Anyone have schematics for this amp?
It's a Harmon Kardon from Heathkit.
There's mention of it being an Otala design.
It's a Harmon Kardon from Heathkit.
There's mention of it being an Otala design.
Did you Google?
I know there's a lot out there.
I ones bookmarked a site with almost everything from Heathkit but can't find it at the moment.
Edit: This fellow seems to have it.
Homepage: http://www.d8apro.com/
/Hugo 🙂
I know there's a lot out there.
I ones bookmarked a site with almost everything from Heathkit but can't find it at the moment.
Edit: This fellow seems to have it.
Homepage: http://www.d8apro.com/
/Hugo 🙂
Anyone ever notice if the LF time constants are screwed up with this amp? I'm seeing large subsonic woofer excursions with it.
It's possible that the electrolytic cap values have shifted with age but I'm seeing it in both channels.
Pete B.
It's possible that the electrolytic cap values have shifted with age but I'm seeing it in both channels.
Pete B.
Maybe PSU instability?
I'm sure the old filter caps have dried up and are in need of replacement.. 😕
I'm sure the old filter caps have dried up and are in need of replacement.. 😕
Took a quick look at the schematic, and the feedback is DC coupled. Only a cap, huge 220uF back to back at the input. The power supply is a bit odd, 4700 uF on the driver stages but with RC filters also.
Noticed that the spec -3dB point is .1 Hz on the low end, so it will pass everything from upstream.
Pete B.
Noticed that the spec -3dB point is .1 Hz on the low end, so it will pass everything from upstream.
Pete B.
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