Re: and then... [message #11308 is a reply to message #11307] |
Thu, 16 March 2006 12:55   |
Damir
Messages: 1005 Registered: May 2009
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Illuminati (2nd Degree) |
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Well, the operating point you choose (Uak/Ia/Ugk) for a given tube determined your primary load impedance. (The term "primary winding resistance" is better used for the "static" DC resistance of the wire). But, practice teach us that it`s only the beginning, a reccomendation. Yes, we have the "standard" SE impedances, mostly - for 300B it is about 2k5, 3k, 3k5, 5k, or so. In principle, with higher values (with the same OP) we`d have a little larger damping factor, lower distortion, but lower power. But, the main difference, IMO, is the quality of concrete device, and not (for example) 3k/3k5 difference. It is complex subject, really - there are books written about OPTs and tube/OPT interactions. The best, (IMO, again) what "average DIY-er" can do is to buy quality OPT with various taps and trying for yourself various connections / OPs. (For example, "Lundahl" LL1620 or 1623.)
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