Wooly mammoth +

[JebemMajke]

So I've recently built Wooly and it's ok, it does its thing, but soon it became really boring on bass, sort of one sided. So ive decided to give it something extra. A AMZ mosfet booster. Its really nice when u can blend in some clean sounds, and especially such a sweet sounding cleans from this mosfet thing. I think ill omit the 5k pot on it and just put 300-400 ohm resistor in its place, maybe a trimpot so i that can dial it in perfectly.
i was using 100 k pot for blend, but i ll need it for some other project, so here are the questions:
1.can i use a 50 k insted?
2. I didnt use any volume pot on my testboard, can i keep 10K a pot as volume or some other higher value would be better?

[PRR]

Use 50K for blend, 50K or 100K for output volume.

If blend is much smaller than 50K it loads the amplifiers.

If the volume after the blend is much smaller than 50K, the 50:50 blend will be much weaker than one or the other.

If we step-up pot values for less loading, say 250K and 500K, the output impedance gets quite high.

[JebemMajke]

Will use 50 k for both. Thanks

[ubersam]

If we step-up pot values for less loading, say 250K and 500K, the output impedance gets quite high.

If the output pot were stepped-up to say, 500k, would adding a buffer after the pot address the higher impedance issue?

[electrosonic]

Are you blending out of phase signals? Does it matter?

Andrew.

[PRR]

> If the output pot were stepped-up to say, 500k, would adding a buffer after the pot address the higher impedance issue?

Sure but.... why add complication and power-use when an appropriate pot-value will do the job?

If the value were something odd like 3Meg or 20 ohms, we might add more electronics to avoid an awkward pot.

Miša *may* live somewhere that pots are not easily bought; but you are in Los Angeles.

Go ahead and buffer. It's not a wrong choice. Just seems unnecessary.

> Are you blending out of phase signals?

By golly, he IS!

> Does it matter?

If both paths were clean, equal gain, and flat frequency response, then somewhere in the middle the sound would just cancel.

I suspect the 2-BJT path will often be clipping, the MOSFET path will often be clean. Summation of a clipper/limiter with a clean is a complicated business. Phase-flip makes it more complicated. Miša seems happy, so I won't worry about theory.

[Jaicen_solo]

Why not take the signal from the drain as well and have a SPDT switch for phase reversal?

[PRR]

> Why not take the signal from the drain as well

It's on the dran now. I assume you mean source.

As-is, signal at drain has gain, source has no gain (slight loss). Wouldn't be _just_ a phase reversal.

I suspect some gain is needed in the lower path, else the high-gain upper path would overwhelm the lower path except when so brutally clipped that you'd hardly hear the lower path for all the racket.

[Meanderthal]

 This got me thinking on the possibilities of deliberately mixing out of phase but differently processed signal. Could be an interesting road to take... I usually try to avoid it, but it might be worth exploring just to see what can really be done with it.

[JebemMajke]

I left this project as it was because I had no time to finish it, and also i had no box. In the mean time i made the box ( ultimate DIY xD ) and finished 2 big muffs ( NYC and IC ), and put them in one enclosure.
Back to the WM. Thing is I have only one 50k B pot and six 50k A pots. I guess i need B for blend but what about volume? Can i use A pot or it needs to be B? Next B pot i have is 250 k, should i use that one? PS this thing works like a charm, it's great on both, bass and guitar. I ve even drilled pot holes in a W shape for ultimate geekness xD

[JebemMajke]

50 k blend and 50 k vol pot = mosfet turns to mud ...

[JebemMajke]

But the wool side sounds much, much better.

[liquids]

50 k blend and 50 k vol pot = mosfet turns to mud ...

Are you trying by blending in full mosfet side, cranked mosfet gain, output volume down to match bypass volume?   These mosfet boosters DO get pretty crazy muddy when they start clipping, if I recall correctly.  Not a problem if it's only an add-on to the crazy sound of the mammoth though.

[JebemMajke]

Well there is a 5 k trimpot and Ive tried it at max gain and than gradually lowering it down. It is still pretty much muddy either way. When i unhooked it and tried it alone it worked fine, but Wooly went back to being useless.