Beomaster 4000 - wicked pop when turning on

3 replies
I have a Beomaster 4000 that I recapped about 3 years ago and put it away in a box.  I got it out recently and hooked it up to a pair of speakers to try it out and noticed I got a pretty serious pop when I turn it on. Turn the volume all the way down - Still get the pop.  Turn off the toggle switch to the speakers, no pop until you engage the speakers that are connected and then... POP!!! I assume this loud fweep is caused by the capacitor pulling current through the speaker when I complete the circuit as a quick on-off-on cycle does not have a pop the second power up when the capacitor is charged.  It is loud enough that I am worried about damaging my old Klipsch Heresys. The question is why is my old Beomaster doing this?  Why don't they all do it?  Once it is through the big pop, it seems to operate normally and sounds good.  Newer receivers have a mute circuit to avoid all this, but these old units somehow managed to get by without. Any suggestions?
My repair guy has called me with the same problem. The loud POP when first turned on. I have 2 Beomaster 4000 amps. When I got the 1st one going it did the pop thing. After running it for a while ( days ) It seems to have gone away. ( Just a small click sound on power up. ) On to the next one. It does the same thing after capacitor replacement( audio caps only ) . Have not tried to run it for an extended time. My repair guy had me order the complete set of tune up parts and capacitor kits from Beoparts. We will see if we get the same problem after a complete work over. I'll keep you posted as to what we find. They both sound fantastic, but he said, pick one and it will sound even better after the overhaul. Graydon

Location: Salt Lake City Utah

Try letting it warm up with the speaker switch off for five minutes or more. Even after the most thorough of adjustments I’ve always had a pop when starting these cold. New capacitors and work are only going to make this receivers more delightful.  
or
BeoWorld Gold Membership card
Join BeoWorld

Register to access the forums, reference material, and exclusive member benefits — including our monthly prize draw.

Become a Member

December 2026 Prize Draw

Gold Members Only

As a Gold member you're automatically entered into our exclusive prize draw — your chance to win iconic Bang & Olufsen products. A unique benefit of BeoWorld Gold membership, every draw brings a new opportunity to win something special.

BeoSound Level

1st Prize

BeoConnect Core

2nd Prize

BeoRemote Halo

3rd Prize