New Distortion Project - The Plexizer

[mojotron]

What is it? I wanted to create a box that got a good Marshall 1959 (Plexi) sound - that's what the Plexizer does.

I built this a few months ago after a lot of experiments with a few JFET projects based on a bunch of Marshall designs and the Dr Boogey and it's really become one of my favorite distortions. The ThunderChief and Dr Boogey have a bit meaner/edgier sound, and I wanted someting with that really warm/smooth distortion that you get from the Marshall 1959 circuit. What I ended up with is a really nice sounding box that I can plug a strat into and get an early Hendrix sound, put in front of some delay/reverb and get an early Eric Johnson sound, or plug in a Gibson and get an early Clapton sound.

I want to thank Bucksears for his help with putting this together and his great layouts - Buck has a layout for this one as well, which he will post later and wampcat1 who helped with advice he posted on the the LPF on the end of this circuit - which works great. I also wanted to thank all of those who contributed to related designs and those that contributed to the Dr Boogie threads, here, especially Bucksears, PaulC, RDV and many others.



Bigger images at:
http://www.mojotronics.com/images/plexizer/Plexizer_sc.JPG - 20% bigger
http://www.mojotronics.com/images/plexizer/Plexizer_sch.JPG - 50% bigger

Notes:
R11 controls Treble
R13 controls Bass
R14 controls Mids
R18 controls Presence -
Note: You can play with the value of C19 - use bigger values (up to 1uF) to get more presence - 100uF is what I use.
Output Pot: I use a 100kA because I think it sounds better, but this circuit has a lot of gain and you could use a 50kA or 25kA if you wanted a bit more granularity on the output control.

On my pedal board, this is a really great compliment to the ThunderChief, Dr Boogey, a Fat Boostered and my Vibin' Champ pedals - covering the entire range of overdrive/distortion for what I need.

I know that some people will not like my statements about God in this schematic. I'll just say this and leave it at that: I know how you feel, I once did not believe in God, I was not one who you would have thought would ever come to know God, and I thought stuff like this was kind of annoying and silly: despite a lot of misinformation floating around out there about God, my only motivation for making these statements is to try to let people know Jesus Christ is real, holds the meaning of life, and will give anyone a true peace in their life that comes from knowing God. I'm not recruiting for any church or want anyone to feel guilty, obligated or to think that somehow I am a better person than anyone else - believe me - that is not the case. There's no financial motivation to this what so ever either. If you would like to talk about it my email address is developerlinux@hotmail.com.

[StephenGiles]

Aha, that reminds me of Hank Wangford's set closer - Joggin' with Jesus! Or Big G, better than a smoke or a cup of tea.

[MetalGod]

Thanks for the schematic, bet the pedal sounds great - will have to try it out.  I could've done with the preaching at the end though.

[bluesdevil]

Holy shit!! Thank you for sharing!!! 

[MartyMart]

Looks great Mike , final vol pot say's just "R" ??  100k perhaps ?

Many thanks

Marty.

[$uperpuma]

Looks great mang!  I was in the studio a couple weeks ago with Zac Maloy and he had a 71 plexi that was out of this world... THE sound... might as well stompbox it   and FWIW, put what you want on your schematics, you took the trouble to make it, if someone doesn't like it, just like TV, they can change the channel, or in this case click over to another thread.  Rock on, 'Tron

-Nate

[mojotron]

Looks great Mike , final vol pot say's just "R" ??  100k perhaps ?

Many thanks

Marty.

Thanks - this is sort of a 'refactor' the the ThunderChief (with tone stack) - adding in a few changes from the 1959 design, as well as taking out one stage, and doning some tweaking to get the gain/sound just right... The sound is a lot like the sound clips of Indyguitarist's PlexiDrive... I'll post some clips later.

Right, I like 100kA, because this sounds better to me, but I think 50kA or 25kA would work great for those that want a more granular volume adjustment.

Bucksears has a layout that he's going to post for this.

[Morocotopo]

Thanks mojotron for sharing. Since you made this, you can put whatever you want in your file, those who don´t like it, don´t look!! 
Soundclips when, you say??   

Morocotopo

[RaceDriver205]

Aye, Got sound clip?
I thought jesus was gods son tho! (and that he died?)

[tungngruv]

Another to add to the list! Thanks once again Mojo, Great job.

[Marcos - Munky]

Thanks a lot for share it. Soundclips???

Just a suggestion to clean the schematic a little, in the preferences there's an option to hide the grid, it will make it more cleaner.

[Nashtir]

yeaah!!!that's cool!!!we are all waiting for samples and the layout!!!

[markm]

I'll add to this too,
Nice work     and when can we see a Layout??

[Bucksears]

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

[mojotron]

Aye, Got sound clip?

Sound clips for the Plexizer:
All recorded using VAMP w/small combo setting w/1x12 cab sim and reverb into a computer sound card

Note: I hit the strings very hard sometimes - I'm really a rock player - so your level of distortion may vary - mine is always quite high as I beat my guitar to death. If I really restrain myself, I can get a lot of different tones out of this box by changing my pick angle/attack and location of my picking. I didn't really bring this out very well in the below clips, but I think the below clips cover the Plexizer's sound fairly well.

Set1:Guitar: Ibanez S470 w/Gibson Classic '57/'57+ pickups

Set1 Clip1:
http://mojotronics.com/smf/p_demo_brown.mp3
- Gain = 50%
- B/M = 100%
-T = 50%
-P = 0

Set1 Clip2:
http://mojotronics.com/smf/p_demo_brown_2.mp3 (settings same as above)

Set1 Clip3:
http://mojotronics.com/smf/p_demo_mid_control.mp3
Settings: everything at 50%

Set1 Clip4:
http://mojotronics.com/smf/p_demo_full_control.mp3
Settings: everything at 100%

Set2: Guitar: Warmoth Strat w/Fender Fat '50's(n/m), HS2(br)

Set2 Clip1:
http://mojotronics.com/smf/p_demo_brown_strat.mp3
Using all of the different pickup combos and tone knob here and there
- Gain = 100%
- B/M = 100%
-T = 50%
-P = 0

Set2 Clip2:
Settings same as Set2 Clip1, using just the br pickup
http://mojotronics.com/smf/p_demo_brown_strat_br.mp3

Set2 Clip3:
http://mojotronics.com/smf/p_demo_full_control_strat_br.mp3
Settings: everything at 100%

My apologies, I should have put these together before I posted the schematic. I recorded these at 6am in the morning (trying not to wake everyone in the house up..); I just slapped 'em down - sorry  if my playing is a little erratic - there's a lot of rough playing in there 

I thought jesus was gods son tho! (and that he died?)

This is really layed out in the first chapter of the book of John (who Jesus is) - God the Father, Jesus - God the Son, and the Holy Spirit are God. Jesus rose from the dead (last few chapters of the Book of John) - this is what easter is all about.

[MartyMart]

Wooh - Mike , that sounds absolutely fabulous !! 

It's just jumped position to my very next build ( small 1.8watt valve amp to finish first )

Great clips,

Marty.

[mojotron]

2xpost...

[The Tone God]

I thought jesus was gods son tho! (and that he died?)

Nice work Mojotron.

Andrew

[choklitlove]

that is one of the funniest things i've ever seen.

[John Lyons]

Oh boy! Here we go!

This is why religion or politics does not belong here. We all know and love building effects, that's why were are here..everything runs smooth and fine. Enter politics and religion and everyone gets uptight and gets on their soap box. Please spare us!!!!!

The schematic looks cool thanks!

John