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La scala Build ( Done)


kg4guy

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That is really coming along nicely!

I found a box I had forgotten I had, and what would I find inside but an additional two autoformers and single woofer choke. Someone very kindly gave me an original Heresy I network (very good condition) for the center channel project, and I decided to build a couple of type 'A' networks to match the Heresy high frequency crossover point. All three front speakers now use the same tweeter and midrange horn, although the Heresy is obviously smaller than the K-horns.

I'm going to take out my other 4kHz/non-autoformer networks to play around with the 6,000 crossover point. When I can get the parts I need to do a 4K crossover with the Heresy, I'll switch back.

I have enough parts to make another pair of 'A's that I can send you to play around with when your La Scalas are done. Here's what I put together yesterday for the Klipschorns. I've always liked the sound of combining different cap types, and frequently parallel them for the needed values -- just like small value plastic film types are often used to bypass electrolytics. The tweeter section on these is also connected directly to the input, with a minor change in capacitance value (close enough to what I needed) to keep the roughly 6,000 cutoff for this first order circuit.

post-10533-1381939362762_thumb.jpg

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That is really coming along nicely!

I found a box I had forgotten I had, and what would I find inside but an additional two autoformers and single woofer choke.  Someone very kindly gave me an original Heresy I network (very good condition) for the center channel project, and I decided to build a couple of type 'A' networks to match the Heresy high frequency crossover point.  All three front speakers now use the same tweeter and midrange horn, although the Heresy is obviously smaller than the K-horns.

I'm going to take out my other 4kHz/non-autoformer networks to play around with the 6,000 crossover point.  When I can get the parts I need to do a 4K crossover with the Heresy, I'll switch back.

I have enough parts to make another pair of 'A's that I can send you to play around with when your La Scalas are done.  Here's what I put together yesterday for the Klipschorns.  I've always liked the sound of combining different cap types, and frequently parallel them for the needed values -- just like small value plastic film types are often used to bypass electrolytics.  The tweeter section on these is also connected directly to the input, with a minor change in capacitance value (close enough to what I needed) to keep the roughly 6,000 cutoff for this first order circuit.

 

Thanks Erik I will have them done tomorrow and will post photos I am also get the Heresy kit speakers tomorrow its going to be a fun day.
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Man .. I didn't know you were hand building them .. I thought you already had cabinets you were refurbishing..... had I known I would have commissioned a second set .... bass bins only

If you still have the shop space ... and time and ... and ... and...... (ha) send me a PM and let me know how much $$ to rip and build a set of bass bins ... I will bring 4x8 sheets of 13 ply Baltic birch to SB.

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Eric, I like the layout of your boards, the look like they would actually fit a LS bin and you'd be able to connect to all the barrier strip terminals. I bought a pair of AA networks that I have to leave loose in my LS because the layout does not accomodate the horn throat. arrrggghh

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Hi, Michael:

Thanks. I had been looking around for some of the motor capacitors I've liked so much, and was able to find 3uf locally for cheap. A longer, narrower board helps with these larger capacitors. Since they don't have leads of their own, a little more point-to-point wiring is necessary. I also think the original Klipsch ground buss works extremely well, and is simple. It's very much the way a common ground is done in tube amps, although I know that some don't care for it. What is good is that it's one solid piece of wire that does not rely on extra connections and crimps of smaller pieces of wire. Each to his or her own there, I guess.

To see if something like what is shown might work for you, you could cut a piece of paper to 6" X 10" to see how it fits in the bin with the barrier strip at the back.

It's sometimes been discussed in the past how the type 'A' seemed to have a slightly higher tweeter output or a little 'brighter' sound than the AA, and I think part of that may be due to a possible mild reduction of series resistance in the 'A' HF branch. The tweeter filter in the AA is also of higher order. In the network shown, I chose to wire the tweeter completely separately from the squawker section, meaning it's connected directly to the input rather than after the 13uf capacitor (that's one extra element that might impose some additional series resistance in the circuit). So, in using the 6k cutoff for a first-order circuit with an 8ohm driver, I needed about 3.3uf for the tweeter filter. I remembered I had some .33uf Solen coupling caps, found them, and replaced the .47 mylars shown in the first picture. The 10uf in parallel with the other 3uf motor run is a Sprague polypropylene.

Someone asked me to post a picture of a type 'A' network, and until the other day I didn't have one.

Erik

post-10533-1381939363589_thumb.jpg

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