[Karlosak]

Hi,
I´ve built a basic CMOY (according to Tangent´s great tutorial) few days ago. It sounds great from my PCDP headphone jack (Sony D-CJ01) but when I swap to the line out (which should sound better) there is no bass and too treble.
What´s wrong with it? I´ve used the line out with my speaker system and it sounds great. So I think the problem could be in impendances of the source and the amp.

So how to make the line out sound better? Should I use larger pot value (and larger R2 resistor) or lower the gain? Please help me, since I don´t understand electronics much.

I´m using standard 10K pot and 100K R2 resistor. The gain 11 and all the other parts are per Tangent´s tutorial. I´m using HD-600 headphones.

Specs of the Sony PCDP (from the manual):

Line output:
Output level 0.7V rms at 47 KOhms
Recommended load impendance over 10 KOhm (->maybe this it?!)

Headphones (stereo minijack):
Approx. 5 mW + Approx. 5 mW at 16 Ohms

Thanks guys for any income.

 

[stereth]

Well, first off, listen to what sounds good. Search the Portable forum to see if anyone has comments on the line out quality. New CD players typically run a long time on a pair of AAs; this means they cut corners on DAC and amp circuitry.

With my CD player (DE-J756), I have to turn on 1/2 bass boost to be able to hear the bass line. And that's probably a bit much for most people here. I just like a little more bass than some people. What kind of headphones are you using?

 

[sacriste]

Maybe the line-out is just plain worse, it could happen, read Duncan mega-review. I have an Aiwa PDCP without line-out and sounds great with a CMOY from the headphone jack. Better bass and treble extension. But I use a lower volume level that the level I set for direct use (and crank up the amp). I think is a matter of distorsion. The jack amp could be weak but has a nice usable range and the amp give me the level I need to drive the cans.

 

[Karlosak]

I agree with you.
But I don´t think that the line out of the player is bad. When I plug it to my integrated amplifier, both outputs sound nearly the same; from what I can hear the line out is even better than the headphone jack.

So I think it has to do with the PCDP <-> CMOY setup. What do you think?

Shouldn´t I find the solution, no problem - headphone jack sounds good to me (it´s just a process of hunting for something better

).

 

[RockysDad]

Is C1 in your amp installed? Try removing them and go straight to your volume pot. But... Be sure to measure the output of your source first and make sure there is no DC present; this could fry your phones! I removed mine and thought the sound was way more full sounding.

 

[Gino]

M using my Panasonic CT-800's line out with a cmoy and it sounds great.

 

[Karlosak]

I´ve removed the C1 capacitor and it has improved a bit but on both outputs(!). So this is not the problem.

I´ve ordered a 50K pot + 500K R2 resistor. So I´ll see if it brings any improvement.

 

[Karlosak]

I´ve changed the pot and it is running great! Maybe the old one was some crapy one or could be not connected properly.
So sorry for bothering you

 

[tangent]

Quote:

Maybe the old one was some crapy one or could be not connected properly.

Much more likely that your CD player's line output is just very weak, and can't take any kind of load.

 

[Gino]

Dont you just love lineouts. Everytime I hook up to the headphone outs by mistake then switch back to lineouts, it's like one big PHEW, THAT'S WHY SOMETHING DIDN'T SOUND RIGHT.

Hmmm I wonder what an external dac will do when I use my portable's optical output. Incidentally is the optical cable for my CT800 proprietary or an regular off-the-shelf item?