replacement forLM 13700

[Diego A]

Hi there!

  I´m building the Merlin Compressor and one of the ic´s a LM13700 (hard to find in my country), is there a good replacement? i have a few CA3080, can i use them in any sort of way?

   Thanks in advance!

[highwater]

A CA3080 will work fine, as long as it's a real 3080 (counterfeits are fairly common).

You can also use an LM13600 (the only difference is in the buffer, which the ET doesn't use).

[Diego A]

A CA3080 will work fine, as long as it's a real 3080 (counterfeits are fairly common).

You can also use an LM13600 (the only difference is in the buffer, which the ET doesn't use).

   So how i do it? since the LM has 16 pins and the 3080 just 8, two of them?

[bluebunny]

The Engineer's Thumb only uses half the LM13700, so one CA3080 is sufficient.

[highwater]

It depends on how you want to build it. The pins on the '3080 are arranged completely differently from a '13x00; you either need a layout (or PCB) that's designed for the 8-pin chip, or an adapter of some kind*.

There is a verified stripboard layout of a '3080-based Engineer's Thumb with at Tagboard Effects. There may be PCB and/or perfboard layouts as-well, but I'm not aware of them.

---

*For testing purposes, the original creators of the 13700 and 13600 made such an adapter from two 3080s, two transistors, sockets, and some wires. Because the Engineer's Thumb only uses one OTA from the '13x00, and doesn't use the buffers, so your adapter would be much simpler than that; just an 8-pin socket and wires to solder where the corresponding pins of the '13x00 would go on.

[Mark Hammer]

Can you obtain an NE5517?  They are essentially the same as an LM13700.

[Diego A]

The Engineer's Thumb only uses half the LM13700, so one CA3080 is sufficient.

  For sure, íll have to figure out the pinout of course.  BTW nice avatar! 

It depends on how you want to build it. The pins on the '3080 are arranged completely differently from a '13x00; you either need a layout (or PCB) that's designed for the 8-pin chip, or an adapter of some kind*.

There is a verified stripboard layout of a '3080-based Engineer's Thumb with at Tagboard Effects. There may be PCB and/or perfboard layouts as-well, but I'm not aware of them.

---

*For testing purposes, the original creators of the 13700 and 13600 made such an adapter from two 3080s, two transistors, sockets, and some wires. Because the Engineer's Thumb only uses one OTA from the '13x00, and doesn't use the buffers, so your adapter would be much simpler than that; just an 8-pin socket and wires to solder where the corresponding pins of the '13x00 would go on.

Thanks!, i´ll see if i can find an adapter.

Can you obtain an NE5517?  They are essentially the same as an LM13700.

  I think i can! it´s the same as NE571N??

[PRR]

> same as NE571N??

Not at all. (Look-up datasheets! While the '571 "can" change gain, it is not set up anything like LM13700.)

LM13700 should be readily available nearly everywhere, by mail/web-order not in a local shop.

[Mark Hammer]

The NE5517 and NE571 share some letters and some numbers, but they are two entirely different chips.  The 5517 is dual OTA-with-buffer, like the LM13700.

[deadastronaut]

i have fake 13700's....   

i breaded up the ET ....no joy. buy from a good dealer. lots of fakes out there

[Diego A]

Many thanks to everyone,  i´ve learned a lot, i found a pcb that i can use for my purposes.

   

[jimladladlooklike]

i have fake 13700's....   

i breaded up the ET ....no joy. buy from a good dealer. lots of fakes out there

How can you tell if they're fake? I have recently finished building the ET and it doesn't sound quite right... how did your breaded version sound?

[merlinb]

Unpopular opinion: 90% of the 'fakes' reported on this site are just people building stuff wrong

[digi2t]

Unpopular opinion: 90% of the 'fakes' reported on this site are just people building stuff wrong

Sooooo, what you're telling me is that I should have been building a buffer, rather than a compressor with that fake 3080.


@#$%.... I feel so stupid.  (face palm)

True story however, I ordered a dozen 2N4854 cans (NPN/PNP pair) from UT Source not too long ago. They're uber rare, the price was cheap, and I thought they would look cool in a Push me Pull you type circuit. Anyway, what I got was cans marked as "Motorola 2N4854"'s. What they tested as was a pair of N-channel JFET's in a can. Got a refund, and they got tossed to the corner of the bench.

Fast forward a couple of months.... I started looking for dual JFET packages to stand in for the obselete TIS70 in the Hi Fli project. For shits and grins, I pulled out one of the "2N4854"'s from UT, and ran them it through the tester. Well guess what... they tested perfect in Vgs (off), Vgs, and Idss range for the Hi Fli.

Go figure.