Wednesday, 4 April 2012

Menatone King of the Britains

Info from the Menatone about the original:

The King of the Britains is based on the famous '67-'68 plexi that was all the rage in the eighties, but, this King is all hopped up on STEROIDS.

This little beast can take you from clean to scream at a twist of its Gain, or a turn of your guitars volume knob.

Demo of the 7 knob version:




31 comments:

  1. See you soon here and on FSB.org ;)

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  2. I'll be doing this very soon, Grounding?

    I usually run;

    ground from switch (Skreddy) to input jack
    ground from volume to output jack
    ground from dc to input jack
    ground from board to dc

    Sounding ok? so where would you send the second ground wire from board on this layout?

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    Replies
    1. All the grounds need connecting together, so you could take one of the board grounds to the input sleeve, the other to the output sleeve, or daisy chain one to the other and then just take one wire to the input sleeve. Basically as long as the grounds are connected together you should be good to do, but make sure you don't create a loop somewhere that could create a lot of noise.

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    2. Jezz this is the one thing that IS simple but frustrates me lol...

      So could I take ALL ground wires to one point?

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    3. Yes all to one point in a star formation is fine, you could use the empty holes on the bottom row of the vero and have everything going there. Or daisy chain in one long line from one to the next. Just avoid anything that could end up like this:

      http://i76.photobucket.com/albums/j6/IvIark_2006/DIY/Groundloopexample.png

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  3. Would I get away with a 20k log for mids? I have some 22k linear but I ordered loads of A20k's I want to use up.

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    Replies
    1. You can use use any taper and it will work exactly the same at the minimum and maxmum settings, but it may not be quite as useful through the entire sweep. Having said that it also has the potential to be more useful depending on where you usually have the mids pot set. If your usual setting of a linear pot is half way, then that would probably be an 80% clockwise rotation of a log pot. That means you have more fine tuning resolution in the scooped to flat mids setting. If you usually have mids boosted slightly, then the log pot would be less useful and a reverse log would give you the greater fine tuning resolution from flat to boosted mids settings.

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    2. I have to ask, where are you getting such odd values 20k and 22k??? I've sometimes looked for these and cant find them, but plenty of 25ks.

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  4. Hi, is this layout verified? I've built this pedal, the signal passes through the circuit, the EQ is OK, but there's no gain... I've the same voltages of the original one, except for Q6 drain, which is 7,5V instead of 5,4V... The stripboard is OK (cut traces, value of components, wiring, etc...)
    Could I solve with a trimpot to bias correctly or not?

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    Replies
    1. It's not verified yet, but it sounds like you're not too far away if you're getting output and your voltages look mostly good. A couple of other people are building it so see what results they get and we can look into it further.

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  5. I'm getting all sorts of squeaks, whistles and buzzes when adjusting the Gain,level and master...with everything on 12, it sounds ok but over that introduces noises etc.

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    Replies
    1. Also, the gain doesn't seem to make a significant difference from 0 to max.. Anyway, To me it doesn't sound great anyway so I've gutted it.. I need to find a another 6 knobber to fit my enclosure now lol

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  6. The zero-gain is a common problem... Vince, could you post your transistors voltages?

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    Replies
    1. Carlo, can you post a front and back pic. Just been over the layout again and can't see any deviation from the schematic, so I'll have a look to see if anything jumps out at me.

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  7. The gain control in this is a simple voltage divider, like a volume control but at the beginning of the circuit after the input buffer. So in the fully clockwise position it's letting the entire signal through and as you move counter clockwise it puts more resistance in the way, and eventually dumps the output to ground completely and so should be totally silent in the fully ccw position. It's the same as the gain control in the Distortus Maximus Vince, does that behave in a similar way?

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  8. Hi Carlos, I'm sorry I have binned it so I can't take any info from my attempt.

    Hi Mark, My gain was acting in the way you described but it wasn't silent at full anticlockwise. I think even if mine had 'worked' I would have recycled it as it sounded really harsh.

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    1. If it wasn't silent at full counter clockwise then the pot was either damaged or it wasn't grounded properly, which could have accounted for the noise. You should give it a bit longer before you bin them mate!

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    2. Haha I know I should mate, If it were a nice effect I probably would of as with the Meathead,RAT etc... but it just didn't warrant saving (in my opinion). For 6 knobs it was just so so... I think I'm like that with all pedals to an extent... I've never plugged into anything that sounds as good as one cable straight into an amp..

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  9. Would this design accept any other FETs? I find J201s to be horrid to find suitable 3, not to mention 6...
    +m

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    Replies
    1. FETs can be more awkward to swap because they may need other tweaks to bias properly, but just try anything with the same pin out. 2N5457, 2N5484, MPF102 etc

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    2. In my experience, the 2N5457s have been quite constant when compared to J201s. For three matched J201s i had to go through 30 to find ones that work together. So for six i'd need to get at least 60 :)

      I'll try this with 2N5457s at some point.
      +m

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  10. Verified, populated this fully expecting to spend a good while switching jfets, fired it up and it worked straight of the bat. All controls work as they should including the gain pot. Not quite sounding as it should but i`m confident it will with a bit of fine tuning the j201`s after all i only expected to get a refernce point to start with, drain voltages aint perfect yet so a little tweaking tomorrow should sort things out. Drain voltages at the moment are,
    Q1-4.72v
    Q2-4.68v
    Q3-5.4v
    Q4-8.98v
    Q5-4.22v
    Q6-6.98v
    The circuit deffo works so should only be a matter of fine tuning, thanks for another great layout.

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    Replies
    1. Awesome, you hero. Particularly so as Carlo couldn't get his working which made this a brave build (although I have gone over it lots and couldn't see any issues). Thanks for verifying, that's 201! :o)

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  11. Looking forward to building this one. Sounds great.

    Any plans to do a layout for the Menatone Pig?

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    Replies
    1. Consider socketing the drain or source resistors for all the JFETs, or even better use appropriate value trimmers instead. The bias may well need tweaking and you don't want to have to solder and de-solder resistors.

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  12. Can anyone post the drain voltages from the orginal what they are supposed to be? I got all but Q4 and Q6 to be in the usual 4.5-5V range, but those two are hovering around 7-8V.

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  13. Built this (again). First with all trimmers and it sounded ok but looked horrific with all trimmers bent everywhere etc so I removed them all and replaced them with the resistors in the layout and it sounded terrible. I'd definitely recommend using sockets or trimmers. After all afternoon messing with it I gave up and binned it. Shame as it has the potential to sound excellent. I just haven't got the patience unfortunately.

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  14. I was wondering, are q4 and q5 biased separately? One of them seems to be biased by the 15k resistor but is the other one biased at all and if so, by which resistor? Or is something happening by the gate of the one fet going into the drain of the other?

    Tx.

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  15. Hello , here is what I found about biasing of the bunch of J201 transistors inside this pedal , values are around transistors symbols :http://revolutiondeux.blogspot.fr/2008/11/menatone-king-of-britons.html

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