ZERO DAC PDF Print E-mail
Monday, 03 January 2011 18:11 | Written by Administrator

This little thing from China was my first project after the long break in my electronics hobby. It doesn’t really matter what particular project you start with, it will give you back a great doze of satisfaction as long as you have fun doing it and finish. So I encourage you to start project that you been putting aside for some time now.

After some reading of DIY enthusiast feedback I decided to buy this DAC with headphone amplifier on EBAY. Out of the box it was sounding not much better than my little SONY portable CD player, almost the same with exception of more defined sound and instruments resolution. Overall solid construction, although it leaves you with feeling of DIY product.

 

This Digital-to-Audio converter uses Analog Devices AD1852 DAC chip - with something like 114 dB S/N ratio and same value of dynamic range. Analog Devices DACs are clear sounding and usually less prone to colorization of the sound (although not thought of as the best sounding DACs by professionals). Receiver chip - almost standard CS8416.

 

Solid construction inside, toroid power transformer. Mods already in, no tube yet.

 

I will not be going into great details of this mod but in short, following plan was growing in my head:


1. Replace input/output connectors (SPDIF, RCA output) with high quality gold plated chassis-mount connectors


2. Basically follow FrankenZERO mod from http://www.head-fi.org/forum/thread/370985/frankenzero-a-bang-for-buck-exploration-with-a-diy-heart skipping step with green sausage bypass capacitors (Russian NOS PIO). I used WIMA MKP capacitors instead which is cleaner way to do it. Extreme extra lengths of leads on green capacitors will pickup noise from whole board. Interferences of higher frequency signals from DAC clock, digital signal and other sources are inevitable. Besides, end result looked so unclean that I decided to risk and use different capacitors.

In short, FrankenZERO mod replaces rectifiers’ diodes and power filtering capacitors and introduces more bypass capacitors on power rails. High quality parts play crucial role here and Pricklely Peete does pretty good job choosing part numbers depending on the section of schematic. This head-fi post is followed by hundreds of comments which are basically dancing around the same theme.


3. I left analog OPAM section untouched for now – it was a weak chain of whole DAC anyway.


Result was very surprising. I used Sony MDR-7506 headphones for first listening and slightly moded Marantz DV8400 as digital source. Sony headphones are unforgiving to the recording, after all – they are pro studio monitors. But now we are getting closer to main idea. First of all – DAC sounded completely different than originally, so much better in fact that I was astounded and listened to the music for the next 6 hours non-stop. But, after some time, I started to get tired of this sound. It was too clear and precise. That led me to idea that it is probably more precise then source recording and, as result, not real.

The idea that I will be promoting throughout my posts on this site is about high fidelity true-to-live sound. With hundreds of point of views on this subject and even more individual preferences to the “color” of sound people like, I will try to stay away from “colors” and try to achieve “close to the source” sound quality. Not an easy task but… lets try.

Some time ago I found www.lampizator.eu web site of polish hi-end enthusiast Lukasz Fikus which inspired me to try some things that my father was talking about. Before you know, first order of Russian NOS tubes was on its way to my house and excitement started to build up inside my brain. Tubes and sockets arrived and build started. I used half a tube per channel (6N6P - 6Н6П) in anode follower circuit, placed after the DAC output filters. Obviously, OPAM was cut out completely (although remained on circuit board for backup purposes). Well, to say that it sounded perfect is to say nothing. Harshness disappeared and I was listening to sweet sound of music for many days without getting tired. In fact, it was addictive: I could not switch it off and wanted to listen more and more.


Construction of tube power supply and tube socket placement


Power supply on top of the top cover


Almost ready... Listening time.


Power supply cover was painted black to match cover. Finally complete.


This is my first story I’m publishing here. If you are interested in this particular build, you can follow links to sites with details (see above). This is not my invention, so I don’t want to copy everything here. Feel free to ask questions – if there is some trend in questions, I will update this article with additional details of my particular build. What are distinct features of my build? High quality components, high quality power supply for tube, arrangement of blocks and choice of ground point.

At this time my ZERO DAC is owned by my friend Tony - he "enjoys" it with JAS BRAVO 2.3 amplifier he can't wait to get rid off (or throw away Tongue out) and put my little tube amp into his setup. Article about little amp will come here soon...


Just to give you a taste of things to come: little tube amp, new ES9018 DAC and Volume Control kit which will be for sale here soon.

Last Updated on Tuesday, 26 April 2011 18:38