JKent

Previously I wrote about recapping the Fives: http://www.classicsp...2557#entry74180

In those cases the speakers had the aluminum plate with point-to-point wiring. Plenty of room, even when installing huge Clarity Caps.

Recently an AK member asked if I would recap his Fives and I said "sure". Only later did I think to ask if he had the pcb version but by then it was too late--I'd committed.

The crossovers arrived in a box along with some new Carli and Surplus caps. Theoretically the wire-wound resistors should be fine but they are all 5w and I've seen burned ones in Model Fives and Twelves (same drivers, bigger box).

So populating the board presented a challenge. Here are shots of the first one. Maybe the second will look a little neater.

The new resistors are all Erse 10w that I had on hand. Mills would have been a bit smaller but they cost 10x what the Erse go for!

I managed to get them all in place but one 15-ohm had to be positioned on top of another resistor. I made a little spacer out of foam board to allow "some" air circulation.

The caps are all attached to the board and in some cases to each other with double-faced foam tape. RTV takes too long to cure and hot-melt glue can damage film caps.

I measured all of the old PVC electrolytics and the new film caps. The new ones were all good but I thought 2.7uF as a replacement for the 3uF was not ideal so I added a 0.22uF that I had on hand. Measured values are in the table below.

The switches were quite oxidized so I sprayed them with De-Oxit. There was some discussion of installing binding posts but I suggested keeping these original and using ring lugs on the speaker wire. Just as well--I think installing binding posts would have been a bit of a chore.

Kent

From High Fidelity March 1980. (Don't be misled by "continued on next page." That's the entire Cizek review. Next page is an AR review).

My first pair of KA-1's (SN 106 & 107) are written up here: http://www.classicsp...7521#entry96948

Those were kind of beat when I bought them and required a lot of detective work (thank you John and Paolo for all the help!). I recently got a second pair (SN 213 & 214), in better shape and discovered a few things:

• They are each stuffed with 9 oz of fiberglass
• The grilles are foam and have a unique design where there is a raised rim on the back that fits into a groove between the speaker cabinet and the front baffle. The grilles are on their last legs and the folks at foamspeakergrilles.com cannot make an exact duplicate, so the new grilles will not have the rim and will instead be held in place with Velcro.
• The mysterious inductor values are still a mystery. I've measured the inductors from one of the new pair so far and L2, L3, L4 and L5 are somewhat different from the values in the schematic that John O'Hanlon drew, based on Paolo's schematic and my measurements. I "suspect" they may have all been the same originally. So far measurements range from about 1.6mH to 2.5mH with DCR about 7.5 to 8.5 ohms.
• Surprisingly, the red and black PVC capacitors--notorious for leakage--were all spot on! But I replaced them with new film caps.

I'll have more information and of course pictures as the project progresses. I'm using Madisound Surplus caps again: Thirteen 10uF caps per speaker, plus three Carli 4.7uF caps. The cost to rebuild both crossovers was about $20! That's 26) 10uF @ 0.50 ea, 6) 4.7uF @ $1.35 ea and four 5 ohm resistors @ 0.42 ea. Can't beat that!

I decided not to refoam the woofers myself but instead sent them to Bill LeGall. He does such a nice job!

The foam diffraction rings will be replaced with felt rings from Madisound.

If this snow ever stops I'll be able to go outside to sand down the Koa wood cabinets.

Interesting note: Friends have commented on how great the first pair of KA-1's sound. They replaced my AR-4x's in the home theater setup. I really love these speakers! One might argue that the crossover design is weird and overly-complex. But they do sound great so apparently Roy knew what he was doing.

Kent

The Twenty Plus is just a Twenty in a nicer package but they seem to go for crazy high prices. Saw a set on ebay today for $350. Needs work but a good buy if you're near Berwick PA: Item number:251239333009

I have no affiliation with this.

Kent

Does anyone have a Cizek logo that I could BORROW? I need one like the one shown in this thread: http://www.classicsp...?showtopic=7728

Figured if there are none for sale maybe I can get my engraver to make a couple of copies for me.

Thanks to anyone willing to help!
Kent