Head phone buffer amp ???

[HA_DA_JA]

Problem:
Home Audio Hobbyist.
My Mic pres dont have headphone sockets.

I run signals through my mic pre insert comp and eq and then into the DIgi 002R.
I wish I could monitor what it sounds like to make adjustments to the signal chain before reaching the Digi 002R. IT is more handy when I do location recording and at home. It also helps with latency issues.
My mic pres dont have headphone inputs so I have to go through DIgi 002R
What solutions/options would there be to make a small headphone socket for running after my mic pres? I guess an external uncoloured unit would much be preffered then hacking up the mic pre casings.
or there must be an easier way that I am just not seeing.
Thanks

[Kurt]

Does the 002 have line or xlr outs for each channel? In my live recording rig I run the analogue outs of my HDD recorder into a cheapo be!@#$%^& line mixer so I can make sure a clean signal is going "to tape". Even better would be to have a full mixer but that takes more money and space.

[HA_DA_JA]

yes something small would be great.
I was looking at something like this.

http://jseaber.com/cMoy/

As it is portable and there are nice options available. Not too interested in the bass boost switch or maybe if I am on the motorbike/ pushbike it could be good.
Cheers

[Kurt]

The nerds on another forum I visit assure me that the Jaycar headphone amd kit is much better than cmoy based ones...

It lives here

[chris p]

Dale

You say "pres" as in plural. Do you want to listen to just one line or more than one? If more than one, then you'll need to mix the signal somehow, and so we are talking a small mixer (or at least the guts of one).

I'd go with the Gyraf headphone amp rather than CMoy, but you'd need to think through the balanced / unbalanced issues and whether you want the same signal in both ears.

http://www.gyraf.dk/gy_pd/hpamp/HP-Amp.pdf

[chris p]

Kurt beat me to the reply - the Jaycar one looks pretty similar to Gyraf, in that it uses high output transistors to drive the outputs.

[HA_DA_JA]

At the moment it would just be one pre at the time just for single instruments and simple setups as this is what I seem to be doing in the last few years.
I have narrowed it down to maybe this with the upgraded Texas Opamp

http://cgi.ebay.com/Biosciencegeek-Head ... 1|294%3A50

[HA_DA_JA]

Wow I just had a look at other people making this device and there seems to be a split whether they use the 2134 or the 2227 or the 2604 or the LM4562 chip. Which is better for this application? o
I have no idea about soldering so the Jaycar unit is no go for me unless someone wants to it for me for a fair price.
Thanks

[chris p]

Dale

Whoa, hang on thar a second, pardner. Way to early to be yakkin' 'bout ICs.

The standard CMOY works on an unbalanced, -10dbv signal. You probably don't want that as you'd at least unbalance your line through to the 002 (dangerous in location work, believe me I know) and may overdrive the IC into clipping, depending on your gain structure.

You want a design that works on balanced signals.

[HA_DA_JA]

I am trying to think why I really want it and I guess I am using it to experiment with sounds through the mic pre eq and comp in the bedroom without the need of powering up the digi and the computer. Just using it to hear how different instruments and voices sound through the pre combo's in a quick set up way.
WIll unbalanced and balanced play an important role in the headphone amp in this scenario?
Cheers

[rick]

dont want to be too much of a smartarse but the solution you seek has been thought of and solved before
actually way before .... its called a console