Erik Mandaville Posted October 23, 2005 Share Posted October 23, 2005 This probably isn't of much interest to some, but I bring it up mainly because some time ago Craig and I were both wondering about the input and phase splitter on this thing (re: Born2's Baldwin). I hadn't really examined the wiring, but Will (the tech/pro metal worker who modified it) and I talked on the phone yesterday, and hung up both wondering about the single 12AX7. I started to wonder if the amp might in fact be a parallel single-ended design, but it's not. The phase inverter is a 'differential' type, which uses a single tube for both input and phase inversion -- very common on many musical instrument amplifiers. I studied the connections, and found some very good on-line examples of this type of inverter Just a small bit-o-info. Erik Quote Link to comment Share on other sites More sharing options...
Painful Reality Posted October 23, 2005 Share Posted October 23, 2005 This probably isn't of much interest to some, (and boy would I understand this). The phase inverter on the HF-81 is a cathodyne type, which uses a single tube for phase inversion -- very common on push pull amplifiers. I studied the connections, and found some very good on-line examples of this type of inverter. Just wanted to share this. BTW, when I built my Ariels, a DIY enclosure design by Lynn Olson, I used a simple first order crossover on the tweeter, letting the mid-bass driver running full range. Happy happy joy joy. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted October 23, 2005 Share Posted October 23, 2005 I rest my case. Quote Link to comment Share on other sites More sharing options...
Guy Landau Posted October 23, 2005 Share Posted October 23, 2005 Jeff, Have you got the schematic for that crossover?[] Quote Link to comment Share on other sites More sharing options...
Painful Reality Posted October 23, 2005 Share Posted October 23, 2005 Guy, I'm so happy you asked. I'm not really good with posting schematics. But I'll gladly say that the crossover was made of a 16 ohms resistor across the binding posts. It was difficult to solder because the binding posts were massive so I had to use a small blow torch I bought at the local Radio Shack. The capacitor, in serie with the signal, was a 2 uF Hovland. Anything else you want to know? Please don't use email for your requests as I'm not sure yet that all people here knows I'm building my own stuff. Quote Link to comment Share on other sites More sharing options...
Parrot Posted October 23, 2005 Share Posted October 23, 2005 You're lucky. You were born with the gift. Gifts, like grace, are bestowed and cannot be learned or earned. Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted October 23, 2005 Author Share Posted October 23, 2005 Dr. (right?) I estimate 99% of the world's population should stay away from DIY speaker building, however I am the President of a company that sells components for loudspeaker DIY projects. So, even though I get requests for such parts, I only sell them to that remaining 1% -- but only after a thorough interview and review of relevant resume' information. True this doesn't generate much capital gain for me, but I'm happy knowing that the other 99% will be happy and well-insulated from the dangers of the really hazardous part -- the dreaded crossover! Be careful, you might cut your hand! Have a nice Sunday, fellas! Erik Quote Link to comment Share on other sites More sharing options...
Parrot Posted October 23, 2005 Share Posted October 23, 2005 I would hope anyone building crossovers is taking the precaution of wearing Kevlar gloves. Quote Link to comment Share on other sites More sharing options...
Painful Reality Posted October 23, 2005 Share Posted October 23, 2005 Dr. (right?) I estimate 99% of the world's population should stay away from DIY speaker building, however I am the President of a company that sells components for loudspeaker DIY projects. So, even though I get requests for such parts, I only sell them to that remaining 1% Erik Wow, selling your parts to 1% of the world population must have made you "richer than astronauts" (if I can steal these words from Homer Simpson). Quote Link to comment Share on other sites More sharing options...
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