Marvel Posted May 21, 2014 Share Posted May 21, 2014 I believe some of the older JBL crossovers were potted as well It certainly keeps a person from pulling them apart and modifying them. Bruce 1 Quote Link to comment Share on other sites More sharing options...
cradeldorf Posted May 22, 2014 Share Posted May 22, 2014 I think one of the problems with this discussion is the fact that you guys are comparing oranges to apples. If I'm correct Dean already laid out the information somewhere around here that an autoformer is akin to a attenuation resistor, where as you guys keep turning it into an inductor like the one used to stop the LF from going too high in a crossover. I don't think they are on the same level. Of course that's Just my .02 and I could be all wrong. Quote Link to comment Share on other sites More sharing options...
Thaddeus Smith Posted March 11, 2015 Share Posted March 11, 2015 here's a fun little tid bit - I just learned that Universal Transformer Co. is 7.9 miles from my house. I might have to see if I can get a tour ... Quote Link to comment Share on other sites More sharing options...
Deang Posted March 12, 2015 Author Share Posted March 12, 2015 I could see EV potting stuff so it didn't break when a speaker was dropped / thrown around by touring guys. No, the networks I'm thinking of were for the Georgian and/or Patrician. Quote Link to comment Share on other sites More sharing options...
Deang Posted March 12, 2015 Author Share Posted March 12, 2015 here's a fun little tid bit - I just learned that Universal Transformer Co. is 7.9 miles from my house. I might have to see if I can get a tour ... Just don't mention my name! Quote Link to comment Share on other sites More sharing options...
Deang Posted March 12, 2015 Author Share Posted March 12, 2015 Well, since this thread is back up: I sent units to both Bob and John Warren for tests. Below is the email I received from Bob after the tests. ----------------------------------------- OK Dean, Here are the results. First test is 1Volt 0 to 25khz. First trace at the top is directly from the source. Each additional trace going down is output in 1 db steps. Second test is 0 to 20khz swept at 31 volts RMS input (top trace) and output attenuated 3 db. That input is about 120 watts for an output of 60 watts. Transformer did not get above room temperature during the test. My power resistor about cooked my workbench. The high frequency roll off you see in the high power test above 22.5khz is the amp. Notice that you see it in both the input and output. I was going to do a precise measurement with 1khz input and measure exactly the db attenuation for each step, but I am happy enough with the traces that I no longer think that test is necessary. Anyway, frequency response is very nice even at crazy power levels. Nothing in what I looked at looked different from my 3636 as far as frequency response and accuracy of attenuation goes. I would not have expected any difference there because UT certainly know hows to count turns ratios. Now that high power test may be significant. I would be afraid to put that much power into a 3636 because somewhere I have in the back of my mind that they are only good for about 100 watts. That monster you had them make seems like perhaps 200 watts might not bother it at all. Anyway, I can’t see a reason in the applications where we use the autotransformers where the larger one has an advantage since power is not a problem there. I guess the next test might be for you to build a pair of type A using a 3670 in one and a 3619ET in the other to see if there is any audible difference. DCR of 3670 is 0.282. DCR of 3636 is 0.326. ------------------------------------------------------------- Quote Link to comment Share on other sites More sharing options...
Deang Posted March 25, 2015 Author Share Posted March 25, 2015 (edited) Well, it's here! Introducing the new 2.54mH coil, designated the 2564. The box showed up yesterday, which had just the first four for my inspection. After handling one and measuring it, I immediately called them back and asked them to wind another 20. I love these guys in part because they're as excited about these new parts as I am.The 2564 is just like the original, but with larger wire, a larger core, and a DCR number that rides about as close to the basement as you can get. Mark Cooper said it took several tries to get something that they were finally happy with. Like the UT 3670, it eschews varnish in favor of wax.Now everyone is free to debate this until the cows come home, but based on what UT told me, I believe Paul Klipsch would have really liked these parts, as they pretty much incorporate everything he asked for. As I stated earlier in the thread, he opted for lesser units because of cost considerations.What certainly needs to be pointed out here is the obvious: as far as the UT 3670 is concerned, it never would have came to be, at least in its present form, without Al and Bob, who really brought the original T2A to new levels of performance, both in measurements and features.The 3670 is a 3619-ET on steroids -- providing an overall reduction in resistance, all air between the windings displaced with wax -- and whatever additional degree of stability/solidity it provides.All of my builds from this point forward will be using these two parts to the exclusion of the others. Pics to follow shortly. Edited March 26, 2015 by Crankysoldermeister Quote Link to comment Share on other sites More sharing options...
Deang Posted March 25, 2015 Author Share Posted March 25, 2015 (edited) One could be critical of the increased size and say there no advantage. In terms of inductance, they would be right. There is a slightly improved resistance spec, and though some might believe I'm overstating the benefits of the wax, please keep in mind that I didn't know of any "benefits" until the people that build this stuff for living told me about them. Paul Klipsch could have specified varnish, but he didn't. Why not? If you're thinking cost, that isn't it, because cost is the same either way. Edited March 26, 2015 by Crankysoldermeister Quote Link to comment Share on other sites More sharing options...
Deang Posted March 25, 2015 Author Share Posted March 25, 2015 (edited) You guys are awesome, thanks for fixing that. My iPhone posts them in the correct orientation everywhere except here. Edited March 26, 2015 by Crankysoldermeister Quote Link to comment Share on other sites More sharing options...
Deang Posted March 25, 2015 Author Share Posted March 25, 2015 I have no idea why those pics are sideways! Quote Link to comment Share on other sites More sharing options...
Thaddeus Smith Posted March 25, 2015 Share Posted March 25, 2015 hittin' the sauce a bit early today? I'm excited to test drive these components. Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted March 26, 2015 Share Posted March 26, 2015 . Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted March 26, 2015 Share Posted March 26, 2015 Dean said: "For scale, you can use the pictures on the first page." New versus Old autoformer size. Quote Link to comment Share on other sites More sharing options...
Frzninvt Posted March 26, 2015 Share Posted March 26, 2015 Nice! Quote Link to comment Share on other sites More sharing options...
seti Posted March 26, 2015 Share Posted March 26, 2015 (edited) This is really interesting. Good research. A+ I am a fan of Slagle's work at intact audio. He baths his transformers in wax. Edited March 26, 2015 by seti Quote Link to comment Share on other sites More sharing options...
Schu Posted March 26, 2015 Share Posted March 26, 2015 in for more wax Quote Link to comment Share on other sites More sharing options...
Thaddeus Smith Posted March 26, 2015 Share Posted March 26, 2015 I should have mine by the end of next week Quote Link to comment Share on other sites More sharing options...
Thaddeus Smith Posted March 26, 2015 Share Posted March 26, 2015 also, this... Looks like I squeezed in right on time. Quote Link to comment Share on other sites More sharing options...
Schu Posted March 26, 2015 Share Posted March 26, 2015 much sadness is felt right now... WTF are they thinking, those things were so successful and so delicious. Quote Link to comment Share on other sites More sharing options...
Thaddeus Smith Posted March 26, 2015 Share Posted March 26, 2015 And so labor intensive and not exactly selling in Apple volume. Quote Link to comment Share on other sites More sharing options...
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