PedalPCB Rockman?

[andrewsrea]

Does PedalPCB have a build something like the MXR Rockman X100 pedal?

My 'sound ' from 1987 to 1992 was a Rockman Sustainer Preamp into a Marshall Jubilee 2553 (small box 50w). Both have long been out of my fold. It was a pretty dated sound, but every once in a while I am nostalgic to jam on that tone.

 

[MarginalPlayer]

The PedalPCB "Proposition Distortion" will get you partway there, distortion side anyway. My "as-builts" were never finished enough to share, but I did a two stripboard versions of parts of the circuit. I would like breadboard another version putting together some ideas/circuits from this forum, but not enough hours in the day. I know the sustainer is another level of complexity, but those were awesome.

 

[Cybercow]

PPCB has no full featured X100 project board. As @MarginalPlayer points out, PPCB's "Proposition" is a buffer-less Rockman Ultimatum pedal; which has the same distortion ranges, when so dialed in can match the EDGE or DIST, as the X100. But none of the CHORUS or ECHO effect.

For those enterprising enough, a thread is posted the ToolBox forum: "Rockman X100 Rev. 10 Schematic Release", laying bare the schematics of the 2 main boards & daughterboards for a fully pedal capable X100.

 

[jcpst]

I know a while back @JTEX had his RockEngine. Not sure if those are long gone or not.

 

[andrewsrea]

I know a while back @JTEX had his RockEngine. Not sure if those are long gone or not.

Looks discontinued.

 

[Gordo]

The MXR pedal is SO damn close but without the reverby sounding delay. For the price it would likely be tough to build it. The Proposition does a pretty convincing edge and distortion as mentioned above.

 

[apierz]

The Rock Star Distortion https://www.pedalpcb.com/product/pcb502/ is a clone of the Colombo Rocker 83 https://colomboaudioelectronics.it/prodotto/rocker83/?lang=en , which aims to sound like the distortion piece of the Rockman.

 

[Robert]

The Proposition would be the best option offered here.

It doesn't have chorus or echo, but neither did the Sustainor.

 

[andrewsrea]

The Proposition would be the best option offered here.

It doesn't have chorus or echo, but neither did the Sustainor.

I noticed the Proposition uses a FET for compression, which the build docs suggest requiring a select FET and the parts list has Q1 as a J201 and the schematic suggest a 2N4339 (which has a different pinout from the J201).

Which is correct and what is the FET being selected for?

 

[Cybercow]

I noticed the Proposition uses a FET for compression, which the build docs suggest requiring a select FET and the parts list has Q1 as a J201 and the schematic suggest a 2N4339 (which has a different pinout from the J201).

Which is correct and what is the FET being selected for?

Any 2N4399, 2N4398 or J201 will work, but it needs to possess a specific Vgs(Off) value of -1.0V @ ±0.10V ; preferably ±0.05V, for it to behave like the original circuit.

 

[andrewsrea]

Any 2N4399, 2N4398 or J201 will work, but it needs to possess a specific Vgs(Off) value of -1.0V @ ±0.10V ; preferably ±0.05V, for it to behave like the original circuit.

Is there a way to purchase said values or you have to buy a bunch, test and weed out until you find the correct Vgs?

 

[Cybercow]

If you also want a CHORUS effect, any Small Clone chorus circuit will dial in a valid X100 chorus effect. The original ECHO effect is a bit more complex than just a delay or reverb. It uses an MN3011/MN3007 combination, where the MN3011 has its 6 taps split between the L/R channels and the 6th tap fed into the MN3007.

 

[Cybercow]

Is there a way to purchase said values or you have to buy a bunch, test and weed out until you find the correct Vgs?

I had to procure dozens of the 2N4399, 2N4398 & J201 JFETs to find the right ones. TTH 2N439x FETs are harder to come by and the SMD versions are difficult to find with the correct Vgs(Off) values. Out of the two hundred J201s I got, I was only able to identify about 3 dozen that fell within the -1.0V @ ±0.10V value; and even fewer within the -1.0V @ ±0.05V values. I have a few of the -1.0V @ ±0.10V valued J201s on hand if you need one.

 

[andrewsrea]

I had to procure dozens of the 2N4399, 2N4398 & J201 JFETs to find the right ones. TTH 2N439x FETs are harder to come by and the SMD versions are difficult to find with the correct Vgs(Off) values. Out of the two hundred J201s I got, I was only able to identify about 3 dozen that fell within the -1.0V @ ±0.10V value; and even fewer within the -1.0V @ ±0.05V values. I have a few of the -1.0V @ ±0.10V valued J201s on hand if you need one.

I appreciate the offer! And that was what i thought, although I didn't expect auditioning 100's. That is brutal!

 

[Cybercow]

I appreciate the offer! And that was what i thought, although I didn't expect auditioning 100's. That is brutal!

TBH&F, I found a LOT of them for cheap years ago before the prices went up and got quite a few. And considering they were stated as NOS at the time, I wanted to test every one to be sure they were good. Matching the for X100, Proposition or other Rockman circuit builds was just a bonus.

There's also another way to use other than "select" JFETs. Instead of using the default values for RB1 & RB2 in a Proposition build, play with the values of those two resistors in increments of 10% till you can measure 2.65v ±0.25v at pin #7 of IC1 with an input signal of 1.0v @ 1K HZ