I would have to look on my board, I was going by the schematic. R10 in any event. Thanks. Nuts, have to go into work in an hour or so, I'll see how far I can get. Really want this working tonight, but it will be tight. At least I can hopefully get this set, then finish remaining signal wiring. I do have the matched set from you guys.
Thanks again,
Russellc
Got you. I will run wires from the center tap of the 2 outputs to ground, sans Cl-60, just a habit from the Pass builds. I thought of this, but I was expecting it to run from where the two sides. Lots I dont understand, not doubting but dont get why the Raw DC output will do same thing as connection on schematic at the two 1N5406 and the 2-5 watt resistor? trying to learn something here about ground. I am not an electronics guru to be sure, but I solder well, can identify parts, and I can follow directions. Just trying to get my head around this grounding!!!
Thanks in advance yet again,
Russellc
Yes but he used diodes bridge ground lifter RF bypassed schemes on mini boards instead of CL-60s. Serving the same task in a different way.
#1855 photo my member Alexkosha:
https://www.diyaudio.com/community/attachments/img_1058-jpg.615560/
Its just a method to reference the chassis at same potential with the PSU/Signal ground so to close possible loop area between the boards and chassis. That's to minimize susceptibility to hum fields and RF fields interference.
Also to establish a heavy fault current return path from boards through chassis to mains protective earth in case of a big mistake. Either direct or safety lifted via diodes or CL-60. Lifted is to make it more anti hum versatile when connected to various audio systems. But direct wiring like in those #2046 & #2050 photos may also suffice in enough situations. By the way, the exact physical point of attaching those chassis going wires on the PSU board ground return lanes isn't much crucial.
#2046 & #2050 photos by member DrPro:
https://www.diyaudio.com/community/attachments/dcg3-jpg.631069/
https://www.diyaudio.com/community/attachments/dcg3_1-jpg.631191/
https://www.diyaudio.com/community/attachments/dcg3-jpg.631069/
https://www.diyaudio.com/community/attachments/dcg3_1-jpg.631191/
Back at it and a small amount of trouble. first fire up, using variac I saw a tiny spark, and I mean tiny on one of the fuse holders on the power supply as I was dialing up power. I disconnected the pre board from the power supply and ramped it back up. I lit up, except the light bar by the fuse that had the tiny spark.
I traded the fuse with a neighbor fuse, and it lit back up and where I put the dead fuse did not. So, looks like just blew that fuse. Why, I dont know.
The only thing different is the grounds hooked up to the 0 points on PS output, and pre board is attached. checking to see if I have a replacement fuse.
Im assuming it is something on the pre board, seems fine with it unhooked from power supply. Looking for shorts or anything obvious.
any ideas would be much appreciated!
Russellc
I traded the fuse with a neighbor fuse, and it lit back up and where I put the dead fuse did not. So, looks like just blew that fuse. Why, I dont know.
The only thing different is the grounds hooked up to the 0 points on PS output, and pre board is attached. checking to see if I have a replacement fuse.
Im assuming it is something on the pre board, seems fine with it unhooked from power supply. Looking for shorts or anything obvious.
any ideas would be much appreciated!
Russellc
I do note the M1-M3 tabs have continuity to ground. Touching one lead to the heatsink and another to any tab also has continuity. Not sure why, does not seem like that should happen? They are mounted with the mica pieces with goop and the little black plastic ring in the metal tab of M1-M3.
Russellc
Russellc
None of those buzzed, so I guess that's OK, like you said, flaw in the insulation bits. I saw someone here with a bar across them, touching the body of the M1-M3 devices with screws on either side. since it doesnt contact the tabs, looks like it may be the way to go.
I dont see where anyone else has mentioned problems with these insulation bits, maybe its operator error? used goop, the mica insulators, put the little black insulator in the tab, use m3 screw and a small washer.
Russellc