Phoenix Gold Phorum

I've had this amp for a few years now, it's served me very well and it's run everything I've thrown at it to insane numbers.

My current setup is the X600.1 with the 528T mod pushing a DD3515 @ 2ohm. It's tipped the meter 151.9db on the TermLab in 3.5cf tuned at 63hz in a 2008 Suzuki Reno.

Now the problem. Recently it started making two noises, though they didn't start at the same time. The sound that started first is like a whine, but it comes from the amp, not the speakers. I think I narrowed it down to one of the vertical boards, the one next to the main coil with the little grey round things. What's that noise?! How can I fix it? I'm good at soldering, and no stranger to electronics, but wtf is that noise?!

The second noise, it's like something is tapping a ground. When driving, the sub pops like a ground is tapping and shorting. All my power and signal cables/wires are fine. When I tap the case of the amp, it pops, like something is grounding. I took the cover off thinking it was shorting to the inputs. Same thing. I double checked all the mounting screws, all tight. I tap the board anywhere and it does the same thing. I can even disconnect the signal input and it continues. Any ideas, guys?

Thank you in advance!
Lee

-EDIT-
Just to clarify, the Xenon isn't used for SPL competing, I strap two M1a's for that and get 155.x db @ ~2800wrms. I just drive it like I stole it and was curious one day to what it did, 151.9db. Sadly, I didn't clamp it to see output power. I'm really disappointed that I didn't, but didn't have a clamp handy either, thinking about it more.

I de-soldered and re-soldered every single point that I could find on all the boards. I used silver solder.

The whine is still there, and it still sounds like it comes from the same area. It comes and goes, though, always has. Its noise hasn't changed a bit.

The weird thump, like a tapping ground, is gone. I don't know where it was happening but it's gone.

Any idea on the whine?? It's not coming from the speakers, not from the sub, it doesn't appear to have any effect by disconneting the inputs. I'm stumped.

Thanks again!

It does appear to sound a lot cleaner since I just put it back in the car! A little more solid and defined. At the moment, it's running un-modded @ 2ohm.

I got a x400.1 from a guy on here that had the same exact whine.

I never did figure out what the problem was, & the amp seemed to work just fine. Sold it to a guy with a very loud car, cant be heard anymore. lol

To cure the whine first confirm the following-

with the cover off, powered on, nothing else connected. Do you hear the whine, if so take an insulated device anything non-conductive, such as a wooden chopstick or an eraser, nothing metal, now apply pressure to the big coil on the board, try to get to the donut that the wire is wrapped around to apply pressure. The amount of pressure required is minimal, weight of your hand should be enough.

If the whine changes under pressure then, disconnect all power and reseal the donut to the wire wrapped around it. This can be done with a clear epoxy spray, lacquer, or even some silicone, silicone can cause heat retention so would be a last option but is the easiest to procure and the most accurate to apply.

What you are hearing in this case is the donut vibrating within it's wire confines under load and the factory bond has broken loose due to vibration from the road or otherwise. If the whine is not corrected it can cause the coil to short leading to all sorts of induction changes or voltage spikes where they do not belong.

With cover off, power on and nothing else connected, YES the whine is present.

I did try pushing on the coil with my fingers, but I was merely pushing on the wire, not the donut inside; it didn't change anything, there was still the whine. Tomorrow I will try what you've described. I didn't think about it, but you make perfect sense.

Thanks!

I've been trying, but it's not whining today. =/

do not use your fingers, that is just asking for trouble. The voltage going through there can cause a nasty bite.

you say it is not doing it now, is the amp warmer today than it was yesterday when you did hear the whine? metal shrinks when cold and expands when warm. So the donut may be held better today if it has been sitting inside all night and is warmer.

It's been doing it for a while, not just the past few days.

I've gotten quite a few good bites, lol. 250v household circuit enough? hahaha

It was warmer today than yesterday. It's never shown a preference to air temperature, but it does usually ween off after the amp warms up. Still no noise at all today, though. I'll go driving more in a lil bit and see if it whines at all.

Still no noise. Wtf? I didn't touch it since I re-soldered the board. After which I installed it and it still whined. Now nothing. I hate electronics.

Gonna upgrade my sub to a 9500 or Z95 motor and a dual 2ohm VC and get me an M3a. I may run this in my van powering another DD3515 for SQ.