The New iRiver AK100: A High-End DAP - Page 200

Quote:

Originally Posted by WindowsX 

 

I'm talking about saving headphone like reducing the deterioration of headset. In long run it could damage low impedance headphones at high volume and possibly oscillations that might occur after years of usage.

You keep harping on about "saving headphones". In order to damage headphones, a user would have to run the volume way above the level at which their own hearing would destroyed. Do you really think someone is going to do that? Particularly the kind of person to buy a RWAK100 (e.g., an audiophile)?

Quote:

Originally Posted by lerxst 

You keep harping on about "saving headphones". In order to damage headphones, a user would have to run the volume way above the level at which their own hearing would destroyed. Do you really think someone is going to do that? Particularly the kind of person to buy a RWAK100 (e.g., an audiophile)?

There're two possibly ways for headphones to be damaged if things went wrong and adding output resistor can help solving that.

1. Too much power burning headphone which can be solved by using with moderation and may probably coupling capacitor to help reducing current load level (Well, that doesn't need much of help actually from portable players driving common phones). This possibly is already explained and resolved so I'm not counting that as real threat now. Just foolishly showing possibility while a lot of people showed me back there already.

2. Oscillations causing DC offset that can damage headphone. As Vinnie tested after modding that it doesn't oscillate, I believe in his statement so the case of having oscillations right after modding is also resolved. However, can anyone confirm that will not ever happen in future? If AK100 is confirmed to never ever having oscillations in its lifetime or long years enough for us to stop using it, removing output resistor is considered safe enough mod and I would buy ones for listening and confirming it myself. But if oscillations can happen in future, it will need proper methods to avoid that. Maybe adding output coupling can solve this problem if someone can to put some custom caps in there. Would be wonderful if blackgate or some nice caps can fit but I doubt it judging from nearly empty space in there.

Quote:

Originally Posted by WindowsX 

 

There're two possibly ways for headphones to be damaged if things went wrong and adding output resistor can help solving that.

 

1. Too much power burning headphone which can be solved by using with moderation and may probably coupling capacitor to help reducing current load level (Well, that doesn't need much of help actually from portable players driving common phones). This possibly is already explained and resolved so I'm not counting that as real threat now. Just foolishly showing possibility while a lot of people showed me back there already.

 

2. Oscillations causing DC offset that can damage headphone. As Vinnie tested after modding that it doesn't oscillate, I believe in his statement so the case of having oscillations right after modding is also resolved. However, can anyone confirm that will not ever happen in future? If AK100 is confirmed to never ever having oscillations in its lifetime or long years enough for us to stop using it, removing output resistor is considered safe enough mod and I would buy ones for listening and confirming it myself. But if oscillations can happen in future, it will need proper methods to avoid that. Maybe adding output coupling can solve this problem if someone can to put some custom caps in there. Would be wonderful if blackgate or some nice caps can fit but I doubt it judging from nearly empty space in there.

The thing is Windows, listening at that volume anyways will destroy your hearing before it destroys the IEM or said headphones so I don't see where this is going?

Quote:

Originally Posted by lee730 

The thing is Windows, listening at that volume anyways will destroy your hearing before it destroys the IEM or said headphones so I don't see where this is going?

As I said volume is not the main issue I'm worrying about. Please clarify second part of number 2. Whether it has risk to have oscillation after long usage or not is what I'm worrying now.

Quote:

Originally Posted by WindowsX 

 

As I said volume is not the main issue I'm worrying about. Please clarify second part of number 2. Whether it has risk to have oscillation after long usage or not is what I'm worrying now.

We're all pretty much in agreement that the RWA mod does not increase the wear or risk of damage to the output FETs by virtue of users avoiding hearing-destroying levels of volume. So, barring that, if oscillation doesn't occur today, why would it suddenly occur after long usage?

Quote:

Originally Posted by lerxst 

We're all pretty much in agreement that the RWA mod does not increase the wear or risk of damage to the output FETs by virtue of users avoiding hearing-destroying levels of volume. So, barring that, if oscillation doesn't occur today, why would it suddenly occur after long usage?

Like hardware fault, parts running out of time having values changes or some leaks, etc. Of course AK100 won't last forever but it'd be sad if iRiver added that resistor to keep oscillation problems away longer if not forever and removing that cause the damage sooner. If AK100 won't have that issue after modding then I guess it's OK to try.

Quote:

Originally Posted by tds101 

@WindowsX: iriver added the resister because they don't have a realistic grasp on what they're doing, or of what a high quality audiophile grade device should be. Vinnie, of Red Wine Audio, did a "professional" mod to the player. He knows what he's doing - unlike most home-grown modders with "ideas" and no experience. He HAS experience,...we ALL trust him.

Have a wonderful day,...

Those two points I asked wasn't actually from iRiver alone you know? I checked from related WM8740 circuit designs to see how resistor was used for there. What I'm certain about is to prevent oscillations is one of main reason designer put resistor before output but I don't know what for if it doesn't oscillate right now. If AK100 won't ever oscillate is fine but what if it can happen in future?

Have been listening to AK100 with IEMs (IE80, SE425, W4R) and over-the-ears (HD25II, B&W P5). My favorite so far is W4R with Shure's large foam tips. IEMs are inconvenient when isolation is not desired.

Listening via ALO International and HD600 with balanced cables is my favorite semi-portable setup.

Only issues so far:

- Missing gapless.

- Occasionally corrupted SD card directory, solved by turning AK100 off and on.

- No line out, thus setting volume to max. for the International and forgetting to turn the volume down when listening directly (ouch).

P.S.: If you use Mac to create FLACs you may want to run dot_clean tool to get rid of all "._songname.flac" files (search via Google for more information).

Guys, stop feeding the troll.

So asking if there's chance to have oscillations in future is considered troll now?

Quote:

Originally Posted by WindowsX 

So asking if there's chance to have oscillations in future is considered troll now?

Dude, just stop.  Please.

kcee, thanks a LOT!!!

That's exactly what I need:))))))))))
 

If you don't know whether there's chance to have oscillations in future or not, you better stop and wait for guys who know answer with good explanations OK? Let's settle with that as I don't want to be trolling or get trolled.

Quote:

Originally Posted by WindowsX 

If you don't know whether there's chance to have oscillations in future or not, you better stop and wait for guys who know answer with good explanations OK? Let's settle with that as I don't want to be trolling or get trolled.

You don't want to be trolling?

Please.  Just stop.