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Old 1st November 2013, 03:10 PM   #1
ttan98 is offline ttan98  Australia
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Default Removing Protection Circuitry From F5

Hi,

I note the following:

1. Peter Daniel wrote somewhere on F5 thread that he noticed that the F5 sound much better with the Protection Circuitry Removed(PCR) i.e. the 2 transistors and associated resistors removed.

2. The F5 with PCR has the same topology as the Profet from France. Looks like the French amp does not worry about the reliability of their amp. Worst still their amp does not have source resistors on their mosfet.

my question has anyone use F5 with the PCR, how reliable or unreliable with this amp be? If I use a DC protection circuit board in front of the amp will it protect my speakers in case the amp fails.

Any comments are welcomed.
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Old 1st November 2013, 05:02 PM   #2
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I have not found that the protection circuit affects the sound.

As to the rest, perhaps you would prefer to build the Profet circuit.

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Old 1st November 2013, 05:10 PM   #3
flg is offline flg  United States
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Is not the ProFET circuit a class AB thingy? (low bias)
Also is there not some variability involved in the values and thresholds for the protection stuff of F5 that may be optimised for protection only and not to effect the "sound"?
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Old 1st November 2013, 05:22 PM   #4
Zen Mod is offline Zen Mod  Serbia
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besides class/Iq , Profet is different in one tiny but also very important detail - feedback arrangement

regarding other one - I'm sure that F5 made on Al heatsink will sound different from same one , made on Bronze heatsink



best protection circuit for your speaker is ........ very fast nail , connected on output terminal , when needed

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Old 1st November 2013, 07:42 PM   #5
generg is offline generg  Germany
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I can say that the F5 driven without protection circuit on my Thiel SCS 2.4 (4R and lower/89dB/1W) sounded better to my ears……

that is all I can say…...
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Old 2nd November 2013, 12:07 AM   #6
labjr is offline labjr  United States
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Quote:
Originally Posted by generg View Post
I can say that the F5 driven without protection circuit on my Thiel SCS 2.4 (4R and lower/89dB/1W) sounded better to my ears……

that is all I can say…...
Think you can hear a difference blindfolded?
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Old 2nd November 2013, 12:10 AM   #7
tinitus is offline tinitus  Europe
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Quote:
Originally Posted by labjr View Post
Think you can hear a difference blindfolded?
no, that would be like eating and holding your nose
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Old 2nd November 2013, 01:02 AM   #8
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i am fairly confident that many have built the Eff Phyve without the protection circuitry.
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Old 2nd November 2013, 01:16 AM   #9
tinitus is offline tinitus  Europe
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I think most here have built without
until now
but more and more appear to be buying pirate parts
they seem to be the ones building with protection curcuit
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Old 2nd November 2013, 02:25 AM   #10
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Quote:
Originally Posted by ttan98 View Post
If I use a DC protection circuit board in front of the amp will it protect my speakers in case the amp fails.
You mean in front of the speakers?
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