Phase 90 Univibe mod. Which caps and what values?

[aab0mb]

I searched for the info and found some discussion but not the actual info in what caps to change and what values to change them to for the Phase 90 univibe mod.
i.e. C? to .47uf etc. 

If anyone could supply a link or info, it would be greatly appreciated.   I just need the locations on the pcb and the values to try.

Muchos Gracias!

[tcobretti]

Ok, I have never seen as explicit an explanation as you are asking for, but I think you can figure it out with a little help.

Here's a schem for the Phase 90.

http://www.geofex.com/FX_images/p180plus.gif

Here's one for a very similar design to the Univibe called the Easyvibe.

http://www.hollis.co.uk/john/easyvibe.jpg

Note that the caps before the 2nd, 3rd, 4th, and 5th opamp stages are different.  They are all .05u in the Phase 90 and they are .015u, .022u, 470p, and 4n7 in the easyvibe. 

So now what you need to do is trace the signal in on your phase 90, and figure out the order of the opamp stages.  Then replace the caps with the Easyvibe values.

[aab0mb]

Thanks for the info.  That should be what I need.  I'll post my results if any.

Appreciative,
A

[mr_fender]

I did the Univibe mod to my Phase 90.  Here's the values I used (from R.G.'s Univibe info):

"The correct values are 0.015uF, 0.22uF, 470pF, and 0.0047uF"

The different caps do add a bit of "vibe", but to me the most identifiable part of the Univibe is the uneven throb that it has.  The Phase 90's LFO and phase stages are too even and neat sounding.  The Univibe caps add a bit more swish to the P90's sound (cool in its own right and worth trying), but it doesn't quite get to Univibe territory.  The Univibe's discreet transistor design and weird LFO give it a "sloppier" character all its own.  I still do like the P90 mod though.  I have it setup with a 4PDT toggle switch so I can switch between stock Phase 90 and Univibe caps.  I also added a Depth pot, Feedback pot, and a Mix pot too for a bit more flexibility.  I used the project from Tonepad.com and got parts from Small Bear (Steve rocks!).  However, if I had it to do over again, I'd have built a Small Stone instead.  The Phase 90 is a quite subtle sounding phaser.  The Small Stone has a much deeper and more resonant sound to it, which I find I prefer.  I'd be interested to hear a Small Stone with the "mis-matched" Univibe caps.  Anyway, the NeoVibe is next on my DIY list...