May 4th, 2012, 10:08 AM
Well, the seemingly straight forward job of replacing the filter caps on this old 69' YBA-1, has turned out to prove the inportance of knowing how to read a schematic and taking more photos... I removed the old caps and thought I'd have the new ones back in while it was still freash in my mind but boy was I wrong Again.. any looking at the schematic, I'm still not 110% right I have the leads hooked up right on the caps..
From what I can figure out is the 2 hot red leads that feed the diodes of recitfier come off on the green wire that supply the first cap, and that feeds the primary of the OT through the red and yellow wires then the secondary which would be the black feeds the 2nd cap...
I also am ugrading to the grounded 110V which is removed presently, but my main concern is the leads on the E-caps..If anyone that has a similar amp could let me know if I'm close or way off, I'd appreciate it...
May 4th, 2012, 02:07 PM
I don't have one of those amps lying around.....but, if you have the schematic, it would be a good time to start learning how to trace that circuit out. You will learn much more by doing that than you will following someone's 'paint by numbers' picture, imho. Each one of those + posts has a contact that provides eletrical current to some component downstream. The schematic will tell you all of this. A schematic won't tell you an exact physical location, but the connections are there for you to understand. You are building amps, so imho you should be reading schematics. I hope this rather direct response is of help.....but I know that it is not the 'quick and easy' answer to your question. This is sort of the difference between giving a man a fish and teaching that man how to fish, right? IN other words....go fishin', young man. (;^)
I have to ask out of curiousity. HOw are those cap cans secured to the chassis???
May 4th, 2012, 02:57 PM
Thanks Wally for the reply and yes sir I have looked at the schematic til my eyes went blurry but I'm still not sure enough to plug it in once I have the new 14/3 wire installed..I just don't want to take the chance of popping the PT as I'd kick myself for not waiting until I got the right answer..I'm already kickin myself for not taking better photos in the first place as I wouldn't be in this mess now...but thank you justthe same
May 4th, 2012, 04:03 PM
Which one do you have??? YBA-1 or the YBA-1 MKII???
May 4th, 2012, 04:16 PM
What values are sitting in those two cans?? I admit that looking at the schematic one might get confused in the beginning...but if you get the correct schematic on paper alongside the circuitboard and start physically tracing what is going on, it will come to you. PErhaps start at the 'end of the chain' and trace backwards?? Fishing takes patience. And....until someone throws you a fish, it seems you have only me to encourage your learning to fish.
May 4th, 2012, 06:47 PM
Hi Wally, I have the YBA-1 and yes sir the schematic you attached is the correct one, without getting your neck too sore from having it turned sideways, off the PT secondary shows the D2, D3, D4, D5, D6, D7 and those are the Diodes for the rectifier and it shows the 2 40x40 450 volt filter caps...
I changed the values and ordered 2 of the 50 x50 500V E-Caps..thinking now I might have been wise to go with the 50X50 and a 32X32 instead...