Is Univibing the Bad Stone possible?

[bluesdevil]

Has anyone done a Bad Stone "Univibe" cap switching mod with success? You can do the mod on the Small Stone as documented here:
http://www.lynx.bc.ca/~jc/pedalsSmallStone.html

I think I'm a bit confused about which caps I would change on the Bad Stone. I'm thinking it's the .047uf. Also according to the schematic I have it looks like the Bad Stone is a 5 stager. I built from this schematic:
http://topopiccione.atspace.com/pjimages/EHBadStone.sch.gif

The pedal is working great already, just would be cool to see if I could get it to vibe also!!!

[A.S.P.]

yes

[bluesdevil]

I think I figured out what four .047uf caps to change for the Univibing.... not sure why I thought it would be 5. I'll post back with details of the results if successful.

[StephenGiles]

Nothing to do with me, but why mod something which is already brilliant. I would be more inclined to build a dedicated Univibe.
Stephen

[Mark Hammer]

The thing I wonder about is how to maintain the shallowness of the notches when more stages are added.  The key to the Univibe seems to be that by distributing phase shift in a less focal way, and by only having to do so for 4 stages, you can get those very gentle broad-and-shallow dips that give the Univibe such a milky sound instead of obvious peaks and dips.  Once you start to add stages, it's not so clear how to maintain that.

Of course, that doesn't mean you can't tap the circuit after 4 stages or skip two somewhere.

[bluesdevil]

Nothing to do with me, but why mod something which is already brilliant. I would be more inclined to build a dedicated Univibe.
Stephen

I totally agree with you. It ended up just thinning it out and sounded puny. I actually found a control setting with the Bad Stone values that actually sounded closer to a Univibe than the cap changes I did!! I've already built a great sounding NeoVibe so I should have known  better, just wanted to try for an "all-in-one" thing.
Nothing ventured, nothing gained.... I'm just sorry I wasted my last bit of solder, DAMN!!!!!

[bluesdevil]

Ah, found a bit of solder from an old spool and had to try again!!! I tried using the original Univibe cap values instead of the suggested smaller ones and it thickened it up to my ears...... I'm liking it!! I used 2 DPDT toggles instead of 4 SPDT's.  The Bad Stone is fantastic on it's own, but the switching cap mod gives it even more of a tonal range if desired.

[lovric]

I remember that somwhere on this forum Mark Hammer and R.G. suggested that the regeneration control might not suit well the Uni-V modification.

[ocoughi]

greatings!

i'm projecting to do some more mods on my mk2 badstone. Trying to find different textures of filter sound, based on the small stone caps mods projects. apparently, this can be done with any kind of phaser?

to bluesdevil: this post is old now, have you made others mods on your bad stone? not only "univibing" it, but changing the 5 (0.047)caps with for exemple five 0.1 caps? or other values? is the diference notable, or with the time you think it's useless?
as lovric suggested, does the feedback pot work well with these mods?

to Mark: how did you "univibe" it without cap changes?

in fact, i would like my bad stone to go more in the bass/low-mids, this means that the manual pot could go lower....

i've alredy done a mod on it, it's an easy trick explained here:
http://fr.audiofanzine.com/phaser-guitare/electro-harmonix/bad-stone-mk2/astuces/t.2645.html

Have a nice day,
Peace
Manu.

[StephenGiles]

"you can have nice envelloppe folower phaser"

Could you explain further please?

[ocoughi]

hi!, it's not exactly an envelloppe follower, i've just recorded some sound with it but is there a way to upload an mp3 here? like any picture?
if not i'll find a way for you to here it....

[ocoughi]

 yep, video here: http://www.youtube.com/watch?v=k3ltEQnL0Qc
taken with the phone, so the sound is a little bit crunchy but it gives an idea of the sound... the feedback is at max all the time.

[Scruffie]

I see... so it's a Manual/Auto Blend so you can have Control of the Manual Sweep while in Auto Mode... not quite sure how it'll work but it sounds interesting enough!

[ocoughi]

yes that's it...the new pot has an on/off switch so turned at off, you get the original pedal fonctions.

[bluesdevil]

ocoughi: Sorry about the delayed reply. Years later reading this thread again, I can't believe the enthusiasm I had.... kinda embarrassing.
The stock Bad Stone caps are the best, really. If you want to experiment just socket the caps and let your ears decide. I did put in a couple of DPDT toggle switches to change out pairs of caps at a time, but prefer the stock values after all is said and done.
You will need a volume booster circuit tacked on the end, especially with the feedback control full up.

[ocoughi]

ahahah!!! yes that's 5 years back!!! sometimes old threads can escape from there grave!!
anyway, nuff thanks for your answer....
Musically....
Manu
PS: now this thread can sleep five years more......