Embedding effects in a bass?

[b3e]

I don't think the issue is in the lack of the input jack that disconnects the circuit. Even if you have a battery powered pedal you can jam it for several hours without draining the battery. What worries me is that you said, the battery runs hot - this shouldn't happen.

 

[Jisch]

I looked at the jack inputs before I cut them off. It's basically a switch that opens when you insert the jack. Since I cut the whole thing off, it should be open, like something is plugged into it. However it's possible they run the power through that jack as well, that's what I need to investigate. This pedal doesn't have provisions to be run via a battery, only by external power, so really there is no need to turn anything off when you pull the cord out, but they may have done it anyway. I'll figure it out and post what I find (and how I find it).

 

[Jon Clegg]

I looked at the jack inputs before I cut them off. It's basically a switch that opens when you insert the jack. Since I cut the whole thing off, it should be open, like something is plugged into it. However it's possible they run the power through that jack as well, that's what I need to investigate. This pedal doesn't have provisions to be run via a battery, only by external power, so really there is no need to turn anything off when you pull the cord out, but they may have done it anyway. I'll figure it out and post what I find (and how I find it).

I don't think there's power switching on the jacks based on the fact that they're both mono or Tip-Sleeve jacks. Usually power switching is done with Stereo or Tip-Ring-Sleeve (TRS) jacks by connecting the negative of the battery to the ring and using the inserted plug to connect that to the circuit ground which is the sleeve. I think the short is where you cut the board. Look at the edges of those cuts with a magnifier.

 

[Jisch]

Ok, I will check them. I am pretty certain I didn't cut anything or short anything there, but it's a good idea to check. I just found out my VOM is dead, it's served me well for 25 year or so. RIP Radio Shack!

With nothing plugged there were long and short terminals (one on the sleeve and one on the tip) that were shorted against each other, when you plug in a cord it opens the connection between the two. I cut both the long and short terminals off the board and connected my input/output to the long arm that connected to the tips. When you insert the plug it appeared to be the only thing connected. I have another donner pedal here that has a similar configuration, I'll open it up to verify, but really I need to get another VOM to make any progress.

 

[Jisch]

This is really weird, but it looks like on the specific pedal I took apart the ground is on the red wire and positive is on the black wire, so I've been connecting batteries backwards on this up until now. I have direct connectivity between the red wire and where the sleeve on the jack would be. I have another Donner pedal and red is positive on that one.

I wouldn't think there is enough current in a 9v battery to blow anything up, but at this point it appears that I've wrecked the pedal. I can get sound out of it with switch turned off, when I turn it on there's no output. I can hear a click when I disconnect the battery, so something is working but no audio through it. At this point I think I have to buy another effect pedal, without a schematic it's pretty much impossible to troubleshoot the actual circuit.

 

[Jon Clegg]

Since the board is DOA, I'd suggest trying to remove the daughter board, just to see if it can be done without having to de-solder it or destroying it; being able to do so would make removing the input/output jacks much easier.

 

[mapleglo]

This is really weird, but it looks like on the specific pedal I took apart the ground is on the red wire and positive is on the black wire, so I've been connecting batteries backwards on this up until now. I have direct connectivity between the red wire and where the sleeve on the jack would be. I have another Donner pedal and red is positive on that one.

I wouldn't think there is enough current in a 9v battery to blow anything up, but at this point it appears that I've wrecked the pedal. I can get sound out of it with switch turned off, when I turn it on there's no output. I can hear a click when I disconnect the battery, so something is working but no audio through it. At this point I think I have to buy another effect pedal, without a schematic it's pretty much impossible to troubleshoot the actual circuit.

I'd be careful about taking measurements on a pedal that is now broken. The fact that you are measuring a ground through the red wire could be the result of burning out the circuit.

 

[Jisch]

On my next one (ouch) I will do things in a more methodical fashion and do things one at a time, that way I can figure things out as I go. This time around I figured out what I wanted to do and did it all at once, a very confident way to go about things, but obviously leaves too many variables when things didn't go well.

The method I used to remove the jacks was easy and clean, and based on my other Donner pedal did exactly what I thought it would. When there is a cord in the jack only the taller metal tang contacts the plug on the tip and sleeve, the lower one gets disconnected.

It appears that the pedal is drawing current at all times, the switch doesn't turn off power, it just switches the audio through or around the circuit.

It's a $49 learning experience, I've had more expensive lessons but I hate that I took something operational and killed it.

 

[Jon Clegg]

Just don't cut the board itself this time. Here's what I'm seeing:

The epoxy of the board is translucent, the traces are opaque; if you put it in front of a bright light you'll see the traces.

 

[Jisch]

Thanks, I will check that in light. I did look at it closely (not through light) and didn't see any traces in that area, but this is another variable I introduced.

 

[Beej]

Man, good eye @Jon Clegg ... Even with a large monitor I didn' see that...

 

[Jisch]

I got the new effect in

and went step by step:

First take it out of the case and make sure everything works:

Next try external power (note reversed leads from the standard "black is ground"

Next solder in input/output wires, the dowels are keeping the contacts open, just to make sure.

Then solder in the paddle switch and replace the footswitch

And everything still worked, except the indicator LED, not a big deal to me, I hadn't drilled a hole for it yet, so I just drilled a shallow indent and filed down the top of the LED so I could install it without it coming through the front anyway.

And got it ready for install

At this point everything stopped working. It was late, I was tired and I had the walnut challenge to get to so I put it aside.

Today I got back to it. It turns out when I was "gently" forcing the effect into the cavity I broke the input connector on the board, it took a little while to find it, it didn't look broken, just no connectivity between the input where the jack was and the switch. I direct wired from the output of the bass to the switch and yay! it's working again

I have some clean up to do on the body. I'll see how things go from a power drain perspective before deciding if I should do an external power source, based on the current draw I think I probably should. Now that I've gone through the process of troubleshooting it, I'll bet I could fix the other one.

I was due upstairs so I rushed this video and recorded it with my phone, bad quality all the way around.

Invalid Link Removed

 

[Jisch]

Final update on this. I have been using rechargeable 9v batteries, they measure somewhat under 9v even when fully charged, but they work fine. The first one was in the bass for about 3 weeks before draining to the point where it wouldn't work. Interestingly the octave effect stopped working, but the bass still had output when in "bypass" mode - it has an EMG pickup that requires power. I figure I had about 2 hours of playing time on the bass during that 3 week period. I see no reason to develop a way to deliver power to it considering what I'm getting out of battery life. If I was going to gig with it, it would be easy enough to bring a couple batteries and change between sets (or maybe at that point I would develop the power solution).

It's really cool to flip the switch and the wing bass goes from a toy to full sized bass, I'm completely happy with how this turned out.

The Donner octave pedal has something like 9 settings dropping a different amount depending on where you put the knob, it goes from a mild detune through to 2 octave drop - some of those intermediate steps are really weird intervals. Really the only one that's applicable to this is the one octave drop. So I could probably cut that selector knob off (for the next one). The one negative of this pedal is that it's not polyphonic, so things get a bit weird when you try to play more than one note at a time, the pedal basically picks the loudest note to reproduce an octave down. You can also use that weirdness to your advantage when playing, the pedal switching from one note to the next loudest has a weird autotune kind of sound.

 

[Slidlow]

Does anyone have experience in embedding an effect in bass? I am about to put an octave effect into my stumpy and am wondering how best to get power to it. I think it will consume too much power to make batteries acceptable. I am not sure if using a stereo plug would lead to noise/hum having that run in the same cable as the outbound audio.

I have been using a stereo 1/4" jack with a microphone cable to get power to my bass since 1985. No issues with noise with DC. Have a stereo jack at the bass end and split it out to a standard 1/4' for the signal to the amp and a typical effects power jack to plug into my modified amp or a separate power supply when using with other amps. Ground is common for the signal and power.

 

[Jon Clegg]

Final update on this. I have been using rechargeable 9v batteries, they measure somewhat under 9v even when fully charged, but they work fine. The first one was in the bass for about 3 weeks before draining to the point where it wouldn't work. Interestingly the octave effect stopped working, but the bass still had output when in "bypass" mode - it has an EMG pickup that requires power. I figure I had about 2 hours of playing time on the bass during that 3 week period. I see no reason to develop a way to deliver power to it considering what I'm getting out of battery life. If I was going to gig with it, it would be easy enough to bring a couple batteries and change between sets (or maybe at that point I would develop the power solution).

It's really cool to flip the switch and the wing bass goes from a toy to full sized bass, I'm completely happy with how this turned out.

The Donner octave pedal has something like 9 settings dropping a different amount depending on where you put the knob, it goes from a mild detune through to 2 octave drop - some of those intermediate steps are really weird intervals. Really the only one that's applicable to this is the one octave drop. So I could probably cut that selector knob off (for the next one). The one negative of this pedal is that it's not polyphonic, so things get a bit weird when you try to play more than one note at a time, the pedal basically picks the loudest note to reproduce an octave down. You can also use that weirdness to your advantage when playing, the pedal switching from one note to the next loudest has a weird autotune kind of sound.

The octave effect is digital and probably has it's own 5 volt regulator so when the voltage drops below it's threshold, it shuts off, the analog side along with the EMG's on the other hand degrades more gracefully.

 

[Jisch]

I have been using a stereo 1/4" jack with a microphone cable to get power to my bass since 1985. No issues with noise with DC. Have a stereo jack at the bass end and split it out to a standard 1/4' for the signal to the amp and a typical effects power jack to plug into my modified amp or a separate power supply when using with other amps. Ground is common for the signal and power.

If this was going to be a daily player or gigging instrument, I'd do the same. I just don't have much motivation to do that now. Good to know there is no hum.

 

[Mister_GothFrak]

This was really cool. Thanks guys! I might try something like this in the future. I think it's a great idea to run simple effects straight from the instrument itself. Pair this with Turner multi-coil pickups where each string can be routed separately? Endless possibilities!