Justblairs Audio and Electronic's Pages

I noticed this Digital to Analogue Converter(DAC) on the Thai forum HTG2.net. It’s a rather nice build based on the Twisted Pear Buffalo II DAC and Placid Power supply kits.  The owner has made good use of Perspex (or like material) to produce what is an interesting looking product.  Using two colours of clear material to sandwich the electronics.  I have seen many Perspex cases before, it’s a popular way to house low voltage electronics in a cheap yet attractive manner.  In fact I have a headphone amplifier and a couple of chip programmers manufactured in a similar style.

Over at Twisted Pear, they are taking orders for the revised version of their Buffalo DAC.  Name wise they have gone for the catchy title “Buffalo II”

In Twisted Pears own literature

“The first generation Buffalo DAC was the first DAC available based on the ESS Technology Sabre-series DACs, then the ES9008. The second generation Buffalo32S was the first DAC available based on the ESS ES9018 Sabre32 DAC chip. In in it's third generation, the Buffalo-II DAC embodies the culmination of our nearly three years of experience working with Sabre DACs, and it our best effort to provide the pinnacle of performance, as well as a high degree of customization.”

Retailing at $249 USD, the DAC boasts an impressive feature set:

I am ashamed to admit it, but I have a DAC project that fell by the wayside a few months ago.  It is the γ1 miniature DAC.  I got so far with the build but hit an unknown problem with the usb receiver section.  I must get back to it when I get my new DSO Nano Oscilloscope and try and sort out the problem. 

Just to add to my shame AMB Laboratories has added a new kit to their repertoire, The γ2 Compact High Performance DAC.  Well to call it new is not exactly right, it is actually an expansion of the γ1 design.  So there is another good reason why I need to debug my stalled project. 

So what does it do?

Jitter of the different transports and connections was measured through the DDDAC1543 without re-clocking. The one with re-clocking seemed to be immune against jittery transports.

TDAC1543 without re-clocking

After posting a link to my original Geocities site in the digital section on www.diyaudio.com, Doede Douma pointed me to his own TDA1543 based DAC (see www.dddac.de). He also paralleled 8 chips, decided for passive output and implemented a re-clocking circuit. The main difference is the battery supply. I was very tempted to build his DAC.

Short time later it was done and I was able compare Doede’s DAC with mine. I have to admit that the DDDAC1543 is even better. It is more dynamic, the music is played on a more quiet background. I could also say, that my DAC is a bit more nervous. Well, the difference is small, but it's there.

I first wanted to find the reason for this difference. But then I was more interested in how (if at all) DDDAC1543 can be improved. I did not change anything on the circuit itself. I only focused on supply caps, coupling caps and I/V resistors. At least in my opinion, there is some space for improvement.

It is not easy to describe differences in sound when exchanging parts. The effects are sometimes hardly noticeable. It's sometimes difficult to distinguish between reality and imagination. Nevertheless, I did some serious listening and I tried to write down what I heard.

Click on the left links to read about my conclusions.

This boards were made for comparing the following issues:

5V vs. 8V supply voltage for TDA1543.

0ne vs. several chips in parallel.

Different output stages:first board from the left:

Active I/V according to Philips datasheet (with opa627).

This circuit allows you to directly combine any decoder/receiver with any converter without re-sampling, oversampling or filtering ICs in between. You only have to figure out how much shifting is required for left and right channel DATA.

Non oversampling DACs are by many people (including me) regarded as better sounding than conventional oversampling systems. The easiest way to enjoy that kind of sound is to build a DAC with the "outdated" TDA1543/TDA1541 DAC ICs or modify an old Philips/Marantz CD player.

But why not building a nonos DAC with higher quality converters like PCM1704, PCM1702 or AD1862? Well, you need to convert serial DATA to parallel DATA which requires some glue logic. Further glue logic is needed to align 16bit DATA with the 20bit or 24bit inputs of these DAC ICs.

The World Wide Web has made the sharing of information easier, more convenient and more rapid than ever before.  It’s not without it’s flaws though the main one being just the huge wealth of sites to peruse, remember and revisit.  It makes it easy for a product to go astray and last week I discovered such a product.