Amptweaker Tight Control

RRJackson

RRJackson

New member
I've been running a 12 db/octave high pass filter in front of the Amptweaker Tight Fuzz circuit. I feel like it makes a really good treble booster set up like that. I keep wondering if there's any way to mod the Tight control in these builds to shave off more bass at a steeper slope? Because having the de-bass-er (debaser?) onboard would be really handy.

-Rob
 
More bass? Yes
Steeper slope, not exactly.
The tight control is just a passive RC filter
1000000404.png
Source: aion fx
You could potentially tack a resistor to ground deer a decoupling cap.
Or build separate filter and squeeze it in the enclosure.
 
jwin615 said:
More bass? Yes
Steeper slope, not exactly.
The tight control is just a passive RC filter
Click to expand...
Could a trimmer pot replacing the resistor be used to change the corner frequency, or would that necessitate changing both the cap and resistor values?
 
R6 set the minimum resistance to prevent a dead short. It's 1% of the total resistance.
As it stands, it sweet from ~15Hz to 1.5k.
You could try adding a 50k or 100k trimmer/pot to ground after C6.
If you find that the circuit has too much low end in general, add a resistance to ground after C1.
Or decrease C1, C16 and/or C9.
A 22n at would give you a corner freq of 152hz. 4.7n would be 712Hz. Note, by adjusting the output cap that much, you'll still have the harmonic content of the low end and this will sound different than reducing low frequencies before the circuit. Better/worse is subjective.
A resistance post C6 or putting the input cap(C1) on a switch would probably be the easiest places to start.
 
jwin615 said:
R6 set the minimum resistance to prevent a dead short. It's 1% of the total resistance.
As it stands, it sweet from ~15Hz to 1.5k.
You could try adding a 50k or 100k trimmer/pot to ground after C6.
If you find that the circuit has too much low end in general, add a resistance to ground after C1.
Or decrease C1, C16 and/or C9.
A 22n at would give you a corner freq of 152hz. 4.7n would be 712Hz. Note, by adjusting the output cap that much, you'll still have the harmonic content of the low end and this will sound different than reducing low frequencies before the circuit. Better/worse is subjective.
A resistance post C6 or putting the input cap(C1) on a switch would probably be the easiest places to start.
Click to expand...

Thank you SO much. This gives me a lot of material for trial and error. I've never really had a treble booster I liked until I started toying with the signal I was feeding the Amptweaker. I'd love to get there with one pedal. Again, I really appreciate the guidance.

-Rob
 
I just started on this and realized there was miscommunication, although I appreciate the assistance. I'm trying to adjust the operational range of the Tight control, not to overall circuit. The idea being to dial in bass cut as needed.
 
If you just want to change the tight control, you are left with adjusting C4 and the tight pot.
You can use an RC calculator to find the cutoff frequency
www.digikey.com

RC and RL Passive Filter Calculator | DigiKey Electronics

Calculate the -3dB cutoff frequency of RC and RL circuits for both Low and High Pass filters using DigiKey’s passive filter calculator.
www.digikey.com www.digikey.com
You're not going to get a steeper cut off with a passive RC but you could raise the frequency.
 
I socketed C4. I started out at .68, which seemed like a lot, but ended up with 1 uF, which seems like more than a lot. Does the thing, though. I'll probably try some other values, but I'm tired. Love this circuit, though. Thank you!

- Rob
 
IIRC, it was somewhere on Jack Orman's site that he mentioned a couple filters in a row will steepen the curve?
Might've read that on Elliot Sound Products' site.

When I searched for it, all I got was a meta-reference to it, me on TalkBass ...
🤷‍♂️

ahhh found it, I think:

AMZ Double Tone Controls

An original clipping circuit that has a different response in high or low parts of the frequency band.
www.muzique.com www.muzique.com





 
You know, I kept messing with upping the capacitor value in the existing circuit until I ended up with a 2.2 uF. Which, you know, that's 22 times the value in the original circuit, but it gets a very natural, cool treble booster sound when you bring it in and the slope is so gradual that it kind of feels like that's just how your guitar sounds. I ended up happy with it.
 
Feral Feline said:
IIRC, it was somewhere on Jack Orman's site that he mentioned a couple filters in a row will steepen the curve?
Might've read that on Elliot Sound Products' site.

When I searched for it, all I got was a meta-reference to it, me on TalkBass ...
🤷‍♂️

ahhh found it, I think:

AMZ Double Tone Controls

An original clipping circuit that has a different response in high or low parts of the frequency band.
www.muzique.com www.muzique.com





Click to expand...

Yeah I was going to suggest just doubling the filter, you need a dual gang pot though, and finding a dual gang C pot can be tricky (though I think Tayda has them).
 
You must log in or register to reply here.
Back
Top