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Failing Eden Problem

BobKos

BobKos

Apr 13, 2007
2,983
4,084
#1
Hi All:

I have a 6 yr old Eden WT-500 that has served me well over the years. It's been babied in my home all those years, so it's not like it has been a road warrior & subject to abuse. Last night - when I REALLY needed it to work right - it started doing this:

Invalid Link Removed

Please excuse the crappy playing.

This morning I was able to reproduce the problem. I popped a new tube into it. Still no good. The problem is pretty inconsistent but it will usually show during a 30 minute session. Last night it pretty much quit altogether after 2 hours of low to moderate volume playing. The failure at that time was irrecoverable. I think temp might be a factor.

Anybody seen this problem that might know of a fix?
 
#2
BobKos, my WT-500 had an issue with some power resistors in the front (preamp) PCBA getting so hot that they were partially melting their own solder joints. For me, the symptom was an intermittent really loud popping sound. Since I did not hear that popping sound in your video, you may have something else going on. If you want more details of my own amp's failure and fix, please let me know.
 
#4
One other possibility is that you have a loose power connection, for example the ac cord coming loose in back. I had that happen a year or so after fixing my power-resistor problem, and immediately was convinced it was the resistor problem returning. The giveaway was that the power lights flashed in time with the drummer. His playing was shaking the loose ac connection.
 
#11
To resolder you've got to remove the preamp board and flip it around to gain access to the solder joints underneath. Most of the labor is getting everything taken apart. The soldering itself is easy. The power resistors in question are usually a pair of large, rectangular, white, 5W resistors on the preamp board (the only power resistors on the preamp PCB).... like this:

10K_5W_Fixed_Cement_Power_Resistor_007001.jpg


I've replaced mine with 10W units to reduce the heat. If you can, I'd suggest removing the existing solder and reflowing with fresh stuff.... :smug:
 
#12
hey thanks for the info.

I found this picture in another thread. My preamp is set up the same but the two white blocks look almost to be 4 smaller blocks, with what also looks like wires soldered together on the top?

Do you know what the point that needs to be soldered should look like?
 

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#13
It'll be the underside of that circuit board as shown in the picture you uploaded. You'll be looking at all the silver bumps on the other side. An ideal solder looks like a miniature pyramid of smooth silver. If you look at where those resistors stick through the board, and the underside has little pyramids but with cracks in them, those are the ones you wanna resolder.

I did this same technique to salvage a Rocktron Guitar Silencer for my brother. Almost every front panel pot's solder points were cracked and worthless. 40 seconds later, I had all those points reheated and reconnected. The only problem with it now is one little red LED, which he didn't even want me to bother replacing. It's key in his guitar rig, and easily performing without flaw since.

This is a dead simple job to do. Just make sure you:

A. - Use a soldering iron with a very small, fine point, so you can be accurate and not touch other solders at the same time.
B. - Don't let the solder melt and trickle over to another trace or solder point and fuse there, that will create a short and screw things up for you.

A steady hand and BRIGHT steady light will make the job easy for you.
 
#14
hit up home depot last night and got myself a soldering pencil kit. practiced a bit before I got the courage to do anything on the preamp board but I went for it and everything seems to work now! Thanks for everyones help.
 
#19
Here are some video clips illustrating the Eden preamp board resistor issue:

http://s196.photobucket.com/albums/aa44/dufftwo/?action=view&current=Eden1.flv

http://s196.photobucket.com/albums/aa44/dufftwo/?action=view&current=Eden2.flv

Note that the above video clips are relevant only to the World Tour (WT-500, 600, 800) and Traveler (WT-300, 400) series amps that were built before redesign of the power section to allow for 2 ohm operation. The latest generation of Eden amps do not appear to be susceptible to this problem.

Cheers,
Duff2
 

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