JK1dotNET
New Head-Fier
- Joined
- Dec 5, 2001
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I'm looking to build a version Szekeres's Class A MOSFET amp using an opamp gain stage similar to the CMOY amp as well as Tomo's constant current source. I'm just wondering how well it will work with higher impedance cans. I have some AGK K-501s (120 ohms nominal) and I'm hoping to get some Sennheiser AD-600s soon (300 ohms nominal). Since this amp acts like a current source instead of a voltage source, will it be able to swing the voltage high/low enough to drive high impedance cans like the AD-600s? (My PS will be 15V regulated)
Also, will the amp be able to drive both sets of cans without any design changes, or will I need to build a version that can change some things with a switch, such as the gain resistors?
One last question: Has anyone experimented with the output capacitor? It suggests a 470uF cap, but recommends a 1000uF replacement if one can be obtained. Can someone comment on the sound difference? (Obviously, a bigger cap here will give better low frequency responce, but how does it sound? Will it muddy up some of the higher frequencies? etc.)
Also, will the amp be able to drive both sets of cans without any design changes, or will I need to build a version that can change some things with a switch, such as the gain resistors?
One last question: Has anyone experimented with the output capacitor? It suggests a 470uF cap, but recommends a 1000uF replacement if one can be obtained. Can someone comment on the sound difference? (Obviously, a bigger cap here will give better low frequency responce, but how does it sound? Will it muddy up some of the higher frequencies? etc.)