Phase90Mods part2

[sugonidamaso]

Hello everyone! I posted while back modding my phase 90 from tonepad. But I just found this perf: http://aronnelson.com/gallery/main.php/v/jdub/Phase+90+perf.PNG.html?g2_imageViewsIndex=1. There's a 4pdt switch involved. My question is there anyway I can change/substitute the switch? It is not available here in my area. Thank you very much!

[Mark Hammer]

If a person approaches the circuit in terms of "How many different sounds can I squeeze out of this?", then I suppose the 4PDT can be useful.  But quite honestly, the cost of all the parts to make a 2nd P90, configured to be a Uni-Vibe, probably wouldn't be much more than the cost of the switch.  It's also the case that switching the caps makes a "pop".  Also, combining a phaser and a Uni-vibe can produce some nice sounds.

So my advice is to just make a 2nd build with the Uni-vibe cap values.  Note that Uni-Vibes are usually very hard to hear/detect at slow speeds.  The notches and peaks produced by phasers are very pronounced, so they can still be heard even when the sweep is very slow.  Vibes produce very shallow and wide "dips" that are hard to notice unless they move quickly.  Finally, vibes do not use any feedback/resonance controls.  So, my advice for the 2nd build - assuming you want a Vibe as well as a phaser - is to use a 100k speed pot, instead of 500k, and omit the 22k feedback cap that Francisco shows in red.

[sugonidamaso]

Thank you for the info Mark! It's been a while since I get my bearings in building again (2 +years:o still lousy ). In addition to my problem is that the P90 I built got a distorted sound(capacitors maybe? Yes, its a while since I stomp my boxes:o just my guitar sometimes). In addition, if I use this vero (I have stocks of this type-too lazy to etch), can I just remove the resonance pot? And change the 22k to 100k pot (I still want the vibe )? what about the script switch?sorry, lots of questions! Thank you very much!