THE ORRONOCO AUDIO DIY

It was about last year that I finished this tube DAC AD1865 using high-performance USB input from JLsound USB receiver module, but somehow, this project was burry in my photo archive, so, I think I will reveal it now. This project starting after my previous DAC project using the same 6DJ8 tube in SRPP configuration as gain-amplifier at the DAC output stage. This SRPP circuit is proven to work best with DAC as gain stage and I've made the best sounding tube DAC  here , at that time with PCM1704 high-performance 24-bit multibit DAC. Although in this project I will use different DAC IC, but one lesson for the key success for good sound is the components selection and individual component upgrade that most of the time will cost more than the whole initial DAC build itself. Fast forward to this DAC build, I will build almost the same DAC but with few different approach. Please continue reading.

If we align our perception in term of vintage resistor-to-resistor (R2R) ladder DAC, it is specific to the over the shelf DAC like Burr-brown and Analog Device DAC. In their golden years of vintage multibit DAC around 80's to 90's, only those two manufacture built DAC IC in this R2R configuration. Philips with TDA1540, TDA1541 and TDA1543 is Dynamic Element Matching DAC, which is also multibit, but different in the internal configuration compare to the R2R DAC. I am pretty sure in those golden era, lot's of money spent in their R&D to achieve the best R2R multibit DAC, starting from PCM53, 54, 56, 58, 61, 63, 1702, 1704 and AD1856, 1861, 1862, 1865. Those DAC exists before this audio industry force them to shift to the more economic and easy to build DAC, it is the Delta Sigma DAC. Fast forward today, audiophile still believe that vintage multibit DAC sound superior to Delta Sigma DAC (hey, it's me:). Moreover, the Delta Sigma DAC is not become a true single bit any...

As a  do it yourself  in audio system, finding the sweet-spot is more exciting and challenging at the same time. This is because you can do by yourself, to match between the components and upgrade the audio system based on what you think they will be improve. There almost no limit in this action, only self-satisfaction and at one point, enough is the finish line. I have made many DAC before. I know how to make a DAC that will be sound marvelous, or just right. And I have them all. The problem now is the other chain in my audio system need to maximized like what I did with the DAC. So, in this post, I shared my listening session activity, changing and replacing DAC, set up the room, and tuning speaker cross-over (again), which all of them are the culprits to finding the sweet-spot.

TDA1543 is a miniature and economic DAC which is the only vintage multibit DAC to use single-rail supply, make it simple to use in the portable circuit. It is stereo 16 bit DAC with popular I2s input format. The nominal voltage supply is 5 volt, but with the tolerance can be supply up to 9 volt maximum, makes this DAC can use passive IV with up to 1.5 K ohm resistor to generate undistorted high voltage line output. With this possibility, no wonder this IC never vanished from the DIY audio popularity. From of my previous TDA1543 DAC project, unfortunately this DAC never sound good for me. I am so curious and never stop experimenting to make this DAC sound better. Finally, I can stay with this TDA1543 DAC with few points that need to be addressed. In this post, I will share the steps that I have tried, which makes this TDA1543 sound good, having its own sound signature which can compete with others high performance DAC.

Since last year, I have been focused on building my own tube amplifier, especially using 300B tube in the single-ended configuration. I got more enjoyable moment when listening music through the tube amplifier instead of solid-state amplifier, especially with the 300B tube amplifier. The sound is more musical, more engagement to the music, and human voice alike compare with the solid-state amplifier. Previously, I also had experience using others tube such as 2A3, KT88, 6L6 and EL34, but I still believe the 300B is a holy grail of all tubes, so I stick to this choice. 300B tube is  direct-heated tube (DHT) , meaning this tube heater also act as the cathode. In the single-ended amplifier, using DHT tube will potentially contribute the hum to the speaker. This is because the power supply voltage along with the noise feed into the heater tube and direct impact to the cathode itself. Annoying hum needs to take care. I took so many lesson when building several 300B amplifier before...

This is the following post regarding building the miniaturized DAC that should sound good, just like full-size desktop DAC. But the difference is in the small chassis. The reason for this is because in my opinion, a DAC unit is not to be shown as the main show unit in the audio system. So let it be hidden somewhere else at the back of the system and let the tube amplifier, speaker and source player as the part of the main show in the audio system. In this post, I will make another DAC using the components that what I have left in my bin. I think in this post, the description will be more in technical. I will try to explain the building concept for the good sounding DAC based on my experienced. This build will be more complex, harder to follow for beginner, but for some reason, I just want to do it. So, let's begin for this AD1865 miniaturized DAC build.