4DPDT switchable Muff Emitter mod.

[finkfloyd]

Got my soldering iron out & russian black muff apart, already changed the tonestack 22k resistor to the triangle 33K version (switchable), though i dont hear a noticible difference
difference was even slighter for the 20K mod for the green russian muff to the point i couldnt tell.

I Want to add a switchable emitter mod, I took the original switching pic from the helpful http://www.beavisaudio.com/techpages/Switches/index.htm
and modified it for a 4DPDT switch


Never used a 4DPDT Before, Is this correct?
Should this successfully change the 3, 390R resistors to jumpers?

ps: Please ignore the resistor values, depicted in the inage

[dano12]

Before you go to the trouble, a few things. First, I think the emitter mods I've seen only apply to Q1, Q2 and Q3. Q4 is simply for gain recovery from the tone stack. So you wouldn't need a 4pdt, only a 3pdt.

Second (and more importantly) my personal experience is that the emitter mods across Q1 and Q2 are so subtle as to be not worth the effort. In my latest muff box, I have SPST switches, one for each of the three emitter resistors. I've them all on, all off, permutations and variations, etc. Q3 is nice in conjunction with the Atari mod, but the other two are kind of lame.

I also found the "noise gate" mod to be a bit doofy. Unless I wired it up wrong, it simply cuts gain and is about as useful as a fish on a bicycle.

Diode switching is great fun and makes a big impact on the sound, especially since you have two sets of clippers to play with.

Finally, I built the Forrest Mimms 555 oscillator on a small sub-board and have been using it inject signal into various parts of the muff. You can dial in a cool "drone" note with the 555 and them jam with stock BMP fuzz. Depending on where you inject the signal, it gets really weird.

Next step is to finish the 10-step sequencer using a 4017 and a 555. The idea is to have a rotary switch that controls which part of the circuit the sequencers sends voltage to.

Pink is the new black, and Muff-modding is the new TS-modding

[finkfloyd]

Hi dano!

The reason was for the 4DPT was I dont have any 3DPT's at hand, and was curious how it worked, and I have 2 4DPT's I got free from Aron (Thanks!)

Also the 4dpt would be handy for 4 component changes , like the tonestack which i was originally going to try, but settled for using a dpdt for 1 component change.
The diode mod would be good, could change all four at once, or use 2 dpts for pairs which would be better i would think.

Your project sounds very interesting! love to hear it when finished!

Thanks
Chris.

[powerplayj]

Before you go to the trouble, a few things. First, I think the emitter mods I've seen only apply to Q1, Q2 and Q3. Q4 is simply for gain recovery from the tone stack. So you wouldn't need a 4pdt, only a 3pdt.

Second (and more importantly) my personal experience is that the emitter mods across Q1 and Q2 are so subtle as to be not worth the effort. In my latest muff box, I have SPST switches, one for each of the three emitter resistors. I've them all on, all off, permutations and variations, etc. Q3 is nice in conjunction with the Atari mod, but the other two are kind of lame.

I also found the "noise gate" mod to be a bit doofy. Unless I wired it up wrong, it simply cuts gain and is about as useful as a fish on a bicycle.

Diode switching is great fun and makes a big impact on the sound, especially since you have two sets of clippers to play with.

Finally, I built the Forrest Mimms 555 oscillator on a small sub-board and have been using it inject signal into various parts of the muff. You can dial in a cool "drone" note with the 555 and them jam with stock BMP fuzz. Depending on where you inject the signal, it gets really weird.

Next step is to finish the 10-step sequencer using a 4017 and a 555. The idea is to have a rotary switch that controls which part of the circuit the sequencers sends voltage to.

Pink is the new black, and Muff-modding is the new TS-modding

You talkin' about mixing and matching diodes or using all 4 (two each in series)... or some switching mods with a few possibilities?

[dano12]

/quote]

I put in switches on both pairs. Each switch goes to a small PCB with a 16 pin DIP socket. That way I can plug in various combinations and A/B them. So far I've tried the stock 1N914s, some germaniums, MOSFETs, and some roasted cashews. All sound great except the cashews--I don't know what the forward voltage is for fatty nuts.