small stone using LM13700

Started by Dimitree, February 12, 2019, 09:44:17 AM

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Dimitree

hello,
can I use LM13700 instead of CA3094 on the Small Stone?
would that work without modifications and give the same results (except less noise luckly)?

thank you

Kevin Mitchell

#1
I believe it'll work in all places but the LFO since the collector of the buffer is shorted internally to V+ in the LM13700. The Small Stone schematic shows that pin connecting to one of it's own inputs. You could simply use an external darlington buffer and accommodate the connection.
Small Stone schematic here

There is already a version of the Small Stone that uses LM13600. Not sure if there's a project file available for this. But worth looking.

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Kevin Mitchell

#3
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Dimitree

than you,
one thing I noticed on those LM13700/13600 schematic adaptions it that the + and - input pins on the OTA are inverted, compared to the original schematic with CA3094. Any reason for that?

Scruffie

Quote from: Dimitree on February 13, 2019, 04:36:45 AM
than you,
one thing I noticed on those LM13700/13600 schematic adaptions it that the + and - input pins on the OTA are inverted, compared to the original schematic with CA3094. Any reason for that?
If you're referring to this schematic;



It's because whoever drew it labelled the + & - wrong  :)

Marcos - Munky

There's the Tonepad Ross Phaser project, which uses LM13600:
http://tonepad.com/getFileInfo.asp?id=99

Btw,
Quote from: Dimitree on February 12, 2019, 09:44:17 AM
can I use LM13700 instead of CA3094 on the Small Stone?
The Small Stone uses CA3080, not 3094.

Scruffie

Quote from: Marcos - Munky on February 13, 2019, 02:45:37 PM
Btw,
Quote from: Dimitree on February 12, 2019, 09:44:17 AM
can I use LM13700 instead of CA3094 on the Small Stone?
The Small Stone uses CA3080, not 3094.
The Tonepad Small Stone uses the CA3080, the original uses the CA3094 (house stamped as EH1048).

Marcos - Munky

Ah didn't knew on that. Every schematic I saw asks for 3080, so I assumed it was the one that was used on the original.