3 preamps with transformer hum, DC on the line?
The isolation transformer (a Tripp Lite IS350) did not change anything. I think I will just live the minor hum. I cannot hear it from my listening position and only hear it when changing records. Would be nice to have it be quiet but we cannot have everything perfect, especially when it is not a necessity. Thanks everyone |
The isolation transformer (a Tripp Lite IS350) did not change anything. Sbrownnw, If you can't send it back, you might try feeding your oppo BDP-93 player from it. Back to your preamp..... What do you have that thing setting on? Would that be working like a sound board? Amplifying the mechanical noise from the torrid xfmr? Reading the owners manual it says the xfmr is suspended to reduce transmission of its vibration to the rest of the circuitry. Did you notice that when you looked inside? In the RECOMMENDATIONS, "Do not place the unit on a glass shelf. We highly recommend placement on wood or granite." And then there is this..... "For best sonic results, correct orientation of the AC plug is important. The prong with the red dot should be connected to the Hot connection of you wall outlet." Is the plug on the end of the power cord just a two wire, 2 blades? Non polarized plug? Plug it in either way? If that is the case make sure the blade with red dot plugs into the Hot of the receptacle. Just throwing some things out there..... Owners manual . Jim |
I returned the isolation transformer within the 30 day return window, which was easy after buying it locally. I might try ordering the parts my own humbuster / dc filter and have one of the two local audio service shops do the assembly. Can someone give me a schematic of the simplest proven design (side by side caps on either the live XOR neutral feed with diodes on each side?) and a high quality parts list that I would need? Should I go with the Bryston, the Crown or a simpler design? It would be great if that parts list included a nice black outer metal case / box if possible plus high quality IEC female connector. I would hope to be able to use one of Porter's power ports also. Jea48, have you done something like this before? I saw a similar thread post by Gbart that he / she has made some of these for Audiogon members, but I am unable to email that user. Please drop me an email if possible: white 78 911 at hotmail dot com TIA again! |
