ECM
100+ Head-Fier
- Joined
- Jan 9, 2004
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No idea what the cap values are on the output jack, but I would venture to say either 10nF or 2.83nF because that's what the PH-1 uses and if it were me building these, I would use what I had on hand. It's just a hunch as I haven't done any math to determine frequency response of a 32ohm load with 10nF or 2.83nF across it.
EDIT: Just took a quick look at the impedance of both values. At 20Hz 10nF is 800Kohm and 2.83nF is 2.8Mohm. At 20Khz 10nF is 795 ohm and 2.83nF is 2811ohms.
Keep in mind this is only the reactance of the cap, not taking into account the output impedance of the op amp or parallel impedance of the headphones.
EDIT 2: Comparing photos of the HPA-2 and PH-1, the size of the caps across the output jack are the same size as the 2.83nF caps in the PH-1.
EDIT: Just took a quick look at the impedance of both values. At 20Hz 10nF is 800Kohm and 2.83nF is 2.8Mohm. At 20Khz 10nF is 795 ohm and 2.83nF is 2811ohms.
Keep in mind this is only the reactance of the cap, not taking into account the output impedance of the op amp or parallel impedance of the headphones.
EDIT 2: Comparing photos of the HPA-2 and PH-1, the size of the caps across the output jack are the same size as the 2.83nF caps in the PH-1.