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Can a squealing/feedbacking guitar pedal harm an audio interface?

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Re: Can a squealing/feedbacking guitar pedal harm an audio interface?

Postby ef37a » Wed Apr 22, 2020 11:58 am

Ah, did not get the power supply point at first reading.

So, do NOT desert us G but the guys at 'thefretboard.co.uk. have had lots of experience with less than well designed pedal supplies.

That said, such problems can be just as much the fault of the pedal design in not keeping signal and supply lines well 'apart'.

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Re: Can a squealing/feedbacking guitar pedal harm an audio interface?

Postby Hugh Robjohns » Wed Apr 22, 2020 12:03 pm

Yes to the protection -- in so far as you'll know what the maximum level can be.

A noise gate won't help since that just mutes the channel when the sound level falls below a certain threshold... but in this case the problem is that the pedal generates full level output in the absence of an input signal.

In your situation, I think I'd run the Behringer pedal on a rechargable battery as -- to me at least -- the cost of that would be easier to tolerate than nasty howlrounds!

If you were interested in some DIY electronics then it might be practical to improve the stiffness of the power supply by fitting some additional smoothing /decoupling capacitors in the supply outputs... but that would require a careful analysis of the existing circuitry before working out how to improve it and then modifying it in a safe way.
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Re: Can a squealing/feedbacking guitar pedal harm an audio interface?

Postby garrettendi » Wed Apr 22, 2020 12:09 pm

Hugh Robjohns wrote:Yes to the protection -- in so far as you'll know what the maximum level can be.

Ok great I'll go ahead with that for now knowing I'm safe equipment/hearing-wise

Hugh Robjohns wrote:A noise gate won't help since that just mutes the channel when the sound level falls below a certain threshold... but in this case the problem is that the pedal generates full level output in the absence of an input signal.

Damn. Ah well, at least now I know it won't help.

Hugh Robjohns wrote:In your situation, I think I'd run the Behringer pedal on a rechargable battery as -- to me at least -- the cost of that would be easier to tolerate than nasty howlrounds!

I could get one of those 9V battery cable things that plug into the power input? It would power from a battery that way with the benefit of my easily being able to disconnect it when not in use. I could then leave the guitar cables connected without running the battery down. It could as you say be rechargable too so I don't keep using up normal batteries.

Hugh Robjohns wrote:If you were interested in some DIY electronics then it might be practical to improve the stiffness of the power supply by fitting some additional smoothing /decoupling capacitors in the supply outputs... but that would require a careful analysis of the existing circuitry before workign out how to improve it...

That's out of my ability I'm afraid!

Anyway, at least I know I can use this pedal safely in the meanwhiles.
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Re: Can a squealing/feedbacking guitar pedal harm an audio interface?

Postby Hugh Robjohns » Wed Apr 22, 2020 12:10 pm

garrettendi wrote:I could get one of those 9V battery cable things that plug into the power input? It would power from a battery that way with the benefit of my easily being able to disconnect it when not in use. I could then leave the guitar cables connected without running the battery down. It could as you say be rechargable too so I don't keep using up normal batteries.

That sounds like a very practical compromise solution to me.
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Re: Can a squealing/feedbacking guitar pedal harm an audio interface?

Postby garrettendi » Wed Apr 22, 2020 12:26 pm

Thanks Hugh. Will order the cable tonight. :thumbup:
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Re: Can a squealing/feedbacking guitar pedal harm an audio interface?

Postby ef37a » Wed Apr 22, 2020 12:51 pm

Maplin used to do a range of 'battery boxes' Get one for 6 AAs and you have 9V with MASSIVELY more capacity than a PP3.

If a search does not throw one up PM me as I am sure I have a spare one kicking around I can Jiffy to you. .. Nuffin but you can buy your own AAs!

Ah, beware a battery clip to co ax power cable? I bet most are wired for the logical centre +ve? Most pedals are not.

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Re: Can a squealing/feedbacking guitar pedal harm an audio interface?

Postby garrettendi » Wed Apr 22, 2020 12:57 pm

I’ve found the Voodoo Labs PPBAT-R which I’ve bought. I checked and it’s centre negative!
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Re: Can a squealing/feedbacking guitar pedal harm an audio interface?

Postby Sam Spoons » Wed Apr 22, 2020 12:59 pm

Simply plugging an unterminated DC plug into the socket will usually disconnect the battery, and is much cheaper than a battery power pack.
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Re: Can a squealing/feedbacking guitar pedal harm an audio interface?

Postby ManFromGlass » Wed Apr 22, 2020 1:16 pm

Brilliant - tip of the day! Thanks.
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Re: Can a squealing/feedbacking guitar pedal harm an audio interface?

Postby garrettendi » Wed Apr 22, 2020 1:26 pm

I've only just realised the Voodoo Labs PPBAT-R is for wiring the battery input from a vintage pedal to a PSU. Not powering a pedal via a battery.

Well that was a waste of £6. I've already ordered it. :thumbdown:

I have some reversed polarity cables from the PSU I have. Could I connect the PPBAT-R to the pedal using one of those so I use the PPBAT-R in reverse?

What if I get the positive/negative the wrong way round when using the pedal??
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Re: Can a squealing/feedbacking guitar pedal harm an audio interface?

Postby garrettendi » Wed Apr 22, 2020 1:32 pm

Found this video: https://youtu.be/RF04VseZ05E

Where do the same thing in my last post. It should work after all! I'm just nervous what will happen if I don't know the polarity after all....
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Re: Can a squealing/feedbacking guitar pedal harm an audio interface?

Postby garrettendi » Sun May 17, 2020 1:40 pm

As a follow up the battery cable worked! I used the polarity converter and it no longer squeals!

I’m still getting a bit of hiss with the high gain pedals but not badly such. Very tolerable and I plan on upgrading PSU this summer!

Next is to try it on my PC amp sims as there’s only so much I can do with a titchy little battery amp.
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Re: Can a squealing/feedbacking guitar pedal harm an audio interface?

Postby ef37a » Sun May 17, 2020 2:04 pm

If you get any 'classic' big guitar amp such as a Marshall or a Mesa really cooking then stop playing you will hear a fair amount of noise, both hiss and usually some hum* especially in a quiet domestic setting or indeed a studio G'.

I would not worry about it too much although you could try a gate plugin if really bothered.

*Not 'our' amps. You will get some unavoidable hiss at very high gains but no hum (other than the guitar!)

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Re: Can a squealing/feedbacking guitar pedal harm an audio interface?

Postby garrettendi » Sun May 17, 2020 2:07 pm

Yes the hiss is directly proportional to the amount of gain I use so I figured to use a noise gate as you suggest.

Are you saying a better PSU probably would not make the difference?
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Re: Can a squealing/feedbacking guitar pedal harm an audio interface?

Postby ef37a » Sun May 17, 2020 2:11 pm

garrettendi wrote:Yes the hiss is directly proportional to the amount of gain I use so I figured to use a noise gate as you suggest.

Are you saying a better PSU probably would not make the difference?

I doubt a better supply would help reduce hiss but you can test this! Run on THE cleanest (but expensive!) supply possible, batteries. That will give you your baseline noise level with a 'perfect' supply.

What I was alluding to earlier was that some players actually like a bit of grunge from the amplifier!

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