Al K., could you look at this please? K-500-5000

[Tom Mobley]

Al,

I built your Al K networks for my DIY LaScalas and was (and am) very pleased with them.

Now I've acquired this 1959-1960 pair of Klipschorns, these have the Jensen woofer, K-55-V on the older wooden sectoral mid horn and the usual EV T-35 tweeters. The stock Klipsch network is labeled K-500-5000, leading me to think it crosses at 500 and 5000. Looks like the woofer is 4 ohms, the 55 is a 16 ohm unit, and the t-35 is a 8 ohm deal. Fairly standard stuff. I guess the wood/fibreglas sectoral mid horn won't make it down to 400.

Would you be willing to suggest values for a network similar to your existing ones but with 500/5000 crossover points? Or, possibly more simplistic, values of inductor and cap for a Type A unit with only inductor, tranny and cap? I'd be willing to buy another set of the autoformers from UT. I want to keep the original networks 100%, use no parts from them.

Thanks for whatever you can do, nad anybody else feel free to jump in too.

Tom

[Al Klappenberger]

Tom,

I would use my network design just as it is. The squawker horn in it has a better chance of going down to 400 than the woofer going up to 500! As to 5000 versus 6000 Hz cross, listen for a problem in that area or us instruments to verify that there really is a problem before you decide what to do.

Al K.

[Tom Mobley]

Thanks, Al. I've accumulated a tone generator so I can use that and the RS dB meter to get a rough idea.

Tom

still thinking about how simple that type A is, one inductor, one T23 and one cap. I could afford to buy the Hovland in that situation. I may do it yet.

Tom

[Tom Mobley]

Al, is it your opinion that your network with the extra parts is good for something like a 2A3 SET amp? I understand it presents a more benign load characteristic to the amp. This is a real advantage when dealing with low powered SET, right?

I might build another set of your crossovers for just the eventuality that I build a SET DIY deal. No low cost option this time, I'll up for the Hovlands.

Tom

[Tom Mobley]

Maybe my memory fails me? I see two caps, 13uf and 2uf on the Klipsch schematic, but remember seeing only one on the crossover Guy built. I'll have to go back and search some.

Tom

{EDIT}: I found a pic of Guys crossover and can see now that I was lost in space, it does have the two caps.

[Al Klappenberger]

Tom,

SET amps are the bare minimum. They need all the help they can get and a stable resistive load is best for them. With no negative feedback, their source impedance goes up making them more sensitive to load variations.

If you are thinking of the "A" network, you thinking of a simple 6 dB / octave design. If that's the case, build a constant impedance 6 dB / octave network instead. It only takes a couple more parts. The schematic has been posted several times by John Albright. Simplicity is only good if it's right. The "A" cuts too many corners.

Al K.