neovibe: 1uf film instead of electros?

[mikey]

I was getting my parts together for a neovibe build and thought about all the 1uf electros being used.  Has anyone tried swapping these for film or do they need to be polar?  I read "The Technology of the Univibe" at GEO but couldnt find the answer.  There was one part saying DC blocked by the 1uF capacitor but not much else on the 1ufs.  I'm always reading about how swapping electros out for film can give a cleaner sound.  I was wondering how/if it would effect the 'vibe.  Any thoughts?

[R.G.]

You may freely put 1uF film caps into the places for 1uF electros in a vibe - or any other application, for that matter. Non-polarized caps can always replace polarized caps if the non polarized caps will fit physically. Polarized caps were invented to be smaller sized in DC polarized applications.

"Need to be polar" is almost never true, and the only apps I can think of are abusive applications in the first place.

Will they sound better?

Maybe. See if you can shoehorn 1uF film caps in and tell us.

1uF film caps small enough to be considered for placement on that board are a relatively newly available item - maybe last 5-6 years.

[mikey]

Thanks for the info.  I'll give it a go.

[RedHouse]

Yes I have, and I think they're better sounding somehow than the electrolytics.
(so did the guy I built it for)

I used those square "stacked" polyester metal film caps (Panasonic I think, from Digikey). Here is a pic of my layout which started life as an old J.C.Maillet/Moosapotamus layout.

I modified it to hold the caps and incorporate JC's LFO mod and RG's wet/dry mix mod. 

[mikey]

I actually have those same Panasonic stacked film caps ... nearly a hundred of them I'm trying to use up.  I've already got them mounted on R.G.'s layout without any problems.  I just had to bend one lead in on each cap.  A few places it gets close to the leads on a nearby resistor or jumper but nothing that cant be fixed with some shrink tube or tape in case the cap gets smashed down.  It looks surprisingly clean. 

Cant wait to get this fired up.  Alas, I have to wait on some parts.

[alderbody]

I had done this replacement of electros with film caps in the past.

It started as the only solution that made my LFO work, but then i thought about replacing the ones in the signal path, too.

It sounded cleaner i guess, but it felt like it wasn't 100% original vibe tone (that's what i was after),
so i finally replaced them again with electros in order to stick to the original design.

of course i kept the ones in the LFO...


the fact is that it surely works!   

[R.G.]

It started as the only solution that made my LFO work,

Can you tell me a bit more about that?

[alderbody]

Can you tell me a bit more about that?

It couldn't oscillate at all, if i remember well.
I started with normal electros and it wouldn't work (no oscillation at slow rate / abnormal osc at higher rates).
After trying everything i got the idea about replacing the caps, so i swapped them with NP's and it started "moving" a little.
The NP's i had were a bit oversized, so -luckily- i ran into some very small film 1uF's in a local electronics shop.

When i put them on, i couldn't believe my eyes! The thing worked fine!

I would highly recommend them for LFO caps.
As for signal, as i wrote above, they sound fine, but to my ears it didn't sound 100% original.
OK, it might be just an impression, but if you consider that there should be a difference in ESR between the two cap types (or not?)

anyway, at least for the time my vibe sounds the best it can do with this setup.