Had a PM asking me how to roll opamps in the D2 Viper.
This is just such a hard thing to do adequately via typing with no photos available. I've give you this bit of information, but I can't do better than this. I am not sure I can answer more questions, because everything is in here.
If you have the opamps soldered onto a DIP8 adpater or those that come ready to plug into the sockets, open your D2 viper. If you don't have them ready to install, you've got the wrong guy.
To start, turn off the amp and unplug it from everything before you start. I don't know what size tool it takes - I got a cheap one at home depot with a bunch of unlabeled tips, and tried them all till I found one that fits. With the amp laying flat, remove only the two top screws on the front panel and the rear panel, and the top half of the amp case can be lifted off.
With the front of the open amplifier facing you, you will see one LT1364 opamp plugged into a socket that lies between the volume knob and battery. Of the 8 pins securing the opamp to the socket on the circuit board, the pin on the left front corner is pin #1. You might want to take a photo of it, so if you have to put it back in you know which way it is facing. After you pry the glue off the edges of the opamp adapter (that is holding it in place), you can pop it out. Use your best judgement to get this opamp loose. Break the amp and it isn't my fault.
The new opamp when viewed from the top will clearly have two rows of 4 pins. If you have one that was soldered onto an adapter, ignore the pins that come right off the chip and only pay attention to the ones near the edges of the adapter. On the adapter, one of the 8 pins will have a square of solder toping it, instead of a circle like the other 7 pins. The one with the Square is pin #1.
If your opamp is not a smaller SOIC opamp soldered onto a bigger DIP adapter, but is actually a DIP8 opamp (like some LM6172), orient the chip so the notch on the top of the chip is on your left. Pin #1 will be the one closest to you on the left.
So, line it up with the empty socket and insert it with pin #1 on the front row, with pin #1 on the left. When you press to seat the opamp into the socket, press on the edges of the adapter not the center where the chip sits, or you may break the solder connections between the opamp and the adapter.
To do the opamp for the ground channel, you will find it to the left side of the battery closer to the rear of the amp (with the front of the amp still facing you). This opamp socket is rotated 90 degrees counter-clockwise. So, instead of the rows of pins running left/right, they run front/back - so pin #1 is now on the front right (with the volume knob of the amp facing you). This means pin #1 will be closest to the battery. Remove and replace as before.
You might need to put a small piece of foam or something soft like styrofoam (but not flammable) on top of the opamp to keep it from unseating when the amp is bumped around or dropped. Or a small amount of blue-tack against the edge of the opamp where it meets the socket could hold it down.
Turn on the amp, plug in headphones and a source (ipod or USB cable), and test it. If it works you can re-install the lid. The amp can pick up RF interference with the lid removed, so if you hear noise like it's picking up the hard drive moving, try putting the lid on first. If that doesn't fix the noise, you may have a bad opamp or one with the wrong specs for the amp design. If it's making painfully loud squealing, or totally silent with music playing, then you did something wrong or you killed the opamp, or it isn't seated tightly, or is in backwards, or it isn't compatable with the amp.