Wednesday, 22 February 2012

Mad Professor Ruby Red Booster

A nice versatile booster here by Bjorn, with switchable buffered or true bypass switching.  I have kept the buffer separate so those who just intend to use it true bypass don't have to bother with the extra components or board size.

Manufacturers info:

BJF design guitar booster/treble booster pedal with master volume

Mad Professor Ruby Red Booster (RRB) is a combination of two boosters and a switchable buffer.

The two boosters are based on the much sought after BJF Little Red Trebler and Red Rooster Booster, connected in that order and with a master volume control.

The RRB can be used as a treble booster, a clean boost or an overdrive unit or any combination of the above. Inside the pedal there is a switch for a high quality buffer. You can set the pedal for true bypass mode or "buffer on" in bypass mode. The Treble Booster is a fine-tuned booster for just the right treble frequency with carefully designed bandwidth and an optimized slope of bass cut.

The booster circuit is designed to overdrive the amplifier inputs from nice shimmer to heavy overdrive, thanks to the massive 40dB of boost. The booster is tuned so that it produces musical distortion by itself on higher boost settings.

You can control the total level of the two boosters with the Master Volume control and also use the Master Volume to achieve distortion from the unit.

The easy to use Mad Professor Ruby Red Booster must be the most versatile high quality booster on market. Build the Mad Professor way: small footprint and big tone.







27 comments:

  1. Had a little head to head time with this today. Fet images are in 180 degress, but pinout is right. I'm up to the point where i get sweet sounds when probing Q3 gate and source, but then something happens... Might be my mistake too, so i'm going to continue this tomorrow.

    But since this is unverified, i thought i'd ask if you have time to check out if everything is right around Q4..

    +m

    ReplyDelete
    Replies
    1. OK I'll look over it later tonight and see if I can spot anything. Thanks for the info

      Delete
    2. Just had a quick look over it and based on the schematics these are the required Q4 connections:

      Gate:
      Boost 2
      1M > ground

      Source:
      14K7 > ground
      22u > 470R > ground

      Drain:
      14K7 > 9V
      1n > 9V
      1u > Master 3

      and that all looks right to me. You haven't used a 470K instead of 470R have you?

      Delete
  2. Found it. My bad. Both positive leads of 22u's were one strip lower than they should be.

    Boost 3 and 1 are in reverse. Otherwise the boost part is verified.

    Now i need to swap the led that i burned during careless troubleshooting. But that can wait till tomorrow. Same as testing this through..
    +m

    ReplyDelete
    Replies
    1. Excellent, I've updated the layout but let me know how you get on tomorrow.

      Delete
  3. This comment has been removed by the author.

    ReplyDelete
  4. Played with it for a while. And like one of my friends says: It doesn't too that much, but it does just fucking that much. (doesn't sound so good in english..)

    Very discreet and beautiful sound. Only other boost i have at hand is SHO, and if compared, this one is sleeky clean, except when treble is maxed. Even then the sound stays well together. It's a real possibility that i will probably replace my SHO clone with this on my main setup. It doesn't seem to give out as much power as SHO, but it's cleanliness is remarkable.

    I get some noise when boost is maxed, but nothing serious. Only thing that puzzles me is something that is probably in the design. Master is just to attenuate the signal. If treble and boost are at 0, then the master does nothing.

    Decided to put this in 1590B, and so omitted the buffer. (yes. just because of my lust for convenience:))

    It's good sounding clean boost/treble boost. I'm still yet try it high volumes, but here at home it gives out at least enough.

    Thanks again Mark!
    +m

    ReplyDelete
    Replies
    1. That sounds strange about the Master Volume. It's a standard volume control and so in the counter clockwise position connects the output to ground. So it should be silent irrespective of the other settings. Sounds like there may be a bad joint on a ground connection somewhere.

      Delete
    2. I'll go through it again, but.. It sounds good the way it is and though the controls are what they are, the sound is compareable to proguitarshop demo.

      I'll take this under magnifying glass tomorrow.
      +m

      Delete
    3. Went it literally through with magnifying glass and got the controls back. Some bridge and/or bad joint. Once again, i should always be more thorough the first time. Would mean less fixing afterwards.

      It isn't that subtle anymore.. :) Which is not a bad thing. There's warm and big sounding overdrive when cranked to the max.

      Great little booster.
      +m

      Delete
    4. http://mirosol.kapsi.fi/varasto/boxes/ruby.JPG
      +m

      Delete
  5. Hi i ve built just the booster layout only three times alrdy but still not working. Ive checked everythings according to layout. Jfets are corrctly oriented so do caps.

    ReplyDelete
    Replies
    1. What voltages are you getting between all the transistor pins and ground?

      Delete
    2. I used matched set of 2N5952s from musikding...
      +m

      Delete
    3. q1>> D - 3.974 S - 3.204 G - 3.216

      Q2 > D - 3.254 S - 2.541 G - 2.542

      Q3 > D - 4.442 S - 3.718 G - 3.724

      Q4 > D - 4.292 S - 3.583 G - 3.587

      Delete
  6. i did not build the buffer circuit. just the booster side

    ReplyDelete
  7. hi everyone i solve my issues. i just nd to turn my jfet over, haha. just checked at the datasheet.
    here are my reading. drain voltage on all jfets is 7.01v ish. Gate are all measured 0v. And Source for Q2&Q4 is 1.88v while Q1&Q3 is 1.455 ish..

    Is this a good reading? can it be improved?

    ReplyDelete
  8. Is it recommended to pair the JFETs? Or buy them paired as mirosol did?

    ReplyDelete
  9. that pedal looks thedurham sex drive? I'm looking for that last one

    ReplyDelete
  10. I just finished building this one. The FET's should be 180 degrees rotated but with the same pin out. Also the boost 1 and 3 should be swaped! For the rest... sweeeeeeeeeeeeet.

    ReplyDelete
    Replies
    1. Thanks for the heads up Arnold, can't believe these corrections have passed me by for so long!

      Delete
  11. What other buffer IC's can I use that are equivalent that I could source from Mammoth? They don't carry the NE5535.

    ReplyDelete
    Replies
    1. http://www.mammothelectronics.com/NE5534P-LOW-NOISE-OPERATIONAL-AMPLIFIERS-p/400-1118.htm
      +m

      Delete
    2. Whoa, just in time. Almost submitted my order without it. Thanks!

      Delete
  12. I really like the switching on this. I want the buffer to use a toggle and the boost to use a 3PDT switch and I would like both effects to have their own LED indicator. The layout above doesn't say anything about where LEDs would go and the switching doesn't follow the traditional off-board wiring laid out o the site. Can you guys help me figure out how to do this?

    ReplyDelete
    Replies
    1. Use the unused left hand pole of the Boost switch for the Boost LED. Instead of a DPDT switch shown, also use a 3PDT switch for the Buffer and again use the third pole for LED switching.

      Delete