Testing 500-series pres (noob questions)

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jeroberts

Member
Joined
Oct 8, 2015
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13
Hi all -- I am new to the DIY world and was wondering what the best approach is to test a custom-build 500 series preamp without damaging your chassis and mic.  Please let me know! 
 
jeroberts said:
...... without damaging your chassis ......

Is the destructive test included  ;D ?

Strangely enough I was about to introduce  our test jig for 500 series ( and for others too) units.

You can obviously stick it in the rack, apply a test signal through the input and monitor it on the output using a scope.

However, if there is any problem it would not be possible to attend the unit when it is in the rack. So, an extensions cable such as this will help you test the module outside the rack conveniently.  It also has test points on the module side card edge connector board allowing you accessing all the pins. You can apply the test signal and monitor the output without using the XLR connections on the rack.

JIG_01a.jpg


The ribbon cable is connected to the module side card edge connector through box header. This board is  inserted  between the module card edge connector and the ribbon cable and allows you to use unbalanced source (signal generator) and measuring equipment (Audio milivoltmeter, DVM scope etc) for general testing, CMRR and SYMMETRY trimming. 

I will introduce the system in the Chamber in detail this weekend.

JIG_02a.jpg

JIG_03a.jpg

JIG_04.JPG

 
Thank you!  That sounds like a good system for testing.  However I actually don't have a chassis at the moment, so I was wondering if there's another way of performing tests.  I asked around elsewhere and people suggested using a lab power supply, but I'm not sure what the appropriate voltages are for 500 series units.  This is the power supply I was looking at:

http://www.amazon.com/gp/product/B000CSQK5E?psc=1&redirect=true&ref_=oh_aui_detailpage_o02_s00

Do you know if it would be able to do the job?
 
I have just completed the manual. I'll try to post  later on tonight.

The 500  module will normally require + - 16V .

That power supply will not do as it is a single output type. So you need a dual output power supply.

If you do not have the rack then you'll need this. It has on board test points which you can directly apply the supply voltage and  access to all of the edge connector pins including inputs and outputs.
 

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