BillFitzmaurice.info

Let me run this by youz guyz...

I have recently purchased a Denon 2 channel mixing board that has two other line inputs for a total of four in. There is a large toggle switch above both faders to go between the two inputs.
I have a 3.5 mm plug to phono cable in there, so that I may be able to use my phone as an aux source, but the level is so low, that I have to turn the gain up on the mixing board to compensate. While this isn't a big issue, it is a nuisance as I have to then turn the gain back down before I switch back to the CD player.

The CD players happen to have a 1/4 stereo headphone out, with a volume control pot on the back.
Tonight I connected the headphone out of the cd player to the board and played the same song, on both the phone and cd player and turned the gain down on the CD player until it sounded good and the VU meter looked close, on both sources.
I also ran a test tone and (vu meter only) tried to make sure both cd players are also now in the same ball park.
While all of this sounds fine, i have to really turn up the gain on the master out of the board.

Is this acceptable or should I look at a preamp for my phone?

I was thinking about a DIY opamp headphone amp in an Altoids can.
http://www.instructables.com/id/Headpho ... /?ALLSTEPS
There are about a million project ideas based around an op amp like this.
I'm worried about noise and sound quality (ok ok it's from a phone i know).
Would this work, or perhaps there are other line level, pre amp, ideas that would be more sutible?
Have you guys seen these projects?
http://sound.westhost.com/project37a.htm

PS, this all runs into my driverack, and i have PLENTY of room to turns gains up or down to compensate. My end goal is to maximize gain structure, attempt to maintain sound quality, and of course not fiddle with gains during a show.

It's hard to imagine that something isn't wrong with the set-up.

That must be a huge difference if you can't make it up with the channel volume controls. Surely your phone has a volume setting you can turn up somewhere, or how could it drive a pair of headphones?

Is it the connection from the phone to the wire? Sometimes I've had a slight connection with phones, but after removing the cases, the jack would fit completely and the volume was drastically increased.

It does work, however even with the phone maxed out, i still need to turn up the channel gain to compensate. The output of the cd players is just way more than the phone.
Its annoying to have to fiddle with the gain, back n forth.
One of the guys from work has a headphone amp that i tried in line. With the amp i was able to get the gain from the phone to match that of the cd player. So it looks like ill go that route.
Now the question is to buy.. or DIY