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Hi there, welcome to my blog - La Revolution Deux. It's an odd name - but I like it! Here you will find all the info on my various DIY Guitar effects builds, amplifiers and guitars. Everything from a humble Ibanez tubescreamer to the holiest KLON Overdrive.

You may also find a few effects builds that I am looking to move on - usually in exchange for other effects/gear/cash. You can always check my ebay account to see what I've got up for grabs.

Have fun, enjoy the blog - Fred Briggs :-)

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Tuesday, 10 July 2012

Blackout Effectors - Mantra Overdrive


More interesting stuff from Blackout Effectors now - the Mantra Overdrive. There's been some hype around this one *and* it comes in a gold enclosure! It doesn't get any better than that :-D

Here's the description of the Mantra Overdrive from the Blackout Effectors website;

"Equally capable of invoking the sacred sounds of a classically refined overdrive AND summoning wickedly raunchy drive, with more crunch on tap than the overdrive moniker usually entails. With such a wide palette of tones and character the MANTRA will feel just as at home at the feet of the stalwart blues crowd as it will the quintessential rock & roll protagonists.

The MANTRA utilizes amp-like circuit architecture, with multiple cascaded MOSFET and JFET gain stages to insure the most natural, touch-sensitive overdrive conditions possible and a seemingly endless range of clean-up with your guitar's volume knob. We burned a lot of midnight oil to make sure that the MANTRA could get down with vintage-type, low output single coils and hot humbucker pickups alike. From gently fingerpicked melodic phrases to bludgeoning riffs that you'll want to play over and over and over..."


With a ProGuitarShop demo video for you;


Sounds pretty sweet and does have a real range of gain available, it's nice and dynamic too - this'll be due to those multiple gain/clipping stages it employs! I always like my "amp like" overdrives (i.e. overdrive circuits that take inspiration from the structure of amplifier pre-amps) to have more tone controls than a simple "treble cut" - I don't think a treble cut gives enough of a convincing EQ curve - the use of the baxandall style tonestack works well though; a plus for the Mantra!

A gutshot of the Blackout Mantra - super clean wiring and construction.
Once again the freestompboxes lot had a peek inside a Mantra overdrive and managed to work something up. The thanks for the majority of work on this one go to KindaFuzzy and RnFR (the tracing was KindaFuzzy and schematic and PCB files are RnFR's);


The circuit structure is slightly more interesting than the standard "Tubes 2 Jfets" topology and shows how mosfets and jfet can be combined to really create an interesting and convincing overdrive clipping structure. The J201 always sounded a little dark to me but with the source resistor set higher as it is in the Mantra (10k) it seems to brighten up a little and not roll off so many highs. It would be interesting to have an option to run either the mosfet section or the jfet section independently for some cool lower gain tones - there's an idea for you modders out there :-)



Here's the freestompboxes.org forum topic for reference; http://freestompboxes.org/viewtopic.php?f=7&t=14562

4 comments:

  1. Es posible que falte c21 en el diagrama?

    ReplyDelete
  2. what would be the low gain mod?

    ReplyDelete
  3. Hello, in the schematic has some voltages values, that I think the trimpots control them, right? Then I thought if the trimpots could just change something on the sound of the pedal, and if I could put in their places some potentiometers to control them, like the volume pot etc, or it will damage the circuit? I'm sorry if the english isn't the best.

    ReplyDelete

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