Quad 34/Diamond Tilt Control

[johnk]

this is a great little circuit from the Quad 34 hi-fi preamp that is also used in the Diamond compressor. depending on what values you use for caps C1 & C2 for the center frequency, CCW boosts the lows and simultaneously cuts the highs, or cuts the lows and boosts the highs CW. it's completely flat and unaffected in the center position.

[IvIark]

Nice one John.  This may be a good pedal for one of those 3 position 4 pole rotary switches so you have 3 useful centre frequencies to choose from.

[YerayM]

Thanks John, I like this little boards, perfect to combine with other effects in one box. I think you have a typo, should be 47nF to get 107Hz center frequency.

For anyone who wants to customize this, last year I made an online calculator for this circuit: http://vulcanofx.blogspot.com.es/p/tilt-eq-calculator.html. The long explanation is here, but basically you specify your desired center frequency, amount of bass boost and amount of treble boost and it calculates the values of C1, C2 and the 47k and 15k resistors. The amount of bass and treble boost can be asymmetric:




Mark, if you add another rotary switch you can vary the boost values, maybe two asymmetric configurations (one bass heavy and the other treble heavy) and one symmetric. This is starting to sound like an interesting EQ build.

[johnk]

yep, you're right, I just made a mistake when a cut and pasted the values. I've corrected it now.
BTW, that's a nice little frequency calculator that you posted. thanks!

[Silver Blues]

Oh cool. Would make a nice addition to some circuits. Can't help but think this would have gone nicely in my Hematoma build...

[Jovi Bon Kenobi]

Wow, this is great. Thanks for isolating this circuit! I have to say, out of all the pedals I own and/or built, That single eq knob is probably my favorite and most appreciated little function. It is why my Diamond Comp never leaves my board.

Fantastic work!

Jesse

[negativefx]

Resurrecting this thread for a quick question...

What's a good center freq for Guitar?  Bass?  How about a Bass VI tuned to E standard one octave below guitar / one octave above bass?

I'm going to build one of these tilt EQs for my Bass VI board and I'd like to set it up so I can switch between bass/guitar/vi.

Thanks!

Edit:  I'm going to take a stab and say 107Hz, 229Hz, and 420Hz? (47n, 22n, and 12n)?  Looks like a pair of DPDT on-off-ons with 12n in the middle, 10n on top, and 35n (thank science for 10% tolerance on a 33n!) on bottom.

[johnk]

Diamond used 900Hz (5n6 caps) for guitar and 250Hz (20n caps) for bass.  10n's for something between them, I've used 10n's and it seems to work well on both bass and guitar.

[negativefx]

Excellent, thanks!

[negativefx]

If I were to implement this switching not only as a standalone pedal, but also in the Diamante Plus vero, would the following caps be the ones I need to switch?

[Dulouz]

Sorry to resurrect this pretty old thread once again, but does anyone have a schematic for this?

I've seen other tilt schems, but they don't seem to match this.

Thanks!

[Sergio]

maybe the difference between vulcanofx.blogspot schematic and johnk layout lays in that johnk used some 2 10k and 1 10uf cap to simplify the circuit from  + - 15 volts to 9 volts supply, i think so he made a voltage reference with those 3 components to the points where schematic uses 0 voltage. Could it be that?

[GrooveChampion]

So no one is gonna talk about the layout having 6 jumpers while it says that its supposed to have 7?