Bottlehead Forum

Bottlehead Kits => S.E.X. Kit => Topic started by: J. Mauro on February 15, 2014, 04:26:21 AM

Title: SEX 2.1 Add 120 Ohm resistors
Post by: J. Mauro on February 15, 2014, 04:26:21 AM

I would love if some one could explain and post pictures of the 120 Ohm resistors in series with the headphone jack on the SEX 2.1. I need to add them to cut down the hum for my D5000 headphones (25 Ohm, 106 dB/mW) and I cannot seem to find any dedicated threads. Since this seems to be a common question, this could be the new go-to thread for it. Thanks in advance.

Title: Re: SEX 2.1 Add 120 Ohm resistors
Post by: mcandmar on February 15, 2014, 06:41:38 AM

Have a look at the schematic attached, that's where you want to add them for the left and right Channel, i.e. between the two red wires and headphone socket.

I've attached a pic of mine, though a little more complicated as the wiring runs to the XLR socket on the left, then onto the regular TRS socket on the right but the principal is the same, snip the red ones and insert the resistors into the path.

Title: Re: SEX 2.1 Add 120 Ohm resistors
Post by: J. Mauro on February 17, 2014, 05:06:10 AM

Thanks for that info. Are there any power requirements for these resistors? Should they be 2 W resistors because that is how much power can go through there or does it matter?

Title: Re: SEX 2.1 Add 120 Ohm resistors
Post by: Paul Birkeland on February 17, 2014, 08:30:03 AM

Quote from: J. Mauro on February 17, 2014, 05:06:10 AM

Thanks for that info. Are there any power requirements for these resistors? Should they be 2 W resistors because that is how much power can go through there or does it matter?

2W would go through if the transformer had a 120 Ohm tap.

1/4 Watt is sufficient for this purpose. 

Title: Re: SEX 2.1 Add 120 Ohm resistors
Post by: J. Mauro on February 17, 2014, 08:35:01 AM

Excellent. Thank you very much.