[BC] Symetrix 528E mic processor problem

[Warren Shulz]

Dave,

Funny part was those 1/4" normal jacks were stable in the units I worked with.  Biggest issue was push buttons.  Some switches were so bad you could not get a stable audio path in or out.  If they would have bifurcated (as you can with symmetry, and mic-line) it may have not been so unstable.  That 15 dB pad switch at mic. level is nuts.  You could put a mic. In a base drum and not over drive the preamp.  More a recording studio unit that broadcast.

These units at 8 to 14 years old are ready for the tar pit but not today.  Agreed any DSP mic processor like Wheatstone, Air Corps etc. With DSP and no switch (or trimmer) contacts would be one big step for man-kind.  But its not in the cards today.

I dialoged with factory and found the 528e was re-done three times since 1998.  Biggest dead end is 16 trimmers.   If you get'em it would be hours of bench time to remove and replace. A test tip is a 55 dB pad and pull live mic audio from another location to do initial setup and test.  One amazing  thing is all EQ trims in detent are flat.  How did they do that.  14 x 3 and all were flat response (sq-wave test) at detent.  The EQ sections are an amazing accomplishment with zero dollar parts.

Warren Shulz
WLS A/F Chicago

-bounces at radiolists.net] From: Dave Dybas

I took the older 528's apart and wired around the 1/4" jacks (cause we never
used them anyway) and a lot of my problems went away. Also sprayed De-Oxide
into the front switches and pots..usually kept them quiet for a year or two.

Never had problems with the DBX-286...but it doesn't perform as aggressively
as the 528's do.

Dave Dybas