Lie Belin AMP260 EQ recap questions

[Sister Ray]

Started racking up a Lie Belin AMP260 EQ module. It's inductor based EQ, some say it's a French version of the Pulteqs, and seen the (completely over-engineered) build quality that wouldn't surprize me at all...

Now, before I start ordering caps, I have some questions about the caps in the unit:

1) There are about 20 or so polystyrene caps in the unit, all very small (pF) values. As far as I've understood, these don't really go bad, and I shouldn't replace them (none of them look bad or are shorted)? (Which would suit me, as some have values that are hard to get by, especially some of in the higher pF range I can't find at all. Space is very tight too). See picture below.


2) Mica caps: There are 2 Mica caps (Steafix), should I replace them? I see conflicting information about that around the interwebs... And if I have to replace them, what type of cap should I use (does that depend on where they are in the circuit too?


3) What type are the transparent brown caps (and what was the manufacturer) in the pictures below? They seem to be some type of foil in a transparent plastic casing. I can't see any leaks or deformation on/in them. The single cap on the first picture has the designation BC4A40, and the two caps on the second picture have the designation BP4A16 printed on them. Last obvious question on these, should I replace them?
and

I would like to change as little as possible on the unit. Of course I'm changing the electrolytic caps, but if any other part doesn't need to be replaced, I won't replace it...

Your help & knowledge will certainly be appreciated!

Greetz & HNY,

Sister Ray

 

[jensenmann]

If it ain´t broken don´t fix it ;-)
There´s absolutely no need to replace anything other than al-electrolytic and tantalum caps. In you pictures I´ve seen none.

 

[Sister Ray]

Thanks, was thinking that indeed

The electrolytics are the big grey with plastic casing on the last picture in the post. F&T makes those in the same value, so that should be OK.

There's actually one more cap that I'd like to identify as to what type it is, see picture below. It's made by S.I.S.:


Regards,

Sister Ray

 

[Sister Ray]

Is anybody able to assist with identifying the types of caps in the posts above?

Regards,

Sister Ray

 

[Niketouille]

Hey,
I own Lie belin SN312G mic preamp. I had to change all the electrolytic caps but I leave all the other ones in place and never had any issues. As far as I remember I use bigger that original caps.
I strongly advise you to build a new power supply, with regulated high and low voltage. The original one is not that good and often introduce hum.
Cheers

 

[Migs 31]

Old thread resurection.

I'm working on a friend's Lie Belin EQ and pre-amp. The EQ is fantastic. The mic pre-amp (SN312G) has a few issues. The Lie Belin people had the good idea to print the schematic on the side of the unit, unfortunately after so many years, part of it has been accidentally scratched. Niketouille if you still around, could you post a pic. of the Schemo if possible. I would be so thankfull, or help with the Resistor and Cap values missing on ours. For the EQ not sure if it's the AMP260EQ we have. Here's a pic. of the babies. Sorry for poor quality of picture.

 

[Niketouille]

here it is

 

[Migs 31]

You are a star.
Our one has a lot of info missing as you can see in the pic. I will compare both and try to make  some sense out of it. Merci encore.

 

[Niketouille]

You are welcome, I'm always happy to help.

 

[Migs 31]

Thanks again Niketouille,

first thing I noticed, there are some differences between your schemo and ours, same principle (2XEF86 + 1X6AU6) but different cap values and slightly different lay out. I will post schemo once completed. Talking about caps, here's a pic of 16uF electrolitic caps that have been replaced by 47uF@450V. As mentioned before the other caps should be left alone, the ones that tend to age badly are the electrolitics. Notice the older caps, compared to the bright blue new El caps.