Vacuum tube Headphone Amp-DAC

The Sennheiser HD 650 is a great headphone with a little bit of sonic ‘magic’ appeal. The attractively priced MassDrop HD 6XX version is a special bargain.

A popular and nice match for the Sennheiser HD 650 / HD 6XX is a vacuum tube headphone amplifier.

The project here was built by Jeremy Young. It was inspired by the Bottlehead OTL headphone amp, but circuit ‘operating points’ were determined to suit a locally made power transformer.

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‘Adagio’ TDA1541A non-oversampling DAC

When I first listened to DACs, I concluded quite quickly that ‘multi-bit’ DACs sounded more like music to me, than ‘bitstream’ DACs – more dynamic & ‘alive’.

The TDA1541 was originally developed by Philips (in 1985) as a high performance stereo DAC.  The ‘A’ version was manufactured between 1989-1995.  It was (is still?) regarded as one of the best sounding DACs ever made.  This chip was used in almost 100 different CD players Continue reading