Wednesday, 19 March 2014

Mesa Boogie Grid Slammer

I was in two minds over posting this because it is almost exactly an Ibanez TS9, but I thought I would just because if someone does want to build one they have a ready made layout and so won't have to look up what changes to make.  To emphasise how close it is I've also included a toggle to switch between Grid Slammer and a TS9. Basically the difference is just a Timmy clipping diode arrangement, but if anyone wants a Grid Slammer or even a TS9 then at least this will give them two pedals in one. :o)

How much mileage are they going to get out of this design?

Info from Mesa about the original:

The GRID SLAMMER™ Overdrive is an overdrive pedal that produces a variable boost in gain over a wide range with a classic, guitar-centric midrange bump that enhances many different playing styles. It’s a true overdrive “specialist” that covers an amazing array of what many top players consider the most expressive and musical ranges of overdrive. From sweet, subtle breakup to a harmonically smoldering overdrive that can both sting and sing, the GRID SLAMMER sets a new bar in legendary overdrive!

PRODUCT FEATURES:

    Designed and Hand-Built in Petaluma, California, USA
    True Bypass On/Off Switching - Bypasses all circuitry when off to ensure no tonal loss
    Gain Control allows you to dial in the perfect amount of vintage breakup or classic overdrive
    Master Level Control provides a variable range of signal boost up to +20db
    Tone Control balances the amount of high frequencies
    On/Off Status LED
    9V Battery Powered or optional AC Powered via External Power Jack Input
    Input & Output Jacks (Nominal Input -20 db)








34 comments:

  1. Was just re-reading "The Goose, the Middleman, the Idolmaker and Gomer Pyle". Funny how this is yet another Tubescreamer. Even Mesa is following suit!

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  2. Hmm, I've just ordered the parts to build a Timmy... decisions, decisions...

    Thanks for all the great work Mark & co. :)

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  3. Hey
    Fun to see my tracing work being made into a layout.
    Excellent work as usual Mark, good idea with the diodes. :)
    cheers / Fredrik (Freppo)

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    1. Aah it's you :o), great work on the schematic!

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  4. I'm actually kinda interested in the idea of a TS with Timmy clipping. Bet it sounds great

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    1. You should probably build a Timmy with TS clipping on a switch... :)
      +m

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    2. Oh yeah? I don't really know much about overdrive pedals because I like to use my ac30 for overdriven sounds. I'm more of a fuzz and booster fan

      But if you recommend the Timmy maybe I'll give it a try. I just have no idea which overdrive is the best build because there are so many!

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    3. All of them! Everyone needs 235 overdrive pedals :o)

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    4. lol So what are your actual favorites, Mark?

      My buddy says the Himmelstrutz overdrives are the best but I don't have the parts to build that on hand, and with a Rickenbacker 660 on layaway, I can't order parts right meow :P

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    5. My top 3 are probably the OD820, Zendrive and Timmy, but there are plenty I haven't built yet so I may have to revise it at some point.

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  5. Dude, what is W for the 20k W pot?

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    1. http://www.taydaelectronics.com/potentiometer-variable-resistors/rotary-potentiometer/w-taper/20k-ohm-w-taper-w20k-tone-control-potentiometer-with-center-detent.html

      You can use linear.
      +m

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  6. No luck with this one. I get an effect like a really badly biased fuzz. You have to hit the strings hard to push the signal out. Tried different 2sc1815's and OpAmps etc.

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    1. Post your voltages mate. I'm pretty confident about this one with it being based on the TS9 layout

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    2. Took the voltages and noticed a 1k in place of a 10k resistor!. Sorted it now. I would definitely recommend building this with the clipping switch. The Mesa side is a VERY loud, cleaner Tubescreamer. Great for using to push a dirty amp, not brilliant on a clean amp but then flip the switch and you have a regular screamer that sounds much better on the clean channel.

      Worthwhile build for anyone that wants more boost from a Tubescreamer.

      So, it's good to go mate, Cheers ;o)

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  7. Replies
    1. It's just used as a variable resistor and so connecting 3 isn't required. You can link 2 and 3 together if you want but it isn't necessary.

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  8. Shouldn't the 4k7 resister after the 47N cap off the drive / clipping circuit go straight to the ground rail?

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    Replies
    1. No it goes to vref which is a virtual ground. It could go to ground equally well, but in this pedal it goes to vref.

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    2. Rodger that.. I traced out the circuit and it looked so muck like a tube screamer i just figured the veroboard drawing got blipped.

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  9. @Vince Wright can u provide gutshots??

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  10. I'm new to studying pedal circuits so forgive me for not knowing basics. It says here that this is a TS9 with timmy clipping. But I'm reading here: http://www.freestompboxes.org/viewtopic.php?t=24190&p=236365 and they are saying it's a Landgraff Dynamic OD with timmy clipping. But looking up the page on here about the Landgraff it says that it mojo'd TS808. I guess I'm asking is that why it doesn't seem to line up with if it's TS9 or 808 based.

    Thanks for any help.

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    1. There isn't very much difference between the TS9 and TS808 with the change being just a couple of the resistor values used at the output buffer, so it could reasonably be described as either. But the 470R and 100K are the values used in the TS9 and so this is closer to that. The Landgraff uses a 100R and 10K which is the classic TS808 values.

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  12. Hello,

    I have recently started building this pedal. I have polarised 1uF caps, will it function correctly with these or does it need un-polarised 1uF caps?

    Thank you.

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  13. Hi there,
    Would a fourth pot. be possible like a contour or a bass control?
    Thx for yr help

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    Replies
    1. http://tagboardeffects.blogspot.fi/2014/01/ibanez-ts808-with-bass-control.html

      Just use two diodes in series for each one and you'll have a Grid slammer with a bass control.
      +m

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    2. Hi mirosol, sorry but I don't understand. Would you mind being more specific?

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  15. Hi there,

    I tried this one over the weeken but don't seem to have any signal going through the circuit, just a buzz that intensifies when the level is increased.

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