This is a very special amplifier. Per ADA, only 7-10 of these were ever built and just for a very particular, well-to-do client. There is no specifications, manual or anything. All this information came directly from ADA. This amplifier is audiophile grade, and that is not overstating the design. This is a large amplifier, labelled for subs, but is completely adept to any reference set up. It has XLRs, large capacitance reserves, and high power and quick response.
For the negative: When it was shipped to me, the shipper relied on a UPS store to package it. It arrived with a couple of heat sinks slightly bent. I could straighten them but it does not affect the amp at all.
Please make an inquiry to ADA for more information about this amplifier. They have designed some special amplifiers and only they have information about them, like the PF-4000.