Hum going up and down with volume along with "reverb" effect[solved]

[r1c0rtez]

With a completed crack build and a semi successful one at that as all the voltage and resistance readings were within spec, i am getting some hum whenever i touch my RCA inputs either with my fingers or inserting a 3.5mm to RCA cable with the source being an ipod classic. I do hear music but the hum is louder than the music playing

I am using HD650's and have tried to recheck all my solder joints, i tried to carry over my habits from work(cnc electronic board assembly) and make sure my wires made full contact with the metal they were to be soldered to. So i tried to hook them whenever possible and if not, made sure they were slanted through the hole and made at least 1 point of contact, sometimes 2. I did recheck almost all my solder joints, mostly ones that were questionable when i had leads coming in from both sides and i went down the ground chain in the manual and FAQ and touched up all my solder joints. Used a lot of the search feature but with so many pages i haven't found my answer...or spending too much time to view the obvious.

Any suggestions?

edit:new problem that i didnt have before i rechecked my joints, im getting a reverb effect with the music echoing over itself and the hum is still there.

 

[Paul Birkeland]

If touching the RCA jacks influences the hum, you will want to carefully inspect the grounding inside the amplifier.  The most important would be the bare wire connecting the "E" terminal on the IEC jack, the #8 lug, and the grounding terminal on the adjacent 6 lug strip. 

If all this is well connected, check the resistance between the #8 screw and terminal 3. 

Did you, by chance, paint the bottom of the chassis plate? 

I feel pretty confident that there's a loose black wire in your amp, it just may take you a little time to find it.

-PB

 

[r1c0rtez]

Thanks for the reply, it turns out I had almost all problems related to outside sources. I have dimmer switches for our bulbs in our house near my testing of the amp ,so I shorted the rcas...dead silent 

I went to a friends house to glue and stain the base. I went through all the resistance and voltage checks with him because he went to trade school to be an electrician while I'm currently in school to study electronics then transfer for EE so we both have interest in testing circuits,everything still within range

Plug in the amp to his garage outlet where he has a single bulb overhead..no dimmers...plugged in the amp to rca cable to his iPhone..no hum!! but still only background vocals and no forefront.

It dawned on me that the rca must not be making full contact somehow ,so I pinch both outside rca jackets and in doing so find that my red rca was the problematic area.

The outside sleeve did not make full contact to pass through an audio signal correctly. I didn't think this was a problem as this rca cable is used from my tv to a cheap Sharp Micro bookshelf system amp I got for Christmas years ago and it works fine. Now I'll have to wait for my base and a new rca cable