Tremelo Noise while not engaged HELP
Moderated By: mods
Ok, I'm about 95% sure it is R9 specifically. That is the limiting resistor feeding I believe an LDR. By lowering that resistor, you're allowing the signal to be drawn into the input of the active tremolo even when bypassed. The bypass on this thing appears to be especially shitty, even if I were going to do a buffered-style input I wouldn't have put the jfet bypass gates where they did. So, bypassing this thing is a little trickier. What to do, first buy a DPDT or 3PDT switch. Then, unsolder the wire going to the board at R15, should be a 10k resistor. Run it to the new switch. I'll post a diagram of how to wire the switch in a bit. You also will be removing the wire to board at the output jack around R1, a 1k resistor. These are your input/outputs that the switch will be hooking together when bypassed. Then, you'll need to rerun wires back to the boards where you removed those two, we'll call them effect-in and effect-out.
Now, we have to conjure up some way to make sure the effect is always on. The current bypass requires the switch to activate a flip-flop to change which jfets are open. We will basically be removing that section. Locate Q3 and Q1. Those are the bypass gates. I need to find the pin out diagram for those jfets to tell you which pads to bridge, but you will be removing those, and bridging the drain and source pins on the PCB. I gotta look that up.
Lastly, if you got a 3PDT switch, we can change the LED also. I BELIEVE, and I need you to verify this for me, that the LED is on a separate board from the main board. There should be two wires from this daughter board called P2 and P3. P3 goes back to the board , through a zener diode and a resistor, then to the + power rail. The second goes into the soft switching area where it gets hooked to ground in the right conditions. We basically will just remove P2 from the main board, and run it to our switch. Again, I'll make a diagram for the switch, but we will be adding a ground wire there so that we connect the P2 line to ground when the effect is engaged.
Ok, I have some things I have to draw up for this, and I need you to verify the daughter board thing. I'll post back soon.
EDIT: Actually, looking at it again, you should be able to just remove Q3 and D2, and that will set the effect into ON mode with out dealing with bridging any gaps.
Now, we have to conjure up some way to make sure the effect is always on. The current bypass requires the switch to activate a flip-flop to change which jfets are open. We will basically be removing that section. Locate Q3 and Q1. Those are the bypass gates. I need to find the pin out diagram for those jfets to tell you which pads to bridge, but you will be removing those, and bridging the drain and source pins on the PCB. I gotta look that up.
Lastly, if you got a 3PDT switch, we can change the LED also. I BELIEVE, and I need you to verify this for me, that the LED is on a separate board from the main board. There should be two wires from this daughter board called P2 and P3. P3 goes back to the board , through a zener diode and a resistor, then to the + power rail. The second goes into the soft switching area where it gets hooked to ground in the right conditions. We basically will just remove P2 from the main board, and run it to our switch. Again, I'll make a diagram for the switch, but we will be adding a ground wire there so that we connect the P2 line to ground when the effect is engaged.
Ok, I have some things I have to draw up for this, and I need you to verify the daughter board thing. I'll post back soon.
EDIT: Actually, looking at it again, you should be able to just remove Q3 and D2, and that will set the effect into ON mode with out dealing with bridging any gaps.
euan wrote: I'm running in monoscope right now. I can't read multiple dimensions of meta right now
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More Cowbell
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More Cowbell
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Sorry man, wife wanted me to hang out watching movies so I haven't gotten to it.
Ok, check out the schem . I'll show you what I'm up to.
Look at Q3. When the jfet has voltage on it's gate, the connection through the drain and source pins closes. This is when the effect is on. That means the only path is through the tremolo circuit. At the same time, the flip flop puts no voltage on the gate of Q1, thus opening the output of the tremolo circuit to the output jack. So, with Q1 and Q3, if there is voltage ON the gate is OFF. If there is NO voltage, it is open.
What we are going to do, is take out the switch that is there, and put in a heavy duty stomper. Thus, we have to make sure that we keep the effect on all the time. We will be bypassing the whole circuit at the switch instead of on the board. SO, in order to make sure all of this happens correctly, we are going to flat out REMOVE Q3. So the only path will be through the tremolo circuit. Now, we have to make sure the output is always open, so we take out the diode D2, so there will be never any voltage on the gate pin of Q1, thus keeping it open all the time.
I normally order 3PDT switches from here, although you can also order them through Smallbear electronics or other places. The downside to my source is that you have to order two at minimum, but they are much cheaper there. That is up to you. I still need to whip up a switch wiring diagram, I'll do that now. Stay tuned for that.
Ok, check out the schem . I'll show you what I'm up to.
Look at Q3. When the jfet has voltage on it's gate, the connection through the drain and source pins closes. This is when the effect is on. That means the only path is through the tremolo circuit. At the same time, the flip flop puts no voltage on the gate of Q1, thus opening the output of the tremolo circuit to the output jack. So, with Q1 and Q3, if there is voltage ON the gate is OFF. If there is NO voltage, it is open.
What we are going to do, is take out the switch that is there, and put in a heavy duty stomper. Thus, we have to make sure that we keep the effect on all the time. We will be bypassing the whole circuit at the switch instead of on the board. SO, in order to make sure all of this happens correctly, we are going to flat out REMOVE Q3. So the only path will be through the tremolo circuit. Now, we have to make sure the output is always open, so we take out the diode D2, so there will be never any voltage on the gate pin of Q1, thus keeping it open all the time.
I normally order 3PDT switches from here, although you can also order them through Smallbear electronics or other places. The downside to my source is that you have to order two at minimum, but they are much cheaper there. That is up to you. I still need to whip up a switch wiring diagram, I'll do that now. Stay tuned for that.
euan wrote: I'm running in monoscope right now. I can't read multiple dimensions of meta right now
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More Cowbell
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Nice! How many do they have? At that price I'll take three. Great find!
Hahahah, this is such a crap drawing, I just whipped it up fast like so it looks like totototototal ass. But hopefully you can get the idea of what I'm getting at with the wiring. If any part doesn't make sense just ask.
Hahahah, this is such a crap drawing, I just whipped it up fast like so it looks like totototototal ass. But hopefully you can get the idea of what I'm getting at with the wiring. If any part doesn't make sense just ask.
euan wrote: I'm running in monoscope right now. I can't read multiple dimensions of meta right now
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Mike
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Only if you want the HardCore Shudders, and if you only use Amp OD and have a parallel FX loop (liek Cowbell) this isn't possible.Doog wrote:Trem should go after the OD really anyways.
I have my Trem up front and like the way it sounds with Amp OD in line after it. If I need hectic trem I just tread on the RAT.
Sounds like PenPen has this all sewn up as usual. He's a genius.
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theshadowofseattle
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More Cowbell
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I picked up the Switches today, 3 for pen pen, 1 for me. 
and a bonus, they are on ebay, they sell them for $3.50 and have thousands of them, and...
THEY HAVE ALUMINUM PEDAL BOX HOUSINGS! I got one, and plan to re-house the modified tremelo pedal into it, the measurements of the box are identical to a boss pedal, no holes drilled out, and if you want the stock bottom plate on a boss pedal that has rubber will fit the new box so you can still use it if you want. I will be posting pics up later tonight of the housing and the switches.
if only I had a cool name for this pedal...
and a bonus, they are on ebay, they sell them for $3.50 and have thousands of them, and...
THEY HAVE ALUMINUM PEDAL BOX HOUSINGS! I got one, and plan to re-house the modified tremelo pedal into it, the measurements of the box are identical to a boss pedal, no holes drilled out, and if you want the stock bottom plate on a boss pedal that has rubber will fit the new box so you can still use it if you want. I will be posting pics up later tonight of the housing and the switches.
if only I had a cool name for this pedal...
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More Cowbell
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http://stores.ebay.com/Global-Freight-Liquidationseuan wrote:Cowbell any chance of them pointing me towards their eBay store/profile?
you may have to ask them about the housings, as I didn't know they had them until I walked into thier place today and he showed me.
Make sure everyone that buys something tells them that I sent you to them, my real name is Brian and not More Cowbell, sorry if this upsets some of you.
I will do a pictorial of this process that pen-pen is helping with and post about it.
Indeed. As usual with making a pedal, you set out with one design idea in mind in terms of how to make it do stuff, and along the way you end up finding ANOTHER way that you just might like more. That is where I am now, I was trying to remove the noise in the design and through my attempts at removing it hit upon another, possibly better way to do the trem. So it is going through yet another revision.bob wrote:Is this the hurb trem? If so this is good news, i'm still gonna be buying one.PenPen wrote:PM'd'd.
As for a name, "Floppy Fat Chick" is my suggestion. "Babyshaker" is reserved by ME for the trem I'm making.
euan wrote: I'm running in monoscope right now. I can't read multiple dimensions of meta right now