Marshall Cab Sim
If I remember correctly this circuit is taken from original Marshall amp which has speaker simulator built in and it should provide frequency response similar to Marshall 4×12″ cab. It can be handy for direct amp-less recording or used in conjunction with Line Out from amp. Below is frequency plot of this circuit.
Files
Click here to download schematic and PCB layout.
Pictorial
Click on a photo to see more details
Hello I am wondering what is the must important part in the frequency we have to achieve in frequency respond
Every speaker sim needs a high and low frequency cutoff. Marshall also has a characteristic mid scoop that gives itthat dryer, more aggressive sound. This speaker sim tries to achieve all three aspects od eq shaping.
i try to change resistor in input… but is still low…. somebody have idea what parts i changes for more bigger output ?
I built this today ,too.
But I had no problem like you.
Output was louder than bypass.
i try this schematic already…. but this schematic output is too small, is very different with bypass… any idea what prats i change for more bigger output ?
Any sound or demo?
hi on the pcb what is the ov is that the ground for the 9v
What is the total cost to build this, and does anyone have a list of all parts so I know what to get because I am new at this
I cant find a 2 nf capacitor anywhere. Could someone post a link please.
2.2n is fine, I think I used that
Great pedal! Did you ever tried it also with acoustic guitar? If so, how is the sound?
Hey man, this looks really sweet and I’m looking to build it but I can’t figure out from either of the diagrams where the LED goes in respect to the PCB… it’s probably just me being dumb but I can’t see it…
it’s not on the pcb at all. I just connected it to +9V through a resistor. There’s no bypass so it’s always on.
Cheers
OH right, cheers man 🙂
Is the output sound clean? or with distortion?
Tks
It’s clean. This simulates only frequency response of a marshall 4×12. You’d need a bit more to simulate cone distortion.
Cheers
I have seen this circuit on another site and on it, there’s a clip
Hi!
I want to build one of these, but I still lack some knowledge when it comes to op-amps.
Most pedals out there use negative tip 9V power supplies, so I experimented in a Circuit simulator with -9V, and my first thought was to just flip all polarities, what goes to Op-Amp In- moved to Op-Amp In+ etc. but that didn’t work as expected. So I tried flipping the Op-Amp inputs one pair at a time, ending up at the exact same configuration as in the schematic, only difference actually being the power supply being -9V instead of +9V (and the output signal having a negative DC offset instead of positive). Is this correct? Is there anything else I must consider?
Short version – Do I need to make any changes to the design/layout to use -9V instead of +9V?
I’m an op-amp noob myself, so can’t help much. I just built the +9V version according to the schem.
Cheers
I guess you confusing negative center of the DC jack with -9V, I didn’t saw pedal with “-9V”, except those positive grounded Germanium fuzz pedals, like the Fuzz Face or so.
How does this speaker simulator sound? Do you have any clips of it?
Hello!
I’m interested in this DIY cab simulator. But I can’t see any visible schematic, circuit or component list. Could you help me?
Thank you for your collaboration.
Hi there, there is a schematic and layout in “Useful links” section of the article.
Cheers
Capacitors in pF range are mica or ceramic, nF range are box film caps and uF range are electrolytics
Hi,
Concerning capacitors, witch ones are film, etc…
Thank you
so, can you list all the components needed?