jea48

Responses from jea48

15A vs. 20A power cord questions
As for the current handling ability of a NEMA 5-15P 15 amp plug vs. a NEMA 5-20P 20 amp plug there isn’t any. If you look at the size of the hot and neutral blades they look exactly the same. Same length, same width, same thickness.What is differe... 
15A vs. 20A power cord questions
Are there any issues with running 15A power cords into a 20A outlet and line? No, not any problem at all.   I am currently using the standard IEC power cords that came with my Rogue Cronus Magnum and VPI Scout 1.1. After about a month or two liste... 
Help With 60Hz Hum PLEASE
Putting my previous speculation in more general terms, I suspect basically that the grounding approaches in the two components, possibly in combination with some condition-related issue (such as a leaky line filter capacitor), somehow caused an in... 
Help With 60Hz Hum PLEASE
Joe, (jo3533),Thanks for doing the test for me. Had I known you had to pull out the rack I would not not have asked you to try it. Thanks again.AL,Looking at the Adcom Amp schematic wiring diagram again, trying to figure out why when all the outer... 
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?>>>>...