I'm not sure if there were more than one model DAC used in the PS1. Now I did find a reference on the web that the PS1 used the AK4309AVM DAC made by Asahi Kasei Microsystems (some have spelled this incorrectly as Ashahi). However, I can't find any datasheets for AVM, but I do find one for the AK3039BVM. You can find a slew of spec sheets at http://www.datasheetcatalog.com/asah...icrosystems/1/
however, I'm not so sure how informative they'll be.
This is not some little hole in the wall company. The DAC itself, is 1-bit and while their use is not unknown in hi-end vendors (Meridian, Arcam, and Sony among others), more typically they're seen in lower end offerings including portable devices. Now, the sampling rate is going to be much higher with a 1-bit DAC. They also tend to be a little cheaper. I also note, FWIW from the spec sheet, that the output of the BVM DAC is well over 3 volts so I'd expect it to stand out so if you want to do any critical comparisons, you've got to find a way to level that playing field with whatever you're comparing it against.
As Steve O. noted, just from the point of view of ease of use, I'd pass. Besides, all you're going to get are crappy games. Whether it's a giant killer or not, I've got no idea. But you ain't got no service or warranty. Could've bought a damned used OPPO and had hi-rez tossed into the mix for about the same money. If you're looking for deals, you're better off hitting up garage sales, thrift shops, and reading the ads in those local advertisers they stuff in your mailbox.