jea48
Responses from jea48
| Forgive my ignorance (vintage amp input question)... Whipsaw,As swampwalker said in his post the disc inputs are phono inputs.You do have two other line level inputs available on the amp though.The two tape inputs RCA jacks on the rear panel. Tape 1 and tape 2.Connect the AV source to one of the Tap... | |
| Help With 60Hz Hum PLEASE Jo3533,Great news! I am glad to hear the dreaded hum/buzz is finally gone.With that said,...... Curiosity killed the cat. Would you try one more test for me?Would you disconnect the wire that you connected to the Marantz chassis and instead connec... | |
| Help With 60Hz Hum PLEASE Al, "Ironically, though, I believe that the symbol for R55 shown nearby on the schematic (connecting digital ground to chassis) is one of the symbols that are used to represent thermistors, yet R55 appears in the photo to be just a jumper. Also, I... | |
| Help With 60Hz Hum PLEASE Al,R47 looks like a thermistor to me.Puzzling to me though it is installed in the R47 circuit board location instead of the R49 location. Unless the circuit trace on the underside of the board was changed before the actual circuit board production... | |
| Help With 60Hz Hum PLEASE Al,Yes, I found it in the parts list of the service manual."R20 ,R21 ,R47 ,R49 ,R51 JUMPER"Thanks.While waiting for Joe to post how he fixed the hum problem I have been looking at the other PDFs he posted last night.I also found a picture, (I beli... | |
| Help With 60Hz Hum PLEASE Hi Al,Interesting comments regarding the R49. At the time of my post Joe had not posted the service manual PDF.I wonder what component R49 is actually made of? It’s not a fuse and technically it is not a jumper. "R" usually designates a resistor. ... | |
| Help With 60Hz Hum PLEASE jo3533, Here is a quote from Charles Hansen.The only way that the case can provide any shielding for the audio circuitry is if it is connected to the signal ground. In addition, if it is left unconnected from the signal ground, then it will create... | |
| Help With 60Hz Hum PLEASE jo3533, Did you buy the Adcom amp new or used? I believe you said in a previous post the amp always had the hum since you have owned it. Is that correct? Did you click on the two links I provided for the sound of 60Hz and 120hz? Does the hum/buzz ... | |
| Help With 60Hz Hum PLEASE I think my post about XLR cables not being plugged in and there being noise was an error. CONFIRMED With the amp connected but not the per-amp there is no noise. Checked it twice tonight.That makes more sense why it doesn’t matter if the Marant... | |
| Help With 60Hz Hum PLEASE Al,Just looked at the picture again. I think you are correct.Jim | |
| Help With 60Hz Hum PLEASE Hi Al,Disregard my last post.https://www.dropbox.com/sh/1rdxqg82pw3ecq9/AAATCANt3v5Vc3kMZ0taSa1na?dl=0Look at picture #3 of the OP’s Link of the XLR connector. Notice that jumper wire from pin 1 to pin 3? Could that be the problem?>>>>... | |
| Help With 60Hz Hum PLEASE Al,From jo3533 first posted message.Quote:So this is what I have done to check the system so far.1. First off I separated all of the components power sources, plugging each component into its own outlet with the amp plugged into the dedicated ... | |
| Audio Research VTM-200 Bias Issue jellybean,F1, 7 ampF2, 4 ampBoth located in AC power line.F3, 1/4 amp Scroll down the page until you come to the power transformer diagram. Start to scroll up keeping your eyes to the far left hand side of the page.You will see 4 dual section caps... | |
| Help With 60Hz Hum PLEASE Thanks Al for the response. Hopefully jo3533 will pick up some RCA shorting plugs.jo3533,Does the hum sound like one of these?60 Hz.https://www.youtube.com/watch?v=E_Sf7rSOU78120Hz.https://www.youtube.com/watch?v=pC4Uzt0qm2E | |
| Help With 60Hz Hum PLEASE jea48 said:I have had instances when a power amp was left powered up and the preamp was turned off. There was not any hum/buzz coming from the speakers. Of course I have never owned a 300 watt per channel amp either. Not relevant; different compon... |