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EQ573 Equaliser / Re: Signal going through the unit but it doesn’t effect the sound

« on: November 25, 2025, 10:57:48 PM »

Fixing the relay worked!


Thanks for your help!

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EQ573 Equaliser / Re: Signal going through the unit but it doesn’t effect the sound

« on: November 18, 2025, 06:31:12 PM »

Thanks, ordered.

I’ll update when I put it in

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EQ573 Equaliser / Re: Signal going through the unit but it doesn’t effect the sound

« on: November 16, 2025, 10:01:15 PM »

Power off, across the diode but with your DMM in ohm mode. You should read around 2k.

Ok power off measuring resistance with a meter probe on either side of D1 gives 0.0ohms
D2 gives 2.8kohms

 both relays and diodes were double checked for proper orientation and are ok. 

Also I did not have to desolder/resolder the relay

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EQ573 Equaliser / Re: Signal going through the unit but it doesn’t effect the sound

« on: November 16, 2025, 02:20:15 AM »

It looks like the relay coil is disconnected.
Check that the relay is in the correct direction (white line on the left).
Can you measure the coil resistance across the diode?
Did you have to desolder and remove the relay during assembly?
The relay may be damaged, try to replace it.

How do I measure coil resistance across the diode?

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EQ573 Equaliser / Re: Signal going through the unit but it doesn’t effect the sound

« on: November 14, 2025, 07:33:34 PM »

When I measure DC voltage across D1 putting a meter probe on either side of the diode, I get 32V when the EQ is is in XLR 

Both switched Off and PRE give me a DC voltage across D1 very low 0.02V

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EQ573 Equaliser / Re: Signal going through the unit but it doesn’t effect the sound

« on: November 10, 2025, 11:11:47 PM »

Ok all of the voltages without running signal were good.  All points A-N tested very close to the target measurement.

The next step was to send a sine wave and test.  Here is where I’ve run into issues.  I don’t know if it’s the way I’m testing though

I have a battery powered behringer cable tester that is also a tone generator.  It has a 1000hz sine wave at +4dbu.  I measured AC voltage at the pins of the XLR and got 1.4v

Plugged this into the unit and measured tp1 and 0v and I get a reading of 0.0 AC voltage on the meter.  

Is this because my sine wave is 1000hz and measuring 1.4VAC from the source?  Or should I be getting a reading?

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EQ573 Equaliser / Re: Signal going through the unit but it doesn’t effect the sound

« on: November 02, 2025, 12:13:34 AM »

Relays look good, in the correct direction.  As are D1 and D2.  R12 also looks good and is the correct ohms.

The switch looks good…I didn’t think it needed to be installed a certain direction, so that could be an issue if it’s directional.  I do get continuity readings on my DMM with it.  

Any other suggestions?

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EQ573 Equaliser / Signal going through the unit but it doesn’t effect the sound

« on: October 30, 2025, 03:25:29 PM »

Just finished building.  

When I send signal through the EQ and twist the knobs.  Nothing is happening. 

There’s nothing shorted to the chassis plate.  No smoking or burning smell.  On visual inspection everything looks normal. 

I’d like to be able to run through some of the voltage tests, but I can’t connect to the test points with my DMM since it needs to be in the rack. 

How can I go about supplying power to it outside of the rack so I can test DC voltages at the various points noted in the troubleshooting guide above?