Krones have several advantages over 66 and 110 blocks.
- They will accept a wider range of wire sizes and insulation types and still make a solid connection, because of the way the contacts cut rather than smoosh.
- Again because of the contact design, they are less susceptible to corrosion and oxidation than 66 blocks in particular. If you have to remove a wire and punch a new one on an old 66 block, you have a very good chance of a bad connection, or no connection. Not so, with Krones.
Krones are a little confusing to people who have grown up with the much simpler 66 and 110 blocks. Krones have internal moving parts: There are contacts inside the block that connect adjacent pairs of punch points, forming a “normal-through.” The conntacts are held together by spring tension, but there are openings above the spring contacts through which test and patch adapters can be inserted. So, a Krone block is also a patch panel. If you need to ask how much the patch cords cost, you can’t afford them… Test and jumper connectors come in several flavors.
– “Look both ways” interrupts the connection between four wires (two pairs forming one balanced connection). Each wire is brought out separately for test or routing.
– “Look one way” breaks the normal-through on both sides of a circuit. One pair is brought out for test or re-routing. You pick which pair by which way you orient the plug. This is different from a regular patch bay that will only bring out the input pair.
– “Winged test adapters” insert themselves between the normal-through contacts, but because they are conductive, they do not break the circuit under test. So, you bridge off the circuit, with NO danger of interrupting or shorting it. Need I say how nice this is, when checking circuits that are in the air chain?
– An oddball nicety is that Krone contacts are grouped in fives. I don’t know if other people have started using SHIELDED Cat5 cable for audio, but if you do, this works out perfectly. Four pairs of audio, then loop the drain wire through the bottom two punch points (see below). That lets you punch two pairs of 8451-equivalent, including shields, to the other side.
The shortcoming of Krone blocks relative to 66 blocks is that fan-out (eg., shield/drain wires, as above) is fairly cumbersome. Some flavors of 66 blocks let you make up to 5 branches off one input wire. Krones are one-to-one, period. It IS possible, though, to set your Krone tool to NOT cut as it punches, so you can loop one input wire through several punch points, to provide some fan-out.