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Issue with two power amps on one preamp output

M

MartinP

New Member
I have a BrAun A2 integrated amplifier with disconnectable pre- and poweramps. The 'pre out' of the BrAun is connected to the 'line in' of a Sonance power amp and the 'line out' of the latter is connected to the power amp of the BrAun. That way I can use both power amps simultaneously. I always switch of the Sonance first. When switching of the BrAun A2 I hear a pretty loud cracking noise in the loudspeakers connected to it. The strange thing is that when the BrAun pre amp is only connected to its own power amp, this noise doesn't occur. I cannot explain this. Does anybody have an idea what causes it? Thanks.
 
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You could always try using a Y-cable from the pre-outs and then that goes into both amps at the same time. Seems like that would be an easier and more direct way of hooking it up so that you could use both amps at once.
 
probably something in the input circuit of the second amplifier discharging and making funny noises. Wild guess, there is a buffer stage between the input on the Sonance and the Line Out, and that circuit powering down is what you're actually hearing. If thats what it is, the Y cable ought to sort that, assuming the amps in parallel don't end up being too much load for the preamp section of the Braun to actually deal with.


Does it change behavior if you turn them off in a different order?
 
Keep it simple. start with this.
If you want to run two power amps off of one preamp, get a pair of these and be done with it.

61xIVubtJSL._SL1500_.jpg


https://www.amazon.com/Speaker-Splitter-Conductor-Shielding-Flexible/dp/B0916WWN9Z/ref=sr_1_6?crid=253SM4FZOGS0W&keywords=male+female+female+RCA+connectors&qid=1642522127&s=electronics&sprefix=male+female+female+rca+connectors,electronics,105&sr=1-6
 
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gadget73 said:
probably something in the input circuit of the second amplifier discharging and making funny noises. Wild guess, there is a buffer stage between the input on the Sonance and the Line Out, and that circuit powering down is what you're actually hearing. If thats what it is, the Y cable ought to sort that, assuming the amps in parallel don't end up being too much load for the preamp section of the Braun to actually deal with.


Does it change behavior if you turn them off in a different order?
Click to expand...
gadget73 said:
probably something in the input circuit of the second amplifier discharging and making funny noises. Wild guess, there is a buffer stage between the input on the Sonance and the Line Out, and that circuit powering down is what you're actually hearing. If thats what it is, the Y cable ought to sort that, assuming the amps in parallel don't end up being too much load for the preamp section of the Braun to actually deal with.


Does it change behavior if you turn them off in a different order?
Click to expand...
If I first turn of the BrAun, I hear a cracking noise in the loudspeakers connected to the Sonance power amp. There are no noises when the BrAun pre amp is only connected to its own power amp using the pre-out/power in bridges.
 
Classic advice is to turn power amps on last, and off first, to prevent such issues. I don't mean to suggest ignoring an actual problem, but it's the safest way to sequence powering a system up and down. Many equipment designs have turn on/off sonic artifacts. Some get worse with age. The idea is to avoid unpleasant surprises.
 
When doing the pre out / main in loopback and split to another amp I find this style of Y cable works well.

The two male plugs go to pre out / main in. The female jack is where you connect the cable to the external amp.

41gqQjE24YL._AC_SY1000_.jpg
 
sqlsavior said:
Classic advice is to turn power amps on last, and off first, to prevent such issues. I don't mean to suggest ignoring an actual problem, but it's the safest way to sequence powering a system up and down. Many equipment designs have turn on/off sonic artifacts. Some get worse with age. The idea is to avoid unpleasant surprises.
Click to expand...
That's what I do. I first turn on the integrated BrAun Amp and then the Sonance power amp. When switching off the equipment I do it the other way around. When switching off the BrAun I hear the already mentioned cracking noise in the speakers connected to it.
 
Connecting all the units, including the power amps to a power center that switches in sequence on/off. This way will make it as simple as one switch controlling the operation in a matter that is best. Amps are delayed at startup, amps first, sources delayed at shut down. Plus offer some filtering of AC line voltage.

799524-a672e9b9-monster-power-hts-3600-mk-ii-power-center.jpg
 
Oerets said:
Connecting all the units, including the power amps to a power center that switches in sequence on/off. This way will make it as simple as one switch controlling the operation in a matter that is best. Amps are delayed at startup, amps first, sources delayed at shut down. Plus offer some filtering of AC line voltage.

View attachment 2457156
Click to expand...
Thanks but I do not think automating the start-up and shut-down cycles will solve the issue of the cracking noise. Nevertheless this is an interesting idea.
 
Oerets said:
Connecting all the units, including the power amps to a power center that switches in sequence on/off. This way will make it as simple as one switch controlling the operation in a matter that is best. Amps are delayed at startup, amps first, sources delayed at shut down. Plus offer some filtering of AC line voltage.

View attachment 2457156
Click to expand...
safest way. i think russound and partsexpress have similar.
 
MartinP said:
Thanks but I do not think automating the start-up and shut-down cycles will solve the issue of the cracking noise. Nevertheless this is an interesting idea.
Click to expand...
Seems like many posters are immune to reading/understanding your situation.

I agree with W99 and others about using "Y" cables. It appears that using the throughput on the Sonance is likely creating your issue.
 
RVT1K said:
The only thing I can think of is a possible difference in input impedance (especially since you are "daisy-chaining) but I don't know if that would cause what you hear.

I would agree with trying Y-cables or a pair of these : https://www.parts-express.com/Gold-RCA-Y-1-Male-To-2-Right-Angle-Female-Red-091-510

I have two amps hooked to the same pre-amp and I'm using those.
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yeah. im running two amps using y-splitters.
works real well.
though mine are mediabridge and substantially well-built.
yes, i misunderstood the original question.
but the answer is still y-splitters. and there is something with the sonance.
maybe to do with daisy-chaining. never been successful trying even though my amps should do it.
didnt get a crackling sound but something was way off. the y-splitters stopped whatever it was.
 
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