[daz_bike]

Hi,

I have noticed that my Zobel Filter on my Ref 9's, which are attached to the speaker terminals, are fried    The resistor is black and I am not sure about the state of the capacitor, but it gives me doubts.

I know that the Zobel is essential to the sound of the V2 and should not be removed entirely.  Can someone please tell me what the values are for the resistor and the capacitor used 

I looked at the Cap, but was unable to determine the value as it is not clear with the writing on the cap.  The resistors are black, so no hope there 

I believe this happened due to disconnecting speaker leads with the amp on or playing.  Something to be careful of if you are configuring your system.  Please turn your amp off .... probably common sense.

Thanks

[daz_bike]

bump

[nuforce-casey]

100 Ohm (1/2 to 2W rated) in series with 0.47uF (100V rated)

[daz_bike]

Thanks Casey.  Nuforce 

[rustydoglim]

Disconnecting the speaker while the amp is powered on is ok.  But if you send in the music signal without the speaker load, then the zobel filter is going to be the only load to handle a high voltage/high power output.   

[daz_bike]

Got it Jason!

Thanks

[mcullinan]

What Zobel Network? Is their something I should be attaching to my amps?
Mike

[nuforce-casey]

Zobel network is internal to all Nuforce V2 amps.  It's the little RC network soldered across the binding posts (inside).

[twist22]

Is there any way to check to health of the Zobel Filter apart from taking the top cover off the amp and looking for blackened resistors ? I have had a speaker lead on the one base amps (biamp setup) knocked out. Nothing was playing when it happened but music was played before it was noticed.

[rustydoglim]

You have to open the top cover to check.

[twist22]

yep, I pulled the covers off and the 2 amps I use for bass duties both have burnt resistors in the zobel filter. The joys of using banana plugs with very stiff speaker leads.
They are are simple to replace so that will not be a problem.
Three questions
(1) can I expect the capacitors to need replacing as well ? Resistors are easy to check with a multi meter. I do not know how to check a capacitor ?
(2) can someone tell me the basics of what the zorbel filter does ?
(3) is the zorbel filter required on the 2 amps that are only used for bass in an active set up ie these 2 amps are directly connected to bass drivers and the active crossover on the input side means they will never be feed any frequencies higher than 250 Hz (depending on the crossover slopes) If they are not required is it better to have the zorbel filters in or out ?

[rustydoglim]

The zobel filter is required to complete the amp's feedback loop. The capacitor should be fine.
Email support with your address and we can send you a set of filters if you can replace it yourself.

[twist22]

Thanks for the advice and offering to supply new resistors. As I am in Australia I will try your local Australian distributor first. Pat is always helpful. I will let you know if he does not have any spares.

Thanks again.