EMA - Chorus EP-16

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modman
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Post by modman »

Some time ago I bought this chorus pedal for 8 EUR -- case is plastic, but the jacks are chassis mounted. It says 'Made in Korea'

http://filters.muziq.be/model/ema/ep18

The outer case says EP18, but the pcb is marked EP16. ICs are M3223L (thin one) M5218AL (two thicker ones). BBDs didn't come from Hongkongsuperseller :wink: ... this time
Here some guts:
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EMA Chorus EP16
EMA Chorus EP16
DSCN4385.jpg (272.65 KiB) Viewed 1362 times
EMA Chorus EP16
EMA Chorus EP16
DSCN4386.jpg (286.59 KiB) Viewed 1359 times
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DiscoFreq
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Post by DiscoFreq »

That's strange because the EP-16 is the distortion and this doesn't look like a multi-function board as with the small Coron pedals (same PCB for several effects).

Interesting, thanks :)
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Post by analogguru »

The BBD and clock driver are original matsushita - probably from 1982. The other components used appear also from the 80´s. What else is written on the chips and on the electrolytics ?

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Post by modman »

Electrolytics are either DKE, DEC or Han Sung.
All three ICs have the Mitsubishi logo. Two of them read M5218AL 252028 the other one (thinnest) M5223L 304003
Transistors: (top to bottom, left to right, except TR5 is under TR4
TR 1-2 = K 3F C3200 GR --> BC320?
TR 3 = K 3G K30A GR --> 2SK30A
TR 4-8 = C945 YC311 --> BC945


Discofreq,

After knowing my aunt Suzanne for 25 years, I was shocked to find out that she's really called Yvonne. But then again I never asked her for gut shots :wink:
I'm curious what's written on the distortion pcb - but I don't think it influences the sound that much.

Do you own any of other EMA pedals or their equivalents?
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Post by analogguru »

Electrolytics are either DKE, DEC or Han Sung.
Not any numbers on them ? anyway the unit appears to have been produced in early 1983....
TR 1-2 = K 3F C3200 GR --> BC320?
= 2SC 3200-GR
TR 3 = K 3G K30A GR --> 2SK30A
TR 4-8 = C945 YC311 --> BC945
= 2SC 945-Y

analogguru
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modman
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Post by modman »

analogguru wrote:
Electrolytics are either DKE, DEC or Han Sung.
Not any numbers on them ? anyway the unit appears to have been produced in early 1983....
So the 23/28 on the BBDs is a date code?
19(M) on the Han Sungs, the other only have temperature ratings on them..
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Post by DiscoFreq »

Lol :)
modman wrote:Do you own any of other EMA pedals or their equivalents?
No, not yet :)

I know Seifukusha from HC has the delay (possibly there are gutshots on HC somewhere?)
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Post by CheapChip »

Sorry for posting on such an old topic but I don't have found any other one about this pedal over the Internet...

A friend gave me this old chorus pedal yesterday as it was out of order.
Actually, there was a broken bypass wire, and except concerning scratchy pots, everything seems fully functionnal.

But some details seem weird:
Turning the Rate pot doesn't seem to change anything or a little :hmmm: Still a slow chorus, there's no way to obtain a vibrato-like chorus...
I had a look at the LFO but as I thought this pedal was a Boss CE-? clone or quite similar, it's rather different. At least concerning the LFO... :slap:
The other thing is that even with the Depth pot maxed, effect is not so big, just a sweet chorus. But when the pot scratches, a sort of "boost" appears in the effect just for an instant.
I've shorted it to see what happens: nothing...

Any idea?
Or better: any schematic?
I've made a layout with the PCB picture above, in order to trace a schematic. But it's such a mess... :slap:

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Post by tube-exorcist »

CheapChip wrote: Any idea?
Or better: any schematic?
I've made a layout with the PCB picture above, in order to trace a schematic. But it's such a mess... :slap:
A Boss CH-1 schematic should lead you to success.
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Post by CheapChip »

:applause: :applause: :applause:
OK!!!
Many many many thanks! :D

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