Seymour Duncan Lava box  [schematic]

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Seymour Duncan Lava box  [schematic]

Postby cpm » 29 Jul 2012, 16:55

This is a nice pedal, not expensive and can be faound cheaper os second hand

A rotary 6 position switch to select some caps for tone shapping and amount of gain.
Two bimos opamps driven into saturaion
I was suirprised at how effectively it cleans with input volume variations, very sensitive.

Most of the component are smd, so no values for the smd caps. Component names match those on the pcb.
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Re: Seymour Duncan Lava box

Postby coldcraft » 30 Jul 2012, 18:39

interesting design. I wonder how it would sound using TLC2262 Dual Opamp, like the tech21 designs.
Black Dynamite wrote:you need to shut the fuck up when grown folks is talkin.
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Re: Seymour Duncan Lava box

Postby Chugs » 30 Jul 2012, 18:50

coldcraft wrote:interesting design. I wonder how it would sound using TLC2262 Dual Opamp, like the tech21 designs.


I thought the same thing.

I wonder how much of an effect the compensation caps are having on the sound.
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Re: Seymour Duncan Lava box

Postby J M Fahey » 04 Aug 2012, 00:24

You mean the switchable caps?
It's similar to Orange's FAC control: small caps ahead of the distortion cutting some bass to make it less muddy.
Going from 1 to 6 they have less and less effect; in the last one (what they call woman tone) all sound goes through as-is.
It has no diodes, Fets , Leds or any other clipping device, just the 2nd Op Amp gets banged against the rails (+9V and ground).
I liked it, although the sound is not really tubey buy like a *good* SS amp driven balls to the wall.
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Re: Seymour Duncan Lava box

Postby Chugs » 04 Aug 2012, 09:07

I used to have an Orange OR120. It was a pretty good amp.

I was talking about the compensation caps across pins 1 and 8 of the opamps not the switchable caps.
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Re: Seymour Duncan Lava box

Postby Throbb7 » 18 Aug 2012, 17:54

Looks like a good place to start if you want to try adding some diodes in the feedback loop, or to ground. :block:
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Re: Seymour Duncan Lava box

Postby jonny4rd » 09 Jul 2013, 16:35

What could I change to add more gain and/or smooth out the drive?
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Re: Seymour Duncan Lava box

Postby roseblood11 » 28 Dec 2017, 20:01

Would be great to know the missing cap values. Does anybody own this pedal?
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