Yeah, Page pretty much has it right here. Except that it is even worse in that the Burr-Brown INA111 versions weren't even the prototype chips used, they were an option available with the prototype. I may be the only person with an INA111 littlebox, plus Chuck has an INA111 littlekit amp kit from Naiant which he used to build his own preamp.
I think the few comps that were done with the littlebox were done by Chuck and I, so they aren't the same as what was generally made by Naiant or available now. It'd be great to see some more littlebox comps done. I just got my INA111 littlebox fitted with user selectable output transformers, so I'll be doing some more comps with it vs the EAA PSP2 soon. Though again these comps won't get at what the current littlebox sounds like in comparison to other preamp choices.
As (more of) an aside, the original littlebox used the Analog Devices AD620, and now uses the AD8821. The prototypes had the option for the TI/Burr-Brown INA111. The Lunatec V2 and V3 used the Burr-Brown INA603 and INA163 respectively. All of these chips listed are various versions of precision intrumentation amps. The INA603 was developed by TI/BB as an upgrade (and drop in replacement I think) to the Analog Devices AD625, which itself was somewhat of a precursor to the AD620. So all the littlebox and Lunatec preamps are built on similar instrumentation amp architectures.
So all this isn't a complete hijack: when I had my 722, I used the Lunatec V3 as a front end to it, at first just feeding the 722 a digital feed from the V3, and then after I did more testing, using the V3 as an analog frontend to the 722. I did use the 722 by itself sometimes, but liked the sound of it better with the V3 in front.
Topic: Why using a preamp with a SD722? (Read 4810 times)