Daddy Dee Posted March 11, 2013 Share Posted March 11, 2013 This crossover was shared with the forum by John Albright and is used by some forum members, including Marvel, who reports pleasing results with LaScalas and SET amps. Here's the schematic, below. I've looked through the forum archives for a pic, but have not been able to locate one. Does anyone have a pic of this crossover they might post? Any take on the crossover and compare and contrast with others would be appreciated. Thanks. 1 Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted March 11, 2013 Author Share Posted March 11, 2013 One thing, does anyone know if the Solen L140.2 Litz 14ga inductor is still made? I haven't been able to locate this part. Should offer the disclaimer that I don't know electronics worth anything and may not be searching appropriately. Quote Link to comment Share on other sites More sharing options...
Marvel Posted March 11, 2013 Share Posted March 11, 2013 Mine are ugly... [] The ones I built left off the lamp and 65 watt resistor for the tweeter protection, since I was using Bob's CT125 tweeters. A couple other changes were made as well. Here's the scematic I used. I'll find a pic somewhere. Bruce Quote Link to comment Share on other sites More sharing options...
Marvel Posted March 11, 2013 Share Posted March 11, 2013 Solen in Canada still has the .2mH 14ga. Litz inductor. I think there is someone in the US that carries these. PartsConnexion in Canada has them, and will ship here. http://www.partsconnexion.com/inductor_solen14.html Bruce Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted March 11, 2013 Author Share Posted March 11, 2013 Thank you Bruce. Interesting. ------------------ Quote Link to comment Share on other sites More sharing options...
tigerwoodKhorns Posted March 11, 2013 Share Posted March 11, 2013 Is there a way to add tweeter attenuation to these? Maybe an L Pad? Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted March 11, 2013 Author Share Posted March 11, 2013 I don't know why an Lpad wouldn't work. Of course, should offer the disclaimer that I don't know much of anything about electronics. Have read some posts on this forum about some downside to Lpads that I couldn't begin to articulate. Back in the day, was doing some experimentation with tweeters on Khorns and found the Beyma cp25 (i think) to be too hot relative to the other drivers. Ran across Al Klappenberger's tweeter attenuators. These are cute little guys that use jumpers to adjust attenuation. They worked really well. http://www.alkeng.com/pad.html Quote Link to comment Share on other sites More sharing options...
seti Posted March 11, 2013 Share Posted March 11, 2013 Is there a way to add tweeter attenuation to these? Maybe an L Pad? Autoformer may be a better route. I've used some from Klipsch and some from ALK. Quote Link to comment Share on other sites More sharing options...
babadono Posted March 11, 2013 Share Posted March 11, 2013 FYI -- Al's pricier tweeter attenuator is autoformer based. Works marvelously IMHO. but babadono Quote Link to comment Share on other sites More sharing options...
Deang Posted March 11, 2013 Share Posted March 11, 2013 The autobulb has some resistance, so it's "a resistor". With the 65 ohm resistor, it acts as an L-pad. I believe it knocks a little over a dB off of the tweeter's output. The bulb doubles as tweeter protection. Faster than a polyswitch if I'm remembering right. After I built about a half dozen pair of these things I got it in my head to just use zeners and to forget about the L-pad. This is the only pair I built with zeners. After I did it, I realized I might have made a mistake. It's a first order tweeter filter and there's quite a bit of energy being sent to that driver. I was concerned that they might start activating too soon, cutting the tweeter's output when they shouldn't be. The customer never complained, and it's been over five years. By then I was building the Super AA, and only got one request (two if you count Bruce) for a pair of these. I got the idea to just built a first order Super AA and called it the Super A -- and built it so the attenuation could be adjusted. I also cheated and changed the 3.3uF to a 2.2uF to reduce a little of the tweeter energy. That was Bobby Crite's idea. I didn't want to use the bulb, zeners, or an L-pad. I'd thought about using another autoformer, but decided that was crazy expensive just to shave a dB or two off. So I called Bob for his thoughts. He said that since I'd already ruined the crossover by using a resistor, might as well go all the way and use the wrong cap. Seriously though, it was a good call -- sounded great. 1 Quote Link to comment Share on other sites More sharing options...
Marvel Posted March 12, 2013 Share Posted March 12, 2013 The autobulb has some resistance, so it's "a resistor". With the 65 ohm resistor, it acts as an L-pad. Almost zip when cold. As too much current flows through the bulb and it heats up (lights up), the resistance goes up and it does its magic with the other resistor.Very nice pic. I wish mine looked as good. Maybe I'll have to redo them. Bruce Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted March 12, 2013 Author Share Posted March 12, 2013 neat work, as always, Dean. Quote Link to comment Share on other sites More sharing options...
djk Posted March 13, 2013 Share Posted March 13, 2013 The #561 or #211-2 automotive lamp has a cold resistance of about 0.5Ω, it will pass transients of 10mS or so (typical musical program material) without heating up. Quote Link to comment Share on other sites More sharing options...
erik2A3 Posted March 15, 2013 Share Posted March 15, 2013 Dee: also regarding the choke -- if you can't find the size you want, you can order slightly higher and unwind a bit til you get what's needed. You need a meter that measures L (inductance), though. That's what I did when winding my own inductors. Edit: or send to me and I'll unwind to the exact value needed and get it to you Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted March 15, 2013 Author Share Posted March 15, 2013 Erik, thanks. That is a really kind offer. So far the project is way out on the horizon. Good to know of the option. Is this a great forum or what! Quote Link to comment Share on other sites More sharing options...
Frzninvt Posted March 25, 2013 Share Posted March 25, 2013 Dean, that is the network you built for my LA Scala center channel speaker. It replaced the other gorgeous one you built with the Jensen PIO caps because I wanted something a little hotter. Still kicking to this day. Have the K-77M, dual phase plug solder terminal K-55V, and the K-33 in it. Quote Link to comment Share on other sites More sharing options...
Deang Posted March 25, 2013 Share Posted March 25, 2013 lol, always wondered why I only had a picture of one of those. I did remember that I built for you, and that's doing pretty good for me these days. Yeah, the half deaf guys need something that knocks the wax out of their ears. Quote Link to comment Share on other sites More sharing options...
moray james Posted July 25, 2014 Share Posted July 25, 2014 This crossover was shared with the forum by John Albright and is used by some forum members, including Marvel, who reports pleasing results with LaScalas and SET amps. Here's the schematic, below. I've looked through the forum archives for a pic, but have not been able to locate one. Does anyone have a pic of this crossover they might post? Any take on the crossover and compare and contrast with others would be appreciated. Thanks. am I right to assume that the DH2A was used for the mid horn? I would imagine that an EV DH1506 or a DH1506HP would also work in this configuration. Thanks for posting this. Best regards Moray James. Quote Link to comment Share on other sites More sharing options...
Marvel Posted July 25, 2014 Share Posted July 25, 2014 DHA2 was the second iteration of John's crossover design, named after his brother Don H. Albright, if I remember correctly. Mine is a version 2, hence the DHA2. I used them with K55 mids and Bob's CT125 tweeters. Bruce Quote Link to comment Share on other sites More sharing options...
moray james Posted July 26, 2014 Share Posted July 26, 2014 oops sorry for my error ands thanks for the correction Bruce. Best regards Moray James. Quote Link to comment Share on other sites More sharing options...
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