echoplex and noise addendum

[Aden Evens <aden@who.net>]

After much experimentation, I have verified that all the RAM is OK. That
is, if I replace either bank (pair) with the original 1MB SIMMs that came
with the unit, then the 'plex works fine, reporting the correct 122 secs of
loop time. It is only when I try to use all four 4 MB SIMMs at once that I
get this self-noise problem. Eh bien?

Aden

>I just got my new echoplex too. Seems like a great unit. It checked out
>fine on arrival. However, after I installed new RAM, it now generates
>constant internal self-noise. That is, even with feedback turned all the
>way down, the feedback light stays aglow, and recording even a silent 
>input
>yields a loop of fairly loud (though not overwhelmingly loud) white noise.
>It does record from the input if I play something into it, it just sums it
>with the static to create a loop with a s/n ratio of 1:1.
>
>I have had extensive experience installing RAM and other components into
>computer equipment and other static-sensitive devices, and I took all
>appropriate precautions when installing the RAM, and had no notable
>problems. The 'plex now indicates the full 198 secs of loop time, so it
>seems to be recognizing all the RAM.
>
>Where is all the fucking noise coming from, and how do I get rid of it?
>
>Thanks,
>
>
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>      Aden
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