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Meiers Crossfed circuit, or Apheared47 mod?

post #1 of 7
Thread Starter 
Which would sound better with the Sennheiser HD-495's? The CMOY with Jan Meiers Cross feed circuit, or the CMOY with the Apheared47 mod? I would like all of your opinions. Thanks.
post #2 of 7
I couldn't tell you, but I can tell you it is easy to find out if you are building it yourself. I really like crossfeed, so chalk one up for the Meier crossfeed -- however, you can always build a separate passive crossfeed unit later if you want. Since the 495s have an impedance of 32 ohms it would seem that the 47 mod would be great for them. Why not just do both? You don't have to use the Hansen board you know.

--
Scott
post #3 of 7
although the 495's are listed as having a 32 ohm impedance and an efficiency of 106 db (they are nowhere near as efficient as 106db@1mw), they really need a higher gain than one would suspect.
post #4 of 7
Thread Starter 
skippy.
what has a higher gain, the 47 or Crossfeed? The 47, right?
Thanks
post #5 of 7
Gain is set by a pair of resistors in the signal path. Therefore, the gain of the Cmoy w/ crossfeed could be set the same as the gain in the 47.
post #6 of 7
The default circuit of a cmoy with crossfeed (i.e. the complete Levallois circuit) has more gain than the default Apheared 47. Apheared designed his amp for more current than the cmoy though, so his gain is only set to ~3, while the default Levallois has a gain of 11. But as JMT said, you can change the 2 resistors (resistor in the feedback, and resistor grounding the inverting input -) to adjust the gain.
post #7 of 7
Thread Starter 
ahhh..ok...makes more sense now. I suppose I will just stick with the CMoy w/ crossfeed then. I can always adjust the gain if I see fit. Thanks for your help.
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