To absorb amp discharge

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Bob in WI

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I'm no tech which is why I'm appealing to the cognoscenti here for guidance. I picked up a PS Audio amp that seems to work fine but it discharges on shutdown & I'm concerned about the long term effect on my speakers, esp the tweeters as the discharge can be crackles. So the seller gave me 4 resistors & said I can use these to absorb the sound. I have a speaker selector switch & I'm going to connect the resistors - (2) Dale DCS 1/2, 1 0 mu 1 %, 7028 & (2) marked the same except 7026. So if I put a 7026 & a 7028 on left & 1 of each on the right, will that absorb the discharge from a 200 wpc amp? Sorry to be long winded but I don't want to make a potential problem an actual problem. Additionally, is it normal for an amp to discharge on shutdown? I haven't noticed it ever before on any of my equipment. TIA
 
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Something ain't right. I'm not familiar with that piece, but someone will come along and help you out.
 
The "discharges" are normal, but it should be a circuit inside the unit to take care of that. Sometimes is just a resistor that shunt the Filter capacitors to ground when you turn of the unit.

But some circuit is not doing it's job. You need to go deeper...
 
Bob in WI said:
I'm no tech which is why I'm appealing to the cognoscenti here for guidance. I picked up a PS Audio amp that seems to work fine but it discharges on shutdown & I'm concerned about the long term effect on my speakers, esp the tweeters as the discharge can be crackles. So the seller gave me 4 resistors & said I can use these to absorb the sound. I have a speaker selector switch & I'm going to connect the resistors - (2) Dale DCS 1/2, 1 0 mu 1 %, 7028 & (2) marked the same except 7026. So if I put a 7026 & a 7028 on left & 1 of each on the right, will that absorb the discharge from a 200 wpc amp? Sorry to be long winded but I don't want to make a potential problem an actual problem. Additionally, is it normal for an amp to discharge on shutdown? I haven't noticed it ever before on any of my equipment. TIA
Click to expand...

Its only most noticable with a amplifier that has no protect relay. A protect relay disconnects your amplifiers from the speakers at power down and you won't hear any filter cap discharge.
 
Bob in WI said:
I'm no tech which is why I'm appealing to the cognoscenti here for guidance. I picked up a PS Audio amp that seems to work fine but it discharges on shutdown & I'm concerned about the long term effect on my speakers, esp the tweeters as the discharge can be crackles. So the seller gave me 4 resistors & said I can use these to absorb the sound. I have a speaker selector switch & I'm going to connect the resistors - (2) Dale DCS 1/2, 1 0 mu 1 %, 7028 & (2) marked the same except 7026. So if I put a 7026 & a 7028 on left & 1 of each on the right, will that absorb the discharge from a 200 wpc amp? Sorry to be long winded but I don't want to make a potential problem an actual problem. Additionally, is it normal for an amp to discharge on shutdown? I haven't noticed it ever before on any of my equipment. TIA
Click to expand...

If you going to use a speaker select switch. Resistors won't be required. Just disconnect the speakers with the switch before you power down the amplifier.
What your actually discharging are the big filter caps on the B+/B- rails. The caps will eventually safely discharge without the added resistors through the circuit.
 
Thanks. So for the time being, I can protect the speakers by simply taking them off line on shut down. But the real issue is to find out if the amp has a protect relay & if it does, I need to get it working properly.
 
Disconnecting the speakers will protect them.

My amp doesn't have protection relays, neither some other old units I've seen, and even in this simple units, there are circuits, shunt resistors, or slow power-off circuits that protect the speakers or disconnect something at power off, or other smart solutions so you don't need to disconnect the speakers, just turning the volume down is enough.

I've never had a 200WPC amp in my hands, but I'm sure your PS Audio amp (as I've seen on the web, they are nice quality units !!!) has something like this too, and almost sure it's not working properly.
 
Bob in WI said:
Thanks. So for the time being, I can protect the speakers by simply taking them off line on shut down. But the real issue is to find out if the amp has a protect relay & if it does, I need to get it working properly.
Click to expand...

Do you hear any " clicks " shortly after flipping the power switch ? If yes - it has a relay. If no and you are getting sound to the speakers- then no it doesn't.
Either that or you have a very ,very quiet relay.
 
Yes, you are right. I was refering to the units I've seen, with protection circuit inside. You just turn the volume down and power off the unit.
 
"Do you hear any " clicks " shortly after flipping the power switch ? "

There is a sizable"switch" (relay?) inside the unit that makes a serious click on power up. Don't know what it does but it is a substantial piece of hardware. I deoxit when I got the unit (the unit was filthy inside, disgusting filthy) but I don't know what it does. I was in a cleaning frenzy......
 
It could be a relay to power-on the power supply, or the speakers relay. You could check that with a schematic or posting here a pict.
 
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