Is my amp dying???

KellyMic

So my basic setup: PC with X-Fi soundcard (I know, but ordering a DAC soon) -> Onkyo Receiver (tape out) -> Mixing board -> dbx Driverack PA -> Crown CE2000 for mids / highs to Polk LSi25's & Crown CE1000 (bridged) for low end to JBL sub.

I use my PC as the main volume control so when down low it isn't a real strong signal but lately the left speaker volume will be very low. For awhile if I went to the PC left/right balance if I quickly turn the left channel to 100% and pull it back down really fast it would come back. That doesn't work now but if I set the left volume to like 75% then after about 5 minutes the left channel gradually fades up to the level it should be. It seems to be getting worse over the past few days.

My short term goal is to get a DAC with volume control and retire to Onkyo & mixer and run the DAC straight to the dbx Driverack (which I use to separate my low/mid/high) via balanced connection to the Crown amps.

Long term is to replace the Crown (to the LSI25's) with a decent 100 watt tube amp.

But if my amp is dying then I'll have to wait a bit longer on the DAC.

The left channel had died out twice now just typing this email, turning it up for a minute or so and it work for bit but then fades back down.

Thank you,

ambiophonics

I would guess that your amp's protection relay is acting up, sometimes they can be removed and you can burnish the contacts, other units use sealed relays which would need to be replaced.

Often times the internal connections on these relays get oxidized, burnt, or just dirty and will cause the symptoms you've described. Many times increasing the volume, or quickly turning the volume up/down bridges the dirty connection and allows normal operation for a bit.

If the relay checks out fine there could be an oxidized connection somewhere else, or a cold solder joint, or a ton of other more serious issues. You have a bit of a confusing setup so I could be way off base here.

KellyMic

I did a little fiddling earlier with my sound card settings and seems to be working. I increased one of the volume settings for higher level output and it has been fine since I posted the thread on my lunch break.

Fingers crossed!

falconcry72

Dude, I'm glad you found a temporary fix, but you really gotta tone back the rig. Simple is better. Especially with LSi's. You got too much unnecessary **** in the rig! A first step would be to 86 the mixing board and the dbx... then go from there.

Cheers,

Ben

KellyMic

That is my plan. The driverack is XLR and the mixer is my only other box with XLR out, and my amps are XLR too. I'm powering a sub too and the driverack lets me have three outputs. I have every feature on the driverack turned off except the crossover. I am getting a DAC soon as I can with balanced XLR outputs. Then I can cut out a lot. If cost was no object I never would have set it up this way. As money allows I will be getting a tube amp too. Then I'll only have DAC -> Amp -> speakers.

I got the speakers and couldn't wait till I got the DAC and amp to hear them! Honestly, it sounds pretty damn good so I can't wait till I get it as I want.