Stuff you wanted to know but were afraid to ask

[szukalski]

I wasn't trying to be snarky and hoping someone legit answers my question with what they like about indie rock

I’m not a big indie fan (Frightened Rabbit aside, that’s some great stuff) but I do like the abundant mid-range in the mix.

I always found indie was the whole “we are cool by not trying to be cool” image. Whilst trying very hard to capture that image. “Look how much I don’t care”.

 

[szukalski]

Indie rock, as with all genre classifications, is an absolutely worthless designator of musical content. As such, the appeal of indie rock is entirely dependent on the track.

Totally agree. Genre aside, it’s the artist transcending the playing experience and breaking through the wall to let the music flow!

 

[spi]

What exactly is the purpose of grounding the circuit input when the effect is bypassed? I see this often, and it *seems* like a good idea, but I can't articulate exactly why this is done. I've also seen schematics for 3PDT breakout boards that ground both circuit input and output. Why or why not do both, if it's worth doing for the input?

Aside from the noise of switching the circuit on, I've heard another reason is that some circuits can cause noise in the bypassed signal path, even with true bypass, by their vicinity to the switch, and grounding the input will help avoid this issue.

 

[Robert]

What exactly is the purpose of grounding the circuit input when the effect is bypassed?

It ensures that the input coupling capacitor is discharged while the circuit is in bypass, otherwise if voltage accumulates it will cause a pop in the signal path when the pedal is switched on.

Also, for high gain circuits it serves as a form of circuit "mute" ... A wildly self-oscillating circuit like the Fuzz Factory™ will bleed into the bypassed signal through the ground path, grounding the input stops the oscillation while the circuit is bypassed.

 

[Aentons]

I wasn't trying to be snarky and hoping someone legit answers my question with what they like about indie rock

When I think Indie Rock. I think about bands like Modest Mouse and Built to Spill and the bands that came out of Sub Pop after "Alternative" started to become Pop Rock. Indie was a reaction to bands getting signed and produced by the major lables to churn out hits that fit a mold. Indie was a way for artist to ensure more creative freedom by sticking with independent labels. So what's good about Indie Rock is that you (potentially) get a wider range of creativity. Indie is now doing what Alternative did before it and turning into mostly junk. Its all just classic rock already anyway.

 

[Chuck D. Bones]

I apologize if this one has been asked and answered already.

"WTF?"

 

[Deperduci]

I didn't want to know Chuck... somethings are just... NOOOPE!!

 

[Diynot]

Why are all expression pedals TRS? I get that you are essentially hijacking three pot lugs, but if a lot of the time the pot in question is simply a variable resistor, there is no need for the ring connection, right? I ask because I am wondering how feasible/useful it would be to make a 1/4in plug attached to a vactrol that could be driven by the Wavelord to be used as an expression control.

 

[Chuck D. Bones]

Very do-able.

In the case where you might need a 3-terminal (TRS) interface, you could connect the Vactrol's LDR between Tip & Sleeve and connect a fixed resistor, something in the neighborhood of 10K to 100K, between Tip & Ring.

 

[Deperduci]

I thought they were TRS(the 2 "hot" or tip wires)was because only 1 cable/jack is involved and how would you send the signal back?

 

[Chuck D. Bones]

This should explain it all:

https://www.ramblefx.com/expression

 

[andare]

Ok here's a big learning moment for me and a duh! moment for you.

I know the value of volume pots in guitars affects how bright they are. The more resistance they have, the less high end bleeds to ground and the brighter the guitar is.
So I suppose this applies to pedals as well.

If I want to make a pedal brighter, should I use a larger volume pot? And vice versa.

So a Fuzz Face has a lot of bass and it uses a 470/500k volume pot to retain high end. Makes sense.

Why does Analogman reduce the bass by using a 1uF input cap only to darken the pedal by using a 250k volume pot?
Doesn't that essentially make the pedal mid-heavy?

 

[Deperduci]

that's what I thought... constant voltage out, pedal replaces normally seen knob on the rheostat/potentiometer, return voltage determines volume. other than the rotating foot pedal, should be amongst the easiest to build, IE got a housing rest is brain donor hard.

 

[Chuck D. Bones]

Here's the low-down on volume controls:
On guitars, Volume controls interact with the pickups, the cable and the next device in the chain.
Pickups have a DC resistance, that's the number we see quoted in advertisements. "Our hot humbuckers are wound to 12K." Pickups also have an AC impedance and that varies with frequency. All magnetic pickups have an electrical resonance, usually in the 3KHz to 8KHz range. At resonance, the pickup signal is strongest, and the pickup's output impedance is also at its highest. Any loading of the pickup, whether it's from the Volume control, Tone control, cable, or the stuff on your pedal board, will affect the pickup's frequency response, especially at resonance. It's the resonant peak that is responsible for a large part of a pickup's brightness. Higher value Volume controls provide a lighter load to the pickups and let more of the "sparkle" come thru.
When we turn the Volume control down, we're putting some resistance between the pickups and the cable, and everything downstream of the cable. The Volume control's resistance and the cable capacitance form a low-pass filter which darkens the tone. This is reason for installing a Treble Bleed on a guitar's Volume control. The Treble Bleed helps compensate for the high freq loss in the cable. It's not perfect, but it helps.
When we introduce resistance between the pickups and the first (active) pedal in the chain, we can affect that pedal's behavior. The Fuzz Face is a prime example. It has a very low, non-linear input impedance. It loads the pickups, reducing the treble and creating distortion right at the input of the pedal. When a pedal advertisement touts "responsive to guitar volume," that's one of the reasons why.

In summary, larger value guitar Volume controls can result in a brighter tone and stronger interaction with pedals.

OK, so much for guitar Volume controls, What about pedal volume controls?
Most pedals have their Volume control at the very end of the circuit. Notable exceptions are any pedal with buffered bypass. Pedals generally have a much lower output impedance than pickups. They are less susceptible to loading from the pedal's Volume control. But, the pedal's Volume control will form a low-pass filter with the capacitance of any cable that comes after it. A larger value Volume control will have a lower cutoff freq. The filtering effect is strongest when the volume control is at the electrical midpoint. That's noon with a B-taper pot, but more like 2:30 with an A-taper pot. At 7:00 and 5:00, the volume control's resistance is zero and then it's not part of a low-pass filter. The original Fuzz Faces did not have tone controls or any filtering at the end. Pedal builders installed large value (500K) Volume controls so that they'd get some filtering from the Volume control and the cable capacitance.

Larger value pedal Volume controls result in a darker tone IF the pedal's Volume control is at the very end of the circuit. The pedal's Volume control can also interact with the next pedal in the chain, much like a guitar's volume control.

Lotta words, I know. Hopefully it makes sense.

 

[andare]

Here's the low-down on volume controls:
On guitars, Volume controls interact with the pickups, the cable and the next device in the chain.
Pickups have a DC resistance, that's the number we see quoted in advertisements. "Our hot humbuckers are wound to 12K." Pickups also have an AC impedance and that varies with frequency. All magnetic pickups have an electrical resonance, usually in the 3KHz to 8KHz range. At resonance, the pickup signal is strongest, and the pickup's output impedance is also at its highest. Any loading of the pickup, whether it's from the Volume control, Tone control, cable, or the stuff on your pedal board, will affect the pickup's frequency response, especially at resonance. It's the resonant peak that is responsible for a large part of a pickup's brightness. Higher value Volume controls provide a lighter load to the pickups and let more of the "sparkle" come thru.
When we turn the Volume control down, we're putting some resistance between the pickups and the cable, and everything downstream of the cable. The Volume control's resistance and the cable capacitance form a low-pass filter which darkens the tone. This is reason for installing a Treble Bleed on a guitar's Volume control. The Treble Bleed helps compensate for the high freq loss in the cable. It's not perfect, but it helps.
When we introduce resistance between the pickups and the first (active) pedal in the chain, we can affect that pedal's behavior. The Fuzz Face is a prime example. It has a very low, non-linear input impedance. It loads the pickups, reducing the treble and creating distortion right at the input of the pedal. When a pedal advertisement touts "responsive to guitar volume," that's one of the reasons why.

In summary, larger value guitar Volume controls can result in a brighter tone and stronger interaction with pedals.

OK, so much for guitar Volume controls, What about pedal volume controls?
Most pedals have their Volume control at the very end of the circuit. Notable exceptions are any pedal with buffered bypass. Pedals generally have a much lower output impedance than pickups. They are less susceptible to loading from the pedal's Volume control. But, the pedal's Volume control will form a low-pass filter with the capacitance of any cable that comes after it. A larger value Volume control will have a lower cutoff freq. The filtering effect is strongest when the volume control is at the electrical midpoint. That's noon with a B-taper pot, but more like 2:30 with an A-taper pot. At 7:00 and 5:00, the volume control's resistance is zero and then it's not part of a low-pass filter. The original Fuzz Faces did not have tone controls or any filtering at the end. Pedal builders installed large value (500K) Volume controls so that they'd get some filtering from the Volume control and the cable capacitance.

Larger value pedal Volume controls result in a darker tone IF the pedal's Volume control is at the very end of the circuit. The pedal's Volume control can also interact with the next pedal in the chain, much like a guitar's volume control.

Lotta words, I know. Hopefully it makes sense.

Thank you Chuck!

Most of it went whoosh over my head but basically volume pot resistance works opposite in pedals, more resistance means a darker pedal right?

Time to test that on a breadboard to see it in action. Let's see if I can darken a Fuzzrite and brighten a Fuzz Face.

 

[Chuck D. Bones]

If you want to simulate the capacitance of a long cable, stick a 100pF to 330pF cap from the pedal output to GND.

 

[Diynot]

Here’s another one that I only just thought ab whilst messing with my Sonic Reducer pedal that leaks a high pitched whine even when in bypass. Why does the common footswitch wiring ground the input of the circuit when in bypass, when conceivably those pedals that may exhibit clock/lfo noise or digital whine when in bypass might benefit (presumably) from grounding the circuit out when in bypass. I guess to answer part of my own question, sometimes the noise is passed from those chips by virtue of proximity to the wiring/insulation.

 

[Chuck D. Bones]

There are a few reasons for grounding the input to a pedal circuit when in bypass mode.
1. High-gain circuits can pick up and amplify radio interference when their inputs are left floating. That amplified noise can then bleed into the bypass signal.
2. High-gain circuits can oscillate when their inputs are left floating. The oscillation can then bleed into the bypass signal.
3. Grounding the input ensures that the input side of the input coupling cap has zero volts on it in bypass mode, which prevents popping when the stomp switch is toggled. An anti-pop resistor serves the same purpose.

Everything inside the pedal is coupled to some degree due to proximity and shared power and ground. We do what we can to minimize stray coupling by carefully routing the traces and wires, using a ground plane on the PCB, grounding the enclosure and pot bodies, etc.

 

[music6000]

Here’s another one that I only just thought ab whilst messing with my Sonic Reducer pedal that leaks a high pitched whine even when in bypass. Why does the common footswitch wiring ground the input of the circuit when in bypass, when conceivably those pedals that may exhibit clock/lfo noise or digital whine when in bypass might benefit (presumably) from grounding the circuit out when in bypass. I guess to answer part of my own question, sometimes the noise is passed from those chips by virtue of proximity to the wiring/insulation.

I was going to ask if the Input goes to Ground in Bypass to stop Bleed from the Circuit on your build.
It's a well known mod to do to older style pedals & standard practice nowadays!

Chuck answered it for you!

 

[mhshizz]

Here's the low-down on volume controls:
On guitars, Volume controls interact with the pickups, the cable and the next device in the chain.
Pickups have a DC resistance, that's the number we see quoted in advertisements. "Our hot humbuckers are wound to 12K." Pickups also have an AC impedance and that varies with frequency. All magnetic pickups have an electrical resonance, usually in the 3KHz to 8KHz range. At resonance, the pickup signal is strongest, and the pickup's output impedance is also at its highest. Any loading of the pickup, whether it's from the Volume control, Tone control, cable, or the stuff on your pedal board, will affect the pickup's frequency response, especially at resonance. It's the resonant peak that is responsible for a large part of a pickup's brightness. Higher value Volume controls provide a lighter load to the pickups and let more of the "sparkle" come thru.
When we turn the Volume control down, we're putting some resistance between the pickups and the cable, and everything downstream of the cable. The Volume control's resistance and the cable capacitance form a low-pass filter which darkens the tone. This is reason for installing a Treble Bleed on a guitar's Volume control. The Treble Bleed helps compensate for the high freq loss in the cable. It's not perfect, but it helps.
When we introduce resistance between the pickups and the first (active) pedal in the chain, we can affect that pedal's behavior. The Fuzz Face is a prime example. It has a very low, non-linear input impedance. It loads the pickups, reducing the treble and creating distortion right at the input of the pedal. When a pedal advertisement touts "responsive to guitar volume," that's one of the reasons why.

In summary, larger value guitar Volume controls can result in a brighter tone and stronger interaction with pedals.

OK, so much for guitar Volume controls, What about pedal volume controls?
Most pedals have their Volume control at the very end of the circuit. Notable exceptions are any pedal with buffered bypass. Pedals generally have a much lower output impedance than pickups. They are less susceptible to loading from the pedal's Volume control. But, the pedal's Volume control will form a low-pass filter with the capacitance of any cable that comes after it. A larger value Volume control will have a lower cutoff freq. The filtering effect is strongest when the volume control is at the electrical midpoint. That's noon with a B-taper pot, but more like 2:30 with an A-taper pot. At 7:00 and 5:00, the volume control's resistance is zero and then it's not part of a low-pass filter. The original Fuzz Faces did not have tone controls or any filtering at the end. Pedal builders installed large value (500K) Volume controls so that they'd get some filtering from the Volume control and the cable capacitance.

Larger value pedal Volume controls result in a darker tone IF the pedal's Volume control is at the very end of the circuit. The pedal's Volume control can also interact with the next pedal in the chain, much like a guitar's volume control.

Lotta words, I know. Hopefully it makes sense.

I still don't quite understand phrases "it loads the pickups down" or "(thing) loads (previous thing in chain)". What does that mean, exactly?