Thanks DF,
A quick modeling in LTSpice actually helped me understand it, essentially it is a "down and dirty" way to take in the "balanced" input from the sound card. It still preserves the only real thing I was looking for and that would be to reject common mode noise injected into what might be a rather longish cable run in my rather "Noisy" listening room. (an old house with all kinds of crazy wiring in the basement.
Since I have 6922's, sockets and all the other stuff needed laying around it sure beats the cost of a pair of Jensen IPT's.
The only other thing I am a tad leary about is the need for 2 more caps in the signal path, the size and quality of which is important to response.
I still think this is how I might proceed since I have decided to passively cross over my mid and tweeters and use the tube xover for bass-mid duties, thus eliminating the heretic SS crossover and its input buffer.
I need a little more gain before the crossover so the PS for this can serve double duty as the PS for another gain stage before the Xover and if I get real ambitious and have chassis room I can squeeze in a phono stage.
A quick modeling in LTSpice actually helped me understand it, essentially it is a "down and dirty" way to take in the "balanced" input from the sound card. It still preserves the only real thing I was looking for and that would be to reject common mode noise injected into what might be a rather longish cable run in my rather "Noisy" listening room. (an old house with all kinds of crazy wiring in the basement.
Since I have 6922's, sockets and all the other stuff needed laying around it sure beats the cost of a pair of Jensen IPT's.
The only other thing I am a tad leary about is the need for 2 more caps in the signal path, the size and quality of which is important to response.
I still think this is how I might proceed since I have decided to passively cross over my mid and tweeters and use the tube xover for bass-mid duties, thus eliminating the heretic SS crossover and its input buffer.
I need a little more gain before the crossover so the PS for this can serve double duty as the PS for another gain stage before the Xover and if I get real ambitious and have chassis room I can squeeze in a phono stage.
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No RIAA suggestions for you. But if you actually enjoyed puzzling out the Broskie
Cathode Follower? Here is my own competitor: Differential White Cathode Follower.
Please note this is a worst case sim with tons of common mode noise and power
supply ripple added for extra aggrivation. So, why is it none in the output???
I can smell ye olde brainwoods burning already...
+2.5VDC bias on V4 is well within common mode rejection range, so not essential.
I was tryin' to fake like a +5V DAC at the time, or quack like a duck, er whatever...
Ground referenced signals work just fine.
Cathode Follower? Here is my own competitor: Differential White Cathode Follower.
Please note this is a worst case sim with tons of common mode noise and power
supply ripple added for extra aggrivation. So, why is it none in the output???
I can smell ye olde brainwoods burning already...
+2.5VDC bias on V4 is well within common mode rejection range, so not essential.
I was tryin' to fake like a +5V DAC at the time, or quack like a duck, er whatever...
Ground referenced signals work just fine.
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Not much time today...but a quick look at the schematic would indicate that "common mode" noise on the lower triode would be inverted on the plate which is tied to the grid of the upper triode cancelling it.
I assume the inverse is true at the top where the reverse happens off the upper cathode to the output?
I assume the inverse is true at the top where the reverse happens off the upper cathode to the output?
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