SL+ / Plexi Hybrid!

[Gee Donner]

I just wanted to tell you guys that I found out a way to mod the Plexi module to to both plexi and SL+ with GREAT result!

I use shunt switching so no poping what so ever when switching signal path!

The "big volume" pot is a push/pull DPDT 500K from allparts.
The module also has a C3 cap switch and a mid voicing switch.
Look at the picture (I'm not a good photografer)
http://www.putfile.com/pic/8285631

When I have time to, I can show you how to do it. Right now I'm going to the airport. 8)
///G

 

[muzapstar]

sounds promising, and awesome. always nice to make one slot into two in these things. Do you plan to mod others for a fee?

-stAr

 

[Soulinsane]

Outstanding It looks like some nice work. Is the modification all in the gain knob? I'm betting this could be done for the SL+ as well. I wish I owned a Plexi to compare parts in my SL+. Again though, awesome work and I can see your parts again. You love carbon resistors more than anyone I know. I wish you didn't travel so much so we could talk more. Are you a mercenary or something :lol:

 

[elpresidente99]

@muzapstar

Which module do you want to mod i'm also interestet to work on Modules modification. Gee is a great guy he helps me to mod my sl+ to a switchable sl+ and Jcm800 Module with tight switch. It sounds great. No i have a E-rect in which I also made a Tight switch, and i also have a Pete modded Ultra but i think i'm not allowed to tell what he does to the modules :roll: .

Hey gee where do i get such a poti.


Greetz

 

[Gee Donner]

Soulinsane,
I get to see a lot of stuff proffessionally but this time it wasn't for work, I was in Ibiza drinking gin & tonic! I'm not really a CC resistor fanatic, but I DO love em in marshall vintage tones a lot. For other circuits I use Xicon metal film resistors because the are very transparent ant quiet. Yes this mod can be done on an SL+ as well, I even think it is easier to do it on a SL+.

Muzapstar,
I've never planned to charge anybody to tell how to mod any modules. Well, if somebody wants it done because they are not comfortable with the solder iron, then maybe I can do it for him/her. The thing is that randall doesn't seem to be very big in europe and there is not a lot of MTS stuff out there and it is very expensive, so if I did offer that service I don't think I would have alot of customers anyway. To me it always sounds like the reason for not getting more amps out on the market is because of randalls poor customer service. I got hit by it myself alot of times so I can understand that.
BUT, if you wanna buy one of my latest line 100w tube heads then it is a different story :wink:

Elpresidente,
If Pete told you not to tell anybody how to do 'his mods', the respect that and keep it to yourself :wink: Give him credits for his research!
The pot is a 500K from allparts but TAD has them too, but maybe they are 1M. Both are fine, the 1M will give you a little bit more treble in the tone.


///G

 

[elpresidente99]

Hey Gee!! Great Guy.

Is there a way to switch between SL+/jcm800 and Plexi.

OT: which part can be broken if there is low volume on the Sl+. I solderd a lot things on SL+ and now there so low volume that i cranked up the level und the Master is about 3 o'clock and there is bedvolume.
Do you know which part the most difference in volume makes.

Can't find the right poti on TAD. Is this the right or an alternativ http://www.thomann.de/at/goeldo_pushpull_poti_500kohm.htm

Greetz

 

[okstrat]

Elpresidente,
If Pete told you not to tell anybody how to do 'his mods', the respect that and keep it to yourself :wink: Give him credits for his research!

///G

What G said. In the case of some of these mods, I spent a LOT of time coming up with them... I'm probably going to have a few solid weeks of time in the XTC stuff that is ongoing right now. I know some of my mod work can seem expensive, but some people (Egnater) thought I was undercharging. When I take all the time into account, it's kinda scary but I'd probably make more money working at a convenience store.

I also don't like sharing some of these mods because of the issues that come up - I don't have time to troubleshoot everything that can happen if one of my mods is used. I was reading earlier about someone that has a module that isn't working right and it's most likely from swapping out C3 - which shouldn't be a big deal at all. My mods are much more complex. Much.

Plus as I stated before, parts I choose are selected for the specific module and value of parts in that module that I'm not going to replace - I don't just grab a .022 part and slam it in, depending on some of the other values on the module I may grab a part that is MARKED .022 but really measures .020 or .024 - when you replace several parts, it does make a difference.

I burn in modules - meaning after I do a modification, I let em run for awhile, and in many cases I take them to gigs or rehearsals to be sure they perform the way they should. I also have a full set of Randall amps (RM20, RM20 combo, RM50, RM100, RT2/50 and RM4, Marshall 4x12s and Randall MTS 2x12) that I use to playtest modules. There's a lot more to what I do than just change out a few coupling caps to orange drops. If that's all I did or if I just tacked parts onto the top of the board without taking them apart, I could turn mods around in 30 minutes tops instead of weeks.

Plus someone could do a homemade mod that was a copy of what I did, and do it poorly/have a bad sounding module, and later on down the line someone thinks *I* did that work. That just kills the value of the work I did, imho... and it's a little prideful of me, but I really enjoy the fact that guys gig with my mods and get compliments on the tone. Doing these mods is kinda like putting my children out into the world.

Pete

 

[JKD]

I was the recipient of some of Pete's prototype modules and he kindly asked that I never show anyone or take any pictures of his modifications...which of course I was quite happy to comply with.

It's not that the work is difficult if you have basic electronics knowledge and soldering skills(*1) but you save all the time in selecting component values, coming up with routing, placement...playtesting etc.

Pete's work is top notch and if there's a problem with the modification he did, he stands behind it.


EDIT: *1 I've bought at least 3 used modules with c3 mods where either the traces underneath was lifted and/or huge blobs of solder were used sat up in little balls (not flowed correctly). I've even managed to lift a trace by being lazy and applying heat via the top side of the board instead of doing it properly.... so maybe it's not so easy

 

[Gee Donner]

Hey Gee!! Great Guy.

Is there a way to switch between SL+/jcm800 and Plexi.

OT: which part can be broken if there is low volume on the Sl+. I solderd a lot things on SL+ and now there so low volume that i cranked up the level und the Master is about 3 o'clock and there is bedvolume.
Do you know which part the most difference in volume makes.

Can't find the right poti on TAD. Is this the right or an alternativ http://www.thomann.de/at/goeldo_pushpull_poti_500kohm.htm

Greetz

Yes, there is a way to switch it and yes, that pot will work. I am short of time right now so I don't have time to explain how to do it though.

As far as your broken module. Doing online troubleshooting is hard because the modules are made on pcb's which makes it hard to see. It is easier with PTPs. Step through all components with a multimeter.

///G