Lm13700 buffer v+

[Locrian99]

So looking at the datasheet this appears to be internally connected but both of these schematics have me questioning this somewhat.



Theres not a pin that available so I’t got to be internally connected. It just seems weird they’d label it v+ and I don’t see a “G” in the valve wizard schematic for that to be connecting to. Before I layout and order pcbs just want to make sure I’m not missing something.

 

[Robert]

Yes, it's an internal connection.

 

[Locrian99]

Yes, it's an internal connection.

it’d be cool if there was a ppcb board of the latest revision

 

[Robert]

Any idea what has changed?

 

[Locrian99]

Any idea what has changed?

What's Changed?
If you're already familiar with the Engineer's Thumb, there are only some small changes to be aware of:

1: This version now has an emitter follower output, which comes free in the LM13700 package. This provides lower output impedance and better stability by buffering the compressor core from the outside world;

2: A compression indicator LED has been added (optional);

3: The Millennium Bypass status LED is now fed from the raw 9V input so it does not affect the rail voltage in the rest of the circuit;

4: A 4.7k end-stop resistor has been added to the ratio control. This makes it easier to access very subtle levels of compression with the pot at minimum.