EHX - Signal Pad  [schematic]

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EHX - Signal Pad  [schematic]

Postby jupagblkxten » 07 May 2010, 19:37

Seems like there's some interest around this pedal so here's the lowdown:

1 meg (log) pot wired as a volume control. 220p (ceramic) cap to ground off the input.

Simple. No battery required.

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Re: EHX Signal Pad

Postby weirdbeard » 07 Jul 2010, 03:35

hi, i'm new at building effects and have been interested in this pedal. could you post a wiring diagram of this? thanks
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Re: EHX Signal Pad

Postby fergus_nz » 07 Jul 2010, 04:34

are you sure the cap goes to ground? :hmmm:
would've thought it'd be a treble bypass something like this: http://seymourduncan.ru/new/s/treble-bleed_mod.jpg
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EHX Signal Pad

Postby xmugmugmugx » 26 Jul 2010, 17:02

I know it's a fairly simple design but i'm having trouble figuring out how to put it together. Anyone have any tips.
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Re: EHX Signal Pad

Postby kdmay » 01 Aug 2010, 12:15

xmugmugmugx wrote:I know it's a fairly simple design but i'm having trouble figuring out how to put it together. Anyone have any tips.


+1 please!! Probably a simple voltage divider network, but I've heard about the use of inductors to retain high end so unsure of the internals. Or if there are any other designs that achieve the same thing I would be interested in ideas
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Re: EHX Signal Pad

Postby okgb » 01 Aug 2010, 14:33

I don't think you would see inductors in a passive design
unless it was a cut circuit otherwise you'd need some make up gain

Is it more than your average gtr volume control ?
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Re: EHX Signal Pad

Postby kdmay » 01 Aug 2010, 21:20

fergus_nz wrote:are you sure the cap goes to ground? :hmmm:
would've thought it'd be a treble bypass something like this: http://seymourduncan.ru/new/s/treble-bleed_mod.jpg


Thanks - I might just build this into a pedal!

lolbou wrote:Topics merged. Use the search function :wink: ...


Apologies - need to touch up on my search skills, didn't even see this.
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Re: EHX Signal Pad

Postby nickeroo » 25 Aug 2010, 13:18

I am a pedal "n00b". How would one make the above description:

"1 meg (log) pot wired as a volume control. 220p (ceramic) cap to ground off the input." foot switch-able?
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Re: EHX Signal Pad

Postby Hides-His-Eyes » 25 Aug 2010, 13:28

nickeroo wrote:I am a pedal "n00b". How would one make the above description:

"1 meg (log) pot wired as a volume control. 220p (ceramic) cap to ground off the input." foot switch-able?


treat it like an effect, and look at the standard effects wrappers on Beavis Audio or Geofex.

http://www.beavisaudio.com/techpages/StompboxWiring/
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Re: EHX Signal Pad

Postby nickeroo » 25 Aug 2010, 13:35

Thank you, but I have a question (sorry!)

What would I do with the V+ pad on the board? Just wire the + of the LED right to the power jack?

Input and output pads would be the lugs on the volume pot?
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Re: EHX Signal Pad

Postby Hides-His-Eyes » 25 Aug 2010, 13:59

What would I do with the V+ pad on the board? Just wire the + of the LED right to the power jack?


Yup.

Input and output pads would be the lugs on the volume pot?


Yup.
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Re: EHX Signal Pad

Postby nickeroo » 25 Aug 2010, 14:54

Well, I wired it up but it is VERY noisy on or off.

When I turn the effect on and turn the vol pot it turns to very loud humming quickly (no guitar).

When I put the effect in the metal box, the effect stops working.

I reckon I have a grounding problem??

I wired the Sleeve of stereo jack onto the vol pot. Also sleeve of the mono jack to vol pot.

I wired the vol pot like a guitar, input from effect to first lug, middle lug is output, centre lug to vol pot casing.

I do not think it should be this hard!
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Re: EHX Signal Pad

Postby Hides-His-Eyes » 25 Aug 2010, 15:39

Try connecting the ground lug to the grounds of the in and output jacks, instead of to itself. :)
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Re: EHX Signal Pad

Postby Dirk_Hendrik » 25 Aug 2010, 16:25

Since I got one for free with a decent designed eq of another brand;

http://www.dirk-hendrik.com/temp/EHX_signal_pad.pdf

Not worth the wear of my screwdriver... :roll: So far for innovation.
Sorry. Plain out of planes.

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Re: EHX Signal Pad

Postby marshmellow » 30 Aug 2010, 22:46

Wooo. And nice output impedance when it's actually in use.
"Treble pad" might be a better name...
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Re: EHX Signal Pad

Postby bobo » 08 Feb 2011, 10:38

When turn down pot the tone also changed. Anyone can advise how to mod it. Thank you
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Re: EHX Signal Pad

Postby mysticwhiskey » 08 Feb 2011, 11:09

bobo wrote:When turn down pot the tone also changed. Anyone can advise how to mod it. Thank you


If you mean you lose treble when you turn down the level pot, then you could probably add a so-called 'treble bleed' cap and resistor in parallel across pins 2 and 3 of the pot, like what is done for guitar wiring. Typical values are say R=150K and C=1nF.

Image

Try it out with some test leads with alligator clips first, see if it makes an acceptable difference.
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Re: EHX Signal Pad

Postby bobo » 08 Feb 2011, 15:48

mysticwhiskey wrote:
bobo wrote:When turn down pot the tone also changed. Anyone can advise how to mod it. Thank you


If you mean you lose treble when you turn down the level pot, then you could probably add a so-called 'treble bleed' cap and resistor in parallel across pins 2 and 3 of the pot, like what is done for guitar wiring. Typical values are say R=150K and C=1nF.

Image

Try it out with some test leads with alligator clips first, see if it makes an acceptable difference.



Yes, it will lose treble when turn down the level pot. I will try per your information. Thank you
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Re: EHX Signal Pad

Postby Kenal » 20 Jan 2012, 08:55

http://www.dirk-hendrik.com/temp/EHX_signal_pad.pdf


And does this scheme work like a RC-filter, doesn't it? What about to remove C2 wiring to the ground to avoid the tone changing?
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Re: EHX - Signal Pad

Postby marshmellow » 06 Jun 2017, 15:37

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