headphone jack noise

[mantis]

I get a good bit of noise from my 2270 headphone jack... when somethign is playing or not, just whenever the headphones are plugged in the noise floor is quite high. I dont get the noise from speakers or preamp out on back. Please advise.

[Oerets]

Have you cleaned the jack at all ? Checked if there's any bad connections or if is loose . What will it do if you wiggle the plug , does it get worse ?

Are the contacts getting a good grip on the plug ?





:music:

[mantis]

I cleaned it a while ago with faderlube. I have no wiggled, I am kind of worried here.... Is there a chance I could destroy my ears here? I never put the preamp volume set to > like 8 or 9. Thanks.

[Oerets]

mantis ,
Try bypassing the jack all together and connect the headphones up and see if you hear any change .

[signal-dude]

mantis said;
"I get a good bit of noise from my 2270 headphone jack... when something is playing or not, just whenever the headphones are plugged in the noise floor is quite high. I don't get the noise from speakers or preamp out on back. Please advise."

Unfortunately this is normal for a 2270. All of mine do (did) the same thing but I have a good fix for the dreaded hiss.

If you look at the schematics you will find that there are two 100 ohm sand resistors on the speaker PC board thats behind the front panel. Also find two 47 ohm resistors that are on the actual headphone jack.

Remove the 100 ohm sand resistor from the pc board and replace it with a 221 ohm metal film, 1/4 or 1/2 watt if you prefer and this will knock down the noise a lot.

To further reduce the noise to lower levels find the ground wire thats tied to the two 47 ohm resistors and add a 20 ohm metal film resistor in series with the ground for the headphones.

On my Grado SR-80 phones or my Koss PRO-4AA phones I now hear very little hiss. And it doesn't seem to affect the dynamics of either set of cans.

Basically you are just building a bigger attenuator for the cans.Do not hook up the headphones to the raw speaker output though. It'll sound like crap and is dangerous for the headphones.

[signal-dude]

signal-dude said;

"Remove the 100 ohm sand resistor from the pc board and replace it with a 221 ohm metal film, 1/4 or 1/2 watt if you prefer and this will knock down the noise a lot."

"To further reduce the noise to lower levels find the ground wire thats tied to the two 47 ohm resistors and add a 20 ohm metal film resistor in series with the ground for the headphones."

Thinking about this further why not just put in a 240 ohm resistor and forget about the 40 ohm in series with the ground wire?

I didn't do this but should work.