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EDEN WT-300 Problems

H

Halebop23

Jun 22, 2025
8
2
#1
Hi everyone, I've been playing for many years with a David Eden WT-300 head (4ohm) combined with a 210XLT speaker.
For some time now I've noticed that I have to increase the gain more and more to get close to clipping and this happens with both passive basses that I use. To be clear, for many years I played with the gain pot set to less than half, lately I've been keeping it at more than 75%. Can anyone help me understand what's happening? Would it be useful to change the valve (i think it's a 12AX7) on the pre-amp?
Thanks.
Luca
 
#5
Straight from the manual:
IMG_8489.jpeg
 
#10
Lo-E said:
Yeah, I took that with a grain of salt. I suppose if you really drive the hell out of it many hours per day…

The tube in my WT-400 has been in there for decades but I don’t drive the input hard or use the head all that often.
Click to expand...
I would hope not, I typically design around 7,500 hours of operation for a 12AX7/12AT7/12AU7 and often see 10,000+ hours of lifespan in some of those circuits. For perspective, 10,000 hours is about 2 hours a day, 5 days a week for 20 years! That would be a hard working amp IME.
 
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#11
Halebop23 said:
Hi everyone, I've been playing for many years with a David Eden WT-300 head (4ohm) combined with a 210XLT speaker.
For some time now I've noticed that I have to increase the gain more and more to get close to clipping and this happens with both passive basses that I use. To be clear, for many years I played with the gain pot set to less than half, lately I've been keeping it at more than 75%. Can anyone help me understand what's happening? Would it be useful to change the valve (i think it's a 12AX7) on the pre-amp?
Thanks.
Luca
Click to expand...
I would be surprised if it was a problem with the tube. When the manual was quoted as saying "It is uncommon for a tube to last less than a year in our circuits. Tube life of several years is not at all uncommon.", I thought...that must be an old manual. And then when I saw the instructions to replace it with 7025 or high quality 12ax7, I knew it was old. Back "in the day" the 12ax7 was the standard preamp tube and if you wanted a low-noise version, the 7025 was it. I checked further in my manuals and in 2003 they framed it as replacing it with an Eden 7025/12ax7 tube (Eden shipped with Ruby tubes). Then in 2005 it was no longer mentioned at all in the manuals.

In about 2007 when I joined the Eden Forum, that question would come up about needing to replace the tube and invariably the moderators would answer that it was highly unlikely because, unless the amp was dropped, those tubes operating at the level they need to generate the warmth in the Eden sound just seem to last almost indefinitely. There's very little stress on them, plus the 12ax7 tubes even then in 2007 were just as low-noise as the older 7025's as long as it was a quality tube. I'd really be surprised if it's the tube.

@agedhorse certainly knows a lot more about tubes in amps than me since he designs amps and he's been working with tubes and amps for so long. He said he expects his designs to get 20-years worth of heavy use out of his preamp tubes. Outside of being damaged by accident, preamp tubes normally last a decade or two.

@Halebop23, I would actually suggest you drop a DM to @Bassmann1968 and ask him about the lack of gain you're experiencing. He was the electronics guru on the Eden Forum, has a mountain of Eden gear and knows them inside and out. He was actually a Eden Authorized Repair Technician, has the schematics for most of them, and can get down in the weeds with you about individual components in the amp if necessary. It may be something that just needs cleaning, or a component that got too hot or something else. He should be able to help you figure out if it's something you can address yourself or if it's tech time.
 
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#12
agedhorse said:
I would hope not, I typically design around 7,500 hours of operation for a 12AX7/12AT7/12AU7 and often see 10,000+ hours of lifespan in some of those circuits. For perspective, 10,000 hours is about 2 hours a day, 5 days a week for 20 years! That would be a hard working amp IME.
Click to expand...
I would only ever expect routine replacement in a busy, commercial rehearsal studio. That’s the only environment in which I would expect a head to see 12+ hour days of constant, hard use. Back when Eden gear was still current enough to be used in such studios, I frequently encountered noisy/microphonic tubes in studio backlines but I suspect that had to do more with vibration than with actual wear of the cathode. Hell, those amps were being used constantly for close to 5,000 hours per year!

Eden heads are long gone from rehearsal studio backlines but that kind of use leaves a mark on every generation of gear, including very current heads. It was definitely not a bad reflection of quality on Eden’s part. 12+ hours a day, 365, of mostly rock musicians…. things are going to break! But, yeah…. I played through some Edens - mostly WT-800s - under those circumstances that absolutely needed new tubes.

…but a NYC rehearsal room might qualify as extenuating circumstances.
 
#14
Something super easy you could try before replacing the tube: is to preform a simple test of Patching your Effects Loop to discover if it solves your issue or not. If simply plugging a guitar cord in-between your Effects Send & Return jacks instantly solves your issue, you will have just diagnosed that the little Shunt in your Return jack simply had a poor connection causing high-resistance where it makes the connection in-between you Preamp & Poweramp sections, anytime your NOT patching an external effects device into these Effects loop jacks.

Then if this test solved your issue, you could simply leave a short angled, guitar pedal cord in place to patch the loop permanently, instead of attempting to clean or replace the defective Effects Return Jack that was causing your issue.

I've circled the little Shunt I'm referring to in this pic:

jack with shunt circled.jpeg
 
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#15
Thanks for the replies.

I don't remember the exact year I bought it, I think it was around 1998 and if I remember correctly (I don't want to get confused with the speaker) it was a used ex-demo in a music shop so it could have actually worked for many hours. As far as I'm concerned I haven't used it much, I'm not a professional and I've always used something else to play at home. A friend of mine bought a new wt-400 a couple of years before me and he's definitely used it a lot more than me, his is still perfect.

Is it normal in your opinion that there's nothing printed on the tube currently mounted?

@RipVanDan I also wrote on the Eden forum years ago and I think I also interacted with @Bassmann1968, the problem is that the Eden Electronics forum doesn't seem to exist anymore! Maybe it changed its name and I can't find it again ... Do you know anything about it?
 
#17
anderbass said:
Something super easy you could try before replacing the tube: is to preform a simple test of Patching your Effects Loop to discover if it solves your issue or not. If simply plugging a guitar cord in-between your Effects Send & Return jacks instantly solves your issue, you will have just diagnosed that the little Shunt in your Return jack simply had a poor connection causing high-resistance where it makes the connection in-between you Preamp & Poweramp sections, anytime your NOT patching an external effects device into these Effects loop jacks.

Then if this test solved your issue, you could simply leave a short angled, guitar pedal cord in place to patch the loop permanently, instead of attempting to clean or replace the defective Effects Return Jack that was causing your issue.

I've circled the little Shunt I'm referring to in this pic:

View attachment 7258253
Click to expand...
thanks, I'll try as soon as I can
 
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#19
anderbass said:
Something super easy you could try before replacing the tube: is to preform a simple test of Patching your Effects Loop to discover if it solves your issue or not. If simply plugging a guitar cord in-between your Effects Send & Return jacks instantly solves your issue, you will have just diagnosed that the little Shunt in your Return jack simply had a poor connection causing high-resistance where it makes the connection in-between you Preamp & Poweramp sections, anytime your NOT patching an external effects device into these Effects loop jacks.

Then if this test solved your issue, you could simply leave a short angled, guitar pedal cord in place to patch the loop permanently, instead of attempting to clean or replace the defective Effects Return Jack that was causing your issue.

I've circled the little Shunt I'm referring to in this pic:

View attachment 7258253
Click to expand...
I've found this to be the most common culprit for scratchy output, low output and even no output in almost every amp I've seen. After having this problem with my Mesa Big Block, I decided to just leave a patch cable in the effects loop. Mesa fixed this in later models by putting a bypass switch in the effects loop.
 
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