A few Green Ringer questions

[mordechai]

I am thinking of putting a Green Ringer into an enclosure following a Fuzz Face circuit...I want to put it on a switch so that I can switch in and out the octave-up while playing.

A few questions, though:

1. Since this will follow a fuzz face, do I needs the initial BJT gain stage in the GR circuit...or can I just wire from the FF Volume pot lug 2 out  to the input of Q2 on the GR?  I noticed on the Mutron Octave Divider, the GR part of the circuit eliminates the Q1 stage since it's being driven fairly hard by an op-amp.  Can I do something similar? 

2. Do you have any recommended value tweaks on the resistors going to the base of the Q2 stage?  On some schematics for the normal GR circuit, it's 15K/4.7K...on the Octave Divider, it's 47K/22K, which I suspect has to do with the way the signal is going into the Q2 stage. 

3.  What is the effect of lowering the twin 68K resistors to 56K (as I see in some schematics)? 

4.  I was thinking of using BAT46 diodes instead of germaniums.  The voltage drop is not quite as dramatic, but still more than something like a 1N914 or the like.  Might this lessen a touch of the ice-picky shrillness of the octave-up effect? 

[Ben Lyman]

Are you planning on breadboarding first? I determined that the GR just needed a little OD/booster in front of it but I liked the Fuzz after the Ringer.
You can check out my version, I call it the Form-Inator:
http://www.diystompboxes.com/smfforum/index.php?topic=113381.msg1050204#msg1050204
In that thread I posted a demo of it by itself and with an Electra following it.

With great help from PRR, I turned the output unity buffer into a booster with volume knob, another consideration for your build.

I had a guy buy a Ge Tone Bender and a Form-Inator from me so I made him a little demo of how I like to do it with my MKII Fuzz after the Ringer, you can check it out on youtube:
https://youtu.be/iczQ2_RoLFk

Just some ideas, hope they help you on your way to something you like 

[Mark Hammer]

The thing to remember about phase-splitter-based frequency doublers is that they will not only double all the frequency content you feed them (including all the harmonics), but they will add harmonic content during the recification.   The result will be that any octave will get lost in all the harmonic content of a fuzz being doubled by another fuzz.

That doesn't mean the idea is foolish.  Rather, if most folks who use an octave fuzz feel they get optimal performance by rolling the treble off a neck pickup, then feeding a Ringer with a Fuzz Face demands some sort of signal conditioning in between the two for the Ringer to deliver its best.

I will say that on my own Ringer, I have a Stratoblaster front end with 3 gain presets to extract decent octave out of varying input signal levels.  I also love my D-Scrambler, which is a modded Distortion+ feeding an Ampeg Scrambler.  So the idea of a hot front end, capable of some sustain (via clipping), feeding a doubler, is sound in principle.

As I see it, the choice is between having some sort of fixed filtering between the FF and GR that is engaged when the GR is engaged, or some sort of variable filtering that is part of the FF to fine tune its output for doubling.

[mordechai]

Well Mark, for my purposes, I plan on having the ringer FOLLOW the Fuzz Face.  I've tested them as separate circuits and I like the resulting tone from that sequence.

What I'm trying to determine is -- in addition to whether or not I need that first Q1 gain stage -- how best to wire both circuits into a single enclosure with a common output.  I've wired two circuits in series before and I don't see why I couldn't just do it that way...but I'm wondering if there's a downside to that in any way, as opposed to having the fuzz ALWAYS going through the GR, but perhaps disengaging the parts of the GR that create the octave until I hit a stompswitch to re-introduce them. 

If there isn't really a substantial benefit to that, then I'd just wire them as separate circuits in series.  But even then...if you can foresee adjustments to the GR that would make it play nice with a Fuzz Face signal hitting it, I'm definitely open to suggestions.

[Mark Hammer]

Well, if I get nicer octaving with an additional gain stage ahead of the Ringer, then I think leaving the Q1 stage in the Ringer is probably for the best.  Being able to push the Ringer hard, by having the FF volume up, can also get some interesting things.
But the Ringer should have some treble-trimming at its input.  You should consider some sort of cap to ground on the input to the Ringer, so that whatever sizzle you get from the FF is tamed before it hits the Ringer.  I'd offer a value, but I think this is just something you have to figure out with your own ears.  Probably wouldn't hurt to start out with 1000pf, and take it in one direction or the other from there,

[LightSoundGeometry]

I have to have my octave first in path..and my vibe ..all right in front even before my RM ..I had a ringer under my pickguard for a while but stomping a foot switch was much easier than toggling (couldnt adapt to toggling an on board effect whilst playing) a switch on the front.

[mordechai]

Well, if I get nicer octaving with an additional gain stage ahead of the Ringer, then I think leaving the Q1 stage in the Ringer is probably for the best.  Being able to push the Ringer hard, by having the FF volume up, can also get some interesting things.
But the Ringer should have some treble-trimming at its input.  You should consider some sort of cap to ground on the input to the Ringer, so that whatever sizzle you get from the FF is tamed before it hits the Ringer.  I'd offer a value, but I think this is just something you have to figure out with your own ears.  Probably wouldn't hurt to start out with 1000pf, and take it in one direction or the other from there,

Well, I'm incorporating the (popular) filter mod, which I think helps filter out some treble and makes the octave stand out more.  Would that do the trick or do you think tacking a 1n to ground on  the front end would still be advisable?

[Mark Hammer]

Well, if I get nicer octaving with an additional gain stage ahead of the Ringer, then I think leaving the Q1 stage in the Ringer is probably for the best.  Being able to push the Ringer hard, by having the FF volume up, can also get some interesting things.
But the Ringer should have some treble-trimming at its input.  You should consider some sort of cap to ground on the input to the Ringer, so that whatever sizzle you get from the FF is tamed before it hits the Ringer.  I'd offer a value, but I think this is just something you have to figure out with your own ears.  Probably wouldn't hurt to start out with 1000pf, and take it in one direction or the other from there,

Do what you were planning, first, and then take additional action if you find it isn't enough.
Well, I'm incorporating the (popular) filter mod, which I think helps filter out some treble and makes the octave stand out more.  Would that do the trick or do you think tacking a 1n to ground on  the front end would still be advisable?