Tech Tip- LA2a Problems
In this blog I want to talk about recording studio history, What is going
on at MSR Studios currently, and provide some tech tips.
Today’s Tip involves the classic LA2A.
DO NOT OPEN, MODIFY, OR ATTEMPT TO REPAIR.
SEND THIS UNIT TO A QUALIFIED SERVICE TECHNICIAN.
I have seen many LA2As with odd and hard to track down problems.
Blowing fuses, working with front panel open but not closed, and
internal snapping sounds are the most common.
We found two units in the shop left over from the Right Track days
that were gutted in an attempt to track down the problems.
My trusty sidekick Ian Kagey ( A tech at MSR Studios ) had the patience
and bravery to go at these units. Risking life and limb to get these
units operational. I’m sure the prior tech thought the problem
was a shorted power transformer or filter cap as I first did.
The problem turned out to be the most common issue with LA2A.
The LA2A contains point to point wiring. The terminal strip to which
the components are attached is screwed tightly to the metal chassis.
The chassis is grounded and is only insulated from the High Voltage
( 300V! ) terminal strip with a thin piece of insulation. This strip
deteriorates over the years and the high voltage shorts to ground
or arcs intermittently causing all kinds of symptoms.
Placing small insulated spacers under the terminal strip cured the issue.
Ian was happy he had one more LA2a to use when mixing his project that night.
Score Ian 1 – gear 0.
© 2009 Bradshaw Leigh
Wow! that’s great, a creative blog.
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