photo: marjorie o'brien
There have been cmoy's, a47's, modified linkwitz crossfeeds, meta42's and now the pimp portable ppa headphone amplifier. The ppa features a modified linkwitz crossfeed, bass boost (still in need of tuning), AD8610 op amps (socketed with Burr Brown opa627 and opa637 in the listening queue), 12 buffers, a battery board housing 12AAA NiMH batteries and a recharge circuit, a toaster and the kitchen sink.
I completed my first headphone amplifier based on the cmoy design with help and soldering direction from Number 6. It sounds good, and I'm looking forward to modifying this circuit before moving onto some others.
I apologize for the terrible pictures. I'll work on something better this weekend.
Update! 6/17/03 Marginally better pictures replace the previous pictures.

