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<div class="">Hello,<br class="">
<br class="">
Inspired by the Alex Ball Video mentioned over at analogue heaven
I wanted to update my page about roland filters with the
information on the System 500.<br class="">
I checked th <a href="http://thomann.de" class="">thomann.de</a> pages
for the pictures of the module and got a little worried<br
class="">
<br class="">
This is the pcb of the 510 (should be one four stage OTA filter
and a VCA)<br class="">
<a class="moz-txt-link-freetext"
href="https://bdbo2.thomann.de/thumb/bdb3000/pics/bdbo/13948871.jpg">https://bdbo2.thomann.de/thumb/bdb3000/pics/bdbo/13948871.jpg</a><br
class="">
<br class="">
This is the pcb of the 521 (should be two four state OTA filters)<br
class="">
<a class="moz-txt-link-freetext"
href="https://images.static-thomann.de/pics/bdb/379516/10742587_800.jpg">https://images.static-thomann.de/pics/bdb/379516/10742587_800.jpg</a><br
class="">
<br class="">
This is the pcb of the 505 (it should be a tranistor ladder
filter)<br class="">
<a class="moz-txt-link-freetext"
href="https://bdbo2.thomann.de/thumb/bdb3000/pics/bdbo/13948906.jpg">https://bdbo2.thomann.de/thumb/bdb3000/pics/bdbo/13948906.jpg</a><br
class="">
<br class="">
<br class="">
<br class="">
The pcb of the 505 is full of LM37000, while there is no OTA in
the original Circuit.<br class="">
The pcbs of the 510 and 521 show not a single OTA, but many parts
which seem to be double transistors - which I would expect for the
505.<br class="">
<br class="">
After a first comparison of the 510 and 505 I thought Thomann
mismatched the pictures, but the 521-pcb looks too similar to the
501-pcb<br class="">
<br class="">
<br class="">
Can you identify what are 6 pin parts on the pcbs for the 521/510?<br
class="">
<br class="">
Florian</div>
<div class=""><br class="">
<br>
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<pre class="moz-signature" cols="72">--
<a class="moz-txt-link-freetext" href="http://www.florian-anwander.de/">http://www.florian-anwander.de/</a></pre>
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