In this country, the traditional way of terminating speaker cable is to use 4mm banana plugs. However, this amp is sold all around the world and in some countries, such plugs would be dangerous, because they would fit straight into a mains socket. For this reason, manufactures discourage the use of 4mm plugs by 'bunging up' the speaker outlets on their amplifiers. This forces customers to use bare-wire, which increases the likelihood of short-circuits and is incredibly tedious, particularly if good quality (i.e. thick) speaker cable is being used. Many of our customers therefore request that we remove the amp bungs for them. Even though it can be tricky and time consuming, we are happy to offer this service totally free of charge. Just as well really, because (as people who have bought the amp elsewhere have found!) this is not something that some customers can do on their own.
The 606 is more powerful and sounds better
not to True HD standard) 
