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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => Pro AV Forum => Topic started by: Tracy Prier on April 08, 2018, 05:54:17 pm

Title: Buzz on recording from Mixer/Amp to laptop
Post by: Tracy Prier on April 08, 2018, 05:54:17 pm
Hello all.

I'm new here and hoping for some help.

Our church is currently using a Wharfedale PMX 700 amp/mixer for popup events.

I am running an RCA/3.5mm audio lead from the audio outs of the amp to a 3.5mm to USB adapter into our laptop in order to record the audio. One of these - http://www.unitek-products.com/search?view=product&id=31

I have connected in a ground-loop-isolater into the line and while it DOES significantly decrease this buzz it isn't totally removing it

You can hear the before and after buzz here:

No isolator - https://drive.google.com/open?id=1LgYU_O1a5u4KFd4i2pOjQg8vVh5VkAAX

with isolator - https://drive.google.com/open?id=1TLJsbMPCTAmBCWPa4T0jmR6NgoN6IN9C

This is NOT coming through the FOH speakers and is still there even if I unplug the laptop power supply.

What could be causing this remaining buzz and how can I eliminate it ??

Thanks in advance

Tracy
Auckland
New Zealand
Title: Re: Buzz on recording from Mixer/Amp to laptop
Post by: Keith Broughton on April 08, 2018, 06:30:49 pm
Hello all.

I'm new here and hoping for some help.

Our church is currently using a Wharfedale PMX 700 amp/mixer for popup events.

I am running an RCA/3.5mm audio lead from the audio outs of the amp to a 3.5mm to USB adapter into our laptop in order to record the audio. One of these - http://www.unitek-products.com/search?view=product&id=31

I have connected in a ground-loop-isolater into the line and while it DOES significantly decrease this buzz it isn't totally removing it

You can hear the before and after buzz here:

No isolator - https://drive.google.com/open?id=1LgYU_O1a5u4KFd4i2pOjQg8vVh5VkAAX

with isolator - https://drive.google.com/open?id=1TLJsbMPCTAmBCWPa4T0jmR6NgoN6IN9C

This is NOT coming through the FOH speakers and is still there even if I unplug the laptop power supply.

What could be causing this remaining buzz and how can I eliminate it ??

Thanks in advance

Tracy
Auckland
New Zealand
I would assume the RCA to 3.5 mm plug is a TRS (3 rings on the plug) and the USB device probably wants to see a tip/sleeve  connection. You need an adapter that combines the left (tip) and right (ring) to a tip/sleeve connector.
For recording, it may be worth getting a better USB audio interface like this..

http://www.musictri.be/Categories/Behringer/Computer-Audio/Interfaces/UCA222/p/P0A31 (http://www.musictri.be/Categories/Behringer/Computer-Audio/Interfaces/UCA222/p/P0A31)

or this...

http://www.musictri.be/Categories/Behringer/Computer-Audio/Interfaces/UMC202HD/p/P0BJZ