Eden WT400 Bass Amp

[bsco]

Thank you very much. The pre-amp schematic I already have...actually it's the same copy as the far right-hand side is cut off...I did not have the power amp schematics. Thanks so much. I'll let you know how I make out with it all.
Cheers,
Bernie

[bsco]

Looking over the schematic......the zener diodes on the plus and minus 15 volt supplies....I assume that they are half watt ratings?? If so I was looking at using 1 watt ratings instead.....ordered a half dozen of both just in case. (very hard to get stuff here locally....pretty much everything has to be ordered....
Cheers,
Bernie

[52 Bill]

The schematic has no part numbers for the zener diodes, do the actual parts have numbers on them?

While I imagine that 1 watt zeners will work here, if you look up the specs for the original part numbers, you will know what wattage they should be.

[bsco]

That's the problem..Whoever worked on this amp before removed the zeners and replaced them with regular rectifier diodes.I have no idea what the proper diode numbers are supposed to be so I ordered some half watt and one watt ones...
cheers,
Berniie

[Amp Kat]

I'm almost sure those zeners are 15v 1 watt and those power resistors added to the power supply are much needed as the original resistors are too low and pull to much current causing the amp to get hot and fail. If it's shabby work than by all means clean it up but they were put there for a reason. Can't defend the zeners with regular diodes as they definitely need to zener the 15 volt +/- rails of the op-amps in the preamp section on the front board. That board is a PITA to take apart so if you don't have to don't do it and I think they added electric tape from the factory to keep a few things from shorting out. Eden used to not give their schematics out at all but in the last 5 years have been putting them out.

[bsco]

Thank you for your reply Amp Kat...Been trying to get on this forum for a couple of days and couldn't connect...must have been some maintenance work being done. Anyway, I had the zeners come in and I replaced them. I also added another 470/5W resistor in series with the other two that are already there for the op amp supply rails.(both rails actually). Then I replaced all op amps with new ones as if they do work they are probably so stressed out that they would fail shortly anyway, so to prevent a call-back I just replaced them. Checked it out yesterday and it works great. Left in on for most of the afternioon and kept going back and plucking on a few bass notes here and there and everything works great. Thank you and a big thanks to everybody that has helped me with this repair. And yes, the repair work was very shoddy and I had to clean it all up. I mounted the diodes on the top of the board where they should have been and then ran the leads to the nearest copper traces as the pads had been damaged and missing. The other diodes were just tack soldered to the bottom of the board.Very shitty work... Doing a good job is one thing that I insist upon...after all if I was paying somebody to do it for me, that is what I would want....Once again everybody, thank you so much for your time and help....
Cheers,
Bernie