BAJA JVM overdrive pedal 040218  [documentation]

Original effects with schematics, layouts and instructions, freely contributed by members or found in publications. Cannot be used for commercial purposes without the consent of the owners of the copyright.
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albru80
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Post by albru80 »

Did you find a different pinout on Google?
You need an extra pole for the LED.
This is the version with two Level pots:
Last edited by albru80 on 08 Feb 2018, 15:10, edited 3 times in total.

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albru80
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Post by albru80 »

Here is a single toggle switch version (OD1/OD2/Crunch) that should fit in a 125B box.
Just in case.

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temol
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Post by temol »

albru80 wrote:Did you find a different pinout on Google?
Yes. Here and here.

T.

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albru80
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Post by albru80 »

Ok.
Pinout was correct. Just needed to be turned 180.
Can't edit any of the previous posts.
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Baja JVM Overdrive.png
Baja JVM Overdrive 2.png
Baja JVM Overdrive 3.png

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Willypp
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Post by Willypp »

Good work, my man!

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Post by rcustoms »

awesome pedal steve ,my work for fsb
JVM PCB SCHEM.jpg
JVM.jpg
cheers
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guitars,pedals and amps.
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Optical
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Post by Optical »

Just a question about the JVM - isnt one or some of the channels pretty much the JCM800 (single channel) preamp with another gain stage (clean boost) in front of it? Switching that boost stage out essentially makes the preamp the JCM800 circuit.
Is that one of the modes modeled here or is that something else that could potentially be added?

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Willypp
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Post by Willypp »

Here's mine so far, using the 3 channel, 2 volume layout. For some reason, the crunch and OD volumes are swapped, and they also interact. I tried removing the volumes and using a marshall tonestack w/LPB1 each for Crunch and OD, that does back to the JVM board, and a master volume from the output of the JVM. The volumes still interacted, and were still swapped (maybe the layout is mislabeled? I haven't checked it properly), so I removed the separate volumes and used a master off the JVM. Sounds great with the tonestack added.
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29101096_1847589748637020_9160625029971443712_n.jpg

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Ichabod_Crane
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Post by Ichabod_Crane »

Let us to know when it's fully verified, please! :wink:

Thanks for the work!

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Post by Nefi_fatobene »

Willypp wrote:Here's mine so far, using the 3 channel, 2 volume layout. For some reason, the crunch and OD volumes are swapped, and they also interact. I tried removing the volumes and using a marshall tonestack w/LPB1 each for Crunch and OD, that does back to the JVM board, and a master volume from the output of the JVM. The volumes still interacted, and were still swapped (maybe the layout is mislabeled? I haven't checked it properly), so I removed the separate volumes and used a master off the JVM. Sounds great with the tonestack added.
What layout did you use? Is it a personal layout?

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Willypp
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Post by Willypp »

It works. I used the big layout with the separate volumes but ended up not actually using the volume controls and just stuck a master volume on the output. There's a switchable eq where the volumes would have been, if that makes sense. Sounds great, but I'm also using it with a sonic stomp and Lart's Simplecabsim. I'll post samples at some stage, but given there's 3 channels x2 modes each that I will have to do at various gain levels it'll be a while before I can be bothered.
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33083902_1922229257839735_4513120440289329152_n.jpg
32835896_1922229237839737_4032484759161536512_n.jpg

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sixthfloor
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Post by sixthfloor »

Great artwork Willy :thumbsup

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Cub
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Post by Cub »

Beautiful, what a pedal! :applause:
I wish I were a chestnut tree, nourished by the sun.
With twigs and leaves and branches and conkers by the ton.

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Ichabod_Crane
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Post by Ichabod_Crane »

Yes, it seems a really great machine, and it has a very nice graphic. Waiting for the knobs! :D

I can't get how exactly you has bypassed the two volume pot, because in the image, right in that spot, the wires hide the wiring on the board. I was trying by myself to write a possible way, but those switch and the two LPB-1 (with the tonestack) take me a bit out of the way. :scratch:
By the way, I can't find the layout of the LPB-1 with the tonestack (Marshall tonestack?). Did you draw it? I'd like to get the layout, please. 8)

Why you use the Sonic Stomp and the cab simulator? Do you use the pedal with your amp?

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Willypp
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Post by Willypp »

On the layout I used, there are two volumes, Crunch and OD.
- Pin one of both pots go to ground, so ignore that.
- Pin three of Crunch Volume (Level 1-3 on the layout) goes to the input of one of the EQ/LPB1s, pin three of OD Volume (marked as Level 2-3 on the layout) goes to the input of the other EQ/LPB1. There is a 2pdt toggle on each EQ so it can be bypassed.
- The output from the EQ/LPB1 goes to their respective returns on the layout (Level 1-2 for Crunch, and Level 2-2 for the OD)
- I didn't put volume knobs on the EQ/LPB1 as I found they interacted with each other, as they did before I included the EQ. In hindsight, I should have used the version with the trimmer so I could balance the bypassed/effected EQ signals.
- I put a master volume on OUT on the layout.

That EQ/LPB1 is tough to find. I'm pretty certain I originally got it from Tagboard, but I can only find their BMP/LPB1 layout.

I use a Sonic Stomp (Madbean Bloviator) and Lart's Cabsim in the DI I built for my pedalboard as I play straight to the desk and a personal powered wedge. I use it because it makes things sound awesome!
Attachments
22195755_1681931865202810_1875262767841535142_n.jpg
Marshall_Tonestack_and_LPB1.png
Marshall_Tonestack_and_LPB1.png (27.66 KiB) Viewed 4455 times
Marshall_Tonestack_and_LPB1_and_Volume_Pot.png
Marshall_Tonestack_and_LPB1_and_Volume_Pot.png (29.53 KiB) Viewed 4455 times

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Ichabod_Crane
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Post by Ichabod_Crane »

Thanks a lot, it wasn't so hard, afterall. I was considering the output master in a wrong place.
Yeah, the LPB was hard to find. Sometime I search in the tagboard's forum, I can see a bunch of layout we can't find in the articles. A good source!
The two volume issue was really werid and annoying. So it's the same if you use the volume of the LPB-1. :scratch:
I guess the problem was first in the circuit.

I attached the schematic of the layout. And there's the schematic that you, Willy, posted. But albru80 said it's not exactly the same of the veroboard layout.

Anyway, the problem of the two Levels, could be in thei position?
Two separate volume controls would be a really good feature.
Attachments
Baja JVM Overdrive 2.png
Baja JVM 3channel 4switches.jpg

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sixthfloor
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Post by sixthfloor »

Ichabod, in the schematic you just posted, wouldn't both volumes knobs interact in some way since they are connected ? Could that be the source of the problem ?

Adding a pole to SW2 would separate them :
Image

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Ichabod_Crane
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Post by Ichabod_Crane »

I think I get what you mean. If really that's the problem, it could be fix it. But maybe I was wrong, I'm not so clever to say if the volume pots connection could be the problem, I hope we can make an attempt. Unfortunately I can't build anything in the next months.
I know your pedal is almost completed, but do you think you can try something for us? How you said maybe you can use the trimmer for the volume on the LPB-1, and maybe use with some clips and a switch to make some experiments. Then you will know what you have to do with your pedal.

No problem if you don't want to do it. :wink:

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albru80
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Post by albru80 »

You can use a 4PDT switch and separate the outputs.
This should fix it.
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Baja JVM Overdrive 4.png

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ppfai
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Post by ppfai »

Hi, I think this would be easier if add extra part.
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JVM3.png

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