mojomc Posted May 28, 2020 Share Posted May 28, 2020 Good day! I recently purchased an ALK Universal XO built by DeanG off of the garage sale. I've always been interested in trying some out and when they came up for sale I figured, why not. They were installed in my '77 LSI's in the early AM this morning. After 6 hours of listening so far we all agree (myself, wife and kids) that we much prefer the original recapped AA's. What we're hearing is instruments are being pushed WAY back, especially guitar riffs when singing is involved. I'm not sure that I would call it anemic but definitely not what I expected. I've rechecked all connections and everything is right and tight and positive and negatives leads are correct. Favorite music that's been played today includes AC/DC, Joe Bonamassa, Dusty Springfield, Etta James, Jeff Healey, Samantha Fish, King Crimson, you get the idea. I'm using the same setup that has changed very little since I inherited the LSI's back in 2016 and includes a dual mono SET amp from forum member Maynard, tubefanatic, being fed by a SONOS ZP90 running through a Schiit multibit DAC so differences in are readily apparent. The tap being as used is tap #6. I'm wondering if anyone with any experience with these XO's has any helpful advice or if this is an expected difference between the AA and ALK Universal? Thanks for any and all replies! Brent Quote Link to comment Share on other sites More sharing options...
jimjimbo Posted May 28, 2020 Share Posted May 28, 2020 What caps are in the pair of AA? Quote Link to comment Share on other sites More sharing options...
mojomc Posted May 28, 2020 Author Share Posted May 28, 2020 The standard Bob Crites specials, sonicaps. Nothing boutique at all compared to the ALKs using claritycap and mundorf supremes. Quote Link to comment Share on other sites More sharing options...
jimjimbo Posted May 28, 2020 Share Posted May 28, 2020 @Deang Quote Link to comment Share on other sites More sharing options...
OO1 Posted May 28, 2020 Share Posted May 28, 2020 1 hour ago, mojomc said: Good day! I recently purchased an ALK Universal XO built by DeanG off of the garage sale. was that the xo that was sold a week ago for 425$ Quote Link to comment Share on other sites More sharing options...
mojomc Posted May 28, 2020 Author Share Posted May 28, 2020 Indeed it was Quote Link to comment Share on other sites More sharing options...
OO1 Posted May 28, 2020 Share Posted May 28, 2020 1 hour ago, mojomc said: I recently purchased an ALK Universal XO built by DeanG -you may want to raise the taps by 3db until you find a sweet spot , the taps are unsoldered on both ends Quote Link to comment Share on other sites More sharing options...
mojomc Posted May 28, 2020 Author Share Posted May 28, 2020 So there is no change to capacitor values when changing transformer taps? Quote Link to comment Share on other sites More sharing options...
OO1 Posted May 28, 2020 Share Posted May 28, 2020 12 minutes ago, mojomc said: So there is no change to capacitor values when changing transformer taps? here are the specs on the ALK -web site page --------the squawker and tweeter can be adjusted A specially designed autotransformer having low DC resistance (0.382 Ohms) and tight coupling provides taps to allow squawker level setting changes by the customer. The choices will be 1 to 18 dB in 1 dB steps, Attenuation is selected without soldering by push-on terminals and without cryptic setting tables. The attenuation settings are clearly written by each tap in dB units. The normal setting will be 6 dB. This adjustment will also allow the use of 8 or 16 Ohm squawker drivers without modification. NOTE: Any transformer that is larger in size is a waste of money. It will handle 50 Watts of power without batting and eyelash with virtually no loss, That is already extravagant considering the power levels through the midrange in a Klipsch loudspeaker will generally be less than ONE Watt! A stable 2, 4, 6 or 8 dB plug-selected L-pad is included to adjust the tweeter level. Quote Link to comment Share on other sites More sharing options...
mojomc Posted May 28, 2020 Author Share Posted May 28, 2020 I'll give it a try this evening as time allows. There is no l-pad on this build. Quote Link to comment Share on other sites More sharing options...
mojomc Posted May 28, 2020 Author Share Posted May 28, 2020 I'll admit I'm very outclassed by the knowledge on this forum and perhaps I jumped further out of my depth than I intended. I've learned much from perusing this forum and I'm thankful for both the goofiness and the typically thoughtful sharing! Quote Link to comment Share on other sites More sharing options...
Deang Posted May 28, 2020 Share Posted May 28, 2020 Hey, I don't design them, I just build them. Even after doing this for 15 years, it's very hard to predict what someone is going to prefer. I tried the Universal several times and always went back to the Type AA. Right, no adjustable l-pad for the tweeter. Most run the stock the tweeter or the B&C de-120, so you don't really need it. The swamping resistor allows for adjustments without requiring the need to change the value of the primary capacitor. On the autotransformer, there are three input taps. Make sure the wire is attached to the tap labeled '0'. Then use output tap labeled '3'. Report back. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted May 28, 2020 Share Posted May 28, 2020 17 minutes ago, mojomc said: I'll give it a try this evening as time allows. There is no l-pad on this build. Then all you can adjust is the mids. From your description they need to be a little hotter. Quote Link to comment Share on other sites More sharing options...
mojomc Posted May 28, 2020 Author Share Posted May 28, 2020 Will do. I'll start with tap 0 and make my way up. We learn by doing and this dark magic of XOs is indeed mystifying. 🤪 Quote Link to comment Share on other sites More sharing options...
babadono Posted May 28, 2020 Share Posted May 28, 2020 I was waiting for DeanG to reply but I agree with cecaa850 from your description it sounds like the mids are attenuated too much. @Deang what autoformer is on that baby? Got a schematic or chart of all the tap adjustments for @mojomc? Or do you have them already mojomc? Quote Link to comment Share on other sites More sharing options...
Budman Posted May 28, 2020 Share Posted May 28, 2020 - Quote Link to comment Share on other sites More sharing options...
mojomc Posted May 28, 2020 Author Share Posted May 28, 2020 I do not have a chart or anything. The transformer is the same as in the pic provided by Budman. I didn't pay attention to both side of the transformer but I seem to recall a 3, 6, 9, and 12 on one side with 6 currently being used. I neglected to note what was used on the opposite side. Quote Link to comment Share on other sites More sharing options...
mojomc Posted May 28, 2020 Author Share Posted May 28, 2020 From reading an older post by DeanG, related to the 3619-ET, to calculate the level of attenuation I would subtract the input tap setting from the output tap setting. Output tap setting - input tap setting = Attenuation At this time I do not know what input tap is being used but this is information easily gathered by uninstalling a network and taking a look. I'll report back when I have a chance to do this. If any of the above is incorrect let me know. Quote Link to comment Share on other sites More sharing options...
Deang Posted May 28, 2020 Share Posted May 28, 2020 The networks used to belong to Budman -- he was the original owner. Move the wire that's on 6, and put it on 3. This will be close to the stock setting. If you want 5db of attenuation, leave it on 6 and move the input wire to -1 (because 6 -1 = 5). If you want 4dB of attenuation, leave it on 6 and move the input wire to -2 (because 6 -2 = 4). The other choices are for those who use more sensitive drivers than the K-55. So, for example, if you wanted 7dB of attenuation, you would have to use input tap -2 and output tap 9 (because 9 -2 =7). So on and so forth ... Quote Link to comment Share on other sites More sharing options...
Deang Posted May 28, 2020 Share Posted May 28, 2020 I'm sure it's on -0, which is where you should leave it. If not, move it back! Dean Quote Link to comment Share on other sites More sharing options...
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