How to make a clean blend?

[MBFX]

I have a fun idea that I need help with. I really love the Voodoo Lab Sparkle Drive, which is a TS with a clean blend. I would like to experiment with fuzz pedals that have a clean blend, because I think that would work really well in my bass rig. I figure it shouldn't be too hard to achieve, but I don't really know where to start. I do have some ideas, though:

1. There probably needs to be a fuzz circuit and a clean boost circuit
2. The clean blend volume needs to scale with the fuzz volume somehow

I know I could buy a Buff 'N' Blend, but I'd like to learn how to do it myself because that is more fun.

 

[chris.knudson]

I have a fun idea that I need help with. I really love the Voodoo Lab Sparkle Drive, which is a TS with a clean blend. I would like to experiment with fuzz pedals that have a clean blend, because I think that would work really well in my bass rig. I figure it shouldn't be too hard to achieve, but I don't really know where to start. I do have some ideas, though:

1. There probably needs to be a fuzz circuit and a clean boost circuit
2. The clean blend volume needs to scale with the fuzz volume somehow

I know I could buy a Buff 'N' Blend, but I'd like to learn how to do it myself because that is more fun.

So, I have achieved this with an effects loop, where I mix my clean signal with a TS. I'm using the effects loop on an HX Stomp, but I am sure this can be achieved with any sort of effects loop where you are blending two different signals. If you can find a circuit that blends two different signal paths, you can achieve this.

 

[MBFX]

So, I have achieved this with an effects loop, where I mix my clean signal with a TS. I'm using the effects loop on an HX Stomp, but I am sure this can be achieved with any sort of effects loop where you are blending two different signals. If you can find a circuit that blends two different signal paths, you can achieve this.

That's definitely the kind of thing I am looking for! Trying to devise a solution that fits in a small enclosure is interesting, though. I suppose the schematic would look something like this:



That would give me everything from 100% clean to 100% fuzz. Is it this simple...?

@BuddytheReow you're really good at these things, do you have a moment to weigh in?

 

[chris.knudson]

Yeah, I think that's right, but I don't know enough about how to design the circuit. I only know how to achieve it with the tools I have at my disposal. I agree that this is a job for @BuddytheReow or @Chuck D. Bones.

 

[MBFX]

Well, I have the Muff Fuzz working. Sounds good! Pretty much what I was expecting - it's a lot like the Electra, but a bit cleaner and sharper and less squishy, and quieter. At full bore, it is a modest boost. I'm going to make an output buffer to give me more available gain, build a Micro Amp, and see about trying a clean blend. Who knows, I might get something nice or I might get a pile of parts to rework.

 

[MBFX]

This is probably a better idea:



There should probably be a trimpot before the blend pot to adjust the max output of the clean circuit

 

[Passinwind]

If you want to do two channel active summing I have a little open source PCB for that:



But if you'd rather roll your own with through hole parts it's a very basic inverting opamp summing circuit, about as cookbook as it gets. I'll be posting all the relevant info on Github once I build up the latest board revision, hopefully in the next week or so.

 

[MBFX]

If you want to do two channel active summing I have a little open source PCB for that:

View attachment 67324

But if you'd rather roll your own with through hole parts it's a very basic inverting opamp summing circuit, about as cookbook as it gets. I'll be posting all the relevant info on Github once I build up the latest board revision, hopefully in the next week or so.

Do you happen to have a schematic on hand you'd be willing to share here? If so, I'd owe you a favor!

 

[Passinwind]

Do you happen to have a schematic on hand you'd be willing to share here? If so, I'd owe you a favor!

This is just a quick and dirty example, we can figure out actual component values once we know what the signal sources are going to look like.

 

[MBFX]

once we know what the signal sources are going to look like

What info do we need?

 

[Feral Feline]

I'd also take a look at the JMK Paralyzer, the Fuzz Dog bass blender, Moonn's take on the Splitnblend and any existing circuits that already have a clean blend.

Study how they each deal with the splitting and mixing. Dunwich Amps had a cool blend, IIRC.

Apart from PPCB's offerings that have a clean-blend, there are some circuits over at Effects Layouts, and Parasit and ... more at MadBean, too.

 

[jwin615]

Down my "things I want to do" list is a blend circuit using an MN taper pot.

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.

 

[Aentons]

Here is the schematic for the TS9B bass tube screamer. It has a clean blend.

 

[BuddytheReow]

So, I've tried just throwing a pot between two outputs and it KINDA works. You can adjust the pot value to get 100% wet or dry, but anywhere in between and the volume drops dramatically. I've struggled with this in the past. Basically, check out schematics to see what's been done before and duplicate that. That's how I would do it.

 

[Fuzzonaut]

Another thing that helps with adjusting the mix to taste is a (simple) low pass filter filter on the clean signal.

Basically, you'd want to be able to boost and lowpass your clean signal.

 

[Passinwind]

What info do we need?

It's useful to know the source impedances and the signal levels, at least. This design can also do negative overall gain if desired, which can be very helpful in some cases.

 

[Feral Feline]

So, I've tried just throwing a pot between two outputs and it KINDA works. You can adjust the pot value to get 100% wet or dry, but anywhere in between and the volume drops dramatically. I've struggled with this in the past. Basically, check out schematics to see what's been done before and duplicate that. That's how I would do it.

Classic phase cancellation.

Try thowing an inverting "buffer" on one (1) of the signal paths just before going into the pot. I've also read about phase alignment circuits that are adjustable below/beyond 180º.



PS: Thought of it but nonetheless forgot to mention in my previous post the Klon as another clean-blend circuit to study.

 

[BuddytheReow]

I wouldn't say phase cancellation, since I took that into account. If you've got, say, a 500k pot between two signals you can get 100% dry and 100% wet. When you are in between those settings, the signal has to go through up to 250k of resistance to make it to the other side. Volume drop. Phase cancellation happens, at least to my ears, when the bottom end goes out and sounds like octave up.

Classic phase cancellation.

Try thowing an inverting "buffer" on one (1) of the signal paths just before going into the pot. I've also read about phase alignment circuits that are adjustable below/beyond 180º.



PS: Thought of it but nonetheless forgot to mention in my previous post the Klon as another clean-blend circuit to study.

 

[MBFX]

Here's an interesting one

 

[jwin615]

I wouldn't say phase cancellation, since I took that into account. If you've got, say, a 500k pot between two signals you can get 100% dry and 100% wet. When you are in between those settings, the signal has to go through up to 250k of resistance to make it to the other side. Volume drop. Phase cancellation happens, at least to my ears, when the bottom end goes out and sounds like octave up.

See above post on MN taper