I was about to solder a Mouser replacement of the WIMA MKS-2 1,0 uF 63V (part 80-MMK5102K63J01TR18 borrowed from SM4 BOM).
Then I saw the SMR4 BOM comment: “Film, 2.5%, WIMA MKS02 63V recommended”.
I did a quick search on the forum, and found that these caps are “nice”  or that better capacitors tolerance, if they will not modify the sound, will have an influence on the tuning of filters .
I’m very ignorant of this, and I was wondering if the Mouser replacement for the “nice” WIMA caps would be a not so good idea, especially with the Ladder Filter which seems one of the most complex to tune (considering its use of four tunable resistances),
when placed on top of another voice card, they do not touch the case…
Which Mouser replacements are you talking about?
as I said (may be not clearly) the replacement part is 80-MMK5102K63J01TR18.
The part to be replaced is the “MKS-2 1,0u 63 V” (Reichelt).
… and then your question make me realize that the replacement parts are 1000pF which is 1nF and not 1uF, as I erroneously concluded (as often with u, n and p), sorry for that.
The thing is, I ordered to Mouser the parts for a TubeOhm Ladder and the parts for an SMR4. TubeOhm provides a Reichelt BOM but not a Mouser one, hence I built my own Mouser BOM. I did an error (among others) with the Ladder: I ordered part 505-MKS021.0/50/10. which are 1uF 10%, and only 50V and not 5mm. When I saw on the SMR4 BOM that the film capacitors were recommended to be WIMA, with the Mouser replacement 80-MMK5102K63J01TR18, I thought I could exchange these parts from SMR4 to Ladder, and I mismatched 1000pF with 1uF.
The correct Mouser replacement part seems to be 80-MMK5105K63J04L4 (Kemet Film Capacitors 63volts 1uF 10%). Since I do not have them, I may order the WIMA caps to Reichelt anyway.
But the answer to the question may still be interesting : would the Kemet caps be a good replacement for the WIMA caps? What makes those WIMA caps so nice?
This is my first time trying to build my own BOM, I think I made various errors and misinterpretations.
Please ignore this discussion while I figure out what has led me to ask this question.
Sorry for the noise.
Capacitance matters. 1uF = 1000nF. 1nF = 1000pf.
Voltage doesn’t matter at all.
Spacing between leads matters (5mm).
The lowest the tolerance the better.
The WIMA caps have a low tolerance.
You can try this: 80-C317C102G1G. These are ceramic, but they are of C0G (NP0) dielectric/temperature coefficient - so they are good for filter applications (low tolerance and good stability).
ok, let’s stick to this simple question then:
Instead of having ordered this part: WIMA 1uF 63V 5mm 
I ordered this one: WIMA 1uF 50V 2.5mm 
Question: would that be ok anyway (50V vs 63V), if I spread the legs so they fit in the 5mm-wide holes?
sorry I did not see your last comment: it seems that the caps I currently own would do then?
That replacement is perfectly fine: we all do a little creative leg bending once in a while. In this case it is easy. The voltage is just a maximum, so 50V or 63V does not matter here.
They are a bit bulky and might touch the neighbouring part - it might be possible to solve with with some creative soldering…
Hi, sorry i have seen this too late. the audio Signal can have a maximum amplitude from round about 7,25 Volt. So the voltage is not so impossible. 40V …63V.
About tolerance, the Resistors/Caps/Diodes and Transistors have tolerances.But today the tolerances are much smaller than 20 …30 jears before.
So 5 % is good in range.
… and it works! Thanks for helping me…