KTpG
100+ Head-Fier
- Joined
- Jan 17, 2003
- Posts
- 455
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- 25
I posted the exact same thread at HeadWize, but just wanted to cover all bases and get everyone's input...
Ok, we all know cathode follower well, since almost every tube design here (and almost every other tube headphone amp) is a cathode follower. I read somewhere that just using a tube in a cathode follower effectively decreases the Zo by a factor of 5.1 or so.
I looked up the Rk of a 6L6 (granted it was taken while in SE pentode) and found it to be 300-ohms. 375 if in triode PP. So, lets say we connect in triode, OTL config (should be possible...). And we get Zo about 400 (to round to be safe...) we get a nice fairly low Zo that would drive 300-ohm cans easily. Correct?
And, if it is not low enough, could we not parallel an extra output tube to cut the Zo in half? (I am going off of knowledge of speaker design... shouldn't the same principle apply for ALL parallel applications involving resistance?)
Any thoughts would be MUCH appreciated. I have been searching for my "perfect" tube headphone amp, and can never find a design to fit my liking, so as always, I set out to make my own... Thanks to all who can provice some info here.
Ok, we all know cathode follower well, since almost every tube design here (and almost every other tube headphone amp) is a cathode follower. I read somewhere that just using a tube in a cathode follower effectively decreases the Zo by a factor of 5.1 or so.
I looked up the Rk of a 6L6 (granted it was taken while in SE pentode) and found it to be 300-ohms. 375 if in triode PP. So, lets say we connect in triode, OTL config (should be possible...). And we get Zo about 400 (to round to be safe...) we get a nice fairly low Zo that would drive 300-ohm cans easily. Correct?
And, if it is not low enough, could we not parallel an extra output tube to cut the Zo in half? (I am going off of knowledge of speaker design... shouldn't the same principle apply for ALL parallel applications involving resistance?)
Any thoughts would be MUCH appreciated. I have been searching for my "perfect" tube headphone amp, and can never find a design to fit my liking, so as always, I set out to make my own... Thanks to all who can provice some info here.
