Another why is this FuzzFace so quiet quesiton?

[m4268588]

That "47n" is the culprit.
159/10.1/.047 ≈ 335Hz

[FingerBlisters]

That "47n" is the culprit.
159/10.1/.047 ≈ 335Hz

My maths must be wrong.

A 100r/47n low pass starts rolling off at around 10khz, which is above what speakers produce. It was intended to just reduce any hiss and sizzle.

Am I missing something? Is there another R value creeping in somewhere that's ducking with the 100 ohm value I have? Something upstream from Q3 perhaps?

I'll take it out and see what I see.

Cheers for the suggestion

Now that I look I could probably put a cap over the vol pot between lugs 2 and 1 to do the same thing.

[antonis]

m4268588 deals with a complex filter consisting of 10k Collector resistor, 10μF output cap, 100R series resistor and 47nF shunt cap..

[FingerBlisters]

m4268588 deals with a complex filter consisting of 10k Collector resistor, 10μF output cap, 100R series resistor and 47nF shunt cap..

Ah. I thought his second line was a typo or a cat walked across the keyboard. Turns out it was a helpful equation.

I removed the 47nf, restored brightness. Now there's too much so I'll amend the 47pf caps in the feedback loops to kill it early.

What fun it is chasing your tail.

Thanks guys, once again!

[PRR]

> I thought his second line was a typo or a cat walked across the keyboard. Turns out it was a helpful equation.

m4268588 knows HTML better than this forum does. (The forum seems to block HTML entity interpretation.)

Character(s)    Literal(s)    Alphanumeric value(s)    Unicode value(s)    Prefer to
Almost equal to    ≈            ≈                      ≈                    ~
https://www.w3.org/wiki/Common_HTML_entities_used_for_typography

So:
159/10.1/.047 ≈ 335Hz
159/10.1/.047 about equal to 335Hz

[FingerBlisters]

> I thought his second line was a typo or a cat walked across the keyboard. Turns out it was a helpful equation.

m4268588 knows HTML better than this forum does. (The forum seems to block HTML entity interpretation.)

Character(s)    Literal(s)    Alphanumeric value(s)    Unicode value(s)    Prefer to
Almost equal to    ≈            ≈                      ≈                    ~
https://www.w3.org/wiki/Common_HTML_entities_used_for_typography

So:
159/10.1/.047 ≈ 335Hz
159/10.1/.047 about equal to 335Hz

Ah yes that makes a lot more sense.

Changing that cap to something around a 6.8n seems to strike a good balance between hiss suppression and high end availability.

Cheers guys.

[Lino22]

If i understand well, the 22uF cap between collectors C1 and C2 shunts the signal, so it ignores the extra starvation resistance, and so the output doesn't get louder with less DC voltage (and thus more collector resistance).
On the other hand, i looks like it will kill the DC fluctuations that come with hard notes, caused by the high resistance of an exhausted battery.

For my curiosity, what would cause a diode on the wiper of the starve pot? Would it help not to let the signal see the extra resistance?

I don't think you need the pull down resistor on the input, the Fuzz pot should do.

[antonis]

For my curiosity, what would cause a diode on the wiper of the starve pot? Would it help not to let the signal see the extra resistance?

Only for half of signal waveform..