Bypass Hiss

Forum dedicated to helping people debug and troubleshoot non-functional pedals or builds. Please use an clear and informative title, indicating circuit and basic problem. Don't forget to mark the issue as fixed if this is the case.
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MuzzledAxe
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Post by MuzzledAxe »

Hi

I am new to stomp box building..... I have so far built a SHO, Meathead, and LPB1 Clone..I got the lay outs from here

http://tagboardeffects.blogspot.co.uk/2 ... mment-form

All work great off battery snap.

Yet I get hiss when hooked up to the DC Socket.

The story so far..

This is what is happening..

I first built the circuit and fired it up no bypass on a battery snap...Worked great

Then I went to wire up the bypass and place it in enclosure without battery snap, on a plastic dc 2.1mm socket so could use my power supply. Then hissing . The pedal still works great, just a hiss. Yet if I turn the pedal up without playing the hiss gets quite turn the pedal down the hiss gets louder...

If I now remove power supply and clip battery snap onto dc socket the pedal fires up no hiss.

I used this wiring diagram for hook up...

http://gaussmarkov.net/wordpress/though ... p-a-1590b/

Here are some pics...

https://s1060.photobucket.com/albums/t456/jamesd741/

Wire color codes..

Orange... Ground
Black... Power In
Purple... In-Out From switch
Pink... Circuit in
Yellow... Circuit out.
White... To number pot..

I have since taken my meathead clone off of battery snap and used a different hook up diagram and the same hiss.

I have changed transistors and the same....

Any help please...

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CHEEZOR
Diode Debunker
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Post by CHEEZOR »

Wait for someone with more knowledge to respond, but it could be a low quality power supply. I used to have one from Radio Shack that made a digital delay pedal make so much noise I thought it was useless (I let it collect dust for a year or two). Then I tried it with a Visual Sound 1Spot and it was quiet as could be. :slap:

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MuzzledAxe
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Post by MuzzledAxe »

Have chandged power supply and still hiss :x :x :x :x :x :x :x

I was advised about power ripple aswell and after placing a cap on the DC socket still hiss... :oops: :oops: :oops: :oops: :oops:

Please some body ride to the rescue :horsey: :horsey:

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Nocentelli
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Post by Nocentelli »

The gaussmarkov layout is good, but doesn't show how to wire the battery AND adaptor jack:
Beavis has a really good page on this -

http://www.beavisaudio.com/techpages/PedalPower/

Hissing that gets louder as the volume is decreased indicates something definitely miswired, quite possibly to do with the ground to the volume control: Even the most outrageous howling, oscillating, uberfuzz circuit should quieten and eventually become silent when the volume is reduced, since volume controls are wired as voltage dividers, so at minimum volume the output is grounded and therefore silent - If it isn't, there's a problem.

Ensure all ground and power connections are as they should be, i.e. all grounds connected EXCEPT the battery snap negative (which goes to the input jack ring), the positive from the battery to the INNER connector on the power jack, and the OUTER positive connector from the power jack to the circuit +9v pad.
modman wrote: Let's hope it's not a hit, because soldering up the same pedal everyday, is a sad life. It's that same ole devilish double bind again...

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MuzzledAxe
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Post by MuzzledAxe »

Cheers

I give that wiring a try...

Could have bought faulty sockets???

If your ever in Headingly having a drink let me know and I will come and buy you pint or two...

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