eml synthesizers

Hello,

I was lucky enough to be handed a free EML 100 the other day. It
powers up, but I get no sound.

Can someone recommend a good repair shop in the Bay Area for these
synths? Also, curious as to what the value of these are.

I have a decent understanding of circuits - are these simple enough to
troubleshoot on my own or should I leave it to the experts (assuming
they are still around!).

thanks kindly.

>
>
> I was lucky enough to be handed a free EML 100 the other day. It
> powers up, but I get no sound.
>

A no-sound-at-all problem may be something simple.
Have you tried plugging directly into the VCO outputs?
If none of them are working, the problem is almost certainly
in the power supply. If they do work, work your way through
the filter mixer, the filter, and then the VCA to see where
the sound is getting stopped.

>
> Can someone recommend a good repair shop in the Bay Area for these
> synths? Also, curious as to what the value of these are.
>

Can't help you with the repair shop, not living in that area.
However, I can tell you this much: the 100 is a lot more rare
than the 101. I'm not sure what kind of demand there is
for the 100, but I see 101's going on eBay for $1500-1700.

Out of curiosity, does your 100 have a blue panel or the
grayish-white panel that the 101's have?

>
>
> I have a decent understanding of circuits - are these simple enough to
> troubleshoot on my own or should I leave it to the experts (assuming
> they are still around!).
>

The 100 is pretty easy to get into. If it's like the 101, there are 5
screws around the perimeter of the panel that hold it in. Remove
those, and the entire panel comes out with all of the circuitry;
nothing is mounted to the inside of the case. The circuit boards
are pretty clean and easy to work on. The biggest problem you
may have is that I'm not aware if there are schematics for the
100 still around anywhere.

Hi David,

Thanks so much for your reply.

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? That should be relatively easy to swap out. I just got done building one of those x0xb0x 303 clones so my soldering iron is begging for more work ;)

My 100 has a blue panel. Another interesting bit about it is that there was a modification done to it. It has 5 additional 1/4" jacks and an additional knob. They are all positioned together to the left of the EML 100 logo on the panel. I am guessing it was not a factory mod since the jacks don't really line up perfectly. They are labeled:

Knob - "input rate"
1/4 jack #1 - "Sampler Input"
1/4 jack #2 - "Sampler Trigger Rate-Ext Output"
1/4 jack #3 - "Trigger Output"
1/4 jack #4 - "Sampler Output"
1/4 jack #5 - No label on this jack

I uploaded a couple of pics to the group page so you can get a better idea of what it looks like:
http://launch.ph.groups.yahoo.com/group/emlsynth/photos/view/d021?b=1
http://launch.ph.groups.yahoo.com/group/emlsynth/photos/view/d021?b=2&m=s&o=0

If you would like additional close-ups of any particular sections, please let me know.

Regarding the schematics. Are the 101 and 100 similar enough that the 101 schematics would be useful in repairing the 100?

Thanks kindly, Sasha



From: emlsynth@yahoogroups.com [mailto:emlsynth@yahoogroups.com] On Behalf Of David Cornutt
Sent: Tuesday, February 05, 2008 9:32 PM
To: emlsynth@yahoogroups.com
Subject: Re: [emlsynth] EML 100

>
>
> I was lucky enough to be handed a free EML 100 the other day. It
> powers up, but I get no sound.
>

A no-sound-at-all problem may be something simple.
Have you tried plugging directly into the VCO outputs?
If none of them are working, the problem is almost certainly
in the power supply. If they do work, work your way through
the filter mixer, the filter, and then the VCA to see where
the sound is getting stopped.

>
> Can someone recommend a good repair shop in the Bay Area for these
> synths? Also, curious as to what the value of these are.
>

Can't help you with the repair shop, not living in that area.
However, I can tell you this much: the 100 is a lot more rare
than the 101. I'm not sure what kind of demand there is
for the 100, but I see 101's going on eBay for $1500-1700.

Out of curiosity, does your 100 have a blue panel or the
grayish-white panel that the 101's have?

>
>
> I have a decent understanding of circuits - are these simple enough to
> troubleshoot on my own or should I leave it to the experts (assuming
> they are still around!).
>

The 100 is pretty easy to get into. If it's like the 101, there are 5
screws around the perimeter of the panel that hold it in. Remove
those, and the entire panel comes out with all of the circuitry;
nothing is mounted to the inside of the case. The circuit boards
are pretty clean and easy to work on. The biggest problem you
may have is that I'm not aware if there are schematics for the
100 still around anywhere.

I took some additional pics and posted to the same album. Looks like there is at least 1 leaky cap. Take a look at this photo:
http://launch.ph.groups.yahoo.com/group/emlsynth/photos/view/d021?b=6&m=f&o=0

So, do you think I should just swap out all the caps on the PSU to be certain?

> -----Original Message-----
> From: sasha
> Sent: Tuesday, February 05, 2008 10:01 PM
> To: 'emlsynth@yahoogroups.com'
> Subject: RE: [emlsynth] EML 100
>
> Hi David,
>
> Thanks so much for your reply.
>
> 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? That should be relatively easy to swap out. I just got done
> building one of those x0xb0x 303 clones so my soldering iron is begging
> for more work ;)
>
> My 100 has a blue panel. Another interesting bit about it is that there
> was a modification done to it. It has 5 additional 1/4" jacks and an
> additional knob. They are all positioned together to the left of the
> EML 100 logo on the panel. I am guessing it was not a factory mod since
> the jacks don't really line up perfectly. They are labeled:
>
> Knob - "input rate"
> 1/4 jack #1 - "Sampler Input"
> 1/4 jack #2 - "Sampler Trigger Rate-Ext Output"
> 1/4 jack #3 - "Trigger Output"
> 1/4 jack #4 - "Sampler Output"
> 1/4 jack #5 - No label on this jack
>
> I uploaded a couple of pics to the group page so you can get a better
> idea of what it looks like:
> http://launch.ph.groups.yahoo.com/group/emlsynth/photos/view/d021?b=1
> http://launch.ph.groups.yahoo.com/group/emlsynth/photos/view/d021?b=2&m
> =s&o=0
>
> If you would like additional close-ups of any particular sections,
> please let me know.
>
> Regarding the schematics. Are the 101 and 100 similar enough that the
> 101 schematics would be useful in repairing the 100?
>
> Thanks kindly, Sasha
>
>
>
> From: emlsynth@yahoogroups.com [mailto:emlsynth@yahoogroups.com] On
> Behalf Of David Cornutt
> Sent: Tuesday, February 05, 2008 9:32 PM
> To: emlsynth@yahoogroups.com
> Subject: Re: [emlsynth] EML 100
>
> >
> >
> > I was lucky enough to be handed a free EML 100 the other day. It
> > powers up, but I get no sound.
> >
> A no-sound-at-all problem may be something simple.
> Have you tried plugging directly into the VCO outputs?
> If none of them are working, the problem is almost certainly
> in the power supply. If they do work, work your way through
> the filter mixer, the filter, and then the VCA to see where
> the sound is getting stopped.
>
> >
> > Can someone recommend a good repair shop in the Bay Area for these
> > synths? Also, curious as to what the value of these are.
> >
> Can't help you with the repair shop, not living in that area.
> However, I can tell you this much: the 100 is a lot more rare
> than the 101. I'm not sure what kind of demand there is
> for the 100, but I see 101's going on eBay for $1500-1700.
>
> Out of curiosity, does your 100 have a blue panel or the
> grayish-white panel that the 101's have?
> >
> >
> > I have a decent understanding of circuits - are these simple enough
> to
> > troubleshoot on my own or should I leave it to the experts (assuming
> > they are still around!).
> >
> The 100 is pretty easy to get into. If it's like the 101, there are 5
> screws around the perimeter of the panel that hold it in. Remove
> those, and the entire panel comes out with all of the circuitry;
> nothing is mounted to the inside of the case. The circuit boards
> are pretty clean and easy to work on. The biggest problem you
> may have is that I'm not aware if there are schematics for the
> 100 still around anywhere.
>

> 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

Laurie Spiegel has a site: http://www.retiary.org/ls/ where you can
hear some EML 100 and 200.
Look under "Obsolete Systems" (I think she means it affectionately!)

synergeezer

>
> Has anyone heard one of these little gems? How does the sound

compare to other synths from the day (Moog, ARP)?

>