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Old 4th June 2004, 08:43 PM   #1
diyAudio Member
Join Date: May 2004
Location: Toronto
Default Remove feedback in Zen V4

Has anybody tried to remove feedback network in Zen V4? (The 221K resistor and the 5pf Cap). What's the sound difference?

Will the length of feedback path influnce the sound? the shorter the better?

I appreciate somebody can give me an idea.
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Old 5th June 2004, 12:51 AM   #2
The one and only
Nelson Pass's Avatar
Join Date: Mar 2001
Of course the gain shoots way up and the damping factor
goes away. If you use an adequate amount of Source
resistance on Q1 to tame the gain and have a well damped
load with a flat impedance, you might just like it. The
overall distortion is higher, but the spectral presentation
is a little more even. Most people would not be able to get
past the damping factor, but it would make a great tweeter
amp, for example.
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Old 5th June 2004, 02:19 AM   #3
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Join Date: May 2004
Location: Toronto
Thanks, Nelson.

I have built the Zen original, without feedback, It sounds excellent(I am not saying the bass, but it's enough for me). The damping factor is about 8.

The Zen V2 and V4 is quite similiar with original zen + BOZ except the current source. and with feedback. The damping factor is around 40, if I am right.

Would the Zen V2 work similiar as the original one if the feedback (3k resistor) is removed? How is the damping factor? I wonder if it's good enough used with high efficiency full range speakers.
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Old 7th June 2004, 06:53 PM   #4
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Join Date: Mar 2001
The original Zen does use feedback - that's how it gets
the DF of 8, otherwise it would have none to speak of.
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