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Topic: Emmons Lashley LeGrand Ultra Match LL30 schematic |
George Biner
From:
Los Angeles, CA
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Posted 23 Jan 2025 9:27 pm |
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Hey
Here is the schematic for this unit -- from 1995
If anybody is familiar with the feed-forward circuit with let me know, I've never seen it.
_________________
Guacamole Mafia - acoustic harmony duo
Electrical engineer / amp tech in West Los Angeles -- I fix Peaveys
"Now there is a snappy sounding instrument. That f****r really sings." - Jerry Garcia |
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Robert Parent
From:
Gillette, WY
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Posted 24 Jan 2025 8:26 am
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Hi,
Is that the correct part number on the op amp? A search for the datasheet turned up nothing.
Robert |
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Jerry Overstreet
From:
Louisville Ky
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Posted 24 Jan 2025 8:34 am
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| UA741 I believe. |
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Larry Hobson
From:
Valley Grande (Selma) Al USA
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Posted 24 Jan 2025 8:44 am Ll30
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| Not familiar with this, what is it ? |
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Jerry Overstreet
From:
Louisville Ky
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George Biner
From:
Los Angeles, CA
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Posted 25 Jan 2025 6:51 pm
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The op amp is a UA741C (tried to upload a corrected schematic image but it ain't working) -- I wanted to get the schematic on the web since it isn't there (in fact very little info at all about this unit)
So I gather it is a boost circuit you plug your guitar into and the output goes into the amp -- similar to a Goodrich Matchbox I guess -- I would say like a Freeloader but that uses a FET instead of an op amp
And forget what I said about a feed-forward circuit -- this is just an inverting amplifier circuit -- the only thing that throws me is the 10M resistor connection -- usually there is no path between the +ve and -ve op amp inputs.
Anyway, the unit I have appears to have a malfunctioning op amp, so I will replace it.
_________________
Guacamole Mafia - acoustic harmony duo
Electrical engineer / amp tech in West Los Angeles -- I fix Peaveys
"Now there is a snappy sounding instrument. That f****r really sings." - Jerry Garcia |
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Jerry Overstreet
From:
Louisville Ky
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Posted 26 Jan 2025 12:13 am
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Yes, as George states, it's a boost and buffering device similar to the Goodrich unit. I don't think there are too many of them out there. I've only heard from a handful of people that know about them or have used/owned them.
I suppose Emmons came up with this to work with Emmons guitars, but the Expand function seems to have more range and a twangier and more open high end than the Goodrich unit to me.
I use the Boost control just as I would a gain or volume control.
I'm using mine with the Fender Artist Dual 10 to liven up some pickups of unknown origin. I like the way it affects the tone better than the Goodrich unit.
I don't use either with the XR16s Carter D10. |
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