little help here

[doplonyo]

hi all its me again... 🙂
this time I want to be help about eq... in my attachment is tone control using opamps... How to make that circuit work with jfet ??? why I chose jfet because I want solid state with tube taste 🙂
I want use it for clean chanel,but if any member want to help me with make me two chanel (overdrive&clean) i'll be more apriciated,and will use it all the time.... all input will be some big help to me...
thanks....

 

[Minion]

It allready uses a Jfet , The TL082 is a Jfet opamp .....

PS:The second half of the TL082 should be configured as an input buffer .....

 

[6L6]

Try it as shown, it will be a good tone control for an instrument amp.

 

[Loudthud]

Just use a JFET source follower as an input buffer. You need to drive the circuit from a low impedance anyway.

 

[doplonyo]

thanks all ... But I mean I'm try to build that tone with transistor (j201) cos many schematics was using stack tone,in this case I want that circuit build with j201 or similiar,cos I thinks playing with transistor more easier than playing with opamp,what about that???

 

[geraldfryjr]

Actually the opposite is true!!
Opamp's are easier to work with than you lead yourself to believe !!!


I am not good at Jfet amplifiers but if you want to use a one in the circuit you can place a Jfet amplifier in place of the opamp as long as it inverts the signal.
I have no idea how to set or determine the gain of a Jfet amp but if it is not an inverting type amplifier you most likely will have an oscillator.

FWIW

jer 🙂

 

[tinitus]

looks like a baxandall feedback control(active)
modded to have 2 bass controls
usually theres only one bass, and one treble
so the question is, will it work properly
or is it a theoretical design ?

hey, Im into trying one myself, and really interested in this 🙂

 

[tinitus]

Try it as shown, it will be a good tone control for an instrument amp.

actually they say this type of active feedback control is the best kind for hifi as well 😉

its very similar to the tilt control used in Quad preamps
I think it only needs one mutual control to work like a tilt

 

[tinitus]

...... I want that circuit build with j201 or similiar....

will show up on google 😉 by the hundred 😀

I think the type of jfet you use is mostly determined by your voltage
j201 should be good for low voltage like 9V
other jfets may work better on slightly higher voltage
depends on how you plan to use your design
battery or regulated supply, outboard, onboard, built in, etc etc

well, I see the one in your tone control uses symmetric +/- supply
so I guess a low voltage battery supply is not your goal ?

 

[doplonyo]

Some schematic using jfet (j201 or similiar) was 15v to 24v,but using tone stack,then I find that attachment, so I want modify that as I want,any picture or attachment to make easier to build that.... Please.

 

[tinitus]

It allready uses a Jfet , The TL082 is a Jfet opamp .....

PS:The second half of the TL082 should be configured as an input buffer .....

maybe you missed it 😉

but if you google baxandall you will find tons of answers to your question(go to google pictures)

well...looks similar, and too good to miss 😀 HeadWize - Project: Designing A Pocket Equalizer For Headphone Listening (A HeadWize Design Series Paper)