Author Topic: irregular output level

December 15, 2021, 04:06:43 PM
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ellendelen

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Hello everybody,

I have been thinking about building some SS modules for quite some time now, in anticipation of building a unit myself, I bought a LA502 second hand from another builder. 

This unit sounds amazing! There's only one weird thing I am experiencing with it, the output level varies between two settings;


its either pretty soft (with about 9db of GR, ratio 3, I have to put the gain to full in order to get a level that's close to the source level) 

or pretty loud (with about 9db of GR, ratio 3, I have to put the gain to about 40 to get the same level as the source level)


I noticed that when it's in the softer setting it might out of the blue switch to the louder setting at some point during the session, but when its loud it won't go back to softer. So I guess the louder setting is the normal behaviour? Sometimes I can 'fix' it by turning my rack on and off a few times. 

The guy I bought it from did not recognise this behaviour. Could it have something to do with my rack? I use a RND R6 rack. Or might there be something else I am overlooking?

Any advise would be much appreciated! 

Thank you!

December 15, 2021, 05:05:03 PM
Reply #1

JPK

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It sounds like a bad solder joint making an intermittent connection.
Can you get the volume shifting by pressing or tapping the gain knob? This would show a defective potentiometer.
Next you need to visually check the solder joints and reflow the ones that look suspicious.
JPK

December 18, 2021, 01:13:12 PM
Reply #2

ellendelen

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I've checked the joints and reflowed quite a few of them. I am still testing, but it seemed to have worked!

Thanks!

December 20, 2021, 06:16:50 PM
Reply #3

JPK

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JPK