Speaker cables

Is there a device or a way to use the modern 1/4" spades on my McIntosh amp with the small screws and the barrier strip?
There is definitely one company that makes a barrier strip-to-spade lug pigtail adaptor (it's called a Spealunker):


$30 for a set of 4. Good luck. BTW, these are meant more for bananas and plain wire, but I think they should work OK with spades if you're careful.
I assembled an adapter for my vintage Fisher tube integrated from plexiglass with off the shelf 5-way binding posts and wire. It works perfectly though maybe not as elegant as the item Nsgarch shows.
My friend bought those but didn't like the construction.
There are alternatives from Cardas CCMS S and
Philmore 45-282G ( with stright wire and banana plug adapter.)
I check on the Spealunkers and was told they work with bananas only. The ones at Audio Classics look well made, cost $149+. Cards will put on spades that work with the barrier strip for $100.00.
I've just recently gone through this, as I'm in the process of doing up some cables for my Mac Amps.

I myself ordered 3/16" Audioquest Spades from RamElectronics, they come in two sizes for up to 14ga, or up to 10ga, and the cost was reasonable enough.

The best spade lug I've seen out there is the billet machined Cardas CMSS, and these generally go for around $11 ea, but not appear to be crimpable, and would need to be soldered.

One has to weigh the advantages, disadvantages, and costs of adapters versus the correct spades.

I can understand going the adapter route if one perhaps has very expensive cables terminated in another fashion, and has future thoughts-wishes of an Amp upgrade that won't have these issues with narrow Barrier Strips. mark