AMP TECHS: EV SXA100 noise problem

[LP2006]

Hope someone sees this who can help me. Long story short, I recently picked up a pair of EV SXA100's on ebay, but they are making a TON of white noise. Listening closer there is also a bit of 60hz ground hum. Since shipping would be extremely expensive to return them, What are my options for repair?

Could they just need new caps? Or am I looking at a total power amp makeover( They are biamped). They still sound O.K. with music through them, but there is also a ton of white noise. For example, my beat to hell JBL eon 15P makes about 10 times less white noise.

Oh, one more thing, I noticed the amount of white noise comming through the speakers is NOT related to where the output trim is set. In other words, they are just as noisy at 1 as they are at 10.

Any suggesyions?

 

[dementedchord]

i've worked on lottsa stuf but never these things so i'll be of limited help... but... the 60hz could likely be eliminated with supply filters... but that doesn't account for the hiss... if i undestand you correctly they both do it right??? see that points to something more systemic/design issue... if it was just an opamp for instance the likelyhood that they would both blow the same is low... get me??? you could try adding some supply decoupling caps around opamps.... typicly .1microfarad between the supply rails or from the rails to ground... gotta feeling though if you want it really working it'll need to see the doc...

 

[LP2006]

Thanks for the reply, good to be pointed in the right direction.

Well, the 60hz actually isn't all that bad. It is only noticeable If I'm right up next to the speaker. I'm gonna email EV and see if this model has a high noise floor on the amps. Man, its hard for me to believe they would put out something this bad though.

On a positive note, I ran some music through the speakers today and it sounded pretty good (except of course for the constant hiss).