Well, it has been some time since my last post. Again, work, family and travel taking me away from audio and music. I am currently enjoying my mobile setup of iPhone 4 and my Earsonics EM4. At home, I am continuing to enjoy music through the computer to the Li Te DAC-AH and the through to the O2 amp. A lovely combination.
A few notes regarding the O2. I cut one of the gain resistors to reduce the gain to unity. I has allowed me to use more the volume control. Before, it was so sensitive there was horrible channel mismatch. But now, I can use it at 9 o'clock. Still not great, but better. Also the volume control on iTune is at 20%. Again, not great. My next task is to reduce the IV resistors and the gain of the opamp on the DAC to reduce gain even further. My aim is to have iTunes/Fidelio at 100% volume, and have sensible levels at my headphones at the 12pm/1pm position.
Have been thinking about the DAC, and how to build one with deliberately low volume, and the mating it direct to a LM based amp (something like 'The Wire' or TPA's Ventus. But have been designing that (or drawing that) and is taking a long time. Also not looking forward to the SMD parts soldering. Not sure when I will have the chance to put it all together, as my soldering gear is back home...
Anyway, not much to report on. Hopefully I will be able to do a few things like publish my 'design' (I use this very roughly cause I am really cutting and pasting...) on the TDA1543 with the Wire. I plan to use the O2 power stage (giving on battery +/-8V ish and on AC +/-12V ish) coupled to a standard TPA SPDIF receiver setup.
