big muff mod

[BassIsFun17]

hey guys,

on my russian muff, i dont feel like enough of my clean signal is getting through.

i was wondering if anyone knows if there is a mod with a way of installing a blend knob in the big muff?

thanks in advance,

rory

 

[SpankyPants]

That'll take up a lot of space and requires some skill on the modder's part. You'll actually need to build a buffer of your clean signal to blend with your fuzz. I'm not sure how plausible it is to try that, but as an alternative, I'd highly recommend the Sanford and Sonny Bluebeard Fuzz. It's a Muff clone with a set amount of clean signal let through, to my knowledge. You'll pay through the nose, but it'll be exactly what you want! It sounds great too.

For examples of this pedal, listen to Mastodon or Russian Circles. Both of them use the Bluebeard.

 

[sonicvi]

well, none of your clean signal is supposed to get through. It actually wouldn't take up much space to add a blend control. A basic buffer/blend circuit can be very small, just an opamp, a few resistors, and a pot. But, my first thought is that if you have to ask then you might not be experienced enough to do it yourself. A simpler mod would be to increase the input cap to allow more bass through and/or modify the tone stack for a different frequency response.

 

[SpankyPants]

well, none of your clean signal is supposed to get through. It actually wouldn't take up much space to add a blend control. A basic buffer/blend circuit can be very small, just an opamp, a few resistors, and a pot. But, my first thought is that if you have to ask then you might not be experienced enough to do it yourself. A simpler mod would be to increase the input cap to allow more bass through and/or modify the tone stack for a different frequency response.

If that is really the case, how plausible would it be to add a clean blend to a LBM? Remember, the LBM is SMD.

 

[sonicvi]

If that is really the case, how plausible would it be to add a clean blend to a LBM? Remember, the LBM is SMD.

I haven't seen the inside of a LBM so I don't really know, but there's obviously a lot less room to work with. You don't need to mod any parts to add the blend, just add a small board in there. So I don't think SMD wouldn't really matter. Though if the jacks are mounted to the PCB then it would require cutting a trace or two to splice in the blend circuit. Actually, the old Russian ones had board mounted jacks, so the black ones probably do as well and would require a cut trace or two. I had to do this to add true bypass to a green one I used to have. Either way, the limiting factor with the LBM is the available space inside, but I'll bet it could be done.

 

[SpankyPants]

I haven't seen the inside of a LBM so I don't really know, but there's obviously a lot less room to work with. You don't need to mod any parts to add the blend, just add a small board in there. So I don't think SMD wouldn't really matter. Though if the jacks are mounted to the PCB then it would require cutting a trace or two to splice in the blend circuit. Actually, the old Russian ones had board mounted jacks, so the black ones probably do as well and would require a cut trace or two. I had to do this to add true bypass to a green one I used to have. Either way, the limiting factor with the LBM is the available space inside, but I'll bet it could be done.

Yeah, the jacks are board-mounted. You think you could add a knob? Should I work something out with Robert Keeley?

 

[343 Salty Beans]

http://www.talkbass.com/forum/showthread.php?t=318602&highlight=Big+Muff+Mod

Scroll down the thread to see (half of) my Big Muff mod...I'm pretty happy with it. I run it on 5ish volts from my PP2+'s 'sag' function, and it works great. I only turn up the Sustain to around 10'00.

With the voltage sagged, the input signal doesn't get boosted enough through the transistor stages to be entirely clipped. It 'appears' to my ears to be a blended signal. It's really quite nice.

If you are feeling low-end loss, then try that mod.

If you are feeling attack loss, then you'll probably need a blender. Or a blend knob.

The blend knob would need a gain stage as the aforementioned buffer (with a trimpot or pot to balance the volume output of the buffer) and a blend (voltage-divider wired) pot after it. The problem is that the gain of the Big Muff's original circuit signal will probably be a lot bigger than the gain of the buffer. I'm assuming you'd need to wire the blend knob after the volume knob of the original Big Muff circuit, and use the volume knob to lower the effected signal before blending. I'd probably just replace that volume knob with a trimpot and use the space left behind for the blend knob. Difficult, but not impossible...since I don't need it, I don't worry about it

 

[BassIsFun17]

http://www.talkbass.com/forum/showthread.php?t=318602&highlight=Big+Muff+Mod

Scroll down the thread to see (half of) my Big Muff mod...I'm pretty happy with it. I run it on 5ish volts from my PP2+'s 'sag' function, and it works great. I only turn up the Sustain to around 10'00.

With the voltage sagged, the input signal doesn't get boosted enough through the transistor stages to be entirely clipped. It 'appears' to my ears to be a blended signal. It's really quite nice.

If you are feeling low-end loss, then try that mod.

If you are feeling attack loss, then you'll probably need a blender. Or a blend knob.

The blend knob would need a gain stage as the aforementioned buffer (with a trimpot or pot to balance the volume output of the buffer) and a blend (voltage-divider wired) pot after it. The problem is that the gain of the Big Muff's original circuit signal will probably be a lot bigger than the gain of the buffer. I'm assuming you'd need to wire the blend knob after the volume knob of the original Big Muff circuit, and use the volume knob to lower the effected signal before blending. I'd probably just replace that volume knob with a trimpot and use the space left behind for the blend knob. Difficult, but not impossible...since I don't need it, I don't worry about it

what exactly is attack?

 

[sonicvi]

Yeah, the jacks are board-mounted. You think you could add a knob? Should I work something out with Robert Keeley?

They're making pots pretty small these days. I'm sure one could be squeezed in there. I personally wouldn't want to attempt it, especially with somebody else's pedal. I'm a bit out of practice with the electronics these days.

 

[Agent Blue]

I have a Sovtek Big Muff that was moded by Mohomods. It's not been moded to where there is a clean blend or anything, however they do replace the internal components with higher quality ones. I can tell a definate difference as far as more lows getting through. If your concern is mainly because of low-end loss you might look into a "Momuff" along with a little EQ adjustment for a temporary solution. Also, Mohomods makes the pedal true bypass along with installing an AC power slot.

 

[343 Salty Beans]

what exactly is attack?

Attack is the initial punch of your bass as you pluck the stream. It's a volume spike before the long, quieter sustain. If you've ever seen an image of a recording of a bass or guitar string being plucked, the large spike is the attack.

 

[Ravens]

I’m resurrecting this thread

I am going to attempt adding a blend control to my Big Muff build. I’m thinking it will probably be a lot simpler to do it on a pedal built from scratch than modding a factory one, and it’s a real easy build.

I thinking of taking the clean signal and running it through a simple opamp buffer and blending it with the muff signal before the volume pot.
100k Lin ok for blend pot?
You think this is going to work?
Is there something I need to think about?

I have built FX kits, FX pedals from scratch and modded a few units before, but I am fairly new to this so ANY input is much appreciated

 

[sonicvi]

A basic opamp buffer set for unity gain is all you need. If you want a little more clean signal you can set the opamp to give you some gain, or add a pot for the negative feedback resistor n the buffer to be a clean volume control. 100K linear is just fine for the blend control. What you want to blend is the outputs rather than from the input. So you split the signal at the input jack, one goes to the muff and one to the the buffer, then blend between those outputs.

Here's a link to several different types of simple buffers. the opamp is the easiest imo.
http://www.muzique.com/lab/buffers.htm

And here's a schematic for how to wire it. Just ignore the send and return jacks and use the ins and outs direct from the pcbs.
http://www.geocities.com/jrtookmyfalseteeth/buffblnd.gif

 

[Ravens]

Thanks for the input!

I had planed on using this buffer

There should be no problem hooking up voltage to this circuit in parallel from the battery, right?

 

[sonicvi]

Thanks for the input!

I had planed on using this buffer

There should be no problem hooking up voltage to this circuit in parallel from the battery, right?

No problem al all. I've used that one before and it works just fine.

 

[Ravens]

im doing some soldering today and im looking at this thing:

I was going to put he buffer in front of the mix pot on the "clean" signal cables, sort of like this:

Clean input--->Buffer--->Mix pot---Out
Muff out-----------------^

wont this work, and why is the other circuit better?

 

[sonicvi]

I would do it the way you describe as well, splitting the signal before the buffer rather than after.

 

[Sir Edward V]

IMO/IME blending clean signal with the LBM doesn't help the fuzz cut through the mix, it lets your clean signal be heard... then the fuzz still suffers from the same problems as before.

My personal solution is going to be to put an output EQ with the pedal so I can boost the mids and cut some highs and lows. I've been talking about this a lot on this forum the last week or so... i will do it whenever I order the parts... haven't got to it yet!

 

[sonicvi]

IMO/IME blending clean signal with the LBM doesn't help the fuzz cut through the mix, it lets your clean signal be heard... then the fuzz still suffers from the same problems as before.

My personal solution is going to be to put an output EQ with the pedal so I can boost the mids and cut some highs and lows. I've been talking about this a lot on this forum the last week or so... i will do it whenever I order the parts... haven't got to it yet!

Or, if you're gonna mod the pedal anyway then mod the tone stack to flatten out the eq curve.

 

[Ravens]

Just to keep this alive...

this is what it looks like at the moment
[Invalid or Expired Link Removed]

i just wired it up to see if my buffer did its job, and if there where any other problems.

It actually works pretty good.

Some things that i have changed along the way so far:
after trying both, I decided on using a 100k log pot for blend instead of a lin. I think it just worked best in this circuit. Also it has a center detent. Pointless, but i had one in my partbox so..
I changed the EQ caps so the tone knob has a wider range, the lowest and highest settings are pretty much unusable now (the highest is pretty painful actually) but it made a MUCH wider sweet spot on the tone knob.
I put the volume knob after the blend pot, this makes sense since now you kan decide the output of the entire unit, not just the OD signal.
I used an LM741 for opamp in the buffer since i have bunch of them at home already, i feel it gets the job done.

Also, i socketed the transistors so i can try different setups. It currently has 2N5089, i would be greatful for any suggestions for other ones that sound good.

Sir Edward V: I dont agree with that logic. The issue IMHO with the muff has not been that the fuzz doesnt cut trough, it does, but that the tonal contents does not. That is; you can hear the fuzz sound but not what you are playing, this is what i tried to solve with this mod.

Im currently fixing up the enclosure, setting up the bypass and such, then i will have some clips for you.