Rockford power 550???? unknown

[Perry Babin]

There is a language issue here. You state (I think) that you don't have an amp meter but your 179 can easily measure current.

Let's try it this way.
Insert a fuse no larger than 10 amps in the B+ line feeding the amp
Clamp all heatsink mounted components tightly to the heatsink
Set the bias pots fully counter clockwise.
Power the amp up
Set the meter to DC volts (lowest range needed)
Connect the meter across one of the 0.1 ohm source resistors
For that same channel, slowly turn the bias pot clockwise until you measure somewhere between 0.5mv and 1mv across the source resistor
Repeat for the other channel

 

[terminatore]

yes there is a problem with the new google translation!

the fluke is well ampere meter from 0 to 400 mili ampere and from 0 to 10 A

 

[Perry Babin]

To find the best translator (may not be google), translate from your language to English and then back to your language and see which one does the best translation.

 

[terminatore]

can you show me
what reference on the schema the resistance of 0.2ohm that I must measure 1millivolt max

Thank you for your help

 

[Perry Babin]

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[terminatore]

 

[Perry Babin]

Did you post is as shown in post #65?

 

[terminatore]

yes I followed your post 65

 

[Perry Babin]

Are you sure? When posted as suggested, the images open in the same window, not in a new window.

 

[terminatore]

here is a screen shot

 

[Perry Babin]

This one is working correctly. The earlier ones were not.

For biasing, Rx36 or Rx49 can be used in each channel.

 

[terminatore]

so I have a problem

I measure in DC volt on:
R149 -27.88
R249 -27.73
R349 -27.44
R449 -27.20
R136 +27.95
R236 +27.77
R336 +27.46
R436 +27.30

I should have 1millivolt maximum?

 

[Perry Babin]

You measure the voltage 'across' the resistor, not referenced to some other point.

 

[terminatore]

I measure black probe on B-

red probe on the resistance visible on the photo

 

[Perry Babin]

I realize that's what you did but you need to measure with both probes directly on the two terminals of the resistor. See attached as an example.

 

[terminatore]

I followed your instructions

I adjust the bias with a load resistance of 6 ohm
the consumption of 1.3 ampere

R149 1 millivot
R249 1 millivolt
R349 1 millivolt
R449 1 milivolt

the setting is very sensitive

the 550x works perfectly the sound is very good

Perry Babin thank you for your help