere. Once you reach higher bitrates then under certain circumstances and depending on your level of concentration/awareness, you often can hear really subtle details in music, not forgetting quality of kit! a good audio setup can make such subtle nuances rather obvious.
I own modded Fostex t50rp's and this is one thing they excel at because of their drivers.
If the hiss only begins when you select a track and press play, then you may well be hearing the recording equipment that the artist used during the recorded passage.
( which you can hear in the background). This would explain why you only hear it in some tracks and not all, as digital recorders are quiete compared to analog ones, also in this day and age studio's record directly onto computers.

 
In this situation, it has nothing to do with the quality of the file, only the quality of the music. Unless you are listening in an an anechoic chamber and blasting the music volume to near-pain thresholds, I don't know of any music that might produce audible noise when taking a higher bitrate file and downconverting this to CD quality.
 
I can hear the same noise being discussed using a $10 pair of USB speakers.  This noise is present on the source material, and it would be heard in any format as long as the exact same master was used.

 

[Audioholic123]

   
In this situation, it has nothing to do with the quality of the file, only the quality of the music. Unless you are listening in an an anechoic chamber and blasting the music volume to near-pain thresholds, I don't know of any music that might produce audible noise when taking a higher bitrate file and downconverting this to CD quality.
 
I can hear the same noise being discussed using a $10 pair of USB speakers.  This noise is present on the source material, and it would be heard in any format as long as the exact same master was used.

I agree...but on a much deeper level, higher bitrates often allows for really subtle details to be heard more clearer. I'm talking about coughs, audible breathing and body movement. Even the noise of a guitarist's fingers moving between each string...stuff like that. I hear these differences all the time when i switch from my ipod to my Hifi, and to me they are obvious....I'm not saying you wouldn't be able to hear these things from cheaper equipment. If you can, then you got yourself a well engineered device!

 

[Currawong]

If I might interrupt the discussion briefly, I would like you all to please welcome castleofargh as the moderator of the Sound Science forum. 

 

[davidsh]

Woah, welcome!
What an interesting turn of events

 

[bfreedma]

If I might interrupt the discussion briefly, I would like you all to please welcome castleofargh as the moderator of the Sound Science forum. 

Never heard of him

Congrats - and remember - no good deed goes unpunished.

 

[sonitus mirus]

  If I might interrupt the discussion briefly, I would like you all to please welcome castleofargh as the moderator of the Sound Science forum. 

 
Wonderful news!  I hope you made certain that he destroyed ALL of the copies of those photos he had of you. 

 

[Roly1650]

Great, that's all we need, a bloody frog who can't capitalise or punctuate.
But his English is better than my French, which isn't that hard.

A most excellent choice.

 

[bfreedma]

This is a test of the CMS (castleofargh moderation system). This is only a test as required by the Department of Audio Sanity. No bans are required due to this system check

• Cables make a night and day difference. Silver is bright, copper is warm
• I have two solid state amplifiers that measure identically. The difference in audible sound between the two is dramatic. My significant other can hear the difference from another room while running the dish washer/band saw
• Science doesn't know everything, therefore my personal experience trumps all known and vetted audio science
• Vinyl. Yeah, I said it, vinyl.
• Anything I choose can be analogous to a car.
• Hi Rez music is always better. And no, I don't have to know why, it just is.
• Whalebats - they're real!
• Price dictates SQ. Always. Without exception.

Repeating, this has been a test of the CMS.

Well, if I'm not banned over this or have the honor of having the first post deleted by our new mod, I look forward to seeing how the Sound Science forum progresses.

All kidding aside, I'm excited to see castleofargh taking on the moderator role.

 

[castleofargh]

 keep your expectations low, and I will not disappoint!
 
not sure I'll be able to change much to what we've all been doing here. outside of PC police where I'll be super bad anyway, think of me as a method to bring back some rational when you feel it left a topic. so that with everybody's help, we can keep things interesting and reasonable without as much frustration as we've been experiencing a few times.
I've been asking for it, I end up being it. so now I'm in a put up or shut up situation ^_^.
while I don't plan on chasing after every and any straw man argument(because I wish to still have a life), someone who is unable to avoid fallacies as a way to argue will be stopped at some point(hopefully just with a talk). even more so when it ends up being the reason why the atmosphere gets bad in a topic.
so when confronted repeatedly with such a problem, come to me before you blow a fuse, insult the guy and get banned in the process by PC principal. I believe that's mostly what I can do that traditional moderation might not.
 
the axiom in here is that we come to sound science to do, at our humble level, what any science tries to achieve, get one step closer to the truth. for that purpose, proper and honest reasoning should be the tool of choice for any argument. long before, popularity contest, rhetoric and fallacies.
on the other hand, this is headfi, and we can't expect everybody to be a master of deductive and inductive reasoning, or to get the merits of lateral thinking before they come posting in here. so it will still be up to you all to try and explain to them why "I heard it" isn't a scientific proof, over and over again.
I see no solution to that problem, at least not before I become world general and make science laws the only laws that don't have to be mine.(might take a few more years, I've had some set backs in my world domination plan).

 

[Thad-E-Ginathom]

Never heard of him

Congrats - and remember - no good deed goes unpunished.

 
Blind test... or he doesn't exist.
 
(Who was that in the previous post?