Adcom GFA-555II problem...
starkiller
Posts: 2,723
Have a 555II i got at an estate sale. Powered up fine, red led stayed on and nothing from the led's showing problems. Hooked it up today and when I power it on i get a hum through both speakers. Didn't try and play anything. All fuses look good..possible that the trouble led's on the front are both burned out?
Computer room Hegeman 1 SpeakersM&K VX-80 subKenwood DP-7010Cambridge Audio CXC Transport Rega DACPrimaLuna Prologue Four AmpAric Audio Tube PreampGarage Jennings Research SquareCustom tube preampCrown XLS-1000Denon DCD-1500II Modded MSB Link DAC
Post edited by starkiller on
Comments
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What kind of hum? Loud and concerning, or kind of just there?____________________
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HT:Onkyo 805, Emotiva XPA-5, Mitsu 52" 1080p DLP / polkaudio RTi12, CSIa6, FXi3, uPro4K
2-chnl : Pio DV-46AV (SACD), Dodd ELP, Emotiva XPA-1s, XPA-2, Odyssey Khartago, LSi9, SDA-SRS 2 :cool:, SB Duet, MSB & Monarchy DACs, Yamaha PX3 TT, SAE Tuner...
Pool: Atrium 60's/45's -
It's pretty loud, course i am sitting right in front of the speaker but still never heard the hum from my luxman m-117....Computer room Hegeman 1 SpeakersM&K VX-80 subKenwood DP-7010Cambridge Audio CXC Transport Rega DACPrimaLuna Prologue Four AmpAric Audio Tube PreampGarage Jennings Research SquareCustom tube preampCrown XLS-1000Denon DCD-1500II Modded MSB Link DAC
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So do you have a source hooked up to the amp?____________________
This post is a natural product. The slight variations in spelling and grammar enhance its individual character and beauty and in no way are to be considered flaws or defects.
HT:Onkyo 805, Emotiva XPA-5, Mitsu 52" 1080p DLP / polkaudio RTi12, CSIa6, FXi3, uPro4K
2-chnl : Pio DV-46AV (SACD), Dodd ELP, Emotiva XPA-1s, XPA-2, Odyssey Khartago, LSi9, SDA-SRS 2 :cool:, SB Duet, MSB & Monarchy DACs, Yamaha PX3 TT, SAE Tuner...
Pool: Atrium 60's/45's -
Hooked up to preamp yes, and of course to speakers...Computer room Hegeman 1 SpeakersM&K VX-80 subKenwood DP-7010Cambridge Audio CXC Transport Rega DACPrimaLuna Prologue Four AmpAric Audio Tube PreampGarage Jennings Research SquareCustom tube preampCrown XLS-1000Denon DCD-1500II Modded MSB Link DAC
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I had fits getting rid of the hum from my 555. It took good heavy cables from my amp to pre, speaker wires had to be run clear from the other cables and power cord.
Once I did that it was fine with no problems.
You might give it a try... -
Hmm, so you don't think its an internal problem? the outlet i have it hooked up to is shared by the fridge, only outlet in the garage....Computer room Hegeman 1 SpeakersM&K VX-80 subKenwood DP-7010Cambridge Audio CXC Transport Rega DACPrimaLuna Prologue Four AmpAric Audio Tube PreampGarage Jennings Research SquareCustom tube preampCrown XLS-1000Denon DCD-1500II Modded MSB Link DAC
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You may have nailed it starkiller, that refrigerator compressor or fan motor(DC) may be the problem. Have you tried just unplugging the fridge from the wall for a minute to check if the amp's hum is gone? When you plug the fridge back in, it may not start right up,(sometimes the relay will kick to overload if unplugged and plugged back in too quickly) Others here may add more input for you.
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well if thats the problem then the adcom goes as that's the only outlet...will try it and see....thanks!Computer room Hegeman 1 SpeakersM&K VX-80 subKenwood DP-7010Cambridge Audio CXC Transport Rega DACPrimaLuna Prologue Four AmpAric Audio Tube PreampGarage Jennings Research SquareCustom tube preampCrown XLS-1000Denon DCD-1500II Modded MSB Link DAC
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Well, a bit of a revelation and umm, forgetfullness on my part
...the preamp switcheable outputs, 1 and 2, output one has the hum and output 2 does not..so, must be a preamp thing and one which i will not worry about 
Now i have to choose between the M-117 or the Adcom to run my center channel in the h/t setup, use the loser as a backup and use the Crest 4000 for garage duty Computer room Hegeman 1 SpeakersM&K VX-80 subKenwood DP-7010Cambridge Audio CXC Transport Rega DACPrimaLuna Prologue Four AmpAric Audio Tube PreampGarage Jennings Research SquareCustom tube preampCrown XLS-1000Denon DCD-1500II Modded MSB Link DAC -
Any way you can add a designated circuit to the room for your system? Usually best to plug a beast of a power amp like the 555 directly to the wall but you only have one wall outlet. I say this because I know the fridge can draw some amps on startup and I know power amps can suck up the amps on startup too, especially drawing from the same outlet,lol.
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if i have to that shouldnt be hard as the system is in the garage where the box is Computer room Hegeman 1 SpeakersM&K VX-80 subKenwood DP-7010Cambridge Audio CXC Transport Rega DACPrimaLuna Prologue Four AmpAric Audio Tube PreampGarage Jennings Research SquareCustom tube preampCrown XLS-1000Denon DCD-1500II Modded MSB Link DAC
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There you go!
