This has been a very long time coming, and I am absolutely thrilled with the final results...... so apologies for the photo spam, especially if you end up seeing this exact same post on several different forums! :evil:
I have just finished up a complete re-case and upgrade of my Buffalo DAC. This is my best attempt at a no holds barred build, while still trying to be a little bit sensible. While it is comprised exclusively of cookie-cutter DIY parts, I would like to think that everything is implemented quite well; I designed it to be clean, functional, and above all, upgradeable.
First some pictures......
Tech highlights:
HiFi2000 Pesante 2U 300mm deep case
FPE panels front (6mm) and back (4mm)
Integrated IEC inlet with DPDT switch, double fused and filter
AMB's E24 with SSR for mains power switching
Two fully shielded and encapsulated 30VA transformers from
SumRTwo TPA LCDPS providing four separate power lines for the digital components
One TPA Placid BP with 2.5" sinks providing power for the I/V and linestage, set at ±15V
TPA SPDIF MUX for input switching
USB input provided by AMB's Gamma1 USB/SPDIF board
TPA Toslink input module
Two additional RCA coax inputs
DAC is an original TPA Buffalo24, fed by I2S from the MUX
I/V and linestage is a TPA IVY with the most recent parts recommendations
1pr each XLR and RCA out
Of everything that went into this build, the thing I am most proud of is the Power/Lock light, as shown below. When power is first switched on, the switch lights blue. When SPDIF lock is obtained, the switch changes to red. It is controlled by the LOCK led from the MUX board triggering an OTTO relay wired to reverse the polarity of voltage fed to a Bulgin dual-colour illuminated switch. Such a simple premise, but I absolutely love the functionality it provides, and the cleanliness of the front panel from not needing separate lights. The only problem with this scheme is that when using ASIO through the USB input, the relay clunks around a lot when pausing/resuming and switching tracks. Certainly something I can live with though.
Silence......
Music playing!
I still need to add a couple of finishing touches, namely a selector knob, connecting the IEC GND to the chassis, replacing the fasteners with socket head screws, and installing 'struts' that connect the top and bottom plates for better structural rigidity - I'm just going to use a 3" long 6-32 standoff for this, but can't justify the Mouser order for just these, so they will have to wait. I would also like to get a shorter internal USB cable.
Now with respect to being upgradeable, I have tried to keep the power and input system very flexible...... any DAC that takes SPDIF or I2S should drop right in, and the power supplies should be able to handle up to 9V for digital and anywhere in the range of ±12-18V for analogue. And there is an absolutely huge amount of room for new DAC, I/V or linestage boards.
Thanks for looking! :)
