So, I've been digging out audio stuff in my basement and fixing it up to keep myself occupied during the pandemic (better than drinking) now that my musical performance career is either over or on hold. I came upon my old analog delay unit the Electro-Harmonix Deluxe Memory Man.
Got on the web to do a little research and realized it's the holy grail of analog bucket brigade delay effects unit still in use 40 years later. In fact the "Edge" in U2 uses it often to create some of the more iconic guitar sounds we all love.
I have one of the second generation "big box" ones, especially collectible, made in 1980 according to the pot codes. Folks are selling these for about 1K$. I bought this one in 1981 for $60.00.
I do recall how rich a reverberation sound this had when i played my lap steel through it in the 80s.
Anyway....I looked up a schematic for it and to my surprise this thing is notated in non-conventional current flow, that is the Plus rail is zero volts and the minus rail common is -15v!
I don't know about you but this disturbs my sensibilities.
Have you found any other equipment schematics notate this way?
Got on the web to do a little research and realized it's the holy grail of analog bucket brigade delay effects unit still in use 40 years later. In fact the "Edge" in U2 uses it often to create some of the more iconic guitar sounds we all love.
I have one of the second generation "big box" ones, especially collectible, made in 1980 according to the pot codes. Folks are selling these for about 1K$. I bought this one in 1981 for $60.00.
I do recall how rich a reverberation sound this had when i played my lap steel through it in the 80s.
Anyway....I looked up a schematic for it and to my surprise this thing is notated in non-conventional current flow, that is the Plus rail is zero volts and the minus rail common is -15v!
I don't know about you but this disturbs my sensibilities.
Have you found any other equipment schematics notate this way?
Most Germanium pedals were positive ground because common Ge is PNP.
Most BBD systems are drawn positive ground because they are really bodged-up memory chips from a time when P-type MOS was popular.
Sorry if this disturbs you.
Most BBD systems are drawn positive ground because they are really bodged-up memory chips from a time when P-type MOS was popular.
Sorry if this disturbs you.
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I suppose I could take that schematic and redraw it conventional. The electrons don't care.
Thanks for the image PRR.
Thanks for the image PRR.