[Sorensiim]

I've read the entire D12 thread and have searched the forums but no luck so far...
 
My Ibasso D12 came with extra opamps and the D12 thread mentions swapping the installed opamps for the included extras or Hiflight's topkit - But nowhere does it say which chips goes where? Sure, it mentions buffers and opamps, but never which is which or where they go. This is probably such basic stuff that you all "just know" how to do it, but I don't wanna fry anything so I'm not gonna just start swapping chips and see what happens. Is there a diagram, picture or just a simple explanation somewhere of which chips goes where? There's currently two silver (painted) chips and two red ones installed - 3 other chips/opamps/Ihavenoideas were included with the D12.
 

 
Any and all help most appreciated.

 

[HiFlight]

 
Quote:

I've read the entire D12 thread and have searched the forums but no luck so far...
 
My Ibasso D12 came with extra opamps and the D12 thread mentions swapping the installed opamps for the included extras or Hiflight's topkit - But nowhere does it say which chips goes where? Sure, it mentions buffers and opamps, but never which is which or where they go. This is probably such basic stuff that you all "just know" how to do it, but I don't wanna fry anything so I'm not gonna just start swapping chips and see what happens. Is there a diagram, picture or just a simple explanation somewhere of which chips goes where? There's currently two silver (painted) chips and two red ones installed - 3 other chips/opamps/Ihavenoideas were included with the D12.
 

 
Any and all help most appreciated.

The buffers (Silver) are used in the 2 sockets that are closest to the 2 large capacitors on the left side of the amp (when viewing from above)
 
The L/R opamps are inserted into either the single center socket (one dual-channel opamp) or the 2 side sockets (two single-channel opamps).   Determining whether an opamp is single or dual channel can be found by doing a google search for the datasheet of the opamp in question. 
 
It is also very important to insert the opamps with the correct polarity.  The #1 pin always points to the left side of the amp.  (towards the 2 large caps)    
 
I would suggest making a diagram including all the markings of the stock configuration before swapping opamps to avoid mistakes. 
 
If you are using single channel opamps in L/R, they should always be used in matching pairs, not 2 different opamps.   Likewise, the dual-channel buffers should also be matched.  Note that only dual-channel opamps can be used as buffers in the D12. 
 
Hope this is of some help to you.  
 
 

 

[Sorensiim]

So, taking a wild stab here, Pin #1 would be the one with a square marking around it on the bottom side?
 
I have pretty good eyes but I simply cannot make out the markings on the included extra opamp 

 
It's not that I don't like the sound of the iBasso, it sounds pretty transparent (to me anyways), leaving me room to use the EQ on my computer. I remember somebody in the D12 thread mentioning something about running the thing without buffers so I'll try it with the two dummies (I suppose they are, one resistor, marked "0" can't really be an opamp, can it?) now.
 
Oh and thanks for your reply!

 

[HiFlight]

Yes, the white square denotes pin 1.  On DIP style opamps, the pin 1 end is marked with a small "U"-shaped notch.  You can try any of the L/R combinations with the bypass buffers.  As buffers can also add a flavor of their own, using the bypass, or "dummy" buffers will allow you to hear the true characteristics of whatever L/R opamp you are using.  It will also extend battery run time.  Some opamps sound better without a buffer, others sound better with a buffer in place.   Let your ears be your guide.
 
Often, hard-to-read opamps can be read by holding them at an angle under a bright light and using a magnifier of some sort such as a loupe.
 
Ron
 
Quote:

So, taking a wild stab here, Pin #1 would be the one with a square marking around it on the bottom side?
 
I have pretty good eyes but I simply cannot make out the markings on the included extra opamp 

 
It's not that I don't like the sound of the iBasso, it sounds pretty transparent (to me anyways), leaving me room to use the EQ on my computer. I remember somebody in the D12 thread mentioning something about running the thing without buffers so I'll try it with the two dummies (I suppose they are, one resistor, marked "0" can't really be an opamp, can it?) now.
 
Oh and thanks for your reply!

 

 

[JoshKrak]

I just got my D12 in the mail yesterday and it's my first headphone amp so I'm quite the amp dummy as well. Thank you both very much for the posts.
 
Just to add, the extra opamp they game me is a L49721. When I start looking to experiment with other opamps, what kind of factors to I need to account for? I know I need them in a DIP package, but are there different sized (like some have more than 8 pins) or are there voltages I need to consider?
 
I'm not sure if the 49721 will give it to me, but I'm going to try to look for a combination that will give me a little more bass on my ATH-w1000x. Any suggestions?

 

[HiFlight]

You do need to make sure that you can differentiate between single-channel and dual-channel opamps, as your D12 can use either.  If you use a dual, you only need one, if a single, you need 2. 
 
The AD8066 is a dual-channel that has nice bass.  You might also try the LT1355 and LT1678.  Both are dual-channel opamps.  8 lead opamps are all you can use. 

 

[JoshKrak]

Just got AD8066 and LT1678 in the mail today. 
 
Wow! I can't believe how much of a difference these little buggers have over the sound. The AD8066 is amazing! The LT1678 on the other did not impress me much. They both seemed have the same about amount of bass but the AD8066 sounded more crisp and didn't seem to change the mids/highs much over the stock where as the LT1678 seemed to loose some clarity up there.
 
Thanks a lot for all the help HiFlight.

 

[Sorensiim]

 
Soo... I've got a pair of HD595 coming in. According to a number of head-fiers in the HD595 appreciation thread, they get a noticeable bump in "punch" when coupled with a 100ohm adapter. Wouldn't  replacing the dummy buffers with 100Ohm resistors accomplish just that?