Eden EN400 Nemesis Output Issues

[70sdiscodawg]

Hi all!

Over the past... Well... Forever, honestly, I've been having this strange issue with my amp. It's an Eden EN400 Nemesis 400W bass amp going into a 4 Ohm Eden 2x10 cab.

Since I mostly record my bass through DI, it goes (relatively) long stretches without being used. Usually, when I turn it on at band practice or at a gig it works. However, at (seemingly) random intervals ranging from anywhere between 10 minutes and 2 hours, it just cuts out, and only the Preamp works. First time this happened was actually during a gig, which definitely didn't cause a panic attack while scrambling to figure out what to do while the rest of my band members kept on playing. When I got home I couldn't reproduce the problem.

The next times I was prepared and had pre-connected the DI output (which works fine when this happens), but of course I would like to actually hear myself through my cab as a monitor.

It seems pretty clear this is a power amp issue of some sort, but what really grinds my gears is that I can't seem to reproduce it at home. I plug it in here and it's fine, then when I take it out for a rehearsal or a gig it just quits on me.

My first suspicion was a temperature-related issue causing it to go into thermal protection. However, as it happened after like 10 minutes of playing I'm pretty sure that's not it. Even in terms of ambient temperature it seems highly unlikely anything thermal is the problem, as it never gets hot to the touch and the fan doesn't even turn on yet.

Now, I also noticed that I've had to turn the Master Volume up pretty high to even match a live drum kit (I'd say at 75-80% or so), which I don't recall being the case when I just got it 8 years ago.

Also, I can't see any burnt or damaged components whatsoever. I am pretty handy with a multimeter, and replacing electronics and components is no big deal for me, so I would love to fix it myself, but as I can't seem to reproduce the issue, I am at a loss.

Do any of you guys have any idea what could be the problem of my beloved EN400? I'd hate to have to replace it, as I've created/moulded my sound around it.

 

[S-Bigbottom]

Exercise the jack of the Effects Return.

There is a switch in there that if not used can get some corrosion built up and cause intermittent connections.

 

[70sdiscodawg]

Thanks for the suggestion, I definitely hadn't thought of that, and could make sense because I never use the effects loop. I "exercised" the Jacks, and couldn't see any buildup or corrosion whatsoever, but gave 'em some anyway.

What that doesn't explain, though, is why it doesn't play at all anymore until a few hours later. I'd expect it to come and go at random, not just go. Also it would have to be some bad luck that I can't seem to reproduce it at home.

 

[agedhorse]

Thanks for the suggestion, I definitely hadn't thought of that, and could make sense because I never use the effects loop. I "exercised" the Jacks, and couldn't see any buildup or corrosion whatsoever, but gave 'em some anyway.

What that doesn't explain, though, is why it doesn't play at all anymore until a few hours later. I'd expect it to come and go at random, not just go. Also it would have to be some bad luck that I can't seem to reproduce it at home.

Sure it explains why.

You need to identity the problem first, or else you are just guessing. Guessing isn’t how you repair amps.

 

[70sdiscodawg]

Sure it explains why.

You need to identity the problem first, or else you are just guessing. Guessing isn’t how you repair amps.

I completely agree with you, which is exactly the reason I'm here. I'm having trouble identifying the problem and was hoping someone at some point had or has seen a similar issue.

If not I'll have to bring it in to my next rehearsal and see if I can force it to fail there to make some measurements in that state. But of course that's not how I would ideally spend a band rehearsal.

Anyways, I can't test the fix at the moment, but will have a look tomorrow to see if I can make some progress.

 

[S-Bigbottom]

Plug a cable in linking the Effects Loop Send and Return together.

If sound stays then it is the Return jack.
If not it is Tech time, nothing we can diagnose over the internet.

 

[S-Bigbottom]

Thanks for the suggestion, I definitely hadn't thought of that, and could make sense because I never use the effects loop. I "exercised" the Jacks, and couldn't see any buildup or corrosion whatsoever, but gave 'em some anyway.

What that doesn't explain, though, is why it doesn't play at all anymore until a few hours later. I'd expect it to come and go at random, not just go. Also it would have to be some bad luck that I can't seem to reproduce it at home.

Here is a copy of another post I did explaining how this works.


For those that do not know this is what the effects return jack looks like. See the nipple between the bottom posts, this is what connects your signal with nothing plugged in. See the signal flow lines.

When a plug goes in the nipple is lifted, breaking that connection and the signal comes from the cable.

When you read on here that an amp is cutting out or the volume is good then suddenly goes and we give advice to check the effects loop to see if it still does it, this is why. If it clears up when inserting a plug then that little nipple had some oxidization on it interrupting the signal. It only takes a small film to interfere so you clean it with a wipe of Deoxit D5 and it's all good. No need to keep in the jumper cables.

Never just spray in the jack as you will get parts that you do not want sprayed and that little nipple is hidden under that post.

A little rant while on jack cleaning, NEVER file or sand to clean the contact points. The coating on them is thin and has a corrosive protected coating on it and when you scratch that off it will rust fast, making your problems come back faster and eventually killing the jack. Also your filings that come off could go somewhere you do not want.
A lite chemical wipe is all you need to clean and protect.

 

[Pulverizor]

Is your speaker cable in good condition?
Have your measured your cabs actual impedence?
Does the amp cut out using an 8ohm cab?
How hot is the amp when it cuts out?

 

[dax21]

I can only chime in with info that these Nemesis amps don't work like most amps do, meaning that on most amps you push the master volume up to 12 o clock and that's largely the apex of the headroom. On Nemesis line the pot is completely linear (I believe that's the term?), meaning you are meant to use it more liberally with very discernable results all the way up. I think this is also stated in the manual if I remember correctly.

I've used the head version of your amp for over a decade now, still my main amp. Never had any issues with overheating and I've abused the power amp in it lots as I mostly go into the effect return anyway. They are robust amps.

Also, make sure to visually inspect the fan for dust as well as make sure that it's running properly.