Headphone level to Line level converter?

Hi. I'd like to have a basic circuit that would take my mixer headphone output to line level so that I can do some DSP manipulation with that line level signal (post Headphone out).

lets call it "converter":
mixer headphone outputs -> "converter" -> DSP box input

Any suggestions?

Herman
 

Mooly

Administrator
Paid Member
2007-09-15 8:14 am
You might find the level is fine as it is. Headphones need current as much as voltage and so the headphone 'amp' may be little more than an opamp configured as a unity gain buffer.

I would try it direct first and see how it sounds and what the levels seem like. At most you would just need a simple resistive divider to reduce level, two resistors per channel.

Figure 1 here:
Voltage divider - Wikipedia

keep Z2 at (say) 1k and begin with Z1 also at 1k and then alter just Z1 up or down to increase or decrease level.

(or just use a 10k dual gang pot in place of the resistors and get infinitely variable level)
 
Guys,
thanks for the encouragement, I'll start with the simple headphone out -->> Balanced line in connection.
QUESTION:
Headphone out has 3-contacts. I'm guessing shared ground+Rchan(pos)+Lchan(pos)
going into...
Balanced inputs is 6 contacts: 3pins for each channel

What's the proper wiring diagram?
 

Pano

Administrator
Paid Member
2004-10-07 6:05 am
Panama
Most modern balanced inputs will also do unbalanced with no problem. Connect the 1/4" headphone plug tip to Left XLR pin 2. Connect the 1/4" ring to Right XLR pin 2. Then connect the sleeve (ground) of the headphone jack to XLR pins 1&3 on each side. Usually that will work.
 
Mooly and RRR,

You were right! All that was needed is the delay box:
Kramer 256LX

It did the job of delaying the headphone output without anything extra and drove the headphones just fine.

Pano,
The routing was per Kramer 256LX user manual, that scenario is in there, clearly illustrated.


Thanks!