And now, rising from the dead...
Had the luck to be able to work on my CD player as part of a project for a lab class at UIUC (Physics of Music, kiddies -- UIUC Head-Fiers need to take it). The last class is Tuesday, and thus I have to present the finished product then, so hypothetically the second revision (perhaps sans reclocking) will be complete by then. The first post in this thread will be updated with a full writeup by the 13th, which is when the final report is due. Comments and suggestions are welcome, as always. Oh, and if someone could give me a quick idea of how to give the Dynahi preamp capability, let me know. I think I know how to do it using a switch between the headphone and preamp out, but can both be in use simultaneously?
The concept this time around is separate, low-profile enclosures for both the power box and signal box. Both cases are Lansing Enclosures, one rackmount-unit thickness each (about 1 3/4"). Combined height will be approximately four inches total, barring considerations for a lid.
Center is the transport, left the DAC, right the Dynahi boards. The only AC in this box passes along the left side of the chassis to the DAC board and transport power supplies on the bottom left. +5V for transport is still a Jung regulator, +9V is an LM317 unit because I found that I couldn't hear a major difference with the two supplies (I could with the +5V, though). At no point does a signal wire (digital or analog) cross paths with a power wire (AC or DC). Using a spring suspension this time around. Current problem is that the transport sits too high in the box, which means I either need to shave down the feet or cut out a larger hole in the cover to allow the whole of the transport to sit outside the box rather than just the upper black frame section. Probably going to go with the latter.
Dynahi amp boards -- went all-out (probably overboard) on resistors here, IRCs for general resistors and Rikens for output resistors. Boards are currently pulling 800mA each, might want to change the 100 ohm resistor in the VAS stage to lower this if heat becomes a big problem. Heatsinks are optimally placed close to the vented side of the enclosure, and if necessary I might add a small, quiet fan in the back to circulate air.
Dynahi power board, which is in the box with the transformers. Voltage out from this goes about eight inches to the back of the power box without passing any AC lines. I'm using two separate Amphenol connector sets on the left and right, left for AC, right for the Dynahi DC and CD player control.
Oy. Much left to do.