D1V33 at 24-bit 96k Fs – using SM5847 & PCM1704

January 4th, 2010

Finally D1V33 is working at 24 bit and 96k Fs after using the better digital filter NPC SM5847 and PCM1704.  Both chips are put on a converter board and plug into D1V33.

The set has been tested using Audio Precision and confirm the set is working at 24 bit & 96kHz sampling frequency.  The FFT measurement are attached below:

D1V33 FFT with the 1kHz signal filtered off, very low noise floor -135dBV!

D1V33 FFT 24bit 96k 5847+1704

On the last photo, you can see that I change the decouple capacitors for Servo DC, Ref DC, BPO DC pins of PCM1704 to Black Gate N series and Elna Stargate type.  The result is that the bass performance of PCM1704 is much better than using FC capacitor.  Now the bass is as deep as PCM63 but with a little bit better clarity in all aspect.

Here is the FFT at -90dbFS and -110dbFS digital signal and you can see the harmonics is better than the on posted on PCM1704 Datasheet.

D1V33 FFT -90dbFS 96k 24bit 5847+1704

D1V33 FFT -110dbFS 96k 24bit 5847+1704

Frequency response and Distortion vs Frequency:

Freq Response & Distortion D1V33 5847+1704

Update on Jan 7th, 2010:

After listening for a week, the conclusion is that PCM1704 bass response is still way far away from PCM63 DAC in the D1V33 platform.  It is still inline with the poorer design of the current output of PCM1704 relative to PCM63.

D1V3 DAC from David – HK

December 17th, 2009


Hi! Spencer: My D1V3 complete. I order the kit in 2008.02 but 2009.09 start assembly. I use 4-PCM1702UK, DIR9001 and SM5842AP.
I buy 2 round transformers from Shenzhen, but when I do test the transformers all burnt ! so I buy 2 from Wha Fei. The FC 1000uf foot print bigger than the PCB. I make a out side power supply.
I go to Chaiwan a steel shop cut and bend the steel sheet (thickness 1mm) for the chassis.  I pay HKD100.00. Then I open the connector holes, brush paint.
The DAC is good sound more detail, compare to my DAC3 – PCM1732 with HDCD (from Taiwan DIYZONE.NET).
Thank you for provide this good kits and your help during my assembly.  I am an old man and have family work.  So take long time to complete the DAC.  David

Update on Dec 27, 2009: Spencer: I replaced the PCM63 to my D1 V3 make some adjustment . Today play music all day. The PCM63 is better bass and more detail. . Thank you . David

Yamaha F1030 – B1 Active Crossover idea

December 11th, 2009

I do not have this equipment but I only have this service manual.  The manual is useful as a analogy active crossover using Buffer stages.  I have attached the circuit diagram of this crossover here and you can use the NP B1 buffer to replace the transistor buffer and then you will get a good B1 active crossover.

I have not tried B1 active crossover using this design yet as I do not need a crossover at this moment.

There is a diyaudio discussion about B1 active crossover @diyaudio.

F1030 circuit here:

F1030 Circuit1

hp 3478A Multimeter

November 13th, 2009

This is a very old 5.5 digit multimeter with first production in 1981 or early.  You can find this meter easily on ebay for $100 to $150 USD which is a real bargin for such a good multimeter.  I use this meter most often for voltage and current measurement.  For audio signal, this meter can easily give you a accurate AC level reading up to 100kHz.  I think this is the “must own” meter for diyer due to it low cost and high performance!  I have two of this.

HP 3478A Technical Data

Some internal photo of hp 3478A:  This is a well design and well built unit even it is a low cost version!

New FFT measurement for Yamaha DA202, DA2X and TDA1541 SZ DAC

November 12th, 2009

Please go back to Yamaha DA202 and DA2x for FFT measurement on Nov 12, 2009.

DA202

DA2X

TDA1541 SZ DAC