Eden WT405, Running at 2 Ohms

[Count Bassie]

Long ago, my handle here was The Nameless. We met here on a deal for a set of Bartolini pickups you wanted for a Smith bass ages ago. Yup, a whole lotta water traveled under a whole lotta bridges. We've spoken on occasion since, but not since the Cold happened, at least. But I see yer posts on occasion, and remember our conversations.

As far as running an Eden amp at 2ohms, only after a certain year did it become "safe" to do so. Early Eden amps would NOT run at 2 ohms. Their stereo heads bridged at 8 ohms only, meaning a 4 ohm load per side was minimum. I used SWR at this time because their amps would bridge at 4ohm, meaning 2 ohms per side.

Later on, about 2003, Eden amps were updated a bit. Their stereo amps would, then, bridge at 4 ohms, thus handle a 2 ohms load per side. That's when the 405, then the 550, were introduced and would, supposedly, run at 2 ohms. I know they run at 2 ohms, my 2nd buddy mentioned earlier does it on occasion. I personally don't like running 2 ohms at all. I've never designed my rigs that way, and as some have said here that can cause unnecessary stress and heat on amps of this vintage. I do run at 4 ohms, tho. And I preferred an amp that would run at 2 ohms, just to believe I wasn't running an amp at it's limit.

Of course I remember! Good to see you around, and thanks for the chime-in.
I don't need to run at 2 ohms most of the time, but my small 215 cab isn't lows-heavy at all, and it occurs that sometimes I might want to run my SWR Goliath-II along with, because it's got a good bit more deep to its push... Figured maybe with them working together I could get a little more dark in my stage-air. Each cab is 4 ohms.
I get the point about the Neutrik, I'll have to get a cable to use that, probably should anyway.
Good to hear from you Dave.

 

[Rip Van Dan]

***CLIP***
Lane Baldwin posted, on the ancient Eden forum well over a decade ago - maybe even two decades ago - how he noticed a definite improvement in tone when he switched to Neutrik with his Eden 610 cabinet (I am not 100% but I think he was using a bridged WT-800C so he was developing a lot of current for the cabinet).

Hey Stuart,
Actually Lane was using the WT800-A version originally, in fact two of them, one for each 610 (Lane's "Thunder Rig"). Those 610's were/are 6Ω cabs and the WT800, although rated to run bridged into 8Ω, could safely run those a 6Ω. That was the one exception at the time to the bridged at 8Ω (4Ω per channel) limit. David Nordschow, who designed both, said the WT800A could safely handle that 6Ω load, so that's what Lane ran. That ran both channels at 3Ω so that bridged at 6Ω and put out 1,000 watts into that cab.

In 2005, the WT800B came out which was the first WT800 that could do 2Ω per channel and bridge at 4Ω with 1,100 watts rms. About a year later they published a WT800C addendum, consisting of just one page listing the changes from the B model to the C model. The easy way to tell them apart is that the C model has "the porchlight", which is a back-lit Eden logo that none of the other WT amps had. Now days both the Eden WTP and the Eden TN amps have the porchlight logo.

Lane did eventually go to the WT800C, and then to the DNA amps once David left Eden and started DNA. Lane had a hard time staying at Eden once David left, but David encouraged him to stay "for the time being". Lane still got involved with DNA before David brought out his first DNS cabs. DNS stands for David Nordschow Speakers.

Lane is the reason I ended up with my WT500/800 amp. He knew I bid on it when David had it for sale on Ebay. I got out bid, but top bidder didn't reach the reserve. He asked me what the best I could offer was. I told him, he told David, and David said yeah. About two weeks later, I had the amp in hand. Lane was such an asset for the Eden Forum before he left! I was asked to "volunteer" as a moderator for the Eden Forum not long after he left.

 

[MrLenny1]

You got me reminiscing.
I ran a WT 400 which did 8 and/or 4 ohms. Not 2 ohms
but it did run hot into a 4 ohm Acme 2x10. Physically hot to the touch.
Swapped the Acme for an Eden 2x10 XST and ran much cooler.

 

[Rip Van Dan]

There are two speaker out jacks on the back of the amp, 1/4" phone jacks. They are labeled "405 watts @ 4 ohms".
There is a Neutrik speaker Jack labeled for 2 ohm use
Do I necessarily need to use the Neutrik jack if I want to run 2x 4 ohm cabs, for a total load of 2 Ohms?
That's it. Thanks!

Before the Speakon outputs were used on the Eden amps, they used Banana connectors, which would allow you to hook up your cabs in either parallel or series using individual wires and bayonet plugs, if you followed their diagram. Most people just bought the bayonet plugs with both positive and negative together instead of separate. Those worked well and you didn't have the chance of a short like you do with 1/4" phone plugs (TS plugs).

Speakon connections are the best. They are safer for cabs/amps because they lock in place preventing disconnection shorts, and also can handle higher power better than the 1/4" plugs. My DNA-800 amp still includes a single 1/4" plug as an "emergency connection" besides the two Speakon connections just in case you end up using a cab that doesn't have Speakon connectors.

The WT405 in all it's previous renditions (WT330, WT390, WT405) does handle down to 2Ω and always has. There are two versions of the WT405. The first version did 250-watts into 8Ω, 405-watts into 4Ω, and 650-watts into 2Ω. The second version had minutely higher power than the first, putting out 655-watts rms into 2Ω. The WT330 and WT390 were discontinued by 2005 when the standalone WT405 manual came out.

David named it the WT405 because of its power into 4Ω, which is where he thought it sounded best. He once remarked that he thought his amps sounded best into a 4Ω load, but that he had to make them 2Ω capable because that's what the market asked for. He seemed to be the only one who thought that though as most people who used it with a 2Ω load thought it sounded and performed great.

The WT405 and its earlier "Time Traveler" predecessors are unusual for the WT series because David didn't use a tube in the preamp to generate the warmth of sound that the Eden WT series was known for. Rather he used a "Golden Ear" chip (THAT-4301) that, among other things, emulated tube warmth in a purely solid state amplifier. The preamp from the WT405 with its built-in adjustable compressor is basically the same as the preamp included in Eden's WTDI pedal, which is why the WTDI sounds so good. That chip is also in the WTDI and Eden's class D Terra Nova amps, which is why my little TN-226 sounds just as warm as my WT500/800 does with its tube in the preamp for warmth.

I've attached 2 files. One is the manual for the WT-330, WT390, and WT405. They are all the same amp but just with different power sections. The second one is the manual for the WT405 second version. In the second version the only difference from the first version is the very slightly higher wattage at 2Ω (655-watts vs. 650-watts).

To get the best sound out of your Eden WT405 (or any Eden WT amp) pay particular attention to the section on "Setting Your Level", which is on page 12 of the "330, 390, 405 manual " and on page 5 of the WT405 manual. You might notice that the dates on the cover page don't make sense. The manual for the WT330, WT390, and WT405 attached below came out in 2003 whereas the single manual for the WT405 actually came out in 2005. That was all Lane Baldwin's fault when he was doing some updating. He, along with David, wrote the manuals, which explains some of the humor you will find in the way they are written.

 

[Rip Van Dan]

You got me reminiscing.
I ran a WT 400 which did 8 and/or 4 ohms. Not 2 ohms
but it did run hot into a 4 ohm Acme 2x10. Physically hot to the touch.
Swapped the Acme for an Eden 2x10 XST and ran much cooler.

That WT400, by the way, is considered to be about the best sounding amp Eden ever made. Every once in a while someone would put one up for sale on the Eden Forum and it rarely stayed up more than one or two days before it was sold. After it was sold, we'd get a lot of messages on the forum from people who had sold theirs; wished they never had; and were moaning because they didn't see the one that just sold in time to buy it themselves.

You mentioned how hot it got with one of your cabs. That would be because you had to use quite a bit more power with it than you do with your D210XST. One of the ways to make your amp run cooler is flip the fan around on the inside so it's pushing air out of the chassis instead of trying to suck it in. Odds are your WT400 has the fan pulling air in instead of pushing it out.

Instead of pulling the air in, that fan cools much better if you flip it around so it pushes the air out. If the back or our amp has round holes over the fan it came from the factory with the fan pulling air in. It wasn't until after Eden started using the oval holes that they started mounting the fans in the other way pushing air out of the chassis to improve the cooling. They finally ended up cutting that entire area out of the back panel and covering it with a chrome cage to facilitate cooling.

If you want to flip your fan around, you just have to remove all those tiny screws to pull the chassis apart and unscrew the 4 screws holding the fan in place. The flip the fan around pointing in the other way and screw it back in place. Then screw all those tiny screws back in to hold the chassis together again and you will have improved your cooling.

Just in case you can use it, I've attached a pdf copy of the WT400 manual here. And you are quite correct, the WT400 has a minimum ohms load of 4Ω. Its predecessor, the WT300, also had a minimum ohms load of 4Ω but has never commanded the love that the WT400 garners.

 

[Count Bassie]

As far as running an Eden amp at 2ohms, only after a certain year did it become "safe" to do so. Early Eden amps would NOT run at 2 ohms....

...Later on, about 2003, Eden amps were updated a bit. Their stereo amps would, then, bridge at 4 ohms, thus handle a 2 ohms load per side. That's when the 405, then the 550, were introduced and would, supposedly, run at 2 ohms.

Before the Speakon outputs were used on the Eden amps, they used Banana connectors, which would allow you to hook up your cabs in either parallel or series using individual wires and bayonet plugs, if you followed their diagram. Most people just bought the bayonet plugs with both positive and negative together instead of separate. Those worked well and you didn't have the chance of a short like you do with 1/4" phone plugs (TS plugs).

Speakon connections are the best. They are safer for cabs/amps because they lock in place preventing disconnection shorts, and also can handle higher power better than the 1/4" plugs. My DNA-800 amp still includes a single 1/4" plug as an "emergency connection" besides the two Speakon connections just in case you end up using a cab that doesn't have Speakon connectors.

The WT405 in all it's previous renditions (WT330, WT390, WT405) does handle down to 2Ω and always has. There are two versions of the WT405. The first version did 250-watts into 8Ω, 405-watts into 4Ω, and 650-watts into 2Ω. The second version had minutely higher power than the first, putting out 655-watts rms into 2Ω. The WT330 and WT390 were discontinued by 2005 when the standalone WT405 manual came out.

David named it the WT405 because of its power into 4Ω, which is where he thought it sounded best. He once remarked that he thought his amps sounded best into a 4Ω load, but that he had to make them 2Ω capable because that's what the market asked for. He seemed to be the only one who thought that though as most people who used it with a 2Ω load thought it sounded and performed great.

The WT405 and its earlier "Time Traveler" predecessors are unusual for the WT series because David didn't use a tube in the preamp to generate the warmth of sound that the Eden WT series was known for. Rather he used a "Golden Ear" chip (THAT-4301) that, among other things, emulated tube warmth in a purely solid state amplifier. The preamp from the WT405 with its built-in adjustable compressor is basically the same as the preamp included in Eden's WTDI pedal, which is why the WTDI sounds so good. That chip is also in the WTDI and Eden's class D Terra Nova amps, which is why my little TN-226 sounds just as warm as my WT500/800 does with its tube in the preamp for warmth.

I've attached 2 files. One is the manual for the WT-330, WT390, and WT405. They are all the same amp but just with different power sections. The second one is the manual for the WT405 second version. In the second version the only difference from the first version is the very slightly higher wattage at 2Ω (655-watts vs. 650-watts).

To get the best sound out of your Eden WT405 (or any Eden WT amp) pay particular attention to the section on "Setting Your Level", which is on page 12 of the "330, 390, 405 manual " and on page 5 of the WT405 manual. You might notice that the dates on the cover page don't make sense. The manual for the WT330, WT390, and WT405 attached below came out in 2003 whereas the single manual for the WT405 actually came out in 2005. That was all Lane Baldwin's fault when he was doing some updating. He, along with David, wrote the manuals, which explains some of the humor you will find in the way they are written.

So is the 405B the second issue we're talking about?

 

[Rip Van Dan]

So is the 405B the second issue we're talking about?

Yes.

 

[David McIntire]

Yes.

Mr Van Dan. You seem quite knowledgeable on these Eden amps. I know some. But never had interest in them to use on the regular. My knowledge is mostly by osmosis, as many of my friends use and love Eden amps. I have a question for ya. If you don't mind.

I have two friends using this style of WT amp. One uses a 405. I know enuff bout that amp, and what you've written here in this thread reinforces what I believe I know.

My other friend uses a WT330. It's one of the first made, matter of fact. Low serial. And made in Montrose. You mentioned in a response here that all versions of this amp; 330, 390 and 405 were stable at 2 ohms. My friend using the 330 has always believed 4 ohms was minimum. Do you believe his amp would be stable at 2? Just curiosity.

 

[Rip Van Dan]

Mr Van Dan. You seem quite knowledgeable on these Eden amps. I know some. But never had interest in them to use on the regular. My knowledge is mostly by osmosis, as many of my friends use and love Eden amps. I have a question for ya. If you don't mind.

I have two friends using this style of WT amp. One uses a 405. I know enuff bout that amp, and what you've written here in this thread reinforces what I believe I know.

My other friend uses a WT330. It's one of the first made, matter of fact. Low serial. And made in Montrose. You mentioned in a response here that all versions of this amp; 330, 390 and 405 were stable at 2 ohms. My friend using the 330 has always believed 4 ohms was minimum. Do you believe his amp would be stable at 2? Just curiosity.

I might have to defer to Armin (@Bassmann1968) about that to be sure. All the info I have on it gives a power rating at 2Ω for it. Specifically is says,
"The WT330 delivers 200 watts RMS output @ 8 Ohms,
330 watts @ 4Ohms
and 420 watts @ 2 Ohms."

But Armin was a moderator on the Eden Forum longer than I was and he was always the electronics guru of the forum. So you might wait until he chimes in. David Nordschow (founder of Eden) almost always named his designs after the power they generated at 4Ω even though a lot of them could go down to 2Ω. He did that because he thought that although they were capable of 2Ω operation, he thought they sounded better running at 4Ω.

People often confused the capabilities of the WT330, WT390, and WT405 with the WT300 and WT400. Both the WT300 and WT400 were much earlier amps and both used a hybrid preamp with a 12ax7 tube in the impedance matching section to generate the warmth in their sound. Neither the WT300 nor the WT400 were capable of 2Ω operation.

 

[mbrain]

That WT400, by the way, is considered to be about the best sounding amp Eden ever made. Every once in a while someone would put one up for sale on the Eden Forum and it rarely stayed up more than one or two days before it was sold. After it was sold, we'd get a lot of messages on the forum from people who had sold theirs; wished they never had; and were moaning because they didn't see the one that just sold in time to buy it themselves.

Now Rip, there you go again. The WT400 was a great amp (love mine) and got accolades as the best of Eden’s offerings tone-wise. But when Eden built 25 more WT400 amps out of old-stock parts for its 30th Anniversary, after they had been out of production for several years, Eden had a problem moving them. So the people who expressed regret at passing up a used version apparently weren’t clamoring to replace theirs.

 

[Rip Van Dan]

Now Rip, there you go again. The WT400 was a great amp (love mine) and got accolades as the best of Eden’s offerings tone-wise. But when Eden built 25 more WT400 amps out of old-stock parts for its 30th Anniversary, after they had been out of production for several years, Eden had a problem moving them. So the people who expressed regret at passing up a used version apparently weren’t clamoring to replace theirs.

Just speaking from experience on the Eden Forum. I was on it daily from 2008 until it was unceremoniously shut off. From about 2010 on, I was one of the moderators. We had a lot of posts "Looking for WT400" in the classifieds on the forum and when we did get one listed in the classifieds, it was usually gone within a day or two.

Those 30-year anniversary models would have been issued in 2006. I didn't realize they only made 25 of those and of course, Eden didn't put out a catalog in 2006. Just checked my catalog files and the normal WT400 was still in the catalog in 2004 alongside the WT550, but in 2005 it was gone. Eden didn't put out a catalog in 2006 and it never did show up in another catalog after 2004.

 

[H Nighttrain]

So, could a WT550 be run exclusively at 2 ohms with no ill effects? Other than sounding a tiny bit poorer in, uh, some way (muddier, compressed,...?)?

 

[mbrain]

So, could a WT550 be run exclusively at 2 ohms with no ill effects? Other than sounding a tiny bit poorer in, uh, some way (muddier, compressed,...?)?

So, could a WT550 be run exclusively at 2 ohms with no ill effects? Other than sounding a tiny bit poorer in, uh, some way (muddier, compressed,...?)?

Yes, the WT550 could run all day at 2 ohms. Announced in May 2003, it was originally rated at 300/500/620 watts for 8/4/2 ohm operation. At some point they bumped it to 750 watts at 2 ohms. It was marketed as an upgraded WT400. Rip is right that the catalogs continued to list the WT400 for a couple of years, but that’s probably because they were trying to sell the remaining run of WT400’s they had. There was a fair amount of nostalgia for the WT400’s, but when Eden produced a limited run for the 2006 anniversary, they had a hard time selling them. The price difference between the two wasn’t much, and so pretty much everyone opted for more power and the ability to run at 2 ohms. For the right price, though, it wasn’t hard to move used WT400.

 

[Bassmann1968]

Mr Van Dan. You seem quite knowledgeable on these Eden amps. I know some. But never had interest in them to use on the regular. My knowledge is mostly by osmosis, as many of my friends use and love Eden amps. I have a question for ya. If you don't mind.

I have two friends using this style of WT amp. One uses a 405. I know enuff bout that amp, and what you've written here in this thread reinforces what I believe I know.

My other friend uses a WT330. It's one of the first made, matter of fact. Low serial. And made in Montrose. You mentioned in a response here that all versions of this amp; 330, 390 and 405 were stable at 2 ohms. My friend using the 330 has always believed 4 ohms was minimum. Do you believe his amp would be stable at 2? Just curiosity.

2 Ohms load is no problem for the 330.