@cheeg the section labeled "Oven Control" in the Lavry DA924 user manual may be informative. The DA924 (DA2002 for consumers) was often considered a "gold" standard in professional audio DACs and not just for its color.
The specific sentence relevant to your question is:
The specific sentence relevant to your question is:
The PCM DAC is constructed of custom made laser trimmed thin film resistor networks; yet any resistor is subject to short term drift due to temperature variations and long term drift due to component aging.