Audio test equipment and procedures
Introduction My thesis for the development of the DDDAC1794-MK3 was to have a as low output impedance and low noise for the on-board regulator as possible (the LT1763). Especially in the low frequencies! In my introduction post on the newly designed DDDAC1794-MK3 (link here) I already showed some measurements from my AP-System. But not…
Introduction Just a small in-between quick & dirty little project… It all started with a R2R DAC from Stefano, which was kindly sent to me for review, by Marcin. By the way…. there is a long thread about this Stefano DAC and the developments over time on the DIY Audio Forum: https://www.diyaudio.com/community/threads/italian-r2r-ladder-dac-no-cpid-dsp.390541/ Point is…
Introduction It is in the name DDDAC… I have spent so many years on DACs, it was about time to follow up on my curiosity on R2R ladder DACs. Not the ones inside a chip – we know them well in the meantime – but the discrete ones. A decade or so ago, very…
More background on this special DDDAC output transformer (OPT) Some History The problem I faced was the small residual DC off set between the DAC outputs (POS and NEG can have somewhere between 0 and 30mV max) This might magnetize the core and introduce more distortion and non linearity. I sought help with Brian…
A fresh new setup after 15 years… Now that I will spend more time in my work shop, it was about time to get things fresh and renewed. After many (15) years of organic and chaotic growth I wanted to get things more organized and all test equipment and work space more handy. Well…
Introduction Inspired by the many reports on the audiophile improvements when using UltraCaps (or super capacitors) in Audio applications, I decided it was time to start looking into this subject myself. For starters I wanted do some tests with it on my own DDDAC. Of course I am also interested in the technical aspects…
Introduction We all know these FFT plots with a noise pattern. I see them all the time in Forums and other websites. The term Noise floor is always close… But is that also the Signal to Noise ratio (S/N ratio)? Or is this the noise voltage output from a voltage regulator for example? NO…
As mentioned in the earlier PR99 blog, I wanted to design and build a universal tape head amplifier. Just for fun and to see what I could squeeze out of the magnetic source, avoiding the internal Revox electronics. Which sounds great, but honestly I still do not get it as it is full with…
I started using this Blog-Site subdomain from dddac.com to blog my audio adventures 🙂 I will be starting to post here several topics and projects. As I have some projects done in the past, it will not be all very chronological, but more what I like to show for now – It will be…