LM13700 Wasp filter (untested)

ickystay · Joined: Nov 15, 2006 Posts: 143 Location: Oregon

Will an LM13700 work to replace the two CA3080's in the Wasp filter? I don't know. I seem to recall guys using them in their DS-7 clones.

Anyway, I made a layout to try. I feel funny posting this among the pro looking PCB's you all fashion, but what the heck. Maybe the electrons wont mind.

This is the Juergen Haible version. Check his site and pick up the schematic here (you'll need it):

http://jhaible.heim.at/tonline_stuff/hj_wasp.html

The PCB will need to be flipped for PNP. Resize to 600dpi or 6 X 6.84 cm or 2.362 X 2.693 inches. No resampling.

Sorry for not testing this.

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vtl5c3 · Posted: Wed Nov 25, 2009 8:17 pm Post subject:

Should work. I remember seeing something in electronotes about the 13x00 being a drop in replacement for the 3080, as long as you overlooked the new features (diodes at the inputs, output buffer).

fonik · Posted: Thu Nov 26, 2009 2:05 am Post subject:

IIRC it is partly even the same IC layout, just with some add-ons (diodes, buffers).

n.d · Joined: Dec 15, 2011 Posts: 52 Location: Talos IV

So, did anyone test this?

isak · Posted: Sat Sep 01, 2012 11:19 pm Post subject:

Hi guys.

Some one test this?
I prefer to use LM13700 instead of 3080.
Is it verifid?

Cheers,
Isak E.

Cynosure · Posted: Sun Sep 02, 2012 9:45 am Post subject:

I didn't make this PCB, but I made two Wasp filters following the schematic and replaced the 3080's with LM13700. It works fine. Apparently it is the exact same IC on the inside, but a few extra features in the LM13700.

isak · Posted: Sun Sep 02, 2012 9:53 am Post subject:

Thank you for your reply.

Can you please share the layout you used?

Cheers,
Isak E.

Cynosure · Posted: Sun Sep 02, 2012 10:52 am Post subject:

I just used perfboard and made it up as I went. The schematic was easy to follow and everything worked on the first try (which doesn't happen half the time I solder something).

isak · Posted: Sun Sep 02, 2012 2:15 pm Post subject:

thank you:)

donpachi · Posted: Sun Feb 08, 2015 11:15 am Post subject:

Only a few years late, I can confirm that the layout works Embarassed

The board was etched and populated about five years ago. This weekend I went into a troubleshooting spree and finally discovered that I had installed a wrong regulator. After fixing this and a bad trace to the resonance pot (courtesy to my etching skills) the filter rocks! Thanks for the layout ickystay Cool

n.d · Joined: Dec 15, 2011 Posts: 52 Location: Talos IV

Great news!
I also need to get into a troubleshooting spree, but now, I know it´ll pay off.

***edit: this has to be the slowest thread ever, btw.***

cyclic · Joined: Mar 15, 2015 Posts: 95 Location: hobart

why does this even need a regulator?

I mean, both those chips should be fine to +12 or +15, and surely if its a case of output levels, then its just a question of choosing a voltage divider appropriately?

while I'm at it:

I'm planning on building one up as an independent box, and plan to use 2x18650 3.7v lithium cells for power (I have ready access to heaps of these due to electric-bike stuff I do).

Really, is there any reason why I can't skip the voltage dividers (2x33k) for the non-inverting inputs of the LM13700s/CA3080s and wire in the mid point of my 2 cells instead (ie use the 'two cell option' instead of the 'voltage divider' option.) These batteries are rated for multi-amp draws, so should be not at all bothered by the draw of this circuit.

I'm not particularly fussed if this is a 'purist' WASP filter, I just want it to be near-enough..

Lance

Grumble · Posted: Thu Feb 25, 2016 2:50 am Post subject:

A pity this filter does not self-oscillate.
Is it at all possible to have a filter made with a 3080 or 13700 to self-oscillate?

donpachi · Posted: Thu Feb 25, 2016 9:50 am Post subject:

Grumble · Posted: Thu Feb 25, 2016 4:45 pm Post subject:

ok, thanx!

wackelpeter · Posted: Fri Feb 26, 2016 2:49 am Post subject:

The Roland VCF's using OTA's do it too...

Build one of These System 100 VCF's and replaced that BA... OTA's with LM13700...

Have posted a stripboard layout for this one somewhere in this Forum...

Grumble · Posted: Fri Feb 26, 2016 3:07 am Post subject:

I wasn't looking to build them, just out of curiosity Cool

But thanks anyway!