tybees21
I think I may have some info for you. I have a 670 also but have not tried to edit the kits but here is what the manual says.
You cannot edit the preset drum kits 1-64.
If you want to base a new kit on a preset drum kit,you can copy the preset kit to a user kit 65-128, then edit it to your liking.
first select a kit you want to edit.
1. Hold down [SHIFT] and press [4] (copy)
2. While holding down [SHIFT] rotate the TEMPO/VALUE dial to select the copy destination for the drum kit. (choose 65-128)
3. If you are sure you want to copy the drum kit,hold down [SHIFT] and press [->ENTER].
The drum kit copying process starts.
*to cancel the operation, release [SHIFT]
4. Once the copy has been completed, release finger from [SHIFT]
This is on page 84 of the manual if you are stuck go to a local music store and ask to see the manual.
Hope this helps. Hope you like your 670. I love mine it has awsome sounds in it!!!!!!
With some compression and some reverb it's amazing how real they sound at least to me they do.
Happy recording