[goodvibes]

SilverEars, that amp will be more dependent on the power supply than anything else. You have a great spot to use those regulators. lm317/337 aren't the absolute quietest but plenty quiet enough, easy to use and responsive if configured properly. Start with a rectified V of at east 1/2 again your intended V and then regulate down. Don't use a switching supply to start or you'll kill it. You can probably find something better sounding than those aluminum caps for their function as well but premier electrolytics will be a bit larger. Replacing 2 resistors per channel to change gain and taking one leg to ground to remove a balanced input is the common way to do almost all amps. No V control? and if so is it at the input? That works fine but isn't optimum. Probably should still be capacitor coupled at the input side to block source DC, especially if using a pot. DX90 is also DC coupled output.
 I know you're excited about the project but probably not in this thread until you hook it up to your DX90.

 Have fun.

 

 

[Wishmasterx]

HO on top is tradition from early time. Is little better for comfort, but it is not too good for layout. DX90 have very good layout - digital area on top (CPU, DAC, LCD, memory, card, ... and supply parts) and on bottom only analog audio parts.

 

[DavidWeinberg]

   
Using the LO, you are only bypassing the internal amp of DX90. The DAC in DX90 directly feeds LO.
 
The Coax Out totally bypass both the DAC and amp of DX90.

Thanks, this is really helpful. However, it the LO bypasses the internal amp, how can I increase the volume on the DX90 and hear the volume increase (without touching my externally amped speaker)?  One of those lingering questions...

 

[SilverEars]

Thanks, this is really helpful. However, it the LO bypasses the internal amp, how can I increase the volume on the DX90 and hear the volume increase (without touching my externally amped speaker)?  One of those lingering questions...

The DAC chip has digital volume control.

 

[jj69]

Originally Posted by jamato8 /img/forum/go_quote.gif

I am listening right now and can not believe the difference. As sure as I write this, some will have an OEM and say they hear no difference. :^)  But really, I am alarmed. Mine are made in Korea and show last month as the manufacture date and each one has a different SN number. If I was iBasso, I would charge a little more and only sell the DX90 or 50 with these batteries. I am going to order a couple of more. The sound is just different but quality. I am very surprised since I was already biased against any real difference. Now who wants to buy some Anker batteries? Kidding. But these are the only batteries I am going to be using. 
 
http://www.ebay.com/itm/New-OEM-EB-L1G6LLU-Samsung-Galaxy-S-III-Verizon-i535-Battery-2100mAh-EBL1G6LLU-/121360170339?ssPageName=ADME:L:OU:US:1120
 
This is where I bought mine. 

 
I just received the battery recommended by Jamato8, purchased from the eBay link above.  Mine is marked "MADE IN KOREA."  Unfortunately, I think there is something wrong with mine.  When charging in the DX90, the battery never reports a full charge.  The DX90 just remains in "Charging" mode indefinitely, even though the battery is indeed fully charged.  This never happened with the stock Pisen battery.  Does this indciate a problem with the Samsung battery's internal circuit?  If so, I want to send it back for a replacement asap. 

 

[jamato8]

   
I just received the battery recommended by Jamato8, purchased from the eBay link above.  Mine is marked "MADE IN KOREA."  Unfortunately, I think there is something wrong with mine.  When charging in the DX90, the battery never reports a full charge.  The DX90 just remains in "Charging" mode indefinitely, even though the battery is indeed fully charged.  This never happened with the stock Pisen battery.  Does this indciate a problem with the Samsung battery's internal circuit?  If so, I want to send it back for a replacement asap. 

On my DX90, when the battery is charged, and the DX90 is off, the green charge circle, says charged. The indicator in the upper right corner with the DX90 shoes that it is plugged into the usb with the orange squiggle, and with the USB unplugged, and the battery charged, all the bars are white, indicating a full charge. If your is doing something else or the green charge circle that indicates charging when the DX90 is off, and you know it should be fully charged, I would think there is something wrong with the battery. 
 
I would email the seller, tell them that the battery does not charge correctly and ask for a replacement. 

 

[burtomr]

 
I would email the seller, tell them that the battery does not charge correctly and ask for a replacement...

 
                      .....battery Made in Japan...

 

 

[Caruryn]

Jamato8 have you compared the anker and the samsung sound quality wise?I would gather you prefer the samsung but in what way is the sound better?I haven't got the  samsung yet but with the anker the sound is dynamic,full and richer vs pisen.

 

[nc8000]

I just received the battery recommended by Jamato8, purchased from the eBay link above.  Mine is marked "MADE IN KOREA."  Unfortunately, I think there is something wrong with mine.  When charging in the DX90, the battery never reports a full charge.  The DX90 just remains in "Charging" mode indefinitely, even though the battery is indeed fully charged.  This never happened with the stock Pisen battery.  Does this indciate a problem with the Samsung battery's internal circuit?  If so, I want to send it back for a replacement asap. 

First time I charged my Mugen battery it took probably 12 hours before the Charging message changed to Charged. Since then it has only taken a few hours

 

[jamato8]

  Jamato8 have you compared the anker and the samsung sound quality wise?I would gather you prefer the samsung but in what way is the sound better?I haven't got the  samsung yet but with the anker the sound is dynamic,full and richer vs pisen.

I find the Samsung to be cleaner. The purity of no sound between notes and the silence is better. This translates to the overall sound improvement.

 

[Caruryn]

Jamato you're the man! By the way you'll be pleased to hear we have the best dap in the world! We finally beat ak240

http://ohm-image.net/opinion/audiophile/rmaa-summary-ibasso-dx90-vs-astell-kern-ak240

 

[SilverEars]

  Jamato you're the man! By the way you'll be pleased to hear we have the best dap in the world! We finally beat ak240

http://ohm-image.net/opinion/audiophile/rmaa-summary-ibasso-dx90-vs-astell-kern-ak240

If you think those parameters reveal the actual performance outputted by headphones.  What is more useful is output measurements of the headphones.  Also would like to see different headphone types as loads.  How did the IMD + Noise % go down with SM2 load from without load?  I would like to see a graph to match the numbers, that would prove those numbers.  You should be happy with iphone 5 if looking at numbers.
 

 

Test	Frequency response	Noise level	Dynamic range	THD	IMD + Noise	Stereo crosstalk
HTC One V	+0.11, -0.10	-81.7	81.6	0.011	0.047	-90.5
HTC One V (headphones attached)	+0.12, -0.04	-81.8	81.7	0.011	0.090	-52.6
HTC One X	+0.02, -0.08	-82.1	82.1	0.137	0.393	-80.7
HTC One X (headphones attached)	+0.10, -0.10	-80.6	80.6	0.174	0.459	-60.8
HTC One S	+0.13, -0.10	-91.0	90.6	0.0089	0.015	-92.6
HTC One S (headphones attached)	+0.13, -0.04	-90.7	90.6	0.011	0.065	-74.0
HTC Sensation XE	+3.46, -0.38	-91.7	91.7	0.012	0.026	-90.7
HTC Sensation XE (headphones attached)	+3.87, -0.56	-91.5	91.6	0.031	0.632	-63.7
HTC Sensation XL	+3.35, -0.42	-85.2	87.2	0.025	0.084	-75.1
HTC Sensation XL (headphones attached)	+3.77, -0.54	-80.2	81.2	0.072	0.569	-64.2
HTC Titan	+0.06, -0.34	-86.9	87.8	0.015	0.244	-75.5
HTC Titan (headphones attached)	+0.34, -0.18	-76.8	77.1	0.057	0.581	-56.4
Apple iPhone 4S	+0.02, -0.11	-91.2	91.2	0.0020	0.012	-93.0
Apple iPhone 4S (headphones attached)	+0.05, -0.10	-91.3	91.3	0.0068	0.071	-66.7

 

[Caruryn]

I'm kidding of course...

 

[jamato8]

  I'm kidding of course...

Sound and what you enjoy is up to the user and nothing more, regardless of measurements or even how they perform under load. I had a friend who loved his LP based system. I could hear no real imaging, the sound was diffuse but he thought is was the greatest. My system based on tubes, as his was, incorporated a non oversampling non filtered DAC system that was based on the Audio Note UK type of DAC. Mine has imaging, depth, and a realism that I love. I find nothing enjoyable about his system. So there you go. I have had an email from an owner of the AK240 and DX90, this a few weeks back, who said he preferred the DX90. Enjoy the music. 

 

[jj69]

  On my DX90, when the battery is charged, and the DX90 is off, the green charge circle, says charged. The indicator in the upper right corner with the DX90 shoes that it is plugged into the usb with the orange squiggle, and with the USB unplugged, and the battery charged, all the bars are white, indicating a full charge. If your is doing something else or the green charge circle that indicates charging when the DX90 is off, and you know it should be fully charged, I would think there is something wrong with the battery. 
 
I would email the seller, tell them that the battery does not charge correctly and ask for a replacement. 

 
Yes, this is exactly how I'm charging the battery - with the DX90 switch off.  However, the green circle never says "Charged" with the Samsung battery.  It just stays in "charging" mode, even overnight.