New Distortion Project - The Plexizer

[mojotron]

I'll have the layout up sometime very soon; today, if I can get a few minutes.
The presence has been modified since this version, I think, so I want to update my PCB and layout as well.
From what I've heard from Mojotron on this circuit, I'm chomping at the bit to build it.

- Buck

Sorry for the last minute changes Buck, thanks for making the layout for this.

I had been trying to make the presence circuit on this a bit more like the Marshall 1959, all of the changes I tried were very subtle; the implementation I left in there on this version is the best I had tried. You can use .1uF to 1uF for the bypass cap across the presence control. I use 1uF for C19 in my sound clips (the difference is pretty slight over using .1uF for C19) - this control as it is gives you a little more chimey high end while not changing the low-end.

If you notice, I use a 4.7k resistor for R17 (in stead of 10k in the 1959 design), and this allows the presence to have a more affect on the sound, as well as providing a little more gain without changing the sound over the original circuits value for what is R17 in the Plexizer.

Mods:
1) If you have a high wattage amp and a 2x12 or 4x12 cab, you could try 10k for R17 if you want a less 'beefy' (slightly less gain/thinner) sound.

2) Use 1uF caps for C10 and C3 - this will fatten up the sound a bit - I like the values with either the .68uF and 1uF caps - .68uF is a bit more 'vintage' sounding. For a strat, I recommend the 1uF caps - unless you want to sound exactly like early Jimi.

3) If you think the sound is a bit too dark, every rig is a bit different, you can remove C20 or C21 - and/or just put these on a dpdt switch to make it switchable.

Thanks everyone! If you build one of these, let me know what you think.

[Bucksears]

No problemo.

Well, here it is. The PCB and parts layout files for the Plexizer can be found here:

http://www.4thlevelmedia.com/stompboxes.html

If anyone sees any mistakes or anything, please let me know. I advise saving the files to your computer and printing them out from something other than Internet Explorer; IE has been known to resize pics when opened within IE.
The two parts that were removed from the schematic are removed from the parts layout, but the pads still remain on the PCB. It's ok, you don't need to populate those two parts. They are marked with red dashed lines on the Parts Layout.
Please post if you build this so we can get some feedback.

Enjoy!!
Buck

[The Furious One]

Ahh yes, I've been waiting for something like this! But now I have to send puma some more money to make me the board LOL!

[RaceDriver205]

Jesus rose from the dead (last few chapters of the Book of John) - this is what easter is all about.

Awesome, I love easter!

Enter politics and religion and everyone gets uptight and gets on their soap box.

Lol, true dat. Everyone gets annoyed at how silly everone else is. RD205 4 governor!   

Sounds like it works pretty good, this Plexizer. I think I have enough distortions tho, I have a hard time telling if any new ones I find will sound different to ones I have. Might build it in the end anyway, just to be sure.

chimey high end

Someone add 'chimey' to the stompbox dictionary 

[Xavier]

Holy cow !!!!!

Thanks for the contribution Mojo !!!!!!

When I have the time I'll work on the perf layout

My Dr. Boogey is not boogeying, so I might use this circuit instead.

[wampcat1]

Holy shit!! Thank you for sharing!!! 

I'm a very devoted Christian myself but I just about fell out of my chair laughing at this one... 

Mojo, those clips sound GREAT!

bw

[brett]

Hi
Cool design.
Obviously a lot of work went into it.
I'll give it a build when there's a layout.  Might be a good front end for a dual Ruby.
cheers

PS

I know that some people will not like my statements about God

So why upset people (e.g. me)?  There are plenty of other sites for that stuff.  Please use them.

[RaceDriver205]

So why upset people (e.g. me)? 

Funnily enough, if we were talking about the great alL@h, no one would dare joke!
At that I say religon talk should end.

[MartyMart]

I'm not offended in any way at all, however, I think that we should do what the
folks at www.18watt.com do , dont allow ANY religious or political chit chat at all

After all , this is an FX forum .... right mods ??

.... not even in the OT section !!
peace ,
Marty.

[The Tone God]

Ah crap, here we go again.

Re: Religion.

Have you guys thought about acting like adults by just ignoring the statements instead of making a silly little fuzz about it ? I would think around here we should not berate somebody for harmless statements but instead focus on thanking them for contributing hoping they will contribute more in the future.

Andrew

[mojotron]

Holy shit!! Thank you for sharing!!! 

I'm a very devoted Christian myself but I just about fell out of my chair laughing at this one... 

Me too..

Mojo, those clips sound GREAT!
...

Thanks Brian, your clips for one of you pedals really inspired me to put something together that would do something like that - smooth Marshall-ish crunch - your advice on the LPF in another thread made a big difference in the authenticity of the sound - at least with my TubeWorks amp and 2x12 H&K cab.

I have a hard time reconciling the need to put 6 knobs on this, but I use them all and they add a bit of versatility. I have tried a number of tone circuits and none of them really hit the right sound. And, the Marshall tone stack just sounds right on this. Anyone have any thoughts on that?

Xavier - if you want to re-cycle your Dr. B board - you can build this on top of a Dr. B layout with some creative use of the back-side of the board. For my prototypes I used Buck's ThunderChief w/Tone Stack layout (with some rather ugly mods) just so I would not have to make an initial layout when I got started with this.

[jonathan perez]

my 6505+ with my Burn Unit/Hellatone 30's/75's sounds SOOOO close to a plexi. but everytime i hear about some new distortion build, i want to build it!

but this time around, i think i for sure am going to build this, as a backup for my rig.

good stuff!

[MartyMart]

Ah crap, here we go again.

Re: Religion.

Have you guys thought about acting like adults by just ignoring the statements instead of making a silly little fuzz about it ? I would think around here we should not berate somebody for harmless statements but instead focus on thanking them for contributing hoping they will contribute more in the future.

Andrew

Andrew, as I clearly stated, I personally dont mind a bit, but the immediate "taking the piss" etc is a bit out
of order from some members.
So my suggestion is just to remove any chace of "all that rubbish happening" by keeping it off here totally.

That was all

MM..

[The Tone God]

Andrew, as I clearly stated, I personally dont mind a bit, but the immediate "taking the piss" etc is a bit out
of order from some members.
So my suggestion is just to remove any chace of "all that rubbish happening" by keeping it off here totally.

That was all

The statements I made was not directly to anyone in particular. If an all out flame war came about I would agree but that hasn't happen, and quite frankly I doubt it will, so I was just encouraging others to look past it if it bothered them so things would not get to the point of having to put furthur restrictions on the forum. I do not want to see a contributer driven away is all.

Its all cool.

Andrew

[$uperpuma]

Ahh yes, I've been waiting for something like this! But now I have to send puma some more money to make me the board LOL!

[MartyMart]

Mike, built and working on stripboard 
Question re voltages :
Q1/Q2/Q4 sitting at 4.5v Q3 at 9v but I;m having problems with Q5 !
Seems to move around and only works properly at about 6v , however
this causes the circuit to have quite a lot of hiss !
I'll keep persuing it, I've built and designed a number of these jfet amp sims
so should be able to solve it , just wondering what your voltages are like ?

Cheers,
Marty
BTW - It's sounding quite like your clips

[MartyMart]

OK, solved it , tuned the trimmer at Q5 by "ear" to remove the hiss
and this works great now
Happens to be 7.1v !!
Sounding great now, many thanks Mike.

Marty.

[John Lyons]

Jeez marty, you don't waist any time at all, do you? Soundclips? (jab, jab...)

John

[MartyMart]

Jeez marty, you don't waist any time at all, do you? Soundclips? (jab, jab...)
John

Well, I'm a sucker for a nice marshall tone !! 

MM

[Bucksears]

So (getting a second opinion), does it do a nice early Marshall tone or what?