Dynaudio BM6A Distortion Fix

How I found a solution to the Dynaudio BM6A distortion problem
Please share, so others can benefit from this also. Thank you.

[@allanvandullemen121]

This fixed my speaker also. Had BC546 and BC556 transistors in my speaker in the driver stage.

[@pixelcomet]

nice!

[@BlueHouseSoundStudio]

Thank you for this video. I have a pair that will crackle and lose sound intermittently. It takes them about 30 min to "warm up" and then its usually never a problem after that. (mainly only one of them) It reminds me of when you have a dirty pot or something and audio is getting stuck somewhere... Do you think this is a relay issue? Thank you

[@pixelcomet]

Yeah similar to a dirty pot, but caused by transistors. Really weird. Mine are running since. Never had a relais problem.

[@RayMaxer]

Hello! How do you get the board disconnected from the radiator? in the part where the transistors are glued up to radiator plate? It's pity you didn't take any photo/video during the proccess

[@pixelcomet]

Sorry, I decided to make the video after the process. I had no problems to disassemble it. The glue should be just heat-conducting paste. Remove the screws and you'll see.

[@RayMaxer]

@@pixelcomet yeah, here, in my case, it was more of a double-sided sticky tape on them, and the paste only on 2 weird cables just pushing against the holes in that radiator plate. Solved that, but now got a prob. dealing with relay legs unsoldering:) very beginner in soldering skills. Thanks!

[@pixelcomet]

@@RayMaxer That sticky tape is a heat conducting matte. They are important and must be put back later. The weird cables with their head in white goo, are temp. sensors against overheating. they must be put back in place also, later. Your relay is toast? The best is, to get an desoldering pump for that. Put flux on the soldering spots, melt them and suck it clean with a pump.

[@RayMaxer]

@@pixelcomet Thank you! I am thinking that maybe relay is at fault, I read several times, owners of BM's had similar problems because of it. My speaker has started distorting (not too heavily) at any level, most of power-ons, but, sometimes, when I kinda jerk the power button on and off rather faster (like 1-2 sec period), the speaker makes a louder thump (relay, I suppose), and it starts playing normal for some time. Decided to try switching a relay. Sorry for my english.

[@pixelcomet]

@@RayMaxer Your english is fine. Yeah sounds like rusty relay contacts. So get a syringe of flux and a de-soldering pump then and proceed as planned. That should work out fine, I guess.

[@OliH-tz9xe]

Hi, Was this a low frequency issue or in the high Frequency range. I'm having some strange low frequency distortion, below about 90Hz, I think the driver is ok. So I think its a fault with the amplifier module

[@pixelcomet]

Hi, I have had crackling like a broken speaker coil. since it was the driving stage, the freq should also reach down to the subs. Hard to say, since I can't hear your sound. I'd suggest: throw them out, no big deal and see, if it helps.

[@jonahwaltonmusic]

Is this the new “classic” BM6A?

[@pixelcomet]

the first one from the past