Wildcat VCF-3 PCB

[vladosh]

Made a layout for VCF-3 from EFM's Wildcat ,it's Oberheim type VCF i built once ,liked it so i thought i'll make another ..there were two errors in the layout which i corrected ,but there's no silkscreen so if anyone's making it gonna have to follow schematic ,that's what i do )) ,for the expo pair i used BCM857 cause i had some ,you can find SMD to DIP adapter at the Buchla 258 thread ,here is schematic and ready for print layout ,it could have been done better i'm sure ,there's a 10K resistor going from the expo converter to the OTA which is missing in the schematic but is included in the layout

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[Baloo]

Thanks a lot .. I will build this one for sure never enough filters.

[vladosh]

Sure Baloo , i still haven't finished mine it's almost done , happy building ))

[Baloo]

Thanks Vladosh you can try this other 2 pole filter:

http://www.analogsynth.de/synths/mod2/ms20filter/rene_ms20_filter_clone%20rev%204.pdf

[vladosh]

i am sure Rene's MS20 VCF is great ,thanks

[vladosh]

there's another error in this layout ,the 10K from output to -15 , but there is room to drill two holes and put a resistor there to fit nicely ,i will update the layout

[n.d]

Vladosh: please do, I´m very interested in this filter.

[isak]

Hi Vladosh.

thank you for the layout.
few questions if i may please.

1. in lopass will it self osc?
2. does your layout is for using BCM857?
3. is it by any chance sound like this :
https://www.youtube.com/watch?v=0ze0O29O11o

?

if it does, i'm in

cheers,
Isak E.

[vladosh]

this is a really filter that i like , it sounds sweet , and at high resonance it's wild but not as bad like steiner can be .. this pcb layout is bit wrong ..around the expo , i never fixed it , and i lost the layout , i plan on making a oberheim sem type , but discrete ota based if i get it to work i will prolly post the layout , i used BCM transistors and rebuilt it on stripboard , i dunno how close it's to the demo you posted , it sounds nice

[isak]

Thank you for replying.

I wating for your oberheim sem
Are you going to make the board using the original scheme?

http://www.pmerecords.com/Docs/SEM-1A.PDF

If so...good luck my friend.

Cheers,
Isak E.

[jbeuckm]

Does the schematic above have any errors? I know that the original schemo was missing a resistor and the layout above was missing a different resistor...

Update: I'm thinking that the 4600 series are more refined than the Wildcat was. I am working mainly from the 4621 and have started 4622:

https://github.com/jbeuckm/EFM_VCF3
https://github.com/jbeuckm/EFM_VCF_4622

[LFLab]

Hey Joe,

Found your eagle files of the wildcat ringmod you did on github. I reworked them to the other ringmod on Yves Usson's site
Thanks!

"Look Ma, no wiring"


Jacks are Thonkiconn, and PCB dims are 50x62 (mm).

[isak]

Hi guys.

Does enybody knows if the mention EMF multiband VCF above is self oscilating in LP or HP mode?

[bamboombaps]

hey great work! is it possible to share these eagle files?

[LFLab]

Sure, I am going to look into getting this into github, so everybody can access the files.

[bamboombaps]

[isak]