Mutron Help

[uncle psychosis]

Hey folks

 

I have built myself a Mutron III (well, almost --- its is a Fuzzdog bulild that is a combination of elements of Madbean’s updated circuits, the Naughty Fish and the Nautilus). 

 

It has the following controls: 

 

• Master Volume (pot)
• Input Gain (pot)
• Peak (pot)
• Sweep (pot)
• Range (two-way toggle)
• Hi-Lo (two-way toggle)
• LowPass-BandPass-HighPass (three-way selector)

 

I am trying to check that the pedal is fully functional but I need some help understanding the controls and the expected behaviour to debug it --- I'm not very experienced with filter effects. 

 

Thw switching is all good and I am able to get some nice filter sounds. But... 

 

What I'm least sure about is the operation of the Range and Hi-Lo toggle switches. 

 

Here's my "problems": 

 

• In one of the two 'Range' positions I don't seem to get any filter effect at all. 
• The Hi-Lo toggle switch seems to be very subtle. 

 

So, can anyone explain to me like I'm five... 

 

1) what these two controls are meant to do

2) an idiot's guide to checking they're setup right

 

(fundamentally I'm wondering if things aren't happening because my instrument has too low an output, or if I've picked silly settings, etc). 

Edited yesterday at 10:41 by uncle psychosis

[LukeFRC]

Is range the up/down switch?

[LukeFRC]

Is range the up/down switch? If it is then expect different input sensitivity to make it work.

 

also does your build use vactrols or seperate led/optical resistor

[uncle psychosis]

Its Vactrols.

 

I'm not sure which switch is which - one of my only complaints about Fuzzdog is that he never explains the controls beyond the labels...

 

Here's the layout

 

https://pedalparts.co.uk/docs/MooTron.pdf

 

I'm now pretty confident that the hi/lo switch is working. It definitely does something!

 

I think I need to try plugging in a bass rather than my telecaster to try out the range switch.

Edited yesterday at 13:16 by uncle psychosis

[ped]

Here’s the original Mutron manual

Musitronics Mutron III manual.pdf

[uncle psychosis]

Thanks, Ped.

 

I definitely think there is something wrong with the Range toggle, but I'm not sure if it's just that analog filters are weird...

[uncle psychosis]

Of course my troubleshooting isn't being helped by there being no easy way to work out which way to set the toggles and rotary to match the original!

[LukeFRC]

This guy has labeled his

 

go for low pass

Turn peak all the way up - that’s going to make the effect more pronounced 
 

then volume is output volume - just whack that up too.

Then set the input gain down… and play notes while switching the range switch - one should sound dark and the other bright. The dark one is “up”

 

stick on that

 

then play notes while turning the input gain up

hit with enough gain the filter should open

 

if it does, it’s working properly 

if it’s already open turn down the signal going into it

if it’s won’t open try boosting the signal 

[uncle psychosis]

yeah its definitely not working correctly. One of the settings for the Range basically either produces nothing, or it produces noise. And the hi-lo switch is doing something, but I'm not convinced its doing what it is meant to. 

 

I don't know if I can face debugging this. The fact that it partially works means that its going to be extremely hard to work out what is wrong 😢  

[LukeFRC]

 

[uncle psychosis]

Yeah. 

 

I *think* what I need to do is to jumper the two toggle switches to rule the two toggles out. If I can get it to sound "correct" like that then I might be able to brave trying to get those switches out --- though it will be a gigantic PITA. 

[LukeFRC]

1 hour ago, uncle psychosis said:

Yeah. 

 

I *think* what I need to do is to jumper the two toggle switches to rule the two toggles out. If I can get it to sound "correct" like that then I might be able to brave trying to get those switches out --- though it will be a gigantic PITA. 

Hold on, the toggle switches, into a pcb are one of the least likely things to be a bug to find.

[paul_5]

Can you post photos of both sides of your board so we can see if there’s anything you might have missed?