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Subject: RE: [emlsynth] EML 100

From: "sasha" <sasha@...>
Date: 2008-02-07

Thanks for the info, Steve.

 

I measured the voltage with a multimeter and all looked ok atthe PSU. I was able to detect voltage even on that cap that appeared to beleaking something out. I can also detect the proper voltage in the various modulesthat are fed from the power supply.

 

Given my limited ability to troubleshoot, and lack of schematic,I handed it over to CAE Sound in San Mateo today for work.

 

I hope that it can be repaired and that it sounds as good as itlooks.

 

Has anyone heard one of these little gems? How does the soundcompare to other synths from the day (Moog, ARP)?

 

From:emlsynth@yahoogroups.com [mailto:emlsynth@yahoogroups.com] On Behalf Of SteveRidley
Sent: Wednesday, February 06, 2008 5:29 AM
To: emlsynth@yahoogroups.com
Subject: RE: [emlsynth] EML 100

 



> I have tried plugging into all the outputs and get absolutely
> no sound. Do you think it's likely that the capacitors on the
> power supply are shot?

Probably the power supply, but not necesarily the caps.
(It's fashionable at the moment to blame the caps
whenever anything dies, but they don't fail dead
short all that often.)

You say it "powers up". Do you mean the mains lamp
comes on, or is there any other sign of life?

I don't have a 100 or a 100 schematic, but if the 101
and 100 power supplies are similar, the mains neon
is after the fuse and mains switch. (Check that
the fuse is the correct value - people often stick
a bigger fuse in when one blows, and blow something
serious up instead. Should probably be 1/4A slow
blow, and certainly not greater than 1A.)

Have you tried to measure the power supply? I assume
it should give +15v/-15v like the 101, or at least
something similar. If you can't measure anything
out of the power supply, check that one side of the
mains transformer has mains and the other side has
two lots of approx 18v AC.

WARNING - IF YOU ARE UNSURE OF YOUR ABILITY TO
WORK SAFELY AROUND EXPOSED MAINS, DON'T DO IT.
No synth is worth dying for. Not even an EML100.

If you have 18v AC but no 15v, measure the voltage
across each of the power supply caps. They should
each have around 25v DC across them.

If there is little or no voltage across the caps,
they could have died, or the rectifier diodes could
have died, or both.

If you have a healthy voltage across the caps but no
+15v/-15v, either the voltage regulators have died
or something has gone short across the power supply.
You could switch it off and measure for shorts on
the output wires from the power supply to the rest
of the synths boards. If you do find a short, you'll
have to disconnect each board in turn too find which
one (or ones) is/are causing the short.

Good luck!

Steve