cool... I just saw this thread. I have an unmodded 660. I have had a lot of problems with brickwalling. I have sucessfully recorded modest volume shows with my c-4's using the internal pad + the -10 pad on the mics. I did buy the unit from oade so I have been planning on sending it back for the bcm mod. Mostly I have used it as a backup on my multi rig and I am able to control the input and have had no real problems. I ran a pair of stealth mics for a couple of shows and made a -40 db attenuator cable to keep the levels down. In one case it wasn't enough and I still brickwalled, and on another case it was too much and I got tons of noise. This was using an unballanced line/attenuator however and the pad itself may have been the source of the noise but I suspect that being at the top end of the dial on an unmodded unit was the bigger culprit.
My plan was to build a ballanced variable attenuator until I could afford the oade mod, but after listening to the self-noise tests on the oade site I am thinking that the bcm is more than just a pad. This all being said, I was fairly pleased with the sound of the stock pre's using the internal and mic pads. This is a nice little box! I hope to get the bcm done soon.
As for the hdd backup... I bought an older compact drive. The model I have is a pd6a. The unit works pretty well but it is quirky. I bought just the shell for about $30 I think, and installed a hdd that I already had. The drive I have in it is a 60gb 7200rpm/8mb cache drive which is way overkill but it is what I had around. I think because this is a highspeed drive it affects the battery useage. With my unit rechargeables don't work. Alkalines will allow me to boot and dump about 3 times. The firmware on this unit only allows for fat16 allacation so a 4gb card won't work. I use a 2 gb card and it works wonderfully. I can drop a full 2 gb card in about 10 minutes. On wall power it works flawlessly and on alkalines, but rechargeable's just don't have enough juice. But... for $30 I can't complain!!!! That is a lot cheaper than another 2 gb card... or in this case 30 of them. I am using a 2gb Ridata card and it works very well.
Matt