JOYO JF-13 AC Tone Guitar Effect Pedal DI Amp Sim

Product Information

I found that R31 measured 22k on the actone while the california sound had 68k in that place.but the calif has added mic sim components which lower the overall volume so removing those to match the actone gave me significant increase in volume. Here are a small "map" of where those components are if you want to tweak them, and a simulation of the frequency responses of the British, Liverpool and AC Tone.

R7 is 100k as in the British. This makes a huge difference in frequency response, as the open-circuit there in the Liverpool creates a big hi-pass slope. E1 is measured as 22n, compared to 18n in the British and 27n in Liverpool. This might be a matter of tolerances, though.

If your hand is steady enough and the tip of your soldering iron fine enough to work with SMD, yes it is. The various echo-machine simulators don't just create echo patterns -- they also simulate the preamp(s) in the original echo-machines so, to get the full effect, they really need to be placed before the AC Tone. I used a SPDT switch, some fine wire-wrap wire, and a tiny bit of good ol' lead-tin solder with flux. To get the right value of the resistor I soldered two lugs of a 10k-pot instead of a fixed resistor and turned it as long as I got nearly the same volume in both positions. Then I disoldered the 10k-pot again and measured the resistance between the affected two lugs. In my case it was around 3k3. So I soldered a fixed 3k3 resistor instead of the 10k-pot and it works great in all positions of the Volume-pot. Maybe values between 2k2 to 3k9 will work. Just have a try or do it with a potentiometer like I did. The AC Tone is a complete amp/cabinet simulator and ideally should be fed straight into a full-range acoustic amp or PA/mixing-desk. A guitar amp will add further colouration -- so you are right to set the tone of the guitar amp as flat as possible.

No, it's not what you think. I've used a few drops of translucent hot glue to make sure that the wires won't come off, i don't trust such a tiny blob of solder from a mechanical point of view. I did also use that to add some stress relief on the ribbon to the footswitch, it's a breakdown waiting to happen, just waiting for your next gig. I forgot to say that each pedal has three curves, corresponding to the Voice/Character control set at 0, 5 and 10. But the amplitude would never reach the theoretical maximum, because of clipping in the following gain stage.Ripdivot wrote:I had some time so I sat down and figured out the speaker sim bypass on the newer PCB. Mine has a dull yellow color, not the nice gold finish of newer units. However, the PCB is identical to the pictures above. Disclaimer : This is an attempt to recreate my previous posts in the "Character Series" thread that were lost in the server move. If your memory is better than mine, please comment.