Yamaha B-2 crackling noise.

Margus.S

Member
Hello!

I am newbie there and I have little problem of my Yamaha B-2.
When I turn it off,then one second I hear crackling noise of my speakers.I have allready changed all Bi-polar capacitors,FET-s power big electrolytic capacitors and all electrolytic capacitors in power pcb plate.Relays are too replaced.Power switch working fine.
I have no more ideas.Please help.
 
Most likely the switches and pots on the front. Check whether the crackling changes when you operate the switches and pots.

Those switches love to be fully dismantled, cleaned and preserved. The pots like some deoxit flushing.

Even better: wire the input signal straight to the driver boards to bypass the pots and input switch. But, then you only have 1 input (not a big deal). There are a few threads where this is discussed and performed with good results:

http://audiokarma.org/forums/index.php?threads/yamaha-b2-input-switch-attenuator-bypass.754945/

http://audiokarma.org/forums/index.php?threads/yamaha-b-2-restoration-journey.742789/
 
I have allready bypassed all input signals,these go right from rca-sockets to driver plate.


Most likely the switches and pots on the front. Check whether the crackling changes when you operate the switches and pots.

Those switches love to be fully dismantled, cleaned and preserved. The pots like some deoxit flushing.

Even better: wire the input signal straight to the driver boards to bypass the pots and input switch. But, then you only have 1 input (not a big deal). There are a few threads where this is discussed and performed with good results:

http://audiokarma.org/forums/index.php?threads/yamaha-b2-input-switch-attenuator-bypass.754945/

http://audiokarma.org/forums/index.php?threads/yamaha-b-2-restoration-journey.742789/
 
If the crackling only happens after powering off, as the PS likely discharges, it would have nothing to do with any pots. It could be an issue in the protection/relay circuitry. Has it done this ever since you completed your work on the amp, or did it start more recently than that?
 
I bought this amplifier last summer and this time allready was that problem.If I turn it on and after 2-5 seconds I turn it off,then the crackling noise(impulse) is very small or not,but if the amplifier works about 10 seconds,then allready have the crackling noise.
If the crackling only happens after powering off, as the PS likely discharges, it would have nothing to do with any pots. It could be an issue in the protection/relay circuitry. Has it done this ever since you completed your work on the amp, or did it start more recently than that?
 
You have a protect relay not " resetting" at power off. Possible welded contacts? Trouble shoot your protect circuit.
 
Last edited:
Both channels.
Something is holding the relay closed "set" at power down. The relay should immediately " reset" when you flip the power switch off.This separates the amplifier output from the speakers. The "crackling" , through the speakers, is your power supply decaying at power down. This decay is and normal condition of a power supply powering down. Bleeding off the stored energy in the various power supply capacitors.If the protect relay circuit was working properly you would not hear anything from the speakers.
 
Last edited:
Hello!

I am newbie there and I have little problem of my Yamaha B-2.
When I turn it off,then one second I hear crackling noise of my speakers.I have allready changed all Bi-polar capacitors,FET-s power big electrolytic capacitors and all electrolytic capacitors in power pcb plate.Relays are too replaced.Power switch working fine.
I have no more ideas.Please help.
Was this phenomena happening before your swapped out any parts ?
 
Did you replace or have you tested (out of circuit) TR217 and TR218?
TR217.png

I'd check/replace C223 at the same time if you haven't already.
 
When I turn it off,then one second I hear crackling noise of my speakers.
Have you tried connecting your speakers to the B speaker terminals to see if it does it there too? That should tell you if it's the relay or the relay holding circuit that's the problem since in most cases that relay is less used.
 
Last edited:
Back
Top Bottom