BAJA JVM overdrive pedal 040218 [documentation]
- bajaman
- Old Solderhand
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Hi folks
I have not built this one as yet, but see no reason why it will not work
This one is based on the Marshall JVM410 OD1 high gain channel (up to just before the passive tone stack as with all my recent high gain preamp models).
Hope some of you enjoy building it and as usual - vero, perf or pcb layouts are most welcome
cheers
bajaman
I have not built this one as yet, but see no reason why it will not work
This one is based on the Marshall JVM410 OD1 high gain channel (up to just before the passive tone stack as with all my recent high gain preamp models).
Hope some of you enjoy building it and as usual - vero, perf or pcb layouts are most welcome
cheers
bajaman
be kind to all animals - especially human beings
- bajaman
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here is channel OD2 instead - slightly less bass response only two capacitor values changed around gain control
be kind to all animals - especially human beings
- bajaman
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But wait - there's more
Here is the crunch channel for a lighter overdrive and flatter frequency response - again only minor changes around the gain control but only three gain stages (two following the gain control).
All these three JVM410 models are based on the "red" gain structure.
enjoy
bajaman
Here is the crunch channel for a lighter overdrive and flatter frequency response - again only minor changes around the gain control but only three gain stages (two following the gain control).
All these three JVM410 models are based on the "red" gain structure.
enjoy
bajaman
be kind to all animals - especially human beings
- Cub
- Cap Cooler
Thank you so much, you're on a roll with the high gain pedals!
That would make for a very nice switch! Speaking of which, would it also be possible to have a red/orange mode switch? Or are there too many parts involved for that to be practical.bajaman wrote:here is channel OD2 instead - slightly less bass response only two capacitor values changed around gain control
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With twigs and leaves and branches and conkers by the ton.
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- Ice-9
- Degoop Doctor
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Congrats Bajaman on a nice series of amp sim circuits, and you have used my favourite 2SK117 Jfet for the input buffer on most which means I will have to have a few of these put on breadboard as soon as I get a moment.
Cheers for the schematics
Cheers for the schematics
It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !
No silicon heaven ? preposterous ! Where would all the calculators go ?
No silicon heaven ? preposterous ! Where would all the calculators go ?
- bajaman
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I will take a look - should be possiblewould it also be possible to have a red/orange mode switch?
cheers
bajaman
be kind to all animals - especially human beings
- bajaman
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I made a small mistake with the Crunch model
Here are the correct schematics for OD1, OD2 and CRUNCH channels with the red gain mode. By adding a small switch and additional resistor to the third gain stage it is easy to convert all of these to the Orange gain mode Just switch the 100 ohm resistor off, if you want the Red gain mode
cheers
bajaman
be kind to all animals - especially human beings
- Cub
- Cap Cooler
This is awesome! OD1 orange is my favourite mode on this amp, very George Lynch! With a OD1/OD2 and an orange/red switch, one pedal will pack four great sounds.bajaman wrote:By adding a small switch and additional resistor to the third gain stage it is easy to convert all of these to the Orange gain mode Just switch the 100 ohm resistor off, if you want the Red gain mode
I wish I were a chestnut tree, nourished by the sun.
With twigs and leaves and branches and conkers by the ton.
With twigs and leaves and branches and conkers by the ton.
- rcustoms
- Resistor Ronker
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mr steve the images are low definition ,please add more pixelsbajaman wrote:
I made a small mistake with the Crunch model
Here are the correct schematics for OD1, OD2 and CRUNCH channels with the red gain mode. By adding a small switch and additional resistor to the third gain stage it is easy to convert all of these to the Orange gain mode Just switch the 100 ohm resistor off, if you want the Red gain mode
cheers
bajaman
- bajaman
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Did you try clicking on each image to expand itmr steve the images are low definition ,please add more pixels
Here are some 300dpi images cheers
bajaman
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I've had a bit of a go at this, bit I have no idea if it's correct - especially in terms of labeling switches, but I don't see why it shouldn't work. If anyone can bang up a vero layout I'll be your best friend (as we used to say in primary school). The idea is that you can bypass the whole shebang, select crunch or OD, select OD1/2 within OD, and select the orange or red modes, with separate gains for each channel, and a volume each for crunch/OD.
So, 5 knobs, 4 footswitches, 3 channels with 2 modes each... Hopefully in something like a DD. Happy to have opinions and constructive criticism. Done in Photoshop.
Willy.
So, 5 knobs, 4 footswitches, 3 channels with 2 modes each... Hopefully in something like a DD. Happy to have opinions and constructive criticism. Done in Photoshop.
Willy.
Not really but it should give the same results.
It always uses the same JFet buffer at the output (the way FausterCraster drawn it).
Adding an op-amp buffer instead shouldn't make any difference and just make the board larger.
The Crunch/ODs are still selectable.
I think it's correct but...
It always uses the same JFet buffer at the output (the way FausterCraster drawn it).
Adding an op-amp buffer instead shouldn't make any difference and just make the board larger.
The Crunch/ODs are still selectable.
I think it's correct but...
Awesome. I was just hoping for separate crunch/OD volumes but I reckon I can live without it. Looking at the layout, you'd need to add a pole to each switch for LED indication, yeah?Not really but it should give the same results.
It always uses the same JFet buffer at the output (the way FausterCraster drawn it).
Adding an op-amp buffer instead shouldn't make any difference and just make the board larger.
The Crunch/ODs are still selectable.
I think it's correct but...