LM709 14 pin opamp question

[hodad]

Datasheet:
http://cache.national.com/ds/LM/LM709.pdf

So what's the deal with the 14 pin version? I've got some Auditronics modules that use these, & I'm hoping to experiment with some different opamps in this thing. Now, if I'm looking at these right, it's got a basic 8 pin footprint in the middle of a 14 pin IC.
So I should be able to drop in a 5534 (which Auditronics later used in the same circuit with minor revisions) without a problem?
It seems like the answer should be yes, but I thought I'd ask some bigger brains before I did anything.

Thanks
Tom

 

[JLM Audio]

HI Tom
Yes that will work fine. If are going to change lots of 709 to NE5534A just watch the total extra current increase. But sounds like you only have a couple of modules not a whole desk so that shouldn't be a problem. Also make sure the comp cap is the right value for the NE5534A.

 

[squib]

as Joe says, yes you can drop in a 5534 to the 14 pin socketed 709. However the compensation cap needs to be placed between pins 5 and 8 of the 5534. You should remove any comp cap present and then solder a 22pF cap directly onto the rear of the pcb between pins 5 and 8
( 5534 pin #'s ). The 22pF value is a conservative starting point to ensure you don't have any VHF oscillations. The first two IC's in the 110 modules run at high enough gains to strictly speaking not need this compensation cap, whereas the IC around which the EQ is built does need it.

 

[hodad]

Thanks for the tips, guys. I actually just picked up a short-loaded (12 channels) 110-8. It's a space hog (& half empty to boot!), so I haven't yet decided whether to keep it whole or do something else with it.
I powered it up & recorded through a couple of channels, & it sounds pretty good. I'm looking forward to seeing what difference the 5534's might make.

Tom

 

[saint gillis]

  I have some old Schlumberger EQ modules using SN 72709 DN, 14 pin, the datasheets found on the internet show a single Op Amp, but the EQ's shematics show dual Op Amps like that :
1: + input #1
2: out comp #1
3: output #1
4: V+
5,6 : comp #2
7: - input #2
8: +input #2
9: out comp #2
10: output#2
11: V-
12,13: comp #1
14: - input #1

  I can confirm that the ICs were connected as described above and it was working, so my question is : does 709 exist in 14 pins dual package?