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<blockquote data-quote="John Roberts" data-source="post: 24028" data-attributes="member: 126">Re: Active vs Passive Direct BoxesThe pad in typical active DI (AFAIK) is generally in the output stage to drop the instrument level down to mic preamp level, or low enough to not overload a typical mic input. A pad on the input would conflict with the design goals of high input impedance and low noise. Transformer DI have a turns ratio but this isn&#039;t literally a pad... no power is scrubbed off, but level and impedances are transformed based on the ratio.&nbsp; I have seen specialty DI for speaker level signals but these were specialty items and not general purpose DI. The one I recall had unique frequency response shaping appropriate for mimicking instrument speaker&#039;s acoustic signature, not GP DI use. So to answer the OP&#039;s question, an active DI could be overloaded by speaker level output, but for that matter a transformer DI designed to accept instrument level signals could also be saturated by speaker levels. It is difficult for me to think of the entire DI category as something that could ever be covered by one design. Two, maybe even three sub categories.&nbsp;&nbsp; JR</blockquote>

[QUOTE="John Roberts, post: 24028, member: 126"] Re: Active vs Passive Direct Boxes The pad in typical active DI (AFAIK) is generally in the output stage to drop the instrument level down to mic preamp level, or low enough to not overload a typical mic input. A pad on the input would conflict with the design goals of high input impedance and low noise. Transformer DI have a turns ratio but this isn't literally a pad... no power is scrubbed off, but level and impedances are transformed based on the ratio. I have seen specialty DI for speaker level signals but these were specialty items and not general purpose DI. The one I recall had unique frequency response shaping appropriate for mimicking instrument speaker's acoustic signature, not GP DI use. So to answer the OP's question, an active DI could be overloaded by speaker level output, but for that matter a transformer DI designed to accept instrument level signals could also be saturated by speaker levels. It is difficult for me to think of the entire DI category as something that could ever be covered by one design. Two, maybe even three sub categories. JR [/QUOTE]

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