Eden Forum Disappears

[Rip Van Dan]

Don't want to make anyone wrong here, but I can tell a significant difference in sound between tubes. Yes, of course the input tube buffers impedance but it is also an amplification stage with much gain. A cathode follower stage. I have a massive improvement in sound using a 5751 vs 12ax7. Also have a massive improvement in sound between a NOS tube and a current production tube.

What I'm trying to say here is that the tube does make a difference in sound, and I have found that the same guides that apply to audiophile tube rolling (such as 'Joes Tube Lore') do apply to eden amps.

Which Eden amp are you referring to and when was it made?

 

[frankie5string]

What I'm trying to say here is that the tube does make a difference in sound, and I have found that the same guides that apply to audiophile tube rolling (such as 'Joes Tube Lore') do apply to eden amps.

Isn't a 5751 tube just lower gain than a 12ax7? It's got a bit more gain than a 12at7, right?
If you didn't have a gain and master volume control, I could see where this could be a thing - but your amp has both, doesn't it?

Wasn't Joes Tube Lore one of those documents that called certain tubes "linear-sounding" or "more vibrant?"

How do you know that what you're hearing isn't just the result of an out-of-spec tube pushing or fighting something in the surrounding circuit? I mean, if it's good it's good, but is it proper to be attributing the sound to just the tube, itself? Or is it some sort of mis-match in the circuit the engineers never intended or designed for? Audiophiles often can't even agree on any type of tube or component that makes something sound better - and remember, that group often pushes $10000 power cables and speaker cables.

 

[old_thumper]

Lol...trick question there...

 

[old_thumper]

I was referring to agedhorse comment.

On that note, can a cathode follower stage affect the tone of the preamp?

I'm thinking of the SWR, Eden and other solid sate amps that use a tube in the preamp portion but it's just a cathode follower set up. No gain, but supposedly gives the amp a warmer sound.

 

[agedhorse]

I was referring to agedhorse comment.

On that note, can a cathode follower stage affect the tone of the preamp?

I'm thinking of the SWR, Eden and other solid sate amps that use a tube in the preamp portion but it's just a cathode follower set up. No gain, but supposedly gives the amp a warmer sound.

Using a cathode follower is a valid approach but because there is so much local feedback, the variations between different tubes are reduced to almost nothing. It does offer high input impedance, and depending on how the cathode go lower is designed and where in the circuit it’s located, it can become non-linear at high drive levels.

As an answer to the question I asked about how much gain a cathode follower circuit has, the answer is always slightly less than 1.

 

[old_thumper]

I was thinking that there was no gain on a cathode follower ( 1:1) but you are saying it's actually less. Never thought of it that way.

In my meager studies of tube amp circuits, I've seen the cathode followers used for driving tone stacks and FX loops. I was guessing that this was done to supply more current but I think you are saying it's done for impedance matching reasons.

My next set of questions isn't about Eden stuff but a bit about Mesa Boogie stuff and Soldano ( and Jet City ) amps.

1) Which amp designer first used cascading gain preamps? Soldano? Mesa Boogie? Others?

When I hear Mesa Boogie and Soldano amps, I've often felt they were very similar in their tone. There is a cleaner and smoother sound to the driven signal with not lots of fizz and harshness. Both amps have that bottom end grunt as well that remains tight and not mushy or wooly.

2) Why is that?

I've wondered ( and I could be totally off in my reasoning ) that it may have something to do with the cascading gain section of the preamp.

3) Does the cascading gain preamp keep the tubes running in a more linear section of the gain for the tube and that tends to limit distortion?

4) Does keeping the gain of the tube in the linear portion promote even harmonics more and limit odd harmonics?

 

[abarson]

I was thinking that there was no gain on a cathode follower ( 1:1) but you are saying it's actually less. Never thought of it that way.

In my meager studies of tube amp circuits, I've seen the cathode followers used for driving tone stacks and FX loops. I was guessing that this was done to supply more current but I think you are saying it's done for impedance matching reasons.

My next set of questions isn't about Eden stuff but a bit about Mesa Boogie stuff and Soldano ( and Jet City ) amps.

1) Which amp designer first used cascading gain preamps? Soldano? Mesa Boogie? Others?

When I hear Mesa Boogie and Soldano amps, I've often felt they were very similar in their tone. There is a cleaner and smoother sound to the driven signal with not lots of fizz and harshness. Both amps have that bottom end grunt as well that remains tight and not mushy or wooly.

2) Why is that?

I've wondered ( and I could be totally off in my reasoning ) that it may have something to do with the cascading gain section of the preamp.

3) Does the cascading gain preamp keep the tubes running in a more linear section of the gain for the tube and that tends to limit distortion?

4) Does keeping the gain of the tube in the linear portion promote even harmonics more and limit odd harmonics?

Why not make this a standalone post instead of commingling it with this Eden thread?

 

[old_thumper]

The thought occurred to me but there isn't really that much traffic for Eden these days and I already had agehorse's attention, so I continued.

Who knows, some folks may want to learn a bit more about how tubes work.

I won't ask any more questions more questions about non Eden topics.

 

[Marko 1]

From what little I know about Eden (I'm a late starter), I can imagine myself as being a fan and user.

Since they're no longer in business, I don't mess with them, though...

I do get tempted when I see that WT800 on GC's used site, but (at $700) I've resisted.

 

[agedhorse]

I was thinking that there was no gain on a cathode follower ( 1:1) but you are saying it's actually less. Never thought of it that way.

In my meager studies of tube amp circuits, I've seen the cathode followers used for driving tone stacks and FX loops. I was guessing that this was done to supply more current but I think you are saying it's done for impedance matching reasons.

My next set of questions isn't about Eden stuff but a bit about Mesa Boogie stuff and Soldano ( and Jet City ) amps.

1) Which amp designer first used cascading gain preamps? Soldano? Mesa Boogie? Others?

When I hear Mesa Boogie and Soldano amps, I've often felt they were very similar in their tone. There is a cleaner and smoother sound to the driven signal with not lots of fizz and harshness. Both amps have that bottom end grunt as well that remains tight and not mushy or wooly.

2) Why is that?

I've wondered ( and I could be totally off in my reasoning ) that it may have something to do with the cascading gain section of the preamp.

3) Does the cascading gain preamp keep the tubes running in a more linear section of the gain for the tube and that tends to limit distortion?

4) Does keeping the gain of the tube in the linear portion promote even harmonics more and limit odd harmonics?

The voltage gain of a cathode follower is usually between 0.95 and 0.98, there will always be some real world losses.

Cathode followers provide both a high input impedance and a low output impedance with current gain. This configuration acts as a buffer and works well when driving lower impedance loads.

A1) It's generally attributed to Mesa Boogie. Randy came up with this early on and actually patented some of the switching topologies.

A2) It's the combination of the intent and the design.

A3) It's more how the over drive is generated and the tone profiles of the various stages within the series of gain stages.

A4) The linear portion of the tube provides the least amount of even and odd harmonics. Cathode followers generally operate in the linear portion unless intentionally overdriven (which is more difficult but not impossible), and the local feedback really linearizes the tube's response which can minimize any/all harmonics depending on intricacies of the particular circuit.

Why not make this a standalone post instead of commingling it with this Eden thread?

Maybe because it addresses a topology that was often used by Eden, and because it's commonly misunderstood or misconstrued?

 

[abarson]

Maybe because it addresses a topology that was often used by Eden, and because it's commonly misunderstood or misconstrued?

Context is always valuable, thanks!

 

[Rip Van Dan]

From what little I know about Eden (I'm a late starter), I can imagine myself as being a fan and user.

Since they're no longer in business, I don't mess with them, though...

I do get tempted when I see that WT800 on GC's used site, but (at $700) I've resisted.

Hey @Marko 1 . When you see a WT800 on any site or as used, you really have to be careful about which WT800 you are looking at. The first WT800's in the 90's are known as the WT800A. They are capable of 400-watts into 4Ω per channel (has two power channels) or 800-watts bridged into 8Ω. That is the power section that I have in my WT500/800, which was upgraded by David Nordschow (David Eden) to 800-watts. That was the original 800-watt power section. To confuse matters there were b, c, and d, upgrades to that model and those b, c, and d markings are typically hand written on the back of the amp, such as WT800b, WT800C, WT800D. Almost all of these used the banana plugs along with 1/4" plugs for the speaker outputs. Basically the cooling and the protection circuits kept improving.

In 2005, the new Model B WT800 was introduced. It also says WT800B on the back, but it uses speakon connectors for the speaker outputs. It has an upgraded power section along with upgraded cooling AND each of the channels now goes down to 2Ω, which enables it to bridge at 1,100-watts into a 4Ω load. It would bridge at 880-watts into an 8Ω load. The following year, Eden started producing the WT800C which had "the porch light". The porch light is a back-lit Eden Logo, which lights up when you turn the power one. So, if you the logo lights up when you turn the power on, that is an Eden WT800C. The newer Eden TN class D amps also have the porch-light, but they are not easily confused with the WT8000C.

A interesting bit of trivia about the WT800C model. Marshall bought Eden the last day of 2011, so call it 2012. They took David's WT800 and WT550 designs and expanded on them, bringing out a new WTP (World Tour Pro) series with the WTP-900 and WTP-600. They introduced those in 2015. These two amps incorporated an additional 12ax7 in the gain section besides the 12ax7 in the impedance matching section of the amp, and you could dial in as much overdrive/distortion as you wanted. Now the new Eden WTP900 could play clean like the older WT800's or with overdrive and outright dirt because Marshall is very good at those circuits.

Bad news was that although it could bridge at 900-watts into 8Ω, it couldn't bridge into a 4Ω load with 1100-watts like the WT800C could. So you couldn't use Eden's D810LT (top of the line 4Ω cab with 4 XLT speakers and 4XST speakers) with it. And, of course, the individual channels could only go down to 4Ω per channel instead of the 2Ω load that the WT800C could handle.

They continued to sell both series of amps for another 2 years but changed the text on the back of the WT800C to show it could only bridge into 8Ω instead of 4Ω. They changed absolutely nothing in the interior of the WT800C amp, just changed the text on the back of the amp from "Bridged Output, 4Ω minimum" to Bridged Output, 8Ω minimum" next to the bridged output. During that first year of selling both, the WT800C outpaced the WTP900 as a fair amount of the market for that power was folks using 810 cabs at 4Ω.

Through a neat trick with the bridged output, you could run two 4Ω cabs bridged because plugging in two 4Ω cabs to the correctly lit up outputs, hooked them up internally in series instead of parallel. This changed the ohms load to 8Ω and delivering a full 900-watts to be split between them. Of course, you could just plug one cab into each power channel by themselves and get the same amount of power. Just don't expect to plug a 4Ω 810 into it with only one power connection.

When we checked with out Eden contact about the "typo" on the back of the latest batch of WT800C amps, we were told they changed it because they weren't comfortable with it running at 2Ω per channel and bridging at 4Ω. Of course it had an 11-year history (since 2005) of it being run that way before Marshall decided they weren't comfortable with it being run that way. Of course that had nothing to do with the fact that their new and "better" amp couldn't match it. To be perfectly honest though, they did run a cooler amp using 2 fans in their WTP series and restricting it to 4Ω per channel and 8Ω bridged....sorry about the rant...

 

[Rip Van Dan]

From what little I know about Eden (I'm a late starter), I can imagine myself as being a fan and user.

Since they're no longer in business, I don't mess with them, though...

I do get tempted when I see that WT800 on GC's used site, but (at $700) I've resisted.

Just as an FYI @Marko 1, they are still in business...barely. Marshall sold them to Gear4Music.com a couple of years ago with the caveat that Marshall would still do the manufacturing. Marshall has been really poor at doing the manufacturing as it is no longer a priority with them. However, according to Gear4Music they are expecting to get back into a good inventory state in the second quarter of 2024. So, it's not out of business, but fair to say it is on life support.

Also, that WT800C amp was about $1600 new, so $700 is not bad for it if it is a true WT800C. Also don't shy away from it if it says made in China. Eden had changed manufacturing facilities in the US again after David left and with new facilities and new techs, went through a few months of terrible quality control and defective amps. Manufacturing then went to China to the factory that had made the Eden Nemesis line for over a decade. And, all the problems suddenly disappeared because those techs had been working on and producing Eden designs for years with virtually no problems.

 

[Marko 1]

Hey @Marko 1 . When you see a WT800 on any site or as used, you really have to be careful about which WT800 you are looking at. The first WT800's in the 90's are known as the WT800A. They are capable of 400-watts into 4Ω per channel (has two power channels) or 800-watts bridged into 8Ω. That is the power section that I have in my WT500/800, which was upgraded by David Nordschow (David Eden) to 800-watts. That was the original 800-watt power section. To confuse matters there were b, c, and d, upgrades to that model and those b, c, and d markings are typically hand written on the back of the amp, such as WT800b, WT800C, WT800D. Almost all of these used the banana plugs along with 1/4" plugs for the speaker outputs. Basically the cooling and the protection circuits kept improving.

In 2005, the new Model B WT800 was introduced. It also says WT800B on the back, but it uses speakon connectors for the speaker outputs. It has an upgraded power section along with upgraded cooling AND each of the channels now goes down to 2Ω, which enables it to bridge at 1,100-watts into a 4Ω load. It would bridge at 880-watts into an 8Ω load. The following year, Eden started producing the WT800C which had "the porch light". The porch light is a back-lit Eden Logo, which lights up when you turn the power one. So, if you the logo lights up when you turn the power on, that is an Eden WT800C. The newer Eden TN class D amps also have the porch-light, but they are not easily confused with the WT8000C.

A interesting bit of trivia about the WT800C model. Marshall bought Eden the last day of 2011, so call it 2012. They took David's WT800 and WT550 designs and expanded on them, bringing out a new WTP (World Tour Pro) series with the WTP-900 and WTP-600. They introduced those in 2015. These two amps incorporated an additional 12ax7 in the gain section besides the 12ax7 in the impedance matching section of the amp, and you could dial in as much overdrive/distortion as you wanted. Now the new Eden WTP900 could play clean like the older WT800's or with overdrive and outright dirt because Marshall is very good at those circuits.

Bad news was that although it could bridge at 900-watts into 8Ω, it couldn't bridge into a 4Ω load with 1100-watts like the WT800C could. So you couldn't use Eden's D810LT (top of the line 4Ω cab with 4 XLT speakers and 4XST speakers) with it. And, of course, the individual channels could only go down to 4Ω per channel instead of the 2Ω load that the WT800C could handle.

They continued to sell both series of amps for another 2 years but changed the text on the back of the WT800C to show it could only bridge into 8Ω instead of 4Ω. They changed absolutely nothing in the interior of the WT800C amp, just changed the text on the back of the amp from "Bridged Output, 4Ω minimum" to Bridged Output, 8Ω minimum" next to the bridged output. During that first year of selling both, the WT800C outpaced the WTP900 as a fair amount of the market for that power was folks using 810 cabs at 4Ω.

Through a neat trick with the bridged output, you could run two 4Ω cabs bridged because plugging in two 4Ω cabs to the correctly lit up outputs, hooked them up internally in series instead of parallel. This changed the ohms load to 8Ω and delivering a full 900-watts to be split between them. Of course, you could just plug one cab into each power channel by themselves and get the same amount of power. Just don't expect to plug a 4Ω 810 into it with only one power connection.

When we checked with out Eden contact about the "typo" on the back of the latest batch of WT800C amps, we were told they changed it because they weren't comfortable with it running at 2Ω per channel and bridging at 4Ω. Of course it had an 11-year history (since 2005) of it being run that way before Marshall decided they weren't comfortable with it being run that way. Of course that had nothing to do with the fact that their new and "better" amp couldn't match it. To be perfectly honest though, they did run a cooler amp using 2 fans in their WTP series and restricting it to 4Ω per channel and 8Ω bridged....sorry about the rant...

Wow, lots of valuable info, sir; thanks so much.

 

[DavidEdenAria]

Hey @Marko 1 . When you see a WT800 on any site or as used, you really have to be careful about which WT800 you are looking at. The first WT800's in the 90's are known as the WT800A. They are capable of 400-watts into 4Ω per channel (has two power channels) or 800-watts bridged into 8Ω. That is the power section that I have in my WT500/800, which was upgraded by David Nordschow (David Eden) to 800-watts. That was the original 800-watt power section. To confuse matters there were b, c, and d, upgrades to that model and those b, c, and d markings are typically hand written on the back of the amp, such as WT800b, WT800C, WT800D. Almost all of these used the banana plugs along with 1/4" plugs for the speaker outputs. Basically the cooling and the protection circuits kept improving.

In 2005, the new Model B WT800 was introduced. It also says WT800B on the back, but it uses speakon connectors for the speaker outputs. It has an upgraded power section along with upgraded cooling AND each of the channels now goes down to 2Ω, which enables it to bridge at 1,100-watts into a 4Ω load. It would bridge at 880-watts into an 8Ω load. The following year, Eden started producing the WT800C which had "the porch light". The porch light is a back-lit Eden Logo, which lights up when you turn the power one. So, if you the logo lights up when you turn the power on, that is an Eden WT800C. The newer Eden TN class D amps also have the porch-light, but they are not easily confused with the WT8000C.

A interesting bit of trivia about the WT800C model. Marshall bought Eden the last day of 2011, so call it 2012. They took David's WT800 and WT550 designs and expanded on them, bringing out a new WTP (World Tour Pro) series with the WTP-900 and WTP-600. They introduced those in 2015. These two amps incorporated an additional 12ax7 in the gain section besides the 12ax7 in the impedance matching section of the amp, and you could dial in as much overdrive/distortion as you wanted. Now the new Eden WTP900 could play clean like the older WT800's or with overdrive and outright dirt because Marshall is very good at those circuits.

Bad news was that although it could bridge at 900-watts into 8Ω, it couldn't bridge into a 4Ω load with 1100-watts like the WT800C could. So you couldn't use Eden's D810LT (top of the line 4Ω cab with 4 XLT speakers and 4XST speakers) with it. And, of course, the individual channels could only go down to 4Ω per channel instead of the 2Ω load that the WT800C could handle.

They continued to sell both series of amps for another 2 years but changed the text on the back of the WT800C to show it could only bridge into 8Ω instead of 4Ω. They changed absolutely nothing in the interior of the WT800C amp, just changed the text on the back of the amp from "Bridged Output, 4Ω minimum" to Bridged Output, 8Ω minimum" next to the bridged output. During that first year of selling both, the WT800C outpaced the WTP900 as a fair amount of the market for that power was folks using 810 cabs at 4Ω.

Through a neat trick with the bridged output, you could run two 4Ω cabs bridged because plugging in two 4Ω cabs to the correctly lit up outputs, hooked them up internally in series instead of parallel. This changed the ohms load to 8Ω and delivering a full 900-watts to be split between them. Of course, you could just plug one cab into each power channel by themselves and get the same amount of power. Just don't expect to plug a 4Ω 810 into it with only one power connection.

When we checked with out Eden contact about the "typo" on the back of the latest batch of WT800C amps, we were told they changed it because they weren't comfortable with it running at 2Ω per channel and bridging at 4Ω. Of course it had an 11-year history (since 2005) of it being run that way before Marshall decided they weren't comfortable with it being run that way. Of course that had nothing to do with the fact that their new and "better" amp couldn't match it. To be perfectly honest though, they did run a cooler amp using 2 fans in their WTP series and restricting it to 4Ω per channel and 8Ω bridged....sorry about the rant...

Thanks for that info! Do you happen to know if changes happened with the Metro series thru the years?

 

[agedhorse]

Hey @Marko 1 .
When we checked with out Eden contact about the "typo" on the back of the latest batch of WT800C amps, we were told they changed it because they weren't comfortable with it running at 2Ω per channel and bridging at 4Ω. Of course it had an 11-year history (since 2005) of it being run that way before Marshall decided they weren't comfortable with it being run that way. Of course that had nothing to do with the fact that their new and "better" amp couldn't match it. To be perfectly honest though, they did run a cooler amp using 2 fans in their WTP series and restricting it to 4Ω per channel and 8Ω bridged....sorry about the rant...

It may have also been because it wouldn't pass regulatory safety testing at 4 ohms bridged.

 

[Rip Van Dan]

It may have also been because it wouldn't pass regulatory safety testing at 4 ohms bridged.

Not really though @agedhorse. They had been running the same amp at that load since 2005 and it had all the safety certifications required. That was 11-years of history on that amp design performing without a problem at 2Ω per channel and 4Ω bridged. The WTP-900 caught a fair amount of heat (bad pun - sorry) about the WTP not being able to bridge into 4Ω on the Eden Forum and we didn't really have a good answer for them. They also complained that the WTP600, which was an updated version of the WT550 wasn't as loud as the WT550. Everyone seemed to like the extra tube in the gain section to dial in anywhere from a little grind or overdrive, all the way to real dirt.

Again though, to be perfectly fair about it, the cooling system was really very well done in the WTP series. It was better than the WT series cooling if for no other reason than they had two fans in different locations pushing the hot air out of the amp instead of just a single one in the WT series.

 

[Rip Van Dan]

Thanks for that info! Do you happen to know if changes happened with the Metro series thru the years?

Yes it did. The Metro improved its power output. It went from 240-watts rms@8Ω/300-watts@4Ω/630-watts@2Ω" up to 300-watts@8Ω/500-watts@4Ω/750-watts@2Ω in 2005. I believe the features all remained the same and the footswitch that came with it enabled you to switch between channel 1 (FET front end - didn't have the warmth of the hybrid front end), and channel 2 (WT Hybrid front end - warmer sound) as long as you were plugged into channel two. When plugged into channel 1, that was the only channel you could play through. But while plugged into channel two, you could set up the EQ's differently from one another and then choose which one you wanted to play through and switch back and forth with the footswitch.

 

[DavidEdenAria]

Yes it did. The Metro improved its power output. It went from 240-watts rms@8Ω/300-watts@4Ω/630-watts@2Ω" up to 300-watts@8Ω/500-watts@4Ω/750-watts@2Ω in 2005. I believe the features all remained the same and the footswitch that came with it enabled you to switch between channel 1 (FET front end - didn't have the warmth of the hybrid front end), and channel 2 (WT Hybrid front end - warmer sound) as long as you were plugged into channel two. When plugged into channel 1, that was the only channel you could play through. But while plugged into channel two, you could set up the EQ's differently from one another and then choose which one you wanted to play through and switch back and forth with the footswitch.

Interesting, my Metro is written in @ 960 watts on the back panel (i assume peak watts)...it is a later Minnesota amp..it had a major issue with the master volume that i resolved with Deoxit contact enhancer after trying D5...otherwise it has been reliable.

I dont hear a significant difference between the 2 channels set flat...both have the enhance and comp (which i dont use the comp) and i do not have the footswitch.

I dont run the amp hard enough to kick on the fan for the most part..... but it is powerful and warm with a remarkable EQ on channel 2, even with the preamp dimed (which i prefer) it is clean and clear and takes pedals well....no matter the cabinet setup, it delivers.

Its a big amp in footprint, i pulled the amp and made a wood cabinet...i regard it is a classic amp design diminished by the fact it was a 'heavy' 2x10 combo amp which by todays standards is not desirable....low and very heavy, the casters were broken and the fur covering out of date lol.....still an iconic amp in my estimation and one well suited for rehearsal and studio imo.

 

[old_thumper]

I have an Eden WT800 A and an Eden WT800B. I think they weigh about 28 lbs, most of which is in that toroidal transformer. It's probably the most "high-end' bass amp I have. I know there are much nicer things out there but I can't afford it or can't carry it ( or both - thinking of an Ampeg SVT - lol ). I really do enjoy the sound of the Eden amps. I can run the EQ flat in the amp and it sounds great ( and I'm using an Eden D410XLT for the cab. Eden doesn't have the name recognition that it used to so the younger folk have moved on and the older folk find the amps and cabs too heavy, so they buy newer lightweight amps and cabs ( like Bergantino or Markbass ). So, if you keep your eyes and ears open, there are those deals that come along. The WT800A I bought from a bass player in his 70s that had moved on to Bergantino and sold me his Eden rig - $400 for the WT800A and $400 for an D410XLT. Both were prestine as this guy took care of his stuff. Getting repairs done on the WT800 can run you some bucks though. I had blown one of the power amp channels in the WT800B and it cost $350 to fix and that was 6 or so years ago. The Eden cabs that have Eden speakers in them can be reconed. It will run about $150 each ( $50 to $75 for the parts and another $50 to $75 in labor ). The Eden cabs with Eminence speakers are not rebuildable. They are a custom speaker made by Eminence for Eden. Eminence doesn't not make recone kits for custom speakers nor do they sell the custom speaker aftermarket. Parts may become scarcer as time goes on.