What is the consensus on the DIY Plexi in a box?

[RollingElbow]

So the guys at Carl Martin gave us the Plexitone, ZVex the Box of Rock.... what can we as DIY'ers conjure up or mix up in the witches cauldron to produce something similar? Obviously there is no substitute for a real Plexi, I'd just be interested in something that gets us into the ballpark. Fat, smooth, gritty, powerful and not overly distorted. I have higher gain for leads.. maybe something that could be boosted? What do we think? BSIAB is already higher gain to my knowledge.. lets try to stick old school.

Thanks.

[Serge]

Runoffgroove's Thor?

[RollingElbow]

I listened to it.. maybe it is the clips, but it really doesn't do it for me. A bit too raspy perhaps...

[RollingElbow]

Listening to the runoffgroove site clips.. only Marty Marts really impresses me.. now i am wondering if that improved design over the thunderchief plus pumped through a real 4 x 12 cab would do it more justice. Anyone have any clips of theirs? Also, where can one find a PCB or a kit for this? Might be cheaper than sourcing parts etc..

Also, by all means, lets here more suggestions..

Thanks

[mojotron]

The Plexizer is my main pedal in front of a TubeWorks 2100 amp.

http://www.diystompboxes.com/smfforum/index.php?topic=50207.0 is the link to the thread; there are some clips in there.

This is close to a ThunderChief w/tonestack - but it has a few changes that focus the tone a little differently.

What is Plexi is many things to many people too...

[vanessa]

So the guys at Carl Martin gave us the Plexitone, ZVex the Box of Rock.... what can we as DIY'ers conjure up or mix up in the witches cauldron to produce something similar? Obviously there is no substitute for a real Plexi, I'd just be interested in something that gets us into the ballpark. Fat, smooth, gritty, powerful and not overly distorted. I have higher gain for leads.. maybe something that could be boosted? What do we think? BSIAB is already higher gain to my knowledge.. lets try to stick old school.

Thanks.

I've always thought that SRV nailed it with his use of the TS808 and a Fender amp. Lacking the compressed sound of a closed back cab, it sounded like a more clean version of a Marshall Plexi. I guess you could get close with a similar setup and a 4x12 closed cab sim? But really there is nothing like having the real thing... 

[jlullo]

rolling,
why don't you take a plexi schem and give it a shot (replacing the triodes with jfets)?

[dosmun]

The Guv'nor is the best I've heard.

[Serge]

I believe also the HAO Rustdriver may give you the Marshall sound.  Haven't heard it in real life though... (it's on my to do list)

[RollingElbow]

Well i've actually thought of giving it a try.. making a pedal that is voiced after a 50 watt non master volume JMP.. would be cool. Too bad I don't really know the theory behind designing.. maybe if i could get an idea from someone because it can't be as easy as replacing tubes with Jfets... or can it. I did build a JMP clone but it has its problems in the output section.. its going in to the shop, once it is out, i suppose i would have a pretty good reference though! Could be fun.. not sure where to start though in understanding theory.. i suppose all it is is pumping 9 volts through it and designing the circuit based roughly on the amp and what other pedals have done.. why don't we do it as a community?

[RollingElbow]

Rust driver has its knocks..apparently the volume and drive are one and one the same.. so you have to crank it.. then when you want it tamed, you have to turn up the amp... but the tone is pretty sweet. That plexizer sounds good though.. i am wondering if some brittleness i hear could be shaved off still too... maybe its just the clips... could also be that it was recorded direct. I think direct recording is a prety aweful soun dmost of the time so i'd love to hear this thing through a cab.

[tcobretti]

I built the ROG Eighteen, and it sounds very similar to my 50w plexi that I sold a couple of years ago.  Knowing ROG and having built several of their amp emulators, I would imagine the Thor would also be a fair imitation, but I have not built it.

[mojotron]

...That plexizer sounds good though.. i am wondering if some brittleness i hear could be shaved off still too... maybe its just the clips... could also be that it was recorded direct. I think direct recording is a prety aweful soun dmost of the time so i'd love to hear this thing through a cab.

Yes - it was recorded direct; and live the sound is more natural - especially at stage volume. But, in general I think all of the pre-amp emulator circuits like these can sound a little edgy compared with the original. A little bit of compression and some EQ can compensate for what the output transformer is doing when you are driving an amp, but there is really no substitute for the transformer. The plexizer is pretty much a jfet-vs-12ax7 adaptation of the Marshall 1959 based preamp.

[RollingElbow]

The ROG 18 has absolutely horrible soundclips on the site... that one interested me as well but wow, what bad clips! Does anyone have better ones? I might look into that THOR.. half the clips were good, the others too edgy. I think through a real amp ratehr than a sim woul dalso make a diff.

[tcobretti]

Those clips of the Eighteen are pretty accurate.  They are slightly thinner sounding than the pedal itself, but otherwise pretty faithful.  If you ran an Eighteen into a cranked poweramp and a 4x12, it will sound very much like a plexi.  Not exact, but as good as any other pedal, especially one so simple.

[petemoore]

why don't you take a plexi schem
  IIRC that's what Thunderchief @ ROG did.
  I had Plexi's, cool. Louder than tarnation, I don't think I really ever heard much plexi type sound out of them when I had them, at least not what 'plexi' means in 9V nomenclature, I had only Marshall 412 Greenback Cabs to run it through, rediculous, scary loud. Without a dirtbox they'd hardly break up nice anyway, I used the Shredmaster to get '9V Plexi' out of my #2 at the time, that or a Fab Tone or Boss unit or whatever I had on hand [this was before DIY].
  IME, a small tube amp sounds alot more 'Plexi' than I ever got out of a Plexi with volumes down, of course part of this stems from the fact that I can tweek @ lower watts more easily and often to find the sweet spots without rattling the neighbors rafters loose, I mean I don't have to put upright plywood sheets in front of the china shelves to keep the china from falling off, and can save what's left of my hearing.
  Perhaps something with an envelope detectors causing slight freq shifts and signal compression or clean blend to distortion [or reverse] to rise in amplitude, dependant on input amplitude, at attack or sustain times, for a longer way around to a more 'plexi' type thing.
  Some roads are long and winding, and don't stop off or terminate exactly where you think they would, hopefully from there you can alter course until you get somewhere nice.
  Those clips of the Eighteen are pretty accurate.  They are slightly thinner sounding than the pedal itself, but otherwise pretty faithful.  If you ran an Eighteen into a cranked poweramp and a 4x12, it will sound very much like a plexi.  Not exact, but as good as any other pedal, especially one so simple.
  I concur and add that the 18 gets very cool and quite close to a big tube amps cranked tone, adjectives aside [not], clean, bouncy, kind of dirty too when pressed, a light/medium distortion.
  Bill had a 100w plexi, it didn't respond at all like either of my 100w plexi's, [those two weren't similar either] we traded for a short time...we decided they were very different beasts.
  Then there are other considerations:
  Plexi into different speaker configurations and types.
  Channel I plexi [low and high]
  Channel II plexi [low or high]
  ..4 input preamp lets you have..
  Plexi with a cross channel patch cable across the top, across the bottom, diagonal leaning left or right...
  Suffice it to say, with all the plexi experiences and related etc., I can't even imagine what one 'actually' sounds like other than a very powerful beast that refuses to distort at any reasonable volume, after that, alone, they are 'rude' until sufficient space and time can be allotted for finding the 'plexi' sound, once you get there though it is too much fun. But for 'normal' volume usage I think they sound best doing 'tubey-clean' or with a dirtbox doing >90% of the distortion honors.
 

[alderbody]

Anyone have any clips of theirs?

Listen to my Thor clips here:

http://www.diystompboxes.com/userfiles/index.php?&direction=0&order=&directory=public_downloads

(everything with the 'alderbody' signature)

There are plenty of combinations with other pedals.
I mostly use a Strat and sometimes a 335. All go to my Fender Twin Reverb.

[MartyMart]

Mr Elbow , The "Eighteen" does do a quite accurate plexi - which are not WILDLY gainey unless
driven by something else at the input.
The ROG boy's felt that the "Thunderchief" was just too gainey - loosing the amps original range
too much, so came up with the "Thor"
Glad that you liked my clip, which is a stereo pair of rhythm parts at 2/3d's gain and a full gain lead
section.
I love it, really sounds like a good "amp" to me and it's a lot of fun with things infront of it too, try a TS
or a treble booster, such as RM or Omega up front -  NICE

[RollingElbow]

MartyMart, does anyone sell a PCB for the Thor? Or can you use a thunderchief PCB with minor changes? Also, i take it you can confirm that it stacks well? Maybe a boost or some additional dirt if the gain is not maxed out on the THOR... thanks for all the responses by the way guys, its nice to post in an environment where people don't get into a huff and puff match simply because you don't praise a pedal they like.Maybe the 18 watt is just not to my ear's liking or the ones I have heard at the 18 watt forum differed... but again, that could be the circuit type. Some sounded like that clip, others sounded meatier. Good observations on what is "plexi" though. Its true, there are many diff flavours depending on the model and components etc.... ultimately the sound we "want" to hear kind of determines what we think is good or not. Maybe i need to design a plexi type pedal with 4 inputs lol! Ooooorr just a toggle switch between high and low similar to the HAO rust driver..... but better! hahaha.

[mojotron]

Anyone have any clips of theirs?

..
Listen to my Thor clips here:
...

Alderbody - those are great clips! Thanks, now I must buid a Thor..

When I saw the 'Lenny' clip I was wondering 'what's a Lenny pedal???'

When I listened I understood - LOL @ myself...  again, great clip.