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2230 Pop with speakers

DrMux

DrMux

Welcome to the Gig.
I noticed when connecting speaker wires with the system off the speakers pop a little. I also noticed a small arc on the speaker terminals when connecting them. I've had this happen every time I connect speakers to this receiver. Could there be a problems with some caps somewhere not discharging? Or is this normal for older receivers?

I tried Pinnacle and JBL speakers, same issue.
 
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The 2230 has cap-coupled outputs. If you run the receiver with no speakers connected, a pair of 2200uF 63V caps will be charged up with no path to discharge. When you connect up speakers it provides such a discharge path, hence your spark.

If you're worried about it you could add a high-value resistor to ground from the positive speaker terminals to bleed off the voltage when you power down.
 
"Normal" I have the same issue with this reciever on two different 2230's. Both have the pop sound and arc.
 
dspear99ca said:
The 2230 has cap-coupled outputs. If you run the receiver with no speakers connected, a pair of 2200uF 63V caps will be charged up with no path to discharge. When you connect up speakers it provides such a discharge path, hence your spark.

If you're worried about it you could add a high-value resistor to ground from the positive speaker terminals to bleed off the voltage when you power down.
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I replaced the power switch in my 2230 with the one recommended in several AK threads. I soldered the original capacitor across the same terminals as the original. Now I get speaker pop when I power on and off about 80-85% of the time. How exactly does one wire a resistor from + speaker terminal to ground? What would I use as ground and how high resistance would I need please? Sometimes it's more on the right speaker, sometimes the left, sometimes both and the pop varies in loudness from a loud CArack to a soft static.
 
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Connect a pair of headphones permanently to the receiver. Put the speaker switch to OFF before powering the receiver, and wait about 30 seconds before switching ON the speaker after powering the receiver. The pop noise should be much reduced with this procedure.
 
ecluser said:
Connect a pair of headphones permanently to the receiver. Put the speaker switch to OFF before powering the receiver, and wait about 30 seconds before switching ON the speaker after powering the receiver. The pop noise should be much reduced with this procedure.
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I followed that procedure except instead of attaching headphones I just put a 1/4" adapter plug in the headphone jack without the headphones and wait about 15 seconds. It eliminated the pop every time although I have no idea why. Switching the speaker button to off and waiting eliminated the pop some but not every time.
 
I found that powering up with the speakers switched on had a thump rather than a pop, which was much more tolerable. Also, never have this receiver on while you are connecting speakers to it.
 
I never have any receiver/ amp on when I'm connecting speakers. Too much risk of shorting the unit by touching the two speaker wires. For my particular 2230 there is something else causing the pop other than the power switch because very occasionally I will hear the pop while the receiver is playing and nothing is being touched. I'm suspecting one of the main filter caps but I'm not sure. On the other hand this is a non original but as close as you can get replacement power switch I installed. But I fail to see how that could cause a spontaneous pop about once an hour.
 
archie2 said:
I followed that procedure except instead of attaching headphones I just put a 1/4" adapter plug in the headphone jack without the headphones and wait about 15 seconds. It eliminated the pop every time although I have no idea why. Switching the speaker button to off and waiting eliminated the pop some but not every time.
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You are correct. In this receiver you don't need to have the headphones connected, a simple headphone jack is sufficient. To understand why it works, you need to look at the schematic. The output of the amplifier is cap coupled by a 2200uF, 63V capacitor. When no speaker is connected to the output, and no headphone jack is inserted in the headphone output, the cap has no way to charge. Inserting a bare phone jack in the phone output has the effect of connecting resistors R013 to R016 at the output side of the output capacitors, and the capacitors can charge through 150 Ohms resistors (100 + 47 to be exact). However, this takes some time to charge since the time constant of this RC circuit is 0.33 second. If you wait 15 seconds or so, the residual voltage at the output side of the output capacitor should be sufficiently low to connect the speakers and the noise (thumb or pop, I don't mind) will be very low.

In most amplifiers, there is no resistor in parallel with the phones, like the 47 Ohms resistors you have in the 2230. For such cap coupled amplifers, you need the headphones.
 
ecluser said:
You are correct. In this receiver you don't need to have the headphones connected, a simple headphone jack is sufficient. To understand why it works, you need to look at the schematic. The output of the amplifier is cap coupled by a 2200uF, 63V capacitor. When no speaker is connected to the output, and no headphone jack is inserted in the headphone output, the cap has no way to charge. Inserting a bare phone jack in the phone output has the effect of connecting resistors R013 to R016 at the output side of the output capacitors, and the capacitors can charge through 150 Ohms resistors (100 + 47 to be exact). However, this takes some time to charge since the time constant of this RC circuit is 0.33 second. If you wait 15 seconds or so, the residual voltage at the output side of the output capacitor should be sufficiently low to connect the speakers and the noise (thumb or pop, I don't mind) will be very low.

In most amplifiers, there is no resistor in parallel with the phones, like the 47 Ohms resistors you have in the 2230. For such cap coupled amplifers, you need the headphones.
Click to expand...

Thanks for that explanation. If I remember the 2230 has a single 4700uF and two 2200uF caps. I don't have a service manual for the 2230.
 
archie2 said:
Thank you. Turns out I had my 2230's confused. It is a 2230B service manual I don't have and can't find on HiFi Search Engine. Probably could use the one for the 2220B as they are pretty much alike.
Click to expand...

I have a copy, PM me your email address.
 
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