Switching Noise

Started by Monkry, November 24, 2012, 07:31:01 PM

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Monkry

Hi all,
I have recently bought a second-hand univibe clone pedal which seems to be operating normally sound wise of but it "pops" when switching on & off
& it also pops when changing from vintage/modern mode (doh, just gave it away)
It uses a heel activated microswitch/relay type switch.
I've trawled the net looking for similar problems & only found one review that mentions it.
My tech went through & couldn't find anything obviously wrong (not having schematics doesn't help) apart from voltage shifting in
parts of the circuit which he thought was odd.
Someone suggested a DC Offset filter.
Is this normal for this pedal & if so, is there a"fix" of any sort.
Any help appreciated.
Thanks,
Lok


R.G.

It is not normal, unless it's a particularly poor "clone". The original, and most of the clones, starting with the Neovibe, do not do it, unless broken or wired incorrectly.

Pops when switching always mean that you're switching DC levels as well as signal, and well-designed, well-built pedals don't do that.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

Monkry

Thanks RG.
I didn't think it was right.
Its a well known brand, just don't want to name to avoid any "flaming".
It looks to have been dropped as the the switch shaft is bent, could have damaged other components when that happened.
I don't like my chances of getting a refund so it's a $200 doorstop.
I've emailed the company & maybe they can help.
My tech checked some of the caps which didn't fix & his next step was to change transistors or the voltage doubler.
Being in Australia with the manufacturer in the US makes it too expensive to return for repairs.
Thanks again,
Lok