[LAU] Hum pickup in DI boxes

Bill Purvis bill at billp.org
Tue Jun 8 17:13:56 CEST 2021

On 08/06/2021 13:43, Rick Green wrote:
> Headphone outputs are a strange beast.  Unbalanced, for sure (a single 
> signal lead for each channel, with a common ground return), but much 
> lower impedance than you would expect for an unbalanced line out.
>   I've struggled as well, trying to find a consistently reliable DI 
> for this application.  There are several on the market which 
> specifically address this issue. Search for 'laptop interface' or 'A/V 
> adapter' to find some of the ones I've tried.
>   I've also resorted on occasion to abandoning the headphone jack 
> altogether, and using an external USB soundcard/interface instead, 
> which provides proper balanced outputs.
> Rick Green
There are various groups who use the building, and bring their own 
laptop/mobile phone, so most of
the interface devices are a non-starter. It has to be something working 
from a 3.5mm TRS plug (and
as it's only a single channel to the mixer, it is effectively a 3.5mm TS 


| Bill Purvis                            |
| email: bill at billp.org                  |

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