Need help finding a circuit

[Teddeeh]

Hey chaps. I need help in trying to find a circuit.

Its literally 2 transistors, 2 resistors and a cap.

I think the resistors measured 1m and 68k

 

[Erik S]

Did you look in the couch cushions?

 

[jwin615]

Oscilator?

 

[jwin615]

Switched DC booster?

 

[Teddeeh]

no i dont think so. Sorry was in a bit of a rush earlier.

So its actually been added on to the back of the eno or ex BMF (muff) pedal. Ill take a photo and post it when i can. Giving the pedal a vastly different gain range, more fuzzy and bottom end.

 

[Teddeeh]

 

[Teddeeh]

there arent any components on the other side of footswitch

 

[jwin615]

Probably a LPB1 on the input

 

[Teddeeh]

No i have managed to locate its part in the circuit and its on the output.

 

[jwin615]

Could also be a buffered bypass
Ia it true bypass?(Bypass with no power applies)

 

[Teddeeh]

no, its true bypass

 

[JohnnyCreepy]

A darlington pair gain stage? Cannot say about those SMD transistors if they’re jfets, si transistors or combination of those two.

 

[jwin615]

I think this is just a boost. If it's strapped to the output, it's probably a bandaid for the circuit being to quiet. Looking at other gutshots of this pedal and this circuitry isn't present.
Also. Nothing to gain tone wise from a simple jfet or BJT boost.

 

[jwin615]

Looking again, A6SHB, Q1 on the daughterboard. That's a mosfet.
Maybe a fixed gain SHO? Q2 as the diode because on leg is tied to an unpopulated R2 so may be floating.
No idea why they would do that...
Also, Google translate says:
小魔方系列
通用小板
=
Small Magic Cube Series
Universal Small Board
V1.0

 

[jwin615]

Is there audio of the center column of the 3pdt?
A mosfet switching the LED would make way more sense..?

 

[HamishR]

View attachment 94946

Dunno what it is but that is some fine soldering right there.

 

[Feral Feline]

Even the EHM drive has five parts...




BazzFuss = 5 parts



This BMF thingy...
...It should at least have a decoupler-cap

 

[Robert]

It's a bypass mute circuit.


The Gate of QX1 (marked FS) is pulled high/low by the footswitch to silence the circuit when the pedal is bypassed.