korg emx-1 power supply noise/ over heating!

[electvibe 8081]

Hi,
I am the proud new owner of a used Korg emx-1 SM. I have only had it a couple of days and all appears to work ok but I have noticed after a couple of hours the unit itself gets hot. The power supply gets hot and over time starts to make a humming noise. It's not loud but in a quiet room it can be heard. Is this normal?

Also The tubes sound abit naff, going from nothing to overkill in a quarter turn of the knob. I have read on this forum that users are opting for the GT ECC83-S tubes. Are these the best?

One last question Is it possible to use an external controller, like the BCR-2000 to have more control over the envelopes?

Any help would be greatly appreciated.

BTW this machine is awesome.

Thanks.

[electvibe 8081]

Just to add a bit more info I have found;

As soon as I turn the power supply on without turning on the emx-1 there is a hum coming from the power supply. It is faint and I had it next to my ear to hear it.

I turn on the emx-1 and play around for about 40 mins and found the power supply is hot and making an audible humming noise which I can hear when everything is quiet. I think the power supply is on it's way out?

What do you reckon?

[Wavemaker]

I've got the old EMX & ESX (smart media versions) and i have the same hum noise coming from the power supply of my esx. If i switch power to emx it comes from emx, so i don't think it's a problem of the module just the power supply unit.

Normally if you get a new power supply there must be no more hum, i'm searchng for a new power supply already. As long as the problem it's not within the main board of the electribe i wouldn't worry that much.

The heat is reasonable after some time of use that shouldn't be a problem. Watch out though coz old and new electribes have different power units, different jacks and i think different voltage.

I have replaced the original vacuum tubes with JJ EC83ES S, for smoother and better sound and they sound beautifuuuul!

[electvibe 8081]

Hey Wavemaker,
Thanks for the advice. I really love this machine. I will contact Korg UK tomorrow and see about a new power supply. Just to be on the safe side, I don't want it having an adverse effect on the EMX.

As for the tubes I think I will definately invest in some new tubes. I've been experimenting on the EMX for about 5 hours today. It's very easy to get lost in this thing.

[electvibe 8081]

Phoned Korg UK tech support today and they confirmed my thoughts about the power supply. It is faulty they said it my last a month or it may die tomorrow. So looks like I'll be getting a new one £35 from korg spare dept.

[neotechtonics]

the SM version of the EMX uses a transformer in the power adaptor. the SD version uses a switching power supply... uses less power, doesnt cause significant heat.

also they're different voltages. not sure which is which but one is 9V the other is 12V... and i think one is AC the other is DC

think the SM is 9V AC cos its a transformer. and the SD is 12V DC. could be wrong.

the heat from the electribe itself is from the tubes (and probably a minimal bit of heat from capacitors and resistors inside)

my EMX-1 SM power adaptor died a couple months back but that was because I forgot to unplug it and lightning fried it (or atleast some kind of power surge) the fuse inside of it didnt even protect it -fuse didnt burn- but i think the fuse is more to protect the EMX.

so I also need to get a new one.. procrastination has gotten the better of me. I really need my old EMX running to start serious work on my live set for later this year.

[electvibe 8081]

Yeah your right the oldr SM version is 9V and the SD is 12V. Ordered my new PSU from Korg so hopefully get it in time for the weekend.

Also been having another look round the net for different tubes. The price varies considerably from £12-£60 and over! Just wondered what the more expensive ones would sound like?

I suppose it's like wine. You can get a cheap bottle for £5 and think it tastes better than a bottle for £50. Sometimes spending more doesn't mean it will be better quality, it terms of sound anyway.

[neotechtonics]

it depends what sounds you're going to be creating. cos different tubes produce different gain-curves and different distortion tones.
I'm wanting to get "smoother" tubes just to warm up my sound without adding grit cos most of my tunes are that side of the spectrum... and if I want some real distortion I'll use my effect pedals.

found a bunch of spare tubes at my mates place.. some ECC82's and some 12AX7s or 12AU7s i think. all still in their boxes. must check again. he was going to throw them out. have no idea what he had them for in the first place. must get them from him and see if any of the pairs are decently matched and what kind of distortion they produce.

think the 12AX7 is the stock EMX tube. a little harsh for my tastes

[electvibe 8081]

I agree. The stock tubes don't really do it for me. They appear to go from nothing to just full on distortion. I want something like your saying, just something to add warmth but also to get some nice harmonic tones in the upper registers.

Have a look at this, it's quite interesting;

http://www.watfordvalves.com/products_harma.asp

[hazabikit]

I've had really good results with the ECC 803 S tubes from Eurotubes:

https://ssl.eurotubes.com/cart/index.ph ... gory_id=73

IME they make the sound smoother and fuller. There are already lots of built-in ways to add different kinds of distortion -- I don't need the tubes to do that, too.

[electvibe 8081]

Got my new power supply and I've ordered the EEC803S tubes

Can't wait to hear them.