F5T Pre-amp + FDA-2A AD1955 DAC in one box

This is a pre-amp plus a FDA-2A in one box.  It was built in year 2012.  I use a old Yamaha DA8X box to house eveythings insides.  See the pdf files at bottom for details.

DAC:

FDA-2A with USB, Optical and AES digital input.  Push button for digital input selection at the front panel.

DAC direct output is available in RCA sockets.

F5T Pre-amp:

Alps volume control from DAC output and note that there is no other analogy input for the preamp.

The pre-amp is based on Nelson Pass F5T power amp design and striped down to only one pair mosfet and lower bias current at about 200mA.  Supplier voltage is at about +/-23V with a small transformer.  Power mosfet is using Toshiba J200 / K1529 pair and casing is acted as the heatsink of power mosfet.

A headphone jack is connected in parallel with the pre-amp RCA sockets.  It can drive most headphones due to sufficient high bias of the power mosfets.

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Details refer to this pdf file: F5T-Pre_DAC

Enjoy!

 

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