3 band trimmer EQ layout

[no one ever]

GGG IC Buffer



trace

[no one ever]

crap.

looking at datasheets... tl071's max input V is 15 and the lf351's input resistance (impedance?) is 10¹²ohms!

thinking of replacing the lf with the tl071 and putting in one of those voltage regulators-on-a-chip thingies.


but, then the power scheme within the vibe would be strained, i think.. the single 15v regulator will feed the eq circuit and the vibe's signal path, and the straight 18v will go to the LFO of the vibe... cross my fingers, i guess.

[no one ever]

crap.

looking at datasheets... tl071's max input V is 15 and the lf351's input resistance (impedance?) is 10¹²ohms!

thinking of replacing the lf with the tl071 and putting in one of those voltage regulators-on-a-chip thingies.


but, then the power scheme within the vibe would be strained, i think.. the single 15v regulator will feed the eq circuit and the vibe's signal path, and the straight 18v will go to the LFO of the vibe... cross my fingers, i guess.

well, they're pin for pin matches, so a new layout isn't a problem.

[no one ever]

whew! ah the wonders of paint.




hope somebody besides me finds this useful. 

[rockgardenlove]

I'm thinking of building one of these..can you post the shematic you used for the buffer?

And what replacement caps might sound better for guitar?

[no one ever]

I'm thinking of building one of these..can you post the shematic you used for the buffer?

And what replacement caps might sound better for guitar?

here you are, sir.


and the cap question is pending. 

[rockgardenlove]

No, I meant the shematic for the buffer...like it needs to go Buffer->EQ->Amp right?  Or else it will load the pickups wrong.

[no one ever]

No, I meant the shematic for the buffer...like it needs to go Buffer->EQ->Amp right?  Or else it will load the pickups wrong.

ah. yes. here ya go. (pdf)

and the buffer is before the eq anyway, so no worries. input is on the left, as is the buffer circuit.

[Ben N]

The confusion is about words only:  I think I see a mosfet buffer stage, not a minibooster (which is a jfet muamp, uses two jfets).  You should be ok, although my guess is that stuck on the output of a reasonably low output impedance effect, a bipolar buffer would work fine, without biasing issues.  Did you look at Jack's buffers article?
Ben

[no one ever]

The confusion is about words only:  I think I see a mosfet buffer stage, not a minibooster (which is a jfet muamp, uses two jfets).  You should be ok, although my guess is that stuck on the output of a reasonably low output impedance effect, a bipolar buffer would work fine, without biasing issues.  Did you look at Jack's buffers article?
Ben

well the third layout is the minibooster w/ buffer mod, using the inverting output. i'll have to modify that one for non-inverting output.

the latest layout uses the simple ic buffer from ggg.

i agree with your 'low impedance' statement, i think i'll remedy that with the minibooster instead of the ggg buffer. its a clean enough boost/buffer for me.

[Pushtone]

The Mini-Booster is half to three quarters the way to a fuzz box. 

I can get a Fender type clean sound out of my new Fat Boostered with the aid of the VOL and GAIN controls but the Mini-Booster is always at least "gritty" when at unity gain. Maybe mine is F*#@-Up?
On second thought, it sounds too good to be that.

But thanks for the 3-band with the GGG buffer as I have parts for that.

I have to admit, the 6-band EQ poster after your 3 band kinda kill the buzz I was feeling about the 3-band. But I'm back into it as I really want a small circuit that can go into an existing stompbox to add bass, or whatever.

Hey no one ever- do you need me to trace any of these and output a pdf?

[no one ever]

The Mini-Booster is half to three quarters the way to a fuzz box. 

I can get a Fender type clean sound out of my new Fat Boostered with the aid of the VOL and GAIN controls but the Mini-Booster is always at least "gritty" when at unity gain. Maybe mine is F*#@-Up?
On second thought, it sounds too good to be that.

But thanks for the 3-band with the GGG buffer as I have parts for that.

I have to admit, the 6-band EQ poster after your 3 band kinda kill the buzz I was feeling about the 3-band. But I'm back into it as I really want a small circuit that can go into an existing stompbox to add bass, or whatever.

Hey no one ever- do you need me to trace any of these and output a pdf?

nah, thats fine. i figured out a way to output a gif and i just scale it in word. thanks for your help though, pushtone! 

although in my experience, the minibooster hasn't sounded dirty at all... hmmm. oh well.

[Ben N]

The confusion is about words only:  I think I see a mosfet buffer stage, not a minibooster (which is a jfet muamp, uses two jfets).  You should be ok, although my guess is that stuck on the output of a reasonably low output impedance effect, a bipolar buffer would work fine, without biasing issues.  Did you look at Jack's buffers article?
Ben

well the third layout is the minibooster w/ buffer mod, using the inverting output. i'll have to modify that one for non-inverting output.

the latest layout uses the simple ic buffer from ggg.

i agree with your 'low impedance' statement, i think i'll remedy that with the minibooster instead of the ggg buffer. its a clean enough boost/buffer for me.

Nope, that is not a minibooster, although it may be an AMZ Mosfet boost in buffer mode.  Go back to AMZ, and you will see that they are two completely different circuits, and the idea expressed here that the minibooster can act as a distortion is misplaced in relation to this circuit (although of course anything with gain can distort if pushed).

[no one ever]

Nope, that is not a minibooster, although it may be an AMZ Mosfet boost in buffer mode.  Go back to AMZ, and you will see that they are two completely different circuits, and the idea expressed here that the minibooster can act as a distortion is misplaced in relation to this circuit (although of course anything with gain can distort if pushed).

right you are! whoopsies. my bad on my faulty naming conventions  . mosfet boost is what i meant all along. and yes, its in buffer mode.

good catch!

[rockgardenlove]

So has anyone worked out those capacitor substitutions?