Urei 560 feedback suppressor mod suggestions?

[Studiogearlover]

hey guys...anyone out there who upgraded a Urei 560? Has a nice transformers and would like to use as a mic pre...so far changed the PSU filter caps but sure something else can be done with it...

There are 2 electrolytics in the signal path, 2 different type ones...both 100uf 25v at the input, and the output. ( C27 and C22) any suggestions for these please?

There are also 3 green foil coupling caps (i remember seeing these types in a Bozak mixer mic pre cards!) 0.1uf ( C17, C18, C23) are these any good? or WIMA's better?

And finally...is it worth changing the quad IC's 4136?

If any of you did any mods I would really be thankful sharing some opinions... many many thanks!

 

[hageir]

Hey a bit late,
but I too have a pair of 560s.

The only mod I've looked into is a reversal of the notch, I've looked at the 545 and 546 schematics; they're quite similar and looks like the boost/cut switch should be easy to implement into the 560!