[paulybatz]

Quote:

Originally Posted by supern0va /img/forum/go_quote.gif You may not have noticed from earlier posts, but I have a D4. My biggest problem with it is that I need to keep changing batteries, and that is a pain IMO. I'm not sure if you have tried both D2+ and D4 before you made the comment that there is no contest/comparison for their DAC; I have not, but I have compared their amp section before; D4 is definitely better, but not by leaps and bounds. Madwolf's suggestion to mod the D2+ is quite appealing; the built-in batt would solve my problem of keep replacing batts, and if the sound is anywhere close to D4 for both DAC and Amp I would be very happy.

I agree a charging circuit would have been nice, however, if you say the D4 is 10% better in SQ, its like what would you prefer listening to...I suggest you get lithium 9V which are rated at 500mah, should give you more run time.


I do get it, swapping batts is a drag

Good luck in your quest for the holy grail.

 

[HeadphoneAddict]

None of the iBasso D1/D2/D3/D10 can drive the HD600 to very loud levels with authority and impact, but the D4 in 9v mode can do it noticeably better. The D4 in 5v mode gives loud enough levels with nice frequency balance, similar to those of the Predator and P-51. This still works for many people who don't need to crank it up and feel the bass.

But the D4 in 9v mode comes closer to the 3MOVE, Pico, Micro Amp and XM5 in power, all which run on 9v. Out of all of those, the 3MOVE seems just a little bit louder with better impact than the other 9v amps. The odd ones out are the Vividaudiotech.com V1 which is charged with 5v, or the TTVJ Portable Milett Hybrid which charges on 6v, but have the power output of a 9v amp with the 300 ohm headphones.

 

[LionPlushie]

sounds like a winner. since its similar to predator and p51 on 5v.

 

[HeadphoneAddict]

Quote:

Originally Posted by LionPlushie /img/forum/go_quote.gif sounds like a winner. since its similar to predator and p51 on 5v.

If you don't need portable, you could also get away with the $99 uDAC for HD600 which at 5v seems a little more powerful than the other 5v amps; but the D4 also gives the ability to get closer to 9v 3MOVE power levels by popping in a battery, and to plug an iPod into it.

 

[qussl3]

Been listening to the D4 for coming to 20 hours and just noticed that there seems to be some crackling on some songs.

Has anyone else encountered this, or has any suggestions?

My setup is as follows,

itunes (mostly lossless) -> D4 dac via usb -> D4 amp out -> srh440

thank you in advance

 

[madwolf]

I believe you set the itunes volume to 100%

Yes I notice the crackling, You could set the volume of your Itunes to 80% and the crackling will go away.

I have not put the D4 under the scope to determine exactly at which point the clipping is happening. Maybe when I have time I will do that.

I strongly suspect it might be that the DAC WM8740 is configured to be slightly higher voltage than the AD8616.

Quote:

Originally Posted by qussl3 /img/forum/go_quote.gif Been listening to the D4 for coming to 20 hours and just noticed that there seems to be some crackling on some songs. Has anyone else encountered this, or has any suggestions? My setup is as follows, itunes (mostly lossless) -> D4 dac via usb -> D4 amp out -> srh440 thank you in advance

 

[madwolf]

This is the measurement from the Output of the AD8616
At the input of the AD8616/output of WM8740 the Signal I pump in using the computer is a Triangle wave. Level set at 100%

Sorry for the poor image, I have one hand on the probe and hand on the camera.


So confirm there is clipping.
Straight off I have not regain from my shock, this is happening to me again.


So how to solve this problem ?

1) You could up the voltage of the AD8616. (Possible to tap from the 5V amp or from WM8740, but could be noisy, need to break traces as well )
2) or reduce the Gain of the AD8616 so that the output voltage is below clipping.

The second option could be easier just change 2 resistor value. Easy mod for anyone who solder. When I finally get to do that will post the solution.

A temporary solution would be to set the volume of your computer to about 80% of max so that the clipping does not occur.

I would need to go through the D4 design again, Look like I would have to keep the D4 for a while longer as my friend would likely ask me to solve this before passing to him.

 

[charlie0904]

madwolf, you are unbelievable. *salutes

 

[qussl3]

Madwolf you as astounding!

I can confirm that reducing the volume has helped with the problem.

Been listening to the same tracks in the last hour at equal or higher volume levels on the D4 but at 80% itunes volume and no hint of crackling can be heard (or maybe i'm just going deaf lol)

Thank you again

If its not too much trouble could you kindly update us on your quest to resolve this clipping issue?

Many thanks again.

Quote:

Originally Posted by madwolf /img/forum/go_quote.gif This is the measurement from the Output of the AD8616 At the input of the AD8616/output of WM8740 the Signal I pump in using the computer is a Triangle wave. Level set at 100% Sorry for the poor image, I have one hand on the probe and hand on the camera. So confirm there is clipping. Straight off I have not regain from my shock, this is happening to me again. So how to solve this problem ? 1) You could up the voltage of the AD8616. (Possible to tap from the 5V amp or from WM8740, but could be noisy, need to break traces as well ) 2) or reduce the Gain of the AD8616 so that the output voltage is below clipping. The second option could be easier just change 2 resistor value. Easy mod for anyone who solder. When I finally get to do that will post the solution. A temporary solution would be to set the volume of your computer to about 80% of max so that the clipping does not occur. I would need to go through the D4 design again, Look like I would have to keep the D4 for a while longer as my friend would likely ask me to solve this before passing to him.

 

[paulybatz]

That is incredible...do let us know the outcome!

Quote:

Originally Posted by madwolf /img/forum/go_quote.gif So how to solve this problem ? 1) You could up the voltage of the AD8616. (Possible to tap from the 5V amp or from WM8740, but could be noisy, need to break traces as well ) 2) or reduce the Gain of the AD8616 so that the output voltage is below clipping. The second option could be easier just change 2 resistor value. Easy mod for anyone who solder. When I finally get to do that will post the solution. A temporary solution would be to set the volume of your computer to about 80% of max so that the clipping does not occur. I would need to go through the D4 design again, Look like I would have to keep the D4 for a while longer as my friend would likely ask me to solve this before passing to him.

 

[qusp]

very cool madwolf, the crowd is easily impressed though as they are not from the dark side

I feel your pain on finding this area after thinking you were done though. what I find most impressive is that you were able to take a photograph with one hand while using the probe with the other

 

[trentino]

If I've decided on the D4/D10 pricerange, and intend to use the device mainly portable with Ipod Classic and IEM's (but also sometimes the dac/amp at home and in the future also bigger head phones) would it be smarter to go for the D10? Or is the D10 just a D4 with coaxial and digital input and rechargeable battery? I don't see myself switching op amps, don't have the knowledge, so which one would be the best overall amp/dac?
Thanks, and sorry for bringing up D10 in a D4 thread!

 

[qusp]

Quote:

Originally Posted by trentino /img/forum/go_quote.gif If I've decided on the D4/D10 pricerange, and intend to use the device mainly portable with Ipod Classic and IEM's (but also sometimes the dac/amp at home and in the future also bigger head phones) would it be smarter to go for the D10? Or is the D10 just a D4 with coaxial and digital input and rechargeable battery? I don't see myself switching op amps, don't have the knowledge, so which one would be the best overall amp/dac? Thanks, and sorry for bringing up D10 in a D4 thread!

thats what they all say

cant comment on your question without bias as I dont have D4, but if you are able to use anything but USB you might consider the D10 because of higher resolution. whether this is outweighed by dual dacs and more voltage swing in the D4 i'm unable to comment

 

[HeadphoneAddict]

Quote:

Originally Posted by trentino /img/forum/go_quote.gif If I've decided on the D4/D10 pricerange, and intend to use the device mainly portable with Ipod Classic and IEM's (but also sometimes the dac/amp at home and in the future also bigger head phones) would it be smarter to go for the D10? Or is the D10 just a D4 with coaxial and digital input and rechargeable battery? I don't see myself switching op amps, don't have the knowledge, so which one would be the best overall amp/dac? Thanks, and sorry for bringing up D10 in a D4 thread!

That's not a fair question, because we don't know know how important battery life and ease of USB charging is to you.

Based on battery life of over 24 hours and USB charging, and using it portable most often with portable phones, the D10 makes more sense. It sounds very similar to my RSA Predator amp, but with a better DAC. Later, when you can afford to swap opamps you can make the D10 sound close to the D4 and P-51 Mustang; but you can't make it as powerful as the D4 for when you move up to some harder to drive full size phones (HE-5, HD600 or HD800). The D10 USB DAC is extremely close to the detail and spaciousness of the D4 via USB, but the D10 via optical on my Mac can be slightly better than D4 if I use 24/96 files.

If you want a slightly better stock sound without swapping opamps, don't mind swapping between a pair of rechargeable 9v batteries often, and would like the extra 9v power for full size phones later, then you could go for the D4 which is also 1/2" smaller in length. Plus you can run it 24/7 off USB 5v with no worry about running out of power because you wont be needing the battery. And in 5v mode it will still be about as powerful as the D10 ever was. As a bonus, with a simple OPA1611A class-A biased opamp swap from HiFlight, you can make the D4 sound almost identical to the P-51 Mustang which is one of the best sounding portable amps I have heard. The D10 with opamp swap is close but still a little behind in treble extension and presence vs the D4 with or without opamp swap.

 

[richbass]

which has better headphone amp ? D10 or D4 ?