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In Reply to: Re: Great topic, Lew! (My Bad) posted by frank on February 25, 2007 at 21:58:54:
So I gather you are finding that 1200 ohms works better than 200K ohms (?) In my preliminary listening last night (using MP1 and comparing 600 ohm load to 200K ohm load), I surprisingly could hear very little difference. At one point I thought that the bass lines were more distinct with the 600-ohm load; at another point I thought the upper mids and treble were better with the 200K-ohm load. I used only one CD, Sarah Vaughn with Oscar Peterson on JVC XRCD. The problem is that my head is full of secretions, because I have had a bad cold for more than a week and a half. I really am in no condition to do critical listening right now. I will continue to switch back and forth until I reach a conclusion.If you soldered your resistor across pins 2 and 3, that was a good idea, because it has much less effect on the grid resistances seen by the input tube sections, as opposed to using two 600-ohm resistors, one from each grid to ground, to achieve the same end. In the latter case, the 600-ohm resistors become in effect the grid resistances; not many tubes are happy with such a low grid resistor value. Nevertheless, this latter is how I configured my amplifiers, one 300-ohm R from each grid to ground, to net an input Z of ~600 ohms. I intend to change over to one resistor between pins 2 and 3 (the grids) next time I work on the amplifiers.
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Follow Ups
- My preliminary results... - Lew 08:06:24 02/26/07 (1)
- Re: My preliminary results... - Jack Williams 11:27:16 02/26/07 (0)
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