Thank you all for your responses. ITT is reassuring to hear that many of you have had good results with your ladder DACs, but those who compare this situation with normal circuit aging issues are missing the point. The reason why resistor degradation could be much bigger issue in higher quality R2R DACs is that the algorithm used to design them demands extremely tight tolerances in resistance value to achieve a small improvement in sound. For example, the Denafrips Terminator specifies resistance values of 0.005%, and 0.02% is common in less expensive designs. In amps and preamps, a drift of 1% in resistance is usually not audible; in a ladder DAC, it would make a huge difference. As stated in @nekoaudio’s post, the Lavry DA924 user manual notes that even custom made laser trimmed thin film resistor networks are “subject to short term drift due to temperature variations and long term drift due to component aging.“ Clearly, the potential is there for R2R DACs to degrade faster than other designs; I’m curious whether any Agoners have experienced this firsthand?
Downside to R2R Ladder DACs?
A sales person I generally trust told me to steer clear of used R2R DACs, since their reliance on high precision resistors causes them to sound best when new, and degrade fairly quickly. It seems reasonable; have others had any experience with this?