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Old 22nd June 2010, 06:48 AM   #8181
osscar is offline osscar  Latvia
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thanks for the advice Master! This definitely helps.
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Old 22nd June 2010, 11:16 PM   #8182
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Quote:
Originally Posted by acold7dusta View Post
has anyone built zobel networks for their F5, or is it not necessary for this topology? I'm running higher capacitance CAT5 cables (10ft)
bump
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Old 22nd June 2010, 11:42 PM   #8183
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Output is stable
But you may have to be careful with source and interconnects
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Old 22nd June 2010, 11:59 PM   #8184
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Quote:
Originally Posted by acold7dusta View Post
bump

If this cable does not work, try an ordinary one instead of adding a zobel.
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Old 23rd June 2010, 12:09 AM   #8185
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Quote:
Originally Posted by acold7dusta View Post
bump
I try a high capacitance speaker cable and fuse blow up.
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Old 23rd June 2010, 12:16 AM   #8186
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thanks for the replies, I'll try ordinary 12ga and see if runs any cooler (couldn't hold my hand to 5 seconds, zobel wasn't helping)

without load, i can hold it comfortable for over 20 seconds
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Old 23rd June 2010, 12:36 AM   #8187
tinitus is offline tinitus  Europe
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quote from F5 manual

A caveat is in order here – this is a very wide band amplifier with a high input
impedance. In order to prevent the output voltage from bleeding back to the
input at very high frequencies (thus making a fine power oscillator), keep the
input and output cables separate, and don’t externally connect the speaker
ground to the input ground. Good ground shielding on the input cables is
important, and caution is called for in using Litz and other specially low
inductance / high capacitance cables. I have not seen a specific example of a
problem, but historically it is to be expected when an amplifier’s bandwidth
exceeds 200 KHz. If the amp makes funny noises, runs extra hot, or blows
fuses, this might be an indicator of such an issue.

quote from above

and don’t externally connect the speaker
ground to the input ground.

I suppose speaker ground(power supply) and input ground(chassis) is seperated by thermistor
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Old 23rd June 2010, 01:41 AM   #8188
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Quote:
Originally Posted by tinitus View Post
quote from F5 manual

A caveat is in order here – this is a very wide band amplifier with a high input
impedance. In order to prevent the output voltage from bleeding back to the
input at very high frequencies (thus making a fine power oscillator), keep the
input and output cables separate, and don’t externally connect the speaker
ground to the input ground. Good ground shielding on the input cables is
important, and caution is called for in using Litz and other specially low
inductance / high capacitance cables. I have not seen a specific example of a
problem, but historically it is to be expected when an amplifier’s bandwidth
exceeds 200 KHz. If the amp makes funny noises, runs extra hot, or blows
fuses, this might be an indicator of such an issue.

quote from above

and don’t externally connect the speaker
ground to the input ground.

I suppose speaker ground(power supply) and input ground(chassis) is seperated by thermistor
I've read that, but after all the countless hours I put into those cables I just REALLY wanted to make them work...
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Last edited by acold7dusta; 23rd June 2010 at 01:57 AM.
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Old 23rd June 2010, 01:55 AM   #8189
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amp's running much more stable (cooler and less noise), and sounds much more "relaxed", with an increase of upper midbass...interesting
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Old 23rd June 2010, 03:59 AM   #8190
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Quote:
Originally Posted by acold7dusta View Post
I've read that, but after all the countless hours I put into those cables I just REALLY wanted to make them work...
Some capacitance across the 100 ohm feedback resistors will
stabilize that. Start with .001 uF and work up to .01uF.

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