|   Slight Adcom Amp problem | jgfoley3
Jul 11, 2001 11:18 AM | | Hello. About 20 or 30 seconds after I shut of my GFA-555, my right speaker emits a sort of high frequency static sound that lasts about .5 - 1.0 seconds and seems to increase in pitch - it's kind of like a "boip". Othe than this the amp is great. Any ideas?
Thanks very much.
John. |
| re: Slight Adcom Amp problem | Kursun
Jul 12, 2001 2:05 AM | | Sounds like the amp circuits gradually losing their stability as the power supply filter capacitors discharge. But you shouldn't hear that sound. I am not familiar with your specific amp, but normally amps have relays that connect its speaker outputs to dummy loads inside, for 3-4 seconds on switch on. After the circuits stabilize the relay switches the amp speaker output to the speakers. When you switch off the amp the relay instantly cuts the signal to the speakers so that you that hear those nasty sounds resulting from capacitor discharche and internal circuits gradually loosing their stability as the power supply voltage slowly drops to zero. My guess is that the speaker relay in your amp is not functioning properly. |
| re: Slight Adcom Amp problem | jgfoley3
Jul 12, 2001 1:31 PM | | Thanks Kursun. I might see if I can get ahold of a service manual and take a look at that speaker realy. Please email me if you have any further ideas. jgfoley3@yahoo.com
John |
| re: Slight Adcom Amp problem | jgfoley3
Jul 12, 2001 1:35 PM | | Kursun
You know, come to think of it, if I shut the amp off but leave the pre-amp on, I will still get sound out of the speakers for at least 5 or 10 seconds, and then it slowly fades - as the capacitors discharge I guess. Hmmm... |
| re: Slight Adcom Amp problem | N2it
Jul 14, 2001 4:35 PM | | I have a 555 II driving the woofers on a pair of kappa 8's
when I turn of the amp I hear a low popping for about 20 secs
probably the caps discharging, Adcom used to say in their sales
brochures to turn the amp off and it would play for 10 to 20
seconds with no line power. I dont like it though |
| re: Slight Adcom Amp problem | Kursun
Jul 15, 2001 12:15 PM | | From your information it seems a design point. I gather Adcom doesn't believe in contacts in the output path, since they oxidize with time. I had seen some purist amps that didn't have loudspeaker A - B on/off switches, for the same reason. It's not pleasing to hear the sound dying away in distortion. But there seems to be no real harm here. Thanks for the info. |
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