Eden NC-250 / NC-320

[waspclothes]

Hey guys, is there a schematic anywhere for an EDEN NC-250 or NC-320?

I know there's a thread from 18 months ago ( http://music-electronics-forum.com/t33293/ ) that came up without a schematic, but I figure it was worth it to ask again.

[Jazz P Bass]

Eden NC-250 Schematic

Mozwell was kind enough to post the file at Electrotanya.com.

[waspclothes]

Mozwell was kind enough to post the file at Electrotanya.com.

Thanks Jazz, unfortunately that schematic doesn't match this amp. The power supply is pretty similar though. Looks like the zener diode for the -15 supply in this amp is blown and shorted. Will replace it and hopefully nothing else is wrong with it, everything looks good otherwise.

[J M Fahey]

Interesting amp.

Straight from the Lateral Mosfet era, I guess that later versions went Bipolar (or went all the way and adapted to Hexfets).

What transistors do you actually have there?

A couple gut shots would be good too, might help others in the future.

In case you need troubleshooting it, at least in this version it uses grounded sources, literally, and speaker Hot comes from the junction of the large filter caps, which is NOT grounded.

I mention it because without signal everything looks fine ... but you start driving it and get weird unexplainable readings

[waspclothes]

Here's the proper schematic: NC320 SCH final.pdf

And a few pictures:

Interesting amp.

Straight from the Lateral Mosfet era, I guess that later versions went Bipolar (or went all the way and adapted to Hexfets).

What transistors do you actually have there?

A couple gut shots would be good too, might help others in the future.

In case you need troubleshooting it, at least in this version it uses grounded sources, literally, and speaker Hot comes from the junction of the large filter caps, which is NOT grounded.

I mention it because without signal everything looks fine ... but you start driving it and get weird unexplainable readings

[Tim81]

Thanks for the schematic and pictures.

I just bought an NC250 15” combo, where the speaker had been replaced and the amp serviced.

The on/off switch was always illuminated when on or off, and I was looking for a schematic to determine if it was wired correctly.

The schematic itself wasn’t that helpful, as the switch in my amp has 4 pins, however by looking at the pictures, I could see that the orange and black wires were on the opposite side, with the black on top. I swapped mine around, but didn’t notice which white wire was which, as there were two.
I turned it on and it worked as I would have imagined, with the power light only being illuminated in the on position.

One more thing I noticed is that there is a yellow wire from the power pcb, which connects to the power cable socket, right next to the brown wire.
On my amp this wasn’t connected, so I plugged it in.
I have no idea about amp wiring, and probably shouldn’t have played around with it, but it seems to have worked so far.

Can anyone confirm that the two white wires to switch won’t do any damage if in the wrong position? One had a red dot drawn on it in pen.

I may have just got them right by mistake, or perhaps it doesn’t matter, as long as they are on the outside two pins of the switch?

My other concern, was the yellow wire which was disconnected when I opened the amp. I plugged it back in, with only the fact that I saw it that way in the picture. I wouldn’t imagine that it just came loose with the vibration of the caster wheels when pushing the combo across pavers and rough ground. Is there any reason that this yellow wire to the power board, labeled AC something, would be disconnected? It seemed to work ok with it disconnected, when I first bought it.

Any help would be appreciated.

[nevetslab]

Thanks for the schematic and pictures.

I just bought an NC250 15” combo, where the speaker had been replaced and the amp serviced.

The on/off switch was always illuminated when on or off, and I was looking for a schematic to determine if it was wired correctly.

The schematic itself wasn’t that helpful, as the switch in my amp has 4 pins, however by looking at the pictures, I could see that the orange and black wires were on the opposite side, with the black on top. I swapped mine around, but didn’t notice which white wire was which, as there were two.
I turned it on and it worked as I would have imagined, with the power light only being illuminated in the on position.

One more thing I noticed is that there is a yellow wire from the power pcb, which connects to the power cable socket, right next to the brown wire.
On my amp this wasn’t connected, so I plugged it in.
I have no idea about amp wiring, and probably shouldn’t have played around with it, but it seems to have worked so far.

Can anyone confirm that the two white wires to switch won’t do any damage if in the wrong position? One had a red dot drawn on it in pen.

I may have just got them right by mistake, or perhaps it doesn’t matter, as long as they are on the outside two pins of the switch?

My other concern, was the yellow wire which was disconnected when I opened the amp. I plugged it back in, with only the fact that I saw it that way in the picture. I wouldn’t imagine that it just came loose with the vibration of the caster wheels when pushing the combo across pavers and rough ground. Is there any reason that this yellow wire to the power board, labeled AC something, would be disconnected? It seemed to work ok with it disconnected, when I first bought it.

Any help would be appreciated.

I have an Eden Nemesis 320 410 Combo amp here in the shop. It will be a few days before I get a chance to pull the amp assembly from it to have a look, though I did find a related schematic to it (perhaps). I've attached that. Primary wiring on each looks to be 240V as opposed to 120V.

eden nemesis RS700 (NA650) Sch.pdf

[Tim81]

Thanks nevetslab, that looks more like what is happening with my amps power switch.

I’ll take the back off the amp tonight to take some photos, and try to identify which of the two white wires go where, and what the yellow wire was.

[g1]

If your power switch now looks like the one in the picture, which of the whites is on top does not matter.

The NC250 you have has a complicated AC receptacle. It is also functioning as the fuse holder and the voltage selector (fuse holder flips upside down). You want to make sure you get it right.

[Tim81]

I took the cover off, and photographed the connections. I can’t seem to be able to upload any, because it says even one, exceeds the quota for file size.
The two white wires are now identified, one of which goes to AC-N on the power pcb, and the other goes to the power plug input socket. And as the black wire from the socket, is next to the white wire from the socket, I plugged those in on the switch together too.
The orange wire is in line with the white wire from AC-N.
I wish there was a way to upload photos, with a reduced quality, cause it makes sense if you see the images.
I’ll try to reduce the size and post them.

[Tim81]

[g1]

Those pics in post #11 are your amp? Earlier you said it was an NC250, it's not? You are on 240V ?

[nevetslab]

Nemesis NC320 Power Panel, 120V wiring

I have an Eden Nemesis 320 410 Combo amp here in the shop. [ATTACH]57327[/ATTACH]

I've opened up this NC320 Power Panel, after getting a couple outside shots. This one IS wired for 120VAC.

[g1]

I think he's got it wired up right, but you can see the labelling on your fuse holder at the IEC socket. If you turn it upside down you change the voltage.
I can't see the labelling on his. My concern is if the holder is the wrong way and you connect to 240V, the amp will blow up.

Here's another pic of the IEC socket/voltage selector:
https://images.reverb.com/image/uplo...c4vjvghfmv.jpg

[Tim81]

Nevetslab,
can you confirm that the white wire from the socket, is horizontally aligned with the black wire from the socket?

g1,
The pictures in post #11 is my amp.
My amp is a NC250 250 watt amp, but as the Eden naming system is apparently confusing, my 250 watt combo amp with 1x 15” speaker, is also called a NC115 when in a combo, like a NC210 has 2x 10” speakers.
But by that logic, what is an NC320 combo, when combined with either a 1x 15”, or 2x 10” speaker ccab?
Unless I have that aspect of the naming wrong, I believe my amp is rated for 250 watt output.

To all,
Which also brings me to the topic of series/parallel wiring of the extension jack.
As far as I can gather, my amps extension jack is wired in series, while it is interally rated at 8 ohms.
If I was to add an 8 ohm extension cab, my amp would not me providing the 250 watts @ 4 ohms, as labeled, but 250 watts @ 16 ohms.
(I’m no amp guru remember, so bear with me if I’m wrong).
I have read that eden combos are wired in series to prevent people overloading the amp with extention speakers, when the internal load is governed my two speakers; whereas, with 1 interernal speaker that won’t happen.
8 ohms and 8 ohms is 4 ohms, 4 and 4 is 2, but 8 and 4 is 5.6??
I’m straying into the realms of bullshitting a bit here, about stuff, I admit I don’t really know; but basically I am concidering, adding a series parallel switch, as the owner of this amp, (before the last one), drilled a hole in the enclosure, and added an input for an extension amp.
When the last owner blew the speaker, and got it fixed, (by the guy who rewired the switch wrong, so the light was on when switched off, but still plugged in), it was recommended to take it out.
So now there is a poorly drilled hole in the front of my amp, which I would like to fill with something useful.
Is that easy to do?
I have wired up over 10 guitars, (an outstanding claim for anyone’s resume, I know), and am familiar with series/ parallel switches for pickups; so I can work that part out myself, but are there any other considerations to take into account?

My final question, (although not literal, as potentially there will be more questions, whilst enjoying correspondence with amp masters), is regarding the yellow wire to to socket that was originally disconnected in my amp when I opened it up; what is the consequence of having it disconnected?
I would suspect that it just rattled loose, as a result of vibration though the caster wheels running over pavers and many bumps on the ground, in arid Australia. (Where I live, hence the 240v amp.)
So, I’m assuming it should be plugged in, but what would have happened if I didn’t want to correct the on/off switch problem, and it was left unplugged, and unoticed?