Hi Andy,
thanks for the explanation. I was roughly aware how a BBD could
be used for a chorus effect, I was mainly surprised that the DX27s
would use a different chip than the DX21, both from the same year.
But I'm starting to think that the engineering team of the DX27s
and that of the DX21 were disjunct groups anyway, particularly
since the DX21 has a switch mode power supply and the DX27s a good
old transformer.
But my question was primarily geared towards the differences of
the 27/100 to the 27s. I would really like to know, if IC12/13
(and related components) are populated in a DX27/100 board.
Cheers, Florian
On 25/05/2020 22:49, AndyHornBlower via
groups.io wrote:
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A chorus circuit like that is based around a BBD chip and a clock
generator.? In this case, MN3204 is the BBD and MN3102 provides
the clock.? There also one or two fixed filters, made with op amps
or transistors.
It seems the MN3207 + MN3102 combination is more common, which was
used in the original Boss CE-1 design, but they used transistors
for the rest of the circuit, which makes it harder to follow:
I found a page with the combination you have, but the example
schematic has been spoiled by photobucket.? If you save the image,
or use View Imager in Firefox, you can see it without their
banner, but you have to squint to make much out:
Maybe you can see a more detailed version if you register and log
in.? The datasheets for the chips should have example circuits
too.
- Andy
