How to make a clean blend?

jwin615 said:
Down my "things I want to do" list is a blend circuit using an MN taper pot.
View attachment 67338
These are used as pan pots and are also used some times in basses as pickup blends.
In the middle position you get 100% of both signals, attenuating one to either side.
It should be as simple as omiting the output pit on each effect, wiring 5o this guy(maybe as "no load") and an output buffer.
One thing to keep in mind is phase. If the dirt effect inverts phase, that will have to be addressed.
Click to expand...
I have a mono-in stereo-out mixer planned using a bunch of these for setting the L-R balance of each channel
 
I thought I was clever, and had a great idea. I made an input buffer, and an output buffer. To see what would happen, I connected the output of the input buffer directly to the input of the output buffer. I then connected the output of the input buffer to the input of a Muff Fuzz, and the output of the Muff Fuzz directly to the input buffer. I assumed this would sum the two signals. That is not what happened. Instead, I have made a siren. Hooray!
 
Aentons said:
I think the output of the MF should go to the output of the output buffer
Click to expand...

That's a good idea! I was thinking of making a clean buffer to go to the Clean pot. Then, the Muff Fuzz input buffer to the Muff Fuzz to the Fuzz pot. These would both feed to a Master pot. Kinda like a ZVex Super Duper, but not.
 
MBFX said:
I thought I was clever, and had a great idea. I made an input buffer, and an output buffer. To see what would happen, I connected the output of the input buffer directly to the input of the output buffer. I then connected the output of the input buffer to the input of a Muff Fuzz, and the output of the Muff Fuzz directly to the input buffer. I assumed this would sum the two signals. That is not what happened. Instead, I have made a siren. Hooray!
Click to expand...


As Tim Cummerford points out in his rig-rundown, the Larsen Effect and Dr Boner is/are an essential part of nature, and politics... 😸

 
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To see how these things work, I moved my "Little Muff" to the bottom half of the breadboard, and built an LPB-1 on the top half. The trimpots are 500K, and they're in place of what will be the "Clean" and "Fuzz" pots. Signal goes in to lug 3, comes out of lug 2, and shunts to ground via lug 1. Lug 2 of each trimpot connects to lug 3 of the master volume pot.

This works well enough. I hear each circuit, I can control the volume and relative volume of each, and it is on the right track. Problems include:

1. If either side is turned all the way down, all sound stops completely

2. I'm pretty sure I'm getting phase cancellation due to the Muff Fuzz inverting the signal, but I'm not sure.

3. The LPB-1 sounds so, so shitty here. I think it's because it and the Muff Fuzz have different input impedance and that is ruining everything

I know how to experiment and fix problems 2 and 3. Can anyone help with problem 1? I'd like to be able to kill either signal entirely.
 

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I can't make it easy to read without heavily simplifying things, but that shouldn't matter TOO much I don't think. The relevant parts are there.
PXL_20240215_193455783.jpg
 
In my limited breadboarding sessions on clean blends, I've found that buffers before each of the two signal chains can work. Meaning the input signal goes into two separate buffers. Buffers do their impedance thing, but also completely stop any other circuit blocks from messing around.

In blending your two circuits, you've got phase cancellation going on.
 
Since you don't seem to have a buffer in front according to your "schematic", that might be cause of your troubles.
Series resistance pots for the mixing as you've drawn it up isn't great.
On phase cancellation: as both the muff fuzz and LPB-1 invert the phase, there shouldn't be any issue give you've done anything right.
Impedances shouldn't be an issue either with an input buffer to split.
There's no need for 2 seperate buffers for signal splitting either.

Take some "inspiration" from the clean blend circuit here:

The only issue I see is that the muff fuzz might not like being placed after a buffer and will be painfully bright. In that case you can put a cap like 470p or so between the base and collector of its first transistor.
 
jesuscrisp said:
Since you don't seem to have a buffer in front according to your "schematic", that might be cause of your troubles.
Series resistance pots for the mixing as you've drawn it up isn't great.
On phase cancellation: as both the muff fuzz and LPB-1 invert the phase, there shouldn't be any issue give you've done anything right.
Impedances shouldn't be an issue either with an input buffer to split.
There's no need for 2 seperate buffers for signal splitting either.

Take some "inspiration" from the clean blend circuit here:

The only issue I see is that the muff fuzz might not like being placed after a buffer and will be painfully bright. In that case you can put a cap like 470p or so between the base and collector of its first transistor.
Click to expand...
Jinx.
 
BuddytheReow said:
In my limited breadboarding sessions on clean blends, I've found that buffers before each of the two signal chains can work. Meaning the input signal goes into two separate buffers. Buffers do their impedance thing, but also completely stop any other circuit blocks from messing around.

In blending your two circuits, you've got phase cancellation going on.
Click to expand...

This is basically what I think I need to learn how to do. The Muff Fuzz actually has an input and output stage that I omitted from my shitty diagram. They are the input and output stages of your standard Big Muff, as shown here:

1708066359329.png

And here are the Muff Fuzz layouts. I didn't actually use a schematic for these... I'm not very comfortable reading schematics that use ICs yet.

1708066380297.png

I built the op-amp version. I actually made two - one exactly to plan, and one with a 100nF input cap. I like that second one a lot better. They both sound good on their own, but much better with the input stage, and WAY better with both the input and output stages. Honestly very plain, but for a P-Bass that's a good thing.

KR Sound said:
Check out how the Bootleg does it with an NE5532A

Click to expand...

Thank you, I will.

jesuscrisp said:
Since you don't seem to have a buffer in front according to your "schematic", that might be cause of your troubles.
Series resistance pots for the mixing as you've drawn it up isn't great.
On phase cancellation: as both the muff fuzz and LPB-1 invert the phase, there shouldn't be any issue give you've done anything right.
Impedances shouldn't be an issue either with an input buffer to split.
There's no need for 2 seperate buffers for signal splitting either.

Take some "inspiration" from the clean blend circuit here:

The only issue I see is that the muff fuzz might not like being placed after a buffer and will be painfully bright. In that case you can put a cap like 470p or so between the base and collector of its first transistor.
Click to expand...

Does the BMP input stage count as a buffer? I'm still unclear on what a buffer actually IS, especially vs a basic transistor amplifier. Do you feel like dumbing it down for me?

I am also interested why my choice of pots for mixing is a bad one. I know it is a bad one, because it sounds shitty and does impractical things, but I am very interested to learn why. Any knowledge you want to throw my way is appreciated!
 
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