Headphone level to Line level converter?

[noviygera]

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]

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)

 

[PRR]

Headphones originally WERE "line level".

Telephone ear-piece connects to telephone line and delivers useful sound.

There's been a LOT of changes over the century+. However it is still a fair bet that a "headphone out" will drive a "line in" well.

 

[billshurv]

Is the old story true that the yellow foamed Senheisers were designed as 600 Ohms so you could just plug them into any mixing desk output?

 

[PRR]

Mine were 2k.

Which WAS a common value for "operator headsets" so the operator could bridge-across an active line to hear if it was in use, without large drop of level.

 

[billshurv]

Ah could have been that. I killed mine 30 odd years ago. But they had a hard life. 424's IIRC

 

[noviygera]

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]

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.

 

[Ken Newton]

Is the old story true that the yellow foamed Senheisers were designed as 600 Ohms so you could just plug them into any mixing desk output?

I loved my Sennheisers. I could not believe they only cost $30, as I recall. A god send to a teenage audiophile like myself at the time.

 

[noviygera]

Pano,
I'll try your suggestion. Thank you.

 

[noviygera]

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!

 

[Mooly]

Pleased you found a solution

I think we were all thinking you had, or that you suspected you had a signal level issue rather than a 'lip sync' issue although it sounds like your new gadget will solve both issues