sfogg Posted December 24, 2003 Share Posted December 24, 2003 Rick, I'm still working on an amp for this testing but I might be able to get down to your place at some point to do the measurements for Al? Shawn Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted December 24, 2003 Author Share Posted December 24, 2003 Shawn, I have a design worked out for a little voltage amp (SS) to run the Zo bridge. I just pulled my high voltage lab power supply out of attic to breadboard it but I haven't gotten the lead out of my butt yet to do it! It will not need a transformer at all. It will just be 2 transisters and a 250V power supply (if it works). If you could run the Zo curve using the SD380, that would be super! Al K. Quote Link to comment Share on other sites More sharing options...
sfogg Posted December 24, 2003 Share Posted December 24, 2003 Al, "I have a design worked out for a little voltage amp (SS) to run the Zo bridge." Cool. The tube amp arrived but I haven't had much of a chance to look it over. Really simple inside though as would be expected. I think one cap may need to be replaced then I'll bring it up on a variac then see about getting a high voltage output ahead of the tranny. "If you could run the Zo curve using the SD380, that would be super!" Should be able to but I'm not sure when. Rick lives about 40-50 minutes away from me but near my parents. BTW, not related to the above but I started to do a harmonic distortion test of an amp but I ran into a problem. I was getting odd order harmonics with my function generator plugged straight into the SD-380. I need to figure out if they are from my generator or in the SD-380 itself. I think I'm going to feed the SD-380 a 500hz signal through the low pass of an ES-600 and feed that into the SD-380. If I still see the harmonics the problem is the SD-380, if not it is my generator. Or I suppose I could just plug the generator into my 1/24 octave RTA to see if the harmonics are there. If it is in my function generator I have the service book for it and it does has a section on adjusting its amplifier stage bias to reduce harmonics so hopefully that is all that needs to be done. Shawn Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted December 25, 2003 Author Share Posted December 25, 2003 Shawn, I breadboarded the voltage amp earlier today. Even as I did it I realized that it wasn't going to generate enough voltage into even a load as high as 1600 Ohms without an additional output stage, and sure enough it didn't! I would have had to add a complementary symmetry transistor pair to the output. I didn't have a pair in the "junk box" that would operate from a 250V source, so I decided not to bother with it. Sorry! If the signal generator you are speaking of is truly a "function generator", they seldom have good clean sine wave output. They literally "carve" a sine wave out of a triangle wave. It's only an approximation. A lowpass filter should clean it up though. The low output of the ES600 should clean it up. I do the same thing here to my HP200CD generator. It's a Wien bridge oscillator. They are a lot cleaner than a function generator. I have a 5th order lowpass that cuts off at about 1400 Hz. It makes output clean down below the 70 dB limit of the SD375. Al K. Quote Link to comment Share on other sites More sharing options...
sfogg Posted December 25, 2003 Share Posted December 25, 2003 Al, "If the signal generator you are speaking of is truly a "function generator", they seldom have good clean sine wave output. " Yes, it is function generator. For its sine wave outputs from 0.1hz to 50kHz it is rated to have harmonics no higher then -65dB. What I was seeing was about -10dB below the fundamental. So if that was coming from the the generator then I'll have to check its amps bias. Shawn Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted December 25, 2003 Author Share Posted December 25, 2003 Shawn, Harmonics of only 10 dB down represent extreme distortion. You would be able to visually see it on an oscilloscope! Al K. Quote Link to comment Share on other sites More sharing options...
sfogg Posted December 25, 2003 Share Posted December 25, 2003 Al, The sine waves looked very clean on the scope. That is why I'm not sure if the harmonics are coming from the generator or of the SD380 may have something screwy with its input circuitry. Shawn Quote Link to comment Share on other sites More sharing options...
3dzapper Posted December 25, 2003 Share Posted December 25, 2003 Just let me know when Shawn. I'm availiable most days and evenings. Just a club meeting or archery league here and there. Plus archery practice most days but I can be flexible with that. I have a State Championship to defend this spring. Rick Quote Link to comment Share on other sites More sharing options...
Tizman Posted December 18, 2018 Share Posted December 18, 2018 My apologies for attempting to bring this very old thread back to life, but I have a question with regard to using the crossover contained in this thread with a 16 Ohm driver on the 511B instead of an 8 Ohm one. My understanding is that the swamping resistor across the terminals of the 3619 transformer should minimize any issues related to doing so. This is based upon my readings of Al's posts in various forums. Is this correct? Would it be prudent to connect to different terminals on the 3619, or use a different resistor? Once again, my apologies..... Quote Link to comment Share on other sites More sharing options...
baron167 Posted December 18, 2018 Share Posted December 18, 2018 My apologies for attempting to bring this very old thread back to life, but I have a question with regard to using the crossover contained in this thread with a 16 Ohm driver on the 511B instead of an 8 Ohm one. My understanding is that the swamping resistor across the terminals of the 3619 transformer should minimize any issues related to doing so. This is based upon my readings of Al's posts in various forums. Is this correct? Would it be prudent to connect to different terminals on the 3619, or use a different resistor? Once again, my apologies..... Friendly suggestion to go to ALK's website and email him directly. I do not think he comes to this forum very often if at all these days. He has been responsive to me via email. That being said, I'm sure some of the other members here will be chiming I'm in efforts to answer your question(s).Sent from my iPhone using Tapatalk 1 Quote Link to comment Share on other sites More sharing options...
Deang Posted December 19, 2018 Share Posted December 19, 2018 12 hours ago, baron167 said: ... I'm sure some of the other members here will be chiming in efforts to answer your question(s). I wouldn’t count on it. He does not come here to answer questions about his products. When someone else tries and fails - he drags them publicly through the mud. 1 Quote Link to comment Share on other sites More sharing options...
mark1101 Posted December 19, 2018 Share Posted December 19, 2018 Email Al and he will help you. I have used his ESNs for years and in the right applications they are excellent. My comments are that sure you can use the terminals on the auto transformer to give you whatever attenuation you need in 1 db steps. The swamping resistor for the squawker (there is one for squawker and one for tweeter) is usually 9 ohms and that will work nicely for 8-16 ohm mid drivers and swamp the mid circuit down to the impedance of the woofer circuit which is the goal of the design. You really don't need to change it.......if you do the math of your 8-16 ohm driver impedance in parallel with 9 ohms you get something in the 4-6 ohm range which is correct for the design. Edit: Comments based on a single K33 woofer ESN design. There are other ALK designs involving dual K33, dual K31, etc. These designs use different circuits and different value swamping resistors. Quote Link to comment Share on other sites More sharing options...
jwc Posted December 19, 2018 Share Posted December 19, 2018 8 minutes ago, mark1101 said: Email Al and he will help you. Agreed. Quote Link to comment Share on other sites More sharing options...
jwc Posted December 19, 2018 Share Posted December 19, 2018 14 hours ago, Tizman said: My understanding is that the swamping resistor across the terminals of the 3619 transformer should minimize any issues related to doing so. That is typically so. I've done it many times with 16 and 8 ohm drivers. Some of the swamping resistors were 10 ohm 1 Quote Link to comment Share on other sites More sharing options...
mark1101 Posted December 19, 2018 Share Posted December 19, 2018 If you read the "white paper" on ALK's website concerning the swamping resistor it explains the reasoning. It eliminates the giant impedance swings associated with using the different taps on the auto transformer, and it facilitates the constant impedance design. So..........what are you thinking about doing? Right now I happen to be listening to my 3-way Jubs that use ALK's latest ESN 500 designed for those. Just a Benchmark DAC-3, C-220 preamp and MC-402 amp pushing on them some. An example of one of the applications I found to work very well. Quote Link to comment Share on other sites More sharing options...
baron167 Posted December 19, 2018 Share Posted December 19, 2018 I wouldn’t count on it. He does not come here to answer questions about his products. When someone else tries and fails - he drags them publicly through the mud. You misunderstood my message. I said to email him directly. And if someone attempts an answer beyond their skill set and fail, I don't blame him.Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
jwc Posted December 19, 2018 Share Posted December 19, 2018 44 minutes ago, mark1101 said: Right now I happen to be listening to my 3-way Jubs that use ALK's latest ESN 500 designed for those. Just a Benchmark DAC-3, C-220 preamp and MC-402 amp pushing on them some. An example of one of the applications I found to work very well. Damn right Quote Link to comment Share on other sites More sharing options...
Tizman Posted December 19, 2018 Share Posted December 19, 2018 mark1101: "So..........what are you thinking about doing?" I have a pair of FH1 with Eminence 15C in them that I would like to combine with a pair of 511B Horns with Renkus Heinz SSD1800 drivers, using the crossover shown in this thread. The Renkus Heinz SSD1800 are 16 Ohm drivers instead of the 8 Ohm shown in the schematic in this thread. My understanding is that other than the impedance mismatch, the RH drivers are a good substitute for the Altecs shown in the crossover in this thread. I have read the Al K white paper on the swamping resistor, and it seems that this resistor will allow for a 16 Ohm driver to be used instead of a 8 Ohm without any other changes to the schematic. Also, It would seem that the swamping resistor will allow me to also change taps on the T2A without any other changes. I know very little about crossovers, and was hoping for confirmation of my understanding of the white paper from folks who understand this subject better than me. Thanks to everyone who has responded to my question! Quote Link to comment Share on other sites More sharing options...
mark1101 Posted December 19, 2018 Share Posted December 19, 2018 I believe you are correct that you would not need to make any changes to accommodate the RH drivers. However, the ALK network designs are based on the woofer specs. I would take a look at those in relation to a K33. Quote Link to comment Share on other sites More sharing options...
Tizman Posted December 20, 2018 Share Posted December 20, 2018 Mark1101: My understanding is that the 15C extends higher in frequency more cleanly than a K33, but that swapping a 15C for a K33 in a La Scala bass bin requires no other changes. Quote Link to comment Share on other sites More sharing options...
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