Little VOODOO VIBE project by Kaputepalla

Redhouse · Post by **Redhouse** » 30 Nov 2007, 05:30

Redhouse wrote:The link is currently not working, has the zipfile moved? (or does someone else have it and want to point me to it?)

-Redhouse

BTW, I just got here, nice place, glad to be here!

Hello?....

....(sound of crickets chirping)....

greenskull · Post by **greenskull** » 30 Nov 2007, 20:21

Try page 6 for KT66's new layout files with mods. Welcome aboard Redhouse!!!!

Redhouse · Post by **Redhouse** » 01 Dec 2007, 04:18

greenskull wrote:Try page 6 for KT66's new layout files with mods. Welcome aboard Redhouse!!!!

Thank you greenskull, I got that and was looking for the original zip file from the first post also.

Redhouse · Post by **Redhouse** » 06 Dec 2007, 04:08

Just an FYI, I got that file "Kaputepalla_Little_VoodooVibe_HiRes_PCB_Transfer.pdf" and it seems to have errors not in the other 2 files "little voodoovibe pcb.jpg" and "kt66_final_full_board_photoshop_letter_print.tif".

In case anybody built the Kaputepalla_Little_VoodooVibe_HiRes_PCB_Transfer.pdf board and has trouble getting it going, see these pads are not connected:

Also, I don't know if it's just RM or an internet thing, but the 4th amp in IC-1 doesn't look right, normally an unused OpAmp shouldn't have the +/- inputs shorted and output floating, proper termination of an unused OpAmp helps reduce current draw (in this case a battery).

Normally the + input is either grounded or raised to 1/2 Vdd/Vss and the output is connected to the - input like this:

theyear2042 · Post by **theyear2042** » 08 Dec 2007, 13:19

hey redhouse

"Kaputepalla_Little_VoodooVibe_HiRes_PCB_Transfer.pdf" is an old file of mine that is wrong.

if you read my earlier posts in this thread you will see that i mention that several of the pads were discconnected due to a photoshop layer being hidden accidently.

also, that pdf layout has now had several updates done my me and so is redundant. the new layout is called "kt66_final_full_board_photoshop_letter_print.tif" and no-one should build the "Kaputepalla_Little_VoodooVibe_HiRes_PCB_Transfer.pdf" layout that i did becasue it has errors.

"Kaputepalla_Little_VoodooVibe_HiRes_PCB_Transfer.pdf" was removed a long time ago so im not sure where you got it from. please delete it.

the new project files by me are available here:
http://rapidshare.com/files/71272549/kt ... e.zip.html

the project files in the above zip file have been built my me personally - they work 100%

regarding the 4th opamp - that is the way the schem was drawn (by Kaputepalla?) and it works fine. if you mod it, let us know how you get on

take care
kt!

greenskull · Post by **greenskull** » 09 Dec 2007, 04:26

Redhouse - There's actually another set of pads you missed. In the upper part center where the the 220k and 1M resistors connect. Yeah, I wished I would've caught the updated pcb before I started, but I think I caught everything.
Actually, I'm not digging the tone of this thing after playing around on it for few days. Does all the tricks, but cuts some bass and sounds a bit sharp to the ears. I tried increasing the input cap, but no real improvement. Let us know what you think after your build.

theyear2042 · Post by **theyear2042** » 09 Dec 2007, 04:56

hey greenskull

the bass cutting is in the phase caps

which 4 caps did you use?

the RT-18 caps are a lot bassier 4n7/3n3/2n2/1n0

if you listen to the mp3 demo i posted you will hear a significant bass increase - but then it sounds more like a regular phaser and less like a vibe

you could always experiment with the caps - or use a switcher to switch the caps

kt!

greenskull · Post by **greenskull** » 09 Dec 2007, 05:23

Hi KT - Thanks, I took notice of the previous posts, but didn't have a rotary switch handy so I used toggle switches for the last 3 stages. Basically I can get the stock RM, Univox UniVibe and Bajaman versions.
I like Bajaman's a lot because it sounds very even and smooth, but that 470pf is icepicky like you mentioned.... I guess that's why RM upped to .047uf, even though it makes the phasing loppy. I have it all crammed up in a 1790NS enclosure, need to get pic posted before I dismantle it again for more experimenting. My NeoVibe sounds huge and warm compared to this thing, I have a feeling it's gonna be more than the stage caps that need to be changed, but what do I know? I'll post results if I hit gold. Thanks again.

greenskull · Post by **greenskull** » 09 Dec 2007, 06:48

Just tried a compressor in front of it and helped quell the piercing tone quite a bit to my liking. Sounding good especially on the neck pickup now. Wish I had room to include that circuit in the same box so I could hardwire it in.

bajaman · Post by **bajaman** » 09 Dec 2007, 07:22

Hi KT66 or the year2042
I think you may have misunderstood me earlier in this post.
The values for the 4 caps that I chose are in the following order
15n, 100n, 470p, 27n.
I think you may have thought i used a different order

I do not know what difference placing any of these cap combinations in a completely different order will do to the sound - maybe worth some experimentation

one thing i do know though - the original 220n cap used in the second stage makes for a very wooly and bassy bottom end - probably okay for organ but way too low for guitar players

The 470p in the 3rd section adds some sparkle to the high end as one would expect - lower this and you gradually loose the high treble response.
I note that this pedal uses 3 x 100n coupling caps between the vibe /chorus/ tremelo switch and last phase stage. I think the original Univibe used 1uf which would explain why the Voodoo Vibe lacks a good bass response - i may try changing these - I will keep the forum posted
Cheers
bajaman

Redhouse · Post by **Redhouse** » 09 Dec 2007, 15:46

theyear2042 wrote:hey redhouse

"Kaputepalla_Little_VoodooVibe_HiRes_PCB_Transfer.pdf" is an old file of mine that is wrong.

if you read my earlier posts in this thread you will see that i mention that several of the pads were discconnected due to a photoshop layer being hidden accidently.

also, that pdf layout has now had several updates done my me and so is redundant. the new layout is called "kt66_final_full_board_photoshop_letter_print.tif" and no-one should build the "Kaputepalla_Little_VoodooVibe_HiRes_PCB_Transfer.pdf" layout that i did becasue it has errors.

"Kaputepalla_Little_VoodooVibe_HiRes_PCB_Transfer.pdf" was removed a long time ago so im not sure where you got it from. please delete it.

the new project files by me are available here:
http://rapidshare.com/files/71272549/kt ... e.zip.html

the project files in the above zip file have been built my me personally - they work 100%

regarding the 4th opamp - that is the way the schem was drawn (by Kaputepalla?) and it works fine. if you mod it, let us know how you get on

take care
kt!

Oh yeah I see it now, thanks. I'm late to this thread and I've got some catching up to do. Thanks for the link, downloading now.

The 4th OpAmp thing isn't a problem, more of an improvement idea.

They say that an unused OpAmp in a dual or quad package will draw current even doing nothing unless the inputs are tied as shown which minimizes it.

Since this is a battery operated vibe (with adapter option) I thought folks might like to know about it.

Here's some appnotes for reference:

http://www.maxim-ic.com.cn/pdfserv/en/an/AN1957.pdf

and page 17.7.3 Unused Sections:
http://focus.ti.com/lit/ml/sloa089/sloa089.pdf

BTW, that TI paper is quite a good read about PCB issues.

Dirk_Hendrik · Post by **Dirk_Hendrik** » 14 Dec 2007, 17:36

Wondering....

Working on a vibe right now based on the shin-ei but with a somewhat more linear approach on the active elements (and therefore a) overdone b) obvious c) cheaper because of ebay component dumping d) unique

) I might have the opportunity of dumping all in a 1590B case...

If:
Someone is able to suggest a smaller size ritary switch than the chunky Lorlins....

Help ??

analogguru · Post by **analogguru** » 14 Dec 2007, 17:43

ITT had some - ELV used them in many applications.
But they are only pcb-mount.

Conrad sold them in 2004 as:
70 57 13-33
70 57 21-33
70 57 30-33
70 57 48-33

analogguru

theyear2042 · Post by **theyear2042** » 17 Dec 2007, 20:58

bajaman wrote:Hi KT66 or the year2042
I note that this pedal uses 3 x 100n coupling caps between the vibe /chorus/ tremelo switch and last phase stage. I think the original Univibe used 1uf which would explain why the Voodoo Vibe lacks a good bass response - i may try changing these - I will keep the forum posted
Cheers
bajaman

let us know if this turns out to increase the bass.

thanks
kt!

bajaman · Post by **bajaman** » 18 Dec 2007, 01:05

let us know if this turns out to increase the bass

I just replaced the three capacitors - used 1uf bipolar types for replacements - made a noticeable difference - warmer and fuller bottom end - I will keep them in there

cheers
bajaman

ps: looking at the kaputella little voodoo vibe layout picture (INPUT GROUND top left and GROUND top right) I replaced the 2nd 3rd and 7th .1uf capacitors along the top row with 1uf bipolar (or non polarised) types.

theyear2042 · Post by **theyear2042** » 18 Dec 2007, 11:28

bajaman wrote:
let us know if this turns out to increase the bass
I just replaced the three capacitors - used 1uf bipolar types for replacements - made a noticeable difference - warmer and fuller bottom end - I will keep them in there
cheers
bajaman

nice - i will try it out

cheers
kt!

theehman · Post by **theehman** » 18 Dec 2007, 14:02

Anybody interested in making me a couple of board sets for this project?

greenskull · Post by **greenskull** » 19 Dec 2007, 01:21

bajaman wrote:
let us know if this turns out to increase the bass
I just replaced the three capacitors - used 1uf bipolar types for replacements - made a noticeable difference - warmer and fuller bottom end - I will keep them in there
cheers
bajaman

ps: looking at the kaputella little voodoo vibe layout picture (INPUT GROUND top left and GROUND top right) I replaced the 2nd 3rd and 7th .1uf capacitors along the top row with 1uf bipolar (or non polarised) types.

Thanks a lot as usual, Bajaman!! I will replace 'em as soon as I have time. I'm really glad you figured out how to improve it.
Happy Holidaze everybody!!!

Redhouse · Post by **Redhouse** » 19 Dec 2007, 13:46

theehman wrote:Anybody interested in making me a couple of board sets for this project?

I sent you a PM.

noelgrassy · Post by **noelgrassy** » 28 Dec 2007, 16:33

Dirk_Hendrik wrote:Wondering....

Working on a vibe right now based on the shin-ei but with a somewhat more linear approach on the active elements (and therefore a) overdone b) obvious c) cheaper because of ebay component dumping d) unique ) I might have the opportunity of dumping all in a 1590B case...

If:
Someone is able to suggest a smaller size ritary switch than the chunky Lorlins....

Help ??

Try the Grayhill rotary switches. Some are resettable [click positions] and all are built NASA grade. Oh yeah, they're "spendy"...

Little VOODOO VIBE project by Kaputepalla [documentation]