Here's the original post...
>>>>>>>>>
From: "John Speth" <
johns@...>
I'd like to share a couple of MOTM modifications that I found useful. Both
are simple and useful.
M120: Socket U3 (74HC08 quad AND) and experiment with using a 74HC86 (quad
XOR) instead. The two devices are pin compatible. Just make sure you use a
74HC86. I used a 74HCT86 from Radio Shack and it worked fine. The reason
for the change was that I was sometimes bothered by the fact that, for low
frequency signals on one of the inputs, the counter would sometimes (1 in 16
chances) come to rest at all 0s and, therefore, completely silence the
output. Using an XOR assures this can't happen. The sound is definitely
not as complex as with using AND gates but it does have a different
character.
M800: Solder a wire from the collector of Q1 to the unused pin of the
trigger jack. I tack soldered a wire from R1 on the component side to J2
and tie-wrapped it down. This allows the EG to function as a complete ADSR
with only a gate signal and no trigger. It will function as shipped when a
trigger plug is inserted. I'm surprised this wasn't designed in. I wonder
if it might be better to use a series resistor of about 5K in this wire to
protect against transients when inserting and removing a trigger plug.
<<<<<<<<<<<<
You will have to figure out which end of R1 connects to Q1 by following the
traces on the circuit board. If you are not confident you can do this, you
should consider getting some help from someone with electronics knowledge.
Hope this gives you the info you need.
Don't use 1/2 watt resistors - way too big! Get Rat Shack 1/8 watt jobs.
Dave Bradley
Principal Software Engineer
Engineering Animation, Inc.
daveb@...
> -----Original Message-----
> From: mark scetta [mailto:n0nspaz@...]
> Sent: Friday, July 23, 1999 11:46 AM
> To: motm
> Subject: [motm] motm800 mod
>
>
> From: "mark scetta" <n0nspaz@...>
>
> ok people i appreciate your responses about the trigger mod for
> the EG but i
> still don't have a clear idea of what to do. would someone spell
> it out for
> this ignorante? what/where exactly do i solder? i have some 10k, 1/2 watt,
> 5% resistors around. will one of these work (instead of jumper wire)?
>
> i have tried searching the onelist archives but after repeated attempts, i
> still get a page full of digests as my result and i'm not about to go
> reading through all of that....
>
> obliged,
> mark
>
>
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