This is an ad for an AUNE headphone amp. I have changed the opamps tp the following:
1. Changed the single Burr Brown 2604 opamp from the amp stage to 2 mono AD797 opamps on Brown dog adapter. This makes a significant difference in the sound specially since we are using two dual mono opamps. The AUNE has a Blue ALPS potentiometer which is totally quiet and has Nichicon and WIMA caps in the signal chain. This is a very high quality system for the price. 
2. Changed the DAC's opamp from the Burr Brown 2134 to the high regarded LM4562. Audiophile products uses this opamp in their spitfire DAC which was rated as teh best DAC below $300 by What Hifi.
3. The AUNE has the following options:
a. USB and SPDIF input for the DAC
b. Analog input for a cd player
You can switch between all three inputs i.e. you can have 3 devices connected to the AUNE using the 3 inputs and switch between them using the front panel switches
c. It has a preout which will bypass the amp stage and directly outputs the DAC stage. This is a fixed preout and here the AUNE works as a stand alone DAC.
4. I am including two power supplies. The original 15V 1A AUNE power supply which is fantastic but am also including an Elpac 18V 1.3A switched power supply. This power supply adds control and lowers the noise floor significantly.
5. I am also including the original opamps i.e. BB2134, BB2604 and 2 dual mono LM6171 opamps (used in Meiers flagship amp). The AUNE will come with the AD797 dual monos and LM4562 installed.
6. This is a fantastic little headphone amp. It is VERY comfortable driving everything upto 300ohms without a sweat but can also drive my 600ohm T1's.
I am asking for $150 + $20 shipping and paypal fees. The mods themselves cost about $100. Please note that the elpac power supply has a IEC connector and does not ship with its own power cable (I was using a ZU Birth cable which I sold).
Please PM me at sberamji@gmail.com
This is easily the best DAC I have heard below $200 and is a very very good headphone amp as well. It has a very refined sound. I selected the LM4562 opamp after comparing many different opamps to my Sim Audio Special Edition Equi CD player. The LM4562 comes closest to the Sim Audio's signature.
