B&K AV5000 Pops when turned off and on

bcline

I just hooked up a used B&K AV5000 series ii 5 channel amp to my surrounds and center channel using my Onkyo TX-SR806 receiver as a preamp. I'm running a Parasound 2250v.2 amp on my SDA-2A mains. The Parasound has been perfect. No pops nothing. But the B&K makes a loud pop on all five speakers when I switch it on and also when switched off. Once on, the amp sounds really good, but I do notice a very faint buzz only on the center channel speaker... nothing on the four surrounds.

So, do I have a problem with the amp and can it be fixed? I know B&K is out of business and I picked up the amp on the cheap. It does not matter the order I turn on preamp and amps. No matter what, I get a pop both when turned on or off.

bcline

Well I guess nobody knows... I have isolated the problem a little more. It appears that the 5th channel which runs my center channel is the only one popping and humming. The other 4 channels are quiet and clean. The center does work otherwise but has an annoying hum always... even if preamp is off. Tried changing cables... ran the center off one of the other channels, etc. Definitely is channel 5 of the amp causing all the problems. Are these amps beyond any repair since B&K is now out of business?

Dennis Gardner

Sounds like it needs a recap job. The pops and the center channel hum are the capacitors charging and discharging on power up/down. B&K is a brand that any decent electronics repair shop should be able to service. You might call A Plus electronics in Park City since they were B&K dealers local to you.

Zentish

you could put the center back on the 806 until you figure it out.

bcline

Dennis Gardner wrote: »

Sounds like it needs a recap job. The pops and the center channel hum are the capacitors charging and discharging on power up/down. B&K is a brand that any decent electronics repair shop should be able to service. You might call A Plus electronics in Park City since they were B&K dealers local to you.

Actually, the owner at A Plus is a good friend. I helped install car stereos for him 30 some years ago. He said B&K is out of business and ATI is not really doing anything to help support them so far. So, I would have to find an independent repair shop that could do it.

bcline

Zentish wrote: »

you could put the center back on the 806 until you figure it out.

Yeah, that is what I have done for the moment. I might instead put the side or rear surrounds back on the Onkyo for now as the center really sounds much better off the B&K and since the majority of sound is through that channel...

Zentish

bcline wrote: »

Yeah, that is what I have done for the moment. I might instead put the side or rear surrounds back on the Onkyo for now as the center really sounds much better off the B&K and since the majority of sound is through that channel...

Makes total sense. Might I suggest you write down whatever it is you end up doing - I keep a notebook near my AVR with all the input and interconnect mappings so when I come back to work on it 6 month later I'm not faced with having to re-map all the cables every time (faulty memory). There are lot of darn cables back there...