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cathode bypass on opt secondary
cathode bypass on opt secondary
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Old 2nd August 2011, 02:54 AM   #1
alexg is offline alexg  Philippines
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cathode bypass on opt secondary
Default cathode bypass on opt secondary

I came across a schematic of an EL84 SE, the cathode bypass is connected to the 8 ohm tap of the OPT secondary.

Haven't encountered this before, so, why is it connected to the 8 ohm tap of the OPT's secondary?

Thanks.
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Old 2nd August 2011, 03:02 AM   #2
e_fortier is offline e_fortier  Canada
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cathode bypass on opt secondary
Hi,

It's called cathode feedback, just like in the attache file.

Basically it reduces distortion greatly, increases damping factor (tighter bass) but needs more input voltage ( just because it's feedback).

I did this on my RH807 and it plays very good.

Rgds,
Eric
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Old 2nd August 2011, 03:04 AM   #3
alexg is offline alexg  Philippines
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cathode bypass on opt secondary
Quote:
Originally Posted by e_fortier View Post
Hi,

It's called cathode feedback, just like in the attache file.

Basically it reduces distortion greatly, increases damping factor (tighter bass) but needs more input voltage ( just because it's feedback).

I did this on my RH807 and it plays very good.

Rgds,
Eric
Eric,

Thanks.

BTW, the schematic you posted is the one I was looking at!
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Old 2nd August 2011, 03:08 AM   #4
dsavitsk is offline dsavitsk  United States
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Tubelab does this on the Simple SE Simple SE schematic

I tried it on a pentode headphone amp, and was not happy with the sound: ecp.cc
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Old 2nd August 2011, 02:54 PM   #5
the_manta is offline the_manta  Germany
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My 1625 amp works this way.
Click the image to open in full size.
A member here gave me a good hint to connect it like in your schematic which doesn't have DC on the speakers (but it is a very small amount, about 10mV). I like the sound.
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