Increment speed Neo Vibe

[spoontex]

Hi,

I want to speed up my Neo Vibe build. Reading this article, I think that I need to down resistors R42 and R43 ( 4k7 to 1k8 maybe ), but I'm not sure. Anybody can confirm it?

http://www.geofex.com/article_folders/univibe/univtech.htm

http://www.geofex.com/Article_Folders/univibe/vibeupdate.pdf

Thanks.

[PRR]

"Usually", the resistors are picked for other reasons, the capacitors picked for time/speed.

[Kevin Mitchell]

Hi,

I want to speed up my Neo Vibe build. Reading this article, I think that I need to down resistors R42 and R43 ( 4k7 to 1k8 maybe ), but I'm not sure. Anybody can confirm it?

http://www.geofex.com/article_folders/univibe/univtech.htm

http://www.geofex.com/Article_Folders/univibe/vibeupdate.pdf

Thanks.

PRR is correct.
A popular modification to increase speed is to replace the 3 series 1uF capacitors in the LFO. Some early variants of the Uni-Vibe had this mod stock. I think that was back when they were made by "Honey", before Shin-ei. Or the story goes something like that.
I think for my replica build I had used .68uF electros and it turned out great.

[spoontex]

Hi,

I want to speed up my Neo Vibe build. Reading this article, I think that I need to down resistors R42 and R43 ( 4k7 to 1k8 maybe ), but I'm not sure. Anybody can confirm it?

http://www.geofex.com/article_folders/univibe/univtech.htm

http://www.geofex.com/Article_Folders/univibe/vibeupdate.pdf

Thanks.

PRR is correct.
A popular modification to increase speed is to replace the 3 series 1uF capacitors in the LFO. Some early variants of the Uni-Vibe had this mod stock. I think that was back when they were made by "Honey", before Shin-ei. Or the story goes something like that.
I think for my replica build I had used .68uF electros and it turned out great.

you mean C19, C20 and C21? I will try 0.68uF.

[antonis]

I had used .68uF electros

I shouldn't use tantalum caps for a timer circuit..

[FSFX]

I had used .68uF electros

I shouldn't use tantalum caps for a timer circuit..

So what is wrong with tantalum? If it is OK for NASA to use in space craft and for the military to use because of its long term stability then it should be OK for the rest of us to use.

There just seems to be so many myths regarding tantalum in these DIY communities.   

[antonis]

So what is wrong with tantalum?

Nothing wrong..
(only when capacitance/space ratio is super tight..)

P.S.
No mood to argue but allow me to have personal experience about "senselessly" failed tantalum caps inside various medical equipments..

[FSFX]

allow me to have personal experience about "senselessly" failed tantalum caps inside various medical equipments.

Well I am sorry to hear that.

[Kevin Mitchell]

you mean C19, C20 and C21? I will try 0.68uF.

Yup! Sorry, forget to get back to this thread.
You could also use 680nF film or ceramic caps for these locations as they don't have to be polarized. I specified electros because that was a replica build based off the original PCB layout and had tried my best to use classic mojo parts (minus the brown phenolic PCB).