Is there a consensus on preamp project? [message #30030] |
Fri, 24 December 2004 13:19 |
colinhester
Messages: 1349 Registered: May 2009 Location: NE Arkansas
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Illuminati (3rd Degree) |
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I assume we're going with whatever schematic Tnuctipun sends us. Are there any lurkers out there thinking about joining in? Even if decide not to build with us, please understand this does eliminate you from the discussions. We're all here to learn, and rest assured I will ask the most basic (dumbest) questions. Don't let the technical talk scare you aware. I'm about as new to this as anyone, and I'm nervous enough for all of us.....Colin
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consensus? [message #30035 is a reply to message #30030] |
Fri, 24 December 2004 19:27 |
PakProtector
Messages: 935 Registered: May 2009
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Illuminati (2nd Degree) |
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now that's asking a lot. relax, I will do any hand holding and question answering that is required. Very little bits of time to do the schematic. I have a few drafts, and should be able to post a pic of the final soon. It is hard to do a proper job of putting everything injust the right place and leave room for all the notes. I think I will publish a seperate list of 'Notes' as numbered ont the schematic. On the CCS, look for an AudioXpress with a Dave Davenport article on his new lonestage. he details using the single DN2540N5 mosfet and provides useful insight as to using them. It is good background on this effort. regards, Douglas
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some PS stuff... [message #30041 is a reply to message #30039] |
Sat, 25 December 2004 05:26 |
PakProtector
Messages: 935 Registered: May 2009
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Illuminati (2nd Degree) |
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I found this on Lundahl's pages. The rectifier is what I had in mind. two diodes and a vacuum diode. I had been talking of the 6CA4, it is a tough tube. peak current capabilities to allow a 40 uF first capacitor specification. We'll be treating it quite gently with a choke input filter. Either way, I offered help, and it is *NOT* conditional on following some specific design I happened to dream up. I have small bits of time, and the schematic is on a temporary hold until I can have longer ones. I do hate keeing you folks in suspense. Merry Christmas y'all! Douglas
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Re: some PS stuff... [message #30045 is a reply to message #30043] |
Sat, 25 December 2004 09:10 |
PakProtector
Messages: 935 Registered: May 2009
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Illuminati (2nd Degree) |
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You need two seperate cathodes. Two Bendix 6754 would do it. And give ~45 second warming time, but they are not a mainsteream valve. If you go directly heated, we'd need a filament winding at each end of the plate winding. Cruise Triode Electronic's Altec page and look at the full bridge on the 1570. It is made from 5R4's. All valve is nice, but in this case additional power Tx expense. We could do a 250-0-250 plate winding...all on a sudden, instead of a $28 power TX, it is nearly double that. regards, Douglas
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