should i drill in to my green russian smallstone phaser??

[iainpunk]

i really want to do the depth knob mod on my green russian small stone phaser, but im afraid i am going to hurt its value

i really want to use it as an vibrato pedal, and it wasn't cheap, so i'm not afraid to hurt the value, but on the other side, it already has lost half its paint and the knob is way to lose and hard to fasten properly....

maybe a trim pot internally, or in the battery compartment....

any insight about modding this ancient artefact?

[soggybag]

Do it if you don't care about historical or collectible ness and don't plan to sell the original. If you think you might want to get rid of it or regret having drilled, make a new one instead. You could try and match the original since you have that for reference.

It's hard to get CA3094's so that might factor into the decision. If you wanted to plan something new you could use two LM13600, I think these are still available, in place of 4 CA3094's.

[willienillie]

Do you actually use the color switch?  If not you could use that hole.  I had one of those back in the mid-90s, I seem to recall the color switch being too extreme for me.

[Mark Hammer]

I modded the dickens out of a black Russian Small Stone, without any guilt whatsoever.  If it was a 6-chip Small Stone, I'd probably save it, but a 5-chip, Russian or not, is no big whoop.  They have terrible stompswitches.

It's been a while since I had it, but I think I added a dry-cancel toggle, a phasefilter switch, and split up the DPDT Color switch into its two functions.  The Color switch adjusts the resonance/feedback, and also adjusts the sweep.  It selects between a faster sweep range with a slightly narrower triangular waveform, and a slower, slightly wider hypertriangular waveform.  The former is best suited to faster speeds, and the latter optimized for long sweeps.  The hypertriangular sweep does a nice job of drawing attention to higher-feedback, but you don't HAVE to use higher feedback with it.  So splitting up the Color switch into its two separate functions is useful.  No wizardry involved, just a pair of SPDT toggles instead of a single DPDT toggle.

Made a nice unit. Lotsa flavors.

[iainpunk]

Do you actually use the color switch?  If not you could use that hole.  I had one of those back in the mid-90s, I seem to recall the color switch being too extreme for me.

i use the color switch alot, i flick it mid song with my foot, so id like to keep the functionality. it resides between two dirt pedals (overdrive in front and a fuzz after).
i want to use it as an vibrato for my other band.

i am just now opening him up and boy, the construction is weird, i didnt expect blue ribbon cables for the led, switches and pot.
i think i found the solution, the switch is going in to the battery compartment. since i never use batteries, easy peasy.

[Mark Hammer]

I thought I had a pic of what I did, and sure enough, I did.  Forgot to mention that I also replaced the stock bypass switch with a 3PDT and LED.  A much better pedal now.

[iainpunk]

I thought I had a pic of what I did, and sure enough, I did.  Forgot to mention that I also replaced the stock bypass switch with a 3PDT and LED.  A much better pedal now.

i just preformed the "no dry"/vibrato mod, but id like to take out the feedback as well
do you have schematics for the mods you preformed? i want to add an internal switch to kill the feedback

[Mark Hammer]

The feedback path shown below already seems to kill the feedback in one of the switch positions.  You can see that the wet signal is tapped off the last phase-shift stage and attenuated by the 3k3/4k7 pair.  It then passes through the 27k and .1uf pair, that are then connected to the 270k resistor and the input to the whole circuit.  The junction of the .1uf cap and 270k resistor are tied to the common of one set of contacts in the Color switch.  In one switch position, the 270k is shunted and the .1 is tied directly to the input, providing feedback.  In the other switch position, the 270k/.1uf junction now goes to ground, dumping the feedback signal, and using the 270k to provide a bit of input attenuation, such that the two Color-switch positions provide reasonably equivalent output levels.

"No dry" involves lifting one end of the 30k resistor that mixes dry with wet just before the output.  It would seem that the work of killing all feedback is already done for you by the Color switch.  I suppose if you wanted to vary how much feedback, you could replace the 27k resistor just before the Color switch with a 10k fixed resistor in series with a 25k variable resistor, to achieve even more resonance than stock, as well as less.  Naturally, grounding the .1uf cap would kill it.

[iainpunk]

after changing stuff around, i decided to use a 50k pot to control the amount of feedback, since i found the original feedback amount already was to much for my taste.

im currently waiting to get caps in, im all out of anything bigger than 2n2, but after that, im permanently changing the all pass caps with the univibe mod values. 1nF, 10nF, 470pF, and 4.7nF

http://www.lynx.net/~jc/pedalsSmallStone.html

i heard that mod at a friend of mine and it sounds amazing, just the amount of magic that came from his unit... wow he has a modern reissue of the small stone phaser, and im in love with the univibe mod, and im probably never going to use the stock values anyway, after having heard the mod, so im not even going to bother with the switches.

thnx, Iain

[Mark Hammer]

Just note that one of the Color switch positions implements an LFO waveform that is really better-suited to very slow sweeps.  I think what you will notice is that the slow sweep rates that work nicely for phasing do not work nearly as well for uni-vibe sounds.  The reason seems to be that where phasing provides notches and peaks one can focus on and still notice, even when they're not moving up or down very quickly, the broad-and-shallow dips of the Vibe are much harder to notice unless the sweep rate is at least medium speed.  They also need to move up and down at relatively consistent rates of change - ideally a sine wave - where the slower Color-switch position accelerates as it sweeps up, and decelerates as it gets to the lower part of the sweep.  Great for phasing, but unappealing for vibing.

That's no reason NOT to use the staggered cap values.  But I think you'll find that the more triangular LFO waveform obtained by one of the Color switch positions is more appropriate/successful than the other for vibing.

[iainpunk]

i alway have my speed knob fairly high, i dont like slow phasers, chorus, tremolo or vibrato. on the other hand, the other lfo wave shape is a normal triangle, not quite a sine as well.
and since i defeated the feedback side of the colour switch, replaced with a 50k trim pot, i can always get some in between sounds when the trim is set on max feedback.

both the trim and the no dry switch are in the battery compartment, for easy-ish access.

cheers, Iain