What are output barrier strips?

If you think you're not familiar with barrier strips, you've probably seen one and not realized it. It's a long block of plastic which holds a number of screw terminals, each one sparated from the next by a low "wall" or barrier. They were standard on amps during the fifties and sixties.

The barriers tend to be set very close to the screws and the screws are close together too, so the best connector is a small spade or nothing at all.

When amp mfrs use barrier strips its often because there are different taps for different speaker loads. You will want to hook your speaker to the appropriate tap and ground. For example, my old Quicksilvers have a barrier strip marked "G", "4" & "8". For 8 ohm speakers, you would use G & 8. For 4 ohm, G & 4.

To be more specific, I have an old McIntosh amp on its way to me that uses barrier strips. I want to use my existing double (biwire) strands of Kimber 4TC, unterminated. Easily doable?

When you say use G & 8, do you mean for each speaker attach the left channel to G and the right to 8 (or vice versa)? Sorry, not crystal clear to me yet.

Whups--don't do that!

There should be one barrier strip for the left--and one for the right--amplifier outputs. Each strip should have a clearly marked ground (-) and probably something designating 4 and 8 ohm taps off the output transformer (the + side). I'm not familiar with the taps on the Macs; its possible--unlikely--there is only one barrier strip, but if so, it should designate left and right connections on it like "LG", "L4", "L8", "RG", "R4", and "R8". There is some variation in marking--the ground might be marked "0"; I think it is on my ARC amps. The 4 ohm tap may say +4, or somesuch.

So, the left speaker ground wire (L-) should be connected to the screw on the barrier strip designated as the left side ground (speaker ground will be whatever color of 4TC you connected to the black or (-) speaker post on the left speaker). The other left speaker wire (the other end of the wires connected to the red/white speaker post or + side on the left speaker) should be connected to the screw on the barrier strip designated as either left side 4 ohm or left side 8 ohm, depending upon the nominal impedence of your speaker.

The right speaker will have the ground connected to the right side ground screw, and the other wire connected to the right side 4 ohm or 8 ohm taps.

I don't think using biwire runs of Kimber will be a problem, but it might be hard to get double runs under the barrier strip screws. Because the Kimber is multistranded anyway, you'll have some fun trying to get the screw to come down solidly on the twisted together wires and make a good connection. Because of that, I'd almost suggest using spades. You'll have to get relatively narrow spades to fit between the raised bits on the barrier strip, and get ones with a fairly healthy diameter for the wire end to fit all the Kimber in. Crimp them solidly and it should work pretty well.

The old McIntoshes are a real pain for big speaker cable. I fashioned up some small spades - banana connectors which worked ok. I ended up just using the pins on my MIT T2 biwires for a more direct connection. With unterminated 4TC you shouldn't have any problem although you may find Edesilva's advice worthwhile.

speaking of barrier strips I need some quality made 10-terminal strips made of quality material (or at least gold plated) does anyone have a source suggestion?
I guess they'd all have to be made of a steel base metal, or the screws would strip right away if made from a soft metal & then tightened very much.

I started wondering about the 5 way binding posts you can buy for home built projects. Usually, there is a shaft that goes through the chassis with a bolt that goes on to secure the whole shebang to the unit. I've seen bad ones with really large diameter shafts, but I believe there are ones with narrower shafts as well. I started wondering, if you got really, really, lucky whether you might be able to screw a 5 way binding post into a barrier strip if you removed one of the screws? Has some relevance for me b/c my Quicksilvers are relatively incompatible with the kimber spades I have--I ended up creating a screw in extender anyway to accommmodate the fact that even the "narrow" spades were wider than the gap in the barrier strip...

Bob-you might try autosound specialty shops. I think I've seen gold plated barrier strips for such uses. I think the "turn your car into a rolling boombox crowd" tends to buy goldplated everything. (Tried to post something last night but it never showed up; must have hit the wrong button or something.)

I have used the cheapo Solen 5-way posts (plastic caps) that screw in place of the barrier strip screws. They are metric but will fit 8-32 strips. Works...