Anything wrong with this fuzz arrangement?

[Ben Lyman]

I wanted to get a little more volume so I moved the output cap right onto the Q2 collector. Is that bad?
Also, since I am going to use a 500k pot at the input, I was wondering if this is the right way to hardwire the R+C from Q2 emitter.

[LightSoundGeometry]

looks like the first part of a tone bender

[Ben Lyman]

looks like the first part of a tone bender

Close! but actually it's just a part of something I am creating myself with a FF circuit. I'm using some very old Ge transistors, Ge diodes, a tone control and possibly even a Si tranny as a boost. It sounds great on the breadboard but I just don't know if that output cap is in a bad way

[peterg]

Don't know if it's bad but breadboarding it will tell you. The 47k and 8k2 resister in series give you 478k2 from power to Q2 collector. You could play around with this value.

[peterg]

Ben. We posted at the same time. If it works on breadboard as you say then it's not bad. Others on the forum could tell you the implication of moving the cap location. Have you read Mr. Keen's fuzz face article?

[blackieNYC]

That 1k is often found to be a pot to ground, and the wiper is the cap to ground. You have the equivalent of a maxed out gain pot. Your input pot will be the gain adjustment. Right?

[Ben Lyman]

Ben. We posted at the same time. If it works on breadboard as you say then it's not bad. Others on the forum could tell you the implication of moving the cap location. Have you read Mr. Keen's fuzz face article?

I did read it awhile back and I don't remember if it mentions this, if it is just a matter of taste/tone or if it is a bad thing as far as voltage, impedance, etc.

That 1k is often found to be a pot to ground, and the wiper is the cap to ground. You have the equivalent of a maxed out gain pot. Your input pot will be the gain adjustment. Right?

Correct, the 500k input pot gives a very nice range of useable distortion tones. I did this before and it works great so I'm pretty sure that part will be okay, unless someone has a mathematical reason not to do it 

[Gus]

Have you read this? http://www.diystompboxes.com/smfforum/index.php?topic=112341.msg1036524#msg1036524 note the tone control

[Ben Lyman]

Have you read this? http://www.diystompboxes.com/smfforum/index.php?topic=112341.msg1036524#msg1036524 note the tone control

Thanks Gus, I forgot about that one, I see the cap is connected right to the collector so I guess it's all good then! I will try that tone circuit on mine too

[GibsonGM]

Only drawback I see is that controlling gain at the input presents a good path for noise to be introduced and amplified. Other than that, there aren't any actual 'rules'! 

[amptramp]

Check how the unit behaves over the range of temperatures it will encounter.  The Vbe of the transistors decrease as the temperature increases, meaning the sound will be different.  If you are using it at home or in a studio it should be fine.  If you are gigging with it, you should simulate the highest temp you will get in storage in your van at high temperatures.  This can be pretty high and the internals will not cool off all that quickly.  Also simulate the lowest temperatures you can expect, even if your tour does not include Nome, Alaska.  Minneapolis can get pretty cold.

[Ben Lyman]

Only drawback I see is that controlling gain at the input presents a good path for noise to be introduced and amplified. Other than that, there aren't any actual 'rules'! 

Thanks! You are right, as a simple FuFace it seems to work fine, no added noise to speak of. I made a demo vid of my Ge FF to show how clean and jangly it can be, really happy with that one. On this pedal however, as I proceeded to add the booster stage it did get noisy so I think I might have to go back to the standard gain control, except with that treble bleed that I had originally been working on. I just don't like the way gain controls get so muddy when turned down, IMHOP it just makes that part of the pedal useless and I would just as soon use a "One Knob Fuzz" instead.

Check how the unit behaves over the range of temperatures it will encounter.  The Vbe of the transistors decrease as the temperature increases, meaning the sound will be different.  If you are using it at home or in a studio it should be fine.  If you are gigging with it, you should simulate the highest temp you will get in storage in your van at high temperatures.  This can be pretty high and the internals will not cool off all that quickly.  Also simulate the lowest temperatures you can expect, even if your tour does not include Nome, Alaska.  Minneapolis can get pretty cold.

Thanks, I am aware (sort of in a rookie way) of this but my touring days are WAY behind me, garage rock and preschool sing-a-longs from here on out! 
Although, I do sell some of these to support Small Bear and Tayda so I do want them to be useable for other people (mostly other daddy rockers) and I seem to remember another member explaining to me how the emitter can have a Ge diode going to the base as a temperature stabilizer on my RM. Is there any tricks like that for Ge FF or TB fuzzes?

[PRR]

> moved the output cap right onto the Q2 collector. Is that bad?

Bad for what?

What is the context??

Taken on face value, the output is "too large" to go into a guitar-amp or almost any pedal. Nearly 3V.

But if we come across your full plan here we see that In Context you *follow* this too-big stage with a diode-clipper AND a trace of tone-loss AND a user-knob. So the too-big becomes slightly-big adjustable to about-right.

To answer the silly question "spot any redundancies"--- if you make a million of them you want to trim every cent first. But in DIY a "redundant" 12-cent resistor is cheaper than the brain-wear to find it and design it out.

8.2K and 470r was so the *direct* (no other stuff) output at the 470r was about guitar-size.

But you not using the 470r tap.

8.2K and 470r with nothing at the junction IS 8.67K. If you can find that value cheaper than the two values, pennies saved.

However if you get 100 transistors and resistors together, you will surely find them all a little different, and some "8.2K+470r" sound just-like some "8.2K". Resistors are 5% so a 410r variation in "8.2K" will happen from one to the next resistor. On top of that there's wide variation in transistors, although your modest Q2 B resistor does give much swamping. I would expect the product to sell fine without the 470r (effectively shorted).

But since it took me 10 minutes to type that, which on Salary might cost $1 (I'll send you my time-card on Friday), I've saved 12 cents and lost 88 cents overall. "Penny wise and pound foolish", as some folks say. "Redundancy", unless gross (whole do-nothing sections), are moot in one-off DIY work.

[Ben Lyman]

and...

SCHOOLED!!! 

Thanks again PRR! 

[Quackzed]

just wanted to underline that the 470k marked resistor should read 470R ,thats 470 ohms not 470,000 ohms... (no k)... this info did get tossed in on the side, but i figure it can't hurt to be sure you saw that...

[Ben Lyman]

just wanted to underline that the 470k marked resistor should read 470R ,thats 470 ohms not 470,000 ohms... (no k)... this info did get tossed in on the side, but i figure it can't hurt to be sure you saw that...

OOPS! Thanks, also be sure to check out my other thread on the final results, it's getting really close now: http://www.diystompboxes.com/smfforum/index.php?topic=112558.0