Archive for the ‘DAC’ Category


Friday, March 9th, 2007

D1V1 was the first revision of clone NP D1 DAC.  It has CS8412 or CS8414 (on daughter board) digital receiver, no 2nd PLL, SM5842 digital filter, 4 x PCM63 in balance mode and Jfet IV (not mosfet IV).  All regulators were using normal 78/79 series 3 pin regulator ICs in digital and DAC section.  Two discrete low noise regulators were used in the Jfet IV section.  This DAC was made as a trial version on jfet IV back in 2007.  The benchmark of this DAC at the time was a Lite DA-50 DAC with PCM63P-K and 6922 tube IV.  This D1V1 won the Lite DAC in smoothness of sound, noise level and image.

Silkscreen Top view:

D1V3 Silk top

CS8414 to CS8412 converter BD

Wednesday, January 10th, 2007

These are the converter boards designed to be used for D1Vx DAC.  It can replace CS8412 in DIP format.

Stock can be purchased in store.


Wednesday, September 6th, 2006

Update on Nov 12, 2009:

Since the Jfet IV of the DAC should be upgraded to K369BL to gain sonic performance, thus this is completed on Nov 12, 2009.  See the last two photos.  Some measurements are done after this modification using AP-2522.  Distotion is about 0.5% but surprisingly, the listen test is quite smooth due to high 2nd harmonics.  See FFT measurement below.


Last update on Sept 6th, 2006:

This is the second kit I do on TDA1541.  Since I only buy the PCB, I can add the Jfet IV for this DAC to test out the overall performance.

It use CS8412, SAA7220 4 times oversample filter, TDA1541 DAC.  The pcb come with a op-amp IV or tube IV but I am not using it at all.

The final version is with Jfet IV + B1 buffer and a volume control.  The target is to drive a power amp from this DAC+Preamp all in one set.  Due to the limitation of TDA1541 performance, the overall result is not as good as the Lite DAC-50 with Jfet IV.

Circuit IV section

Circuit DAC

TDA1541 Thomas DAC

Sunday, July 9th, 2006

This is not a great DAC overall.  Sound is below Lite DAC-50.





Lite DAC-50

Friday, June 9th, 2006

This is my first PCM63 DAC.  It uses CS8414, DF1704 and PCM63P-k x 2 pcs.  The IV is resistor with 6922 SRPP tube output stage design.  Overall the sound is smooth but it lacks of details.  It is more or less the problem of SRPP and output drive is not good enough for most transistor preamp due to high output impedance.  Thus it will also be sensitivity to signal cable used.

First modification is to use D1 mosfet IV, the result is improved on clarity and details.

Second modification is to use Jfet IV (K170BL).  Later the IV is upgrade to K369BL in Jan, 2010.

Third modification is to add super low noise regulator.

Fourth modification is to add a power transformer and also two output audio couple transformer for balance mode.