Pooge's RAKK dac
Return to Gallery
Switches from left to right are: power,
input select, and Tent clock in/out.
I wanted the Tent clock to be defeatable so I could send DVD sound through DAC.
On the left are the RCA and XLR
The switches select the proper grounding for the type of output used.
The middle pair of RCA's are Tent clock outputs for PLL sound and the clock for the transport.
The right pair of BNC connectors are inputs.
Closeup of rear connections. The BNC
inputs are isolated ground types.
If I did it over, I would have used the type that ground to chassis.
Inside of unit, showing DAC boards and
output transformers mounted on a
raised aluminum panel. The panel provided a rigid support and for mounting
of the transformers, the wires running below the panel as needed and for
shielding. I ended up grounding the input shields to the chassis via
capacitors. I am using a series connected set of resistors on the RCA
outputs as I/Vs until I can get single value Mills ordered.
I found some nylon washers to sandwich
between the transformers and support
panel that fit perfectly. They are the nylon rings that fit in PVC drainpipe
fitting that come with P-traps, etc. The Tent board is over top of the DAC
board. The input transformers are mounted on the under side of the DAC
board. I used two 75-ohm coax inputs, so I converted the XLR input to 75-ohm
by jumpering pin 3 to pin 1 on the XLR input on the board to ground the
75-ohm input. This prevented pops in the output when lights were switched
on. Grounding the input BNC shields to chassis also eliminated the pops.
View showing output transformer leads
coming up through insulated sleeves
through the support panel, and the connections of the front panel switches
on the right. The upper switch is a SPDT that connects either the Tent clock
output or the Tent clock input to the DAC input from the Tent clock. I used
panel mount BNC inputs instead of board mounted input jacks so I could place
the boards as close to the front panel as possible to shorten the path to
the front switch for clock selection.
Closeup of back panel. I originally used a
twisted pair on a BNC input
because the I was in a hurry to listen to the DAC, and the coax was rather
stiff and difficult to manage. When I later connected the second input, I
managed to take the time to use coax, which I plan to use to replace the
twisted pair on the other input, because I think the coax sounds slightly