BAJA JVM overdrive pedal 040218 [documentation]
- rcustoms
- Resistor Ronker
Information
awesome pedal steve ,my work for fsb
cheers- Optical
- Breadboard Brother
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?
Is that one of the modes modeled here or is that something else that could potentially be added?
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.
- Ichabod_Crane
- Resistor Ronker
Let us to know when it's fully verified, please!
Thanks for the work!
Thanks for the work!
What layout did you use? Is it a personal layout?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.
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.
- sixthfloor
- Breadboard Brother
Great artwork Willy
- Ichabod_Crane
- Resistor Ronker
Yes, it seems a really great machine, and it has a very nice graphic. Waiting for the knobs!
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.
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.
Why you use the Sonic Stomp and the cab simulator? Do you use the pedal with your amp?
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.
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.
Why you use the Sonic Stomp and the cab simulator? Do you use the pedal with your amp?
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!
- 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
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- Marshall_Tonestack_and_LPB1.png (27.66 KiB) Viewed 4470 times
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- Marshall_Tonestack_and_LPB1_and_Volume_Pot.png (29.53 KiB) Viewed 4470 times
- Ichabod_Crane
- Resistor Ronker
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.
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.
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.
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.
- sixthfloor
- Breadboard Brother
- Ichabod_Crane
- Resistor Ronker
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.
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.