Eden NC-250 / NC-320

[nevetslab]

Line Voltage Select done with Fuse Holder

[ATTACH=CONFIG]57373[/ATTACH][ATTACH=CONFIG]57374[/ATTACH][ATTACH=CONFIG]57375[/ATTACH][ATTACH=CONFIG]57376[/ATTACH][ATTACH=CONFIG]57377[/ATTACH]

The IEC Power Connector/Fuse module on your rear panel is of the type that also functions as the AC Mains Voltage Select. The AC Mains wiring on both your amp and mine are the same on that IEC/Fuse module, as well as the AC Mains Switch. To change to 120VAC, you pop it out and rotate it, while changing the Fuse Value. T4A GMC size (5 x 20mm) would be what you'd want. Chances are there is a T2A fuse installed.

I just re-read your last post, and see you are in a 240V country (Australia), so your amp IS wired correctly for 240V, based on the Selection mark on the voltage rating to the left of the Mains connector/fuse holder. I can confirm the WHT wire (AC Mains N terminal) is adjacent to the BLK wire (AC Mains L terminal) on the Mains/Fuse module. Your YEL wire which was unplugged from the AC Mains/Fuse module IS connected correctly, so your guess was correct.



Eden 4012.038_na320.pdf

On page 7 in the owner's manual I've attached (NC320 Bass Amp, but will suffice for your NC250 regarding AC Mains Fusing & Voltage Selection), the instructions on selecting Line Voltage are shown.

[nevetslab]

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?
[ATTACH=CONFIG]57389[/ATTACH]

From Juan Fahey's reply back in 2014: " 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".

The internal speaker is sitting between the Power Xfmr's Center Tap and Ground, to which the Current Output from the FET Output stage is connected. The External Speaker Jack placed that in series with the internal speaker, NOT in parallel (which would lower the overall load impedance). I forgot to measure the DCR of the four 10" woofers of my cabinet when I had removed the power amp panel to photograph. I'm guessing (without pulling the panel again to check) that the four 10's are all 8 ohm, wired series-parallel, and would be a 200 W amp.

NC320 SCH final.pdf

If indeed that is true, switching the Speaker On/Off to Off would also switch off what gets plugged into the Ext Spkr jack. This IS a strange amp.

I zoomed in on the photo I had taken of the 3-pair of Output devices on the heat sink, and they ARE 2SK1058 N-Ch MosFET's and 2SJ162 P-CH MosFET's as called out on the NC320 Schematic which was provided by waspclothes back in 2014.

[g1]

As far as I know, this amp has a 4 ohm internal speaker and does full power as it sits. That is why the ext.spkr. jack is in series, the amp can not drive lower than 4 ohms.
So when you add an external spkr., the amp delivers a bit less power, but you get the benefit of more speaker area.

[Tim81]

I have read a number of forums claiming that the extension socket, which is labeled 250 watts @ 4ohms; is a lie, because the internal load is 8 ohms and, as the extension cab is wired in series, the amp sees 16 ohms.
I took the grille off today, to take out the speaker to gather information to support this claim, and as result, had to stuff around replacing speaker mounting screws that snapped when taking out the main speaker.
I tell you, who ever installed the new speaker, was a dodgy fellow. The screws had two different thread spacings, and some were very tight in the holes, also because the upgraded non original speaker had different hole positions to the original, there were new poorly aligned holes, haphazardly drilled, with in some locations, divits evedencing two previous misaligned attempts to drill a hole.
Anyway, the 15” speaker is FANE 300w 8 ohm, and the original tweeter is 8 ohm also.

The resistance measured with with the amp removed, at the connection outside the cab, was 7.5 ohm.
The the FANE 15” unplugged by itself was 8.1 ohms.
The tweeter unplugged by itself was 9.6 ohms.
With the amp connected, and the 15” unplugged; the tweeter, (measured at the crossover pcb), was 4.1 ohms.
And finally, with it all back together, a cable plugged into the extension input, measured 14.2 ohms.
I’m not sure if that information is helpful in justification to add a series/parallel switch or not, but it seems to me that the internal load, at least, is 8 ohm.
Attached are some pictures.

[Rcgp1978]

Hola. Buenas tarde. Saludo desde Chile. Desde hace año tengo un Edén Némesis NC 320 2x10 lo compré usado. En un concierto se me presentó un problema, la cual, se quemó los transistores de poder. Resulta de que mí amplificador, estaba modificando y lo llevaron a 250 watts de poder. Con seguí los planos gracias a usted. Tengo una duda al respecto de este cableado. Le en enviaré foto. Espero que me pueda ayudar con esta situación con el orden de los colores. Gracias

[Rcgp1978]

No sé si me entiende. El código de colores que trae mí amplificador en ese conector es ROJO, AZUL, naranja y blanco. Viendo algunas imagen que publicó son distintos al orden. Allí comienza AZUL, NARANJA, BLANCO Y ROJO. DISTINTO AL DE MÍ AMPLIFICADOR.

[Rcgp1978]

Here's the proper schematic: [ATTACH]31837[/ATTACH]

And a few pictures:
[ATTACH=CONFIG]31838[/ATTACH]
[ATTACH=CONFIG]31839[/ATTACH]
[ATTACH=CONFIG]31840[/ATTACH]

Hola. Saludos. Mí es Roberto. Le escribo desde Chile. Tengo un amplificador de bajo Edén Némesis NC 320. Resulta cuando lo compré estado, no sabía que estaba modificado. Gracias a ustedes, veo fotos pero no veo con claridad el orden de todos los cables de su imagen, que está distinto al de mí amplificador. Le enviaré fotos para ver si usted me puede ayudar y espero también entienda lo que le quiero decir porque de electrónica no sé mucho. La imagen q usted presenta empieza con color azul y así sucesivamente