Small Stone Mod problem NE-1

[BillyJ]

We did the mods to my friends SS.
http://diystompboxes.com/sboxforum/viewtopic.php?t=18301&highlight=

The blend Mod works but only when in the shallow mode.
In the deep mode it goes from wet to wet either side of the pot or at least a blended signal.

BTW I I put the blend pot in by taking out the two mixing resistors like moose suggests.
Mark I was concerned about the notch effect but am told it sounds like it should to him but the blend not working properly in deep mode is a bugger....

Dry lift works in all various settings.

I'll get back under the hood and see if I can figure something I did stupid.
rats I was all patting myself on the back on this one too.  

[BillyJ]

bump

[moosapotamus]

I think what you describe makes sense. Check the SS scheme. With the color switch on (in deep mode) the signal from the output of the phase stages is fed back into the input section (regeneration). In other words, when the color switch is on, you have wet signal on both legs of your blend pot.

Getting it to work as a continuous blend, from completely dry to completely wet, looks kinda tricky. You might need to add an addtitonal input buffer and maybe replace the color switch with a 3PDT toggle so you can switch the connections to the blend pot when you switch to deep mode. Maybe someone else can think of a better way, tho.

~ Charlie

[BillyJ]

Moose thanks..Shoot I didn't even look at that but sure enough plain as day...oh well he isn't too bummed. He was (and I) were more concerned with it doing something wrong...
I did notice some loss of effect when panned fully to the wet side and am now wondering if this is that notch effect Mark talked about...
Well shoot cool mods all the same!!!

[Mark Hammer]

Hmmm,

I thought I had replied to this, but my net connection at home (and Netscape in general by my typing) gets interrupted so frequently, I lose track of what has and hasn't been successfully transmitted.

There are occasions where a true blend control works wonders and others where it is maybe even the lesser of options.  In the case of the Small Stone, my own preference is to use a switch+pot solution.  My reasoning is this.  There are plenty of occasions where you'd want more dry than wet (e.g., when you need a subtler effect or the regen is cranked so high that you need to turn the wet down to achieve a reasonable balance), but very few where you'd want or need more wet than dry...at least in amounts other than 100% wet.

So, what I'd recommend is using a simple dry-lift SPST toggle in combination with a wet-amount pot.  The wet-amount control turns into a 22k fixed resistor plus 100k pot (wired as variable resistor in series, from the stock 27k fixed resistor.

If I said one rarely neds more wet than dry, why a 22k fixed resistor?  Simple.  Maximum notch depth requires a perfect 50/50 mix of wet/dry.  Component values/tolerances for the 27k and 30k fixed resistors used to achieve a 50/50 wet/dry mix bring you very close but may not nail it perfectly.  Use of the 22k+100k values described will provide enough assurance of *less* resistance than you need for 50/50 balance that you can easily dial in 50/50 with the pot, in addition to dialing the wet signal into the background.

[BillyJ]

No Mark you did reply but it was another thread..
I wasn't sure at the time if my friend was looking for a wetter mix than stock or drier or both so I went with Mooses suggestion.
It works pretty fine and dandy too. I might have approached the whole mix thing a bit different if I had been wise enough to see it wasn't going to function on deep mode but it he doesn't really use it in that mode so it's ok.
He is going in to the studio to record with it next week and needs it back tomorrow or I might try the approach you mention Mark...in fact I think when he is done recording I am goin to do it that way.
Curiously in his SS (First re-issue I believe) that 27k R is a 30K....
I think I found a few 30K's in this circuit like that too...
Thanks for all the help everyone. These mods do have some really useful tones. I would suggest them to anyone wanting to turn their SS into a new animal.
Thanks again!!!

[Mark Hammer]

If you haven't done the phase-filter mod, try it out.  You'll be glad you did.  The wet-only phase-filter setting is sexy as hell.  The only comparison I can think of in nature is a mango, where it tastes like a hundred other things you can think of for just a split second before it changes again.

[BillyJ]

We did the Univibe mod using JC values, the Phase-Filter mod on the last two stages on one switch, and the dry-lift Vibrato mod, and the blend.
It really is awesome and I really like the 'Uni", phase-filtered, lifted dry at  fast speed.
Altogether it rocks!!! I dig it so much I habve already made a PNP for a SS.
I probably should have tried to tweak the board to accomodate the mods mine will get but this one I modded solidly and a clone should be no more difficult.
Mark, Moose, JC and all those others who's names escape me thank you all!!

[Mark Hammer]

Congrats!

I'd love to hear a sound-sample that would require 4 hands to create: two to play the instrument and 2 to gradually "mutate" the pedal configuration.  It's really quite remarkable what happens to this thing as you start to alter its structure.  It ends up being something that only resembles a phase shifter insomuch as it has an LFO and goes nyawr-nyawr-nyawr repetitively (I can't mimic the pitch shift with words!)

As I may have noted on another thread, I have 85% of a dual Ross Phaser built.  One is hardwired for Univibe mode, and the other is wired for vibrato and phasefilter options.  They each have their own LFO, but you can slave them both to the LFO from one of them.  In principle, you can have 4 Univibe stages, 2 regular same-cap allpass stages, topped off by 2 lowpass stages, in that order, driven by the same LFO, with resonance/regeneration for the last 4 stages.

I'm anxious to hear how this behemoth will sound.  Certainly, 8-stage phasers don't sound that dramatically different from 4 stagers but this particularly bizarre combination of distributed and clustered phase-shift plus lowpass should be a bit of a surprise. Being able to have the first one in vibrato mode in sync with the second in wet+dry mode will be interesting.