Tonebender mkII with bipolar circuit wiring

[Johnny Lemonhead]

Hi,

I have recently converted my tonebender from germanium PNP negative to positive and it is now wired according to this diagram:



The fuzz works nice and quiet with a battery, but I would like it to run from the wall with a common negative ground power supply.
To do this, I made a bipolar circuit according to this:

http://www.tonepad.com/getFile.asp?id=118

My question is - how do I go about wiring the bipolar circuit to the positive ground tonebender? I never dealt with a positive ground effect before and the wiring is different than the one explained over at tonepad.

Any help will be appreciated. Thank you.

[Johnny Lemonhead]

Bumping this for future newbies like myself who want to drive their positive ground fuzz with a negative ground PS. Thanks.

[PRR]

Why do you need a bipolar supply?

You need a single 9V supply. Swap the + and - when converting from PNP to NPN.

The only way you get in trouble is when you -share- supplies across different-ground pedals.

[Johnny Lemonhead]

Thanks for replying, PRR. I appreciate it.

Sorry for not making myself clear - It's largely due to insufficient knowledge and experience in electronics and pedal building.

The diagram I published in the original post is the current wiring of the pedal. I would like to power it with a single PS that powers all of my other regular negative ground pedals, so I thought about using the bipolar power circuit from tonepad, but just the negative output.

Have I got this all wrong? Is there another simpler way of achieving this without using a separate PS?

[dthurstan]

I'm sure I've heard on here that it works. Here it is http://www.diystompboxes.com/smfforum/index.php?topic=77088.0.

I haven't done this myself, but I have built a bipolar supply for a tremolo and I assume you connect +9 to +9 on the circuit and common ground to ground.

The tonepad schematic also includes a transistor switch, so you can have power switching for the input. Then you need to use 1 of the extra poles on the 3pdt switch for the led. Does that make sense? It might help if you draw your on schematic for wiring up. It helps me get it straight in my head.

Dave

[Johnny Lemonhead]

Thanks for the help, dthurstan.

I started the thread you mentioned one year ago

Since then, I converted the negative ground tonebender to the wiring above and finally built the bipolar circuit. I want to try it, but seeing that the wiring is so different on the positive tonebender, I'm not sure how to connect the bipolar circuit to it.
Tonepad says to connect one of the wires to the ring of the input jack, but the positive tonebender uses that for power (as seen above), so I'm a bit confused. Still a newbie when it comes to pedal making and electronics, so I need specific instructions, like paint by numbers.

[dthurstan]

Doh! 

I didn't look who posted that.

Imagine the battery & dc jack are gone from the ggg layout. Use the schematic @ the bottom of bipolarpdf as your guide for the power. U have to connect the ring of i/p jack to ring of bipolar, take the grd from the bipolar & connect to grd of ggg layout. Then -9 bipolar to -9 of ggg layout juntion of R2, R3, R5 & C1 where the dc jack & batt used to connect to. Don't connect +9 from the bipolar to anything. Everthing else should be wired up following the ggg layout. Is that any clearer?  It's kinda confusing but the grd from the bipolar is now grd for the tonebender & -9 is sorta being generated by the bipolar. Does any1 wanna confirm what I'm saying, I'm sure it's right but I haven't built it so.

I'm thinking of building this and a pnp fuzzface, I was hoping I couldget away with neg grd circuits but this is making me rethink that. I'm worried bipolar will take up 2 much space, I wanna put em in 1590B's & Im vero'ing them. I'm gonna breadboard them up 1st & hope 4 the best.

[Paul Marossy]

I came here from the wah power thread, because of the "shrieking" mentioned: http://www.diystompboxes.com/smfforum/index.php?topic=84998.0

Is your power supply the traditional transformer type wall wart or a switching type? Switching type power supplies can sometimes introduce a high pitched whining into audio circuits. It seems that more and more you are seeing the switching type power supplies these days.

Anyway, if you're not sure how to tell the difference, a switching type power supply will be smaller and much lighter than the conventional wall wart.

[petemoore]

  No simple answer, you've a 'complicated' [bunch of things that add up to stuff that isn't understood, such as the ring/sleeve switch, how power supplies work, float, and how a floating 9v can be applied...either way around.
  Gnd. can be anything but we choose gnd. as a place to drive a stake into to get a DC reference which is common...generally just connecting to a water pipe works.
  A circuit can be + or - from "Gnd.".
  "Gnd. could be 300v "Floating", connect + to ground and you have a -300v potential, connect - to ground and you have a +300v potential.
  DC blocking caps...block DC [input and output caps].
  If you connect + to Gnd. And - to Gnd., a common shorted condition is created [test for non-shorting conditions before applying power to a circuit].
  The way I figured out what switches do and don't do is by testing the jacks/plugs, DC connectors [anything with a connector or switch], with the related items that might throw the switch [such as inserting a plug] or switches.
  Familiarization also entailed removing wires and figureing out exactly what goes where // when on some of the mechanical items, they held 'secret' connections...conditions just so, DMM at the testplatform...some of them have to be 'dug out', and don't just pop right out.

[Johnny Lemonhead]

OK, it's much more clearer, yet I'm still not sure where should I connect the -9 from the DC jack.
Tell me if I got this correctly: the regular negative pin PS connects to the DC jack. The +V from the jack is connected to the power-in of the bipolar, ring to ring, ground to ground and -9 output of the bipolar to the former place where the -9 of the DC jack connected to. The battery is not affected by the bipolar so its negative pole also feeds the tonebender. The battery plus is connected to the lower positive pole of the DC jack. What confuses me is the negative pole of the DC jack. Does it go to ground along with the bipolar ground or somewhere else?

Yeah, I know it's pretty stupid, but I'm still new at this...

I really appreciate the help, dthurstan.

I'm worried bipolar will take up 2 much space, I wanna put em in 1590B's & Im vero'ing them. I'm gonna breadboard them up 1st & hope 4 the best.

I etched the bipolar layout from tonepad and it's pretty small, although I'm using a 125B enclosure, so there's extra room. You can also check this out: http://www.diystompboxes.com/smfforum/index.php?topic=77769.msg639491

(vero layout for a MAX1044 converter).

I came here from the wah power thread, because of the "shrieking" mentioned: http://www.diystompboxes.com/smfforum/index.php?topic=84998.0

Is your power supply the traditional transformer type wall wart or a switching type? Switching type power supplies can sometimes introduce a high pitched whining into audio circuits. It seems that more and more you are seeing the switching type power supplies these days.

Anyway, if you're not sure how to tell the difference, a switching type power supply will be smaller and much lighter than the conventional wall wart.

It's the normal bulky type. I heard somewhere that the switching type are less ideal for analog pedals, so I preferred to play it safe.
I think it would be better to complete the -9+ conversion and then debug if the squeal persists. Thanks, Paul.

[Johnny Lemonhead]

I ended up connecting the negative pole of the DC jack to ground because it probably was the logical thing to do. The bipolar circuit works perfectly and the squeal is gone.
No hum, no squeal and the pedal can now share a negative PS with all the rest of the pedals. No 220uf cap was needed because of the regulated PS.

Thanks for all the help!

Next stop - etching the enclosure.

[Paul Marossy]

I ended up connecting the negative pole of the DC jack to ground because it probably was the logical thing to do. The bipolar circuit works perfectly and the squeal is gone.
No hum, no squeal and the pedal can now share a negative PS with all the rest of the pedals. No 220uf cap was needed because of the regulated PS.

Cool. I thought it could possibly be the power supply, so I threw that out there. Glad you got it figured out. 

[Johnny Lemonhead]

the regular negative pin PS connects to the DC jack. The +V from the jack is connected to the power-in of the bipolar, ring to ring, ground to ground and -9 output of the bipolar to the former place where the -9 of the DC jack connected to. The battery is not affected by the bipolar so its negative pole also feeds the tonebender. The battery plus is connected to the lower positive pole of the DC jack. Negative pole of DC jack goes to ground.

Everything still works great... except the LED doesn't light up.

Right now it's connected exactly as shown in the diagram above, but I didn't do any changes despite the addition of the bipolar. I'm not sure how to connect it properly.
I hope this will be the last debug for this pedal...
Thanks!

[Johnny Lemonhead]

Solved - LED positive to 3pdtd ground, Negative lead to the -9 output of the bipolar.

[dthurstan]

Hey

Glad you got it up & running. Cheers for the tips 4 bipolar supply. I'm gonna breadboard all my builds from now on to see if there are going to be any problems etc. I'm sure I'll be able to fit em in their enclosures, Ill just tape em up good.