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mod the kingslayer for no dual ganged pot

Started by mganzer, April 08, 2013, 07:20:18 PM

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mganzer

Hello guys;
i want to remove the clean pot of kingslayer for no use dual gang pot and apply in place the jmk blender from http://www.madbeanpedals.com/forum/index.php?topic=3414.0
so this way i have total control for blend clean/dirt signal using only single ganged pots.
In the effect section is only dirty signal.
See attached schematic (simplified) is enough take out the clean pot and pin2 conection with post clipping section and conect this section to ground?

Thanks for the helping guys!

madbean

If you are going to connect the filter network around R14 to ground it is probably not going to sound very good. You will need to play with those values quite a bit, esp. if you are skipping the tone-stack altogether. Otherwise it will be pretty dark sounding.

Additionally, you don't need to double up on input buffers. IC1B is not necessary---just take your clean signal from the output of IC1A then send that to your blend pot.

Lastly, nothing around IC2A makes sense to me. You should probably eliminate everything between R3 and C6.

Really, it seems like it would be much easier to split the dual gang pot in the existing design into two single pots and see if you like it that way.

midwayfair

You can just put both halves of the dual gang on separate 100K pots in the stock kingslayer. No need for a second circuit in there.

The dual gang in the Kingslayer IS a blend control. It blends the clean signal (taken from the buffered signal created by IC1A), which is passed onto IC2. The other half of IC1 is the overdrive section, which is then summed with the clean output going into IC2.

The schematic is different enough from the Kingslayer or klone that it's hard to make suggestions. You have two input buffer stages, so you could drop one. The treble is no longer active, so you might have some signal loss, and the clean boost stage is gone -- I'm not sure what the total output will be like, but you almost certainly will have far more output from the OD than the clean.

Again, the simplest thing to do unless you're dead set on ditching the charge pump and active treble, is just to put both halve of the dual gang on separate pots. FWIW, every time someone does that, they say that all the best settings are at or near the same settings you'd get using a dual gang.

EDIT: also, the 5532 is a bad choice for this circuit. It makes a ton of noise. It's just okay in the OD section, but really bad in the clean boost of a klone.

mganzer

If i split the dual gang pot i will obtain blend control like sparkle drive? the clean IS a mix control?
I will not skip the tone stack. just not put in the schematic because have no correspondency with my questions. In reality i quite curious about use the bandaxall in the place of active treble...

midwayfair

Quote from: mganzer on April 08, 2013, 08:51:28 PM
If i split the dual gang pot i will obtain blend control like sparkle drive? the clean IS a mix control?

Yup.

Let's go through the schematic. The Kingslayer and Klones can be broken down into a few simple building blocks.
We have four OP amps. In the KS, this is one quad op amp.

IC1A is a unity buffer. You'll note pins 8 and 9 are directly connected, and there is a small amount of tone shaping (R5-R7, C5) mostly to keep the signal quiet.

There are three ways "out" from the unity gain buffer:
-Buffered bypass: C5 is the decoupling cap.
-Clean: C4 is the decoupling cap.
-OD: C2 is the decoupling cap.

The buffered bypass out has a voltage divider that works like a 100K pot turned down just a hair ... again, just to keep the signal quiet and helps prevent DC offset popping.

The clean pot is simply a (backwards) voltage divider volume control, and lug 2 leads to a band-pass filter that, combined with the active treble, sounds pretty neutral in tone. In reality, it's cutting some subs, which helps keep things tight when pushing an amp, and the treble is only really neutral pretty high on the treble control, so there is a very, very subtle mid-hump. This is also part of the overall sweetening/"magic" of the sound.

The "dirt" pot is a voltage divider at the input of the overdrive op amp (IC1B). As it's turned clockwise, the resistance between the input and ground decreases, letting in more signal to pin 12, and simultaneously decreases resistance between pin 12 and ground (R10 and R11 set the maximum gain).

When the dirt control is at minimum, no signal passes into the dirt section.

When the clean pot is at maximum, no clean signal bypasses the dirt section.

The final two op amps have the same function for both clean and dirty signals.

If you think about this for a moment, there's a catch: Your clean signal is not amplified like the dirt signal. So if you turn the clean pot all the way up, and the dirt all the way up, the dirt will be WAY louder than the clean signal. But if you're using that much dirt ... you probably aren't interested in hearing the clean signal anyway.

mganzer

Thank you so much for the patience brian and midwayfair.
I have another doubts:
What the function of components around r15? is just tone shaping of clean's section out signal?
incasein order to removal the clean section this group have to be removed too, leaving only the input buffer section, the clipping section, tonestack and output...how much this "cut" affect the overall tone of kingslayer?

midwayfair

Quote from: mganzer on April 09, 2013, 01:29:19 AM
Thank you so much for the patience brian and midwayfair.
I have another doubts:
What the function of components around r15? is just tone shaping of clean's section out signal?
incasein order to removal the clean section this group have to be removed too, leaving only the input buffer section, the clipping section, tonestack and output...how much this "cut" affect the overall tone of kingslayer?

I'm not sure why you're intent on removing so many parts of this circuit. Have you built it already? Have you played through it or a klone and deciding that there was something about the gain or clean sound that you didn't like? What, in short, are you trying to accomplish with this modification?

The clean boost is very flat eq-wise. People really, really, really like the clean sound on this pedal. Enough that some of them use it as a purely clean boost with the gain on 0.

Removing the clean boost section will sacrifice a lot of treble content (remember, it's ACTIVE treble, not a passive cut -- removing it means LESS treble) in a pedal that's already (to my ear) somewhat dark sounding.  You'll lose some output -- the gain section is loud, but unless you're running it around noon the gain side alone isn't above unity. (R19 and R22 boost the signal a lot.)

mganzer

Yes man, i build one. In fact i like, but i like much more the drive part of effect. the intent is put it in 1590A without smd components. The easy way is take out what maybe dont need cause is pretty big circuit for an od...
Thank you for help me to understand how the circuit works. I will put it in breadboard and test when i have some more time to spent....


mganzer