Can I use 2 dual op amps for quad?

[ppatchmods]

Is there a design I can build on perfect to convert 2 dual op amps to a quad op amp?

[petemoore]

  Can be recommendable even.
  For each triangle a Single OA, for 2 triangles a Dual, but four traingles assigned to 1 quad opamplifier.
  Perhaps separating the power supply lines [ie using singles or duals instead of 1 quad] will offer greater independance from one trangle influencing another through a common power supply line.   

[Mark Hammer]

You're confusing me, and possibly via a typo.  Are you asking about a perfboard project where a pair of duals can simply be stuck in the same place without having to change the wire routing?  If so, no, because a quad op-amp has 14 pins and a pair of duals have 16.

Are you asking if there is any sort of functional difference between a quad and a pair of duals? The answer is, no, unless the duals and quad are of different families (e.g., a pair of 1458s is not exactly the same thing as an LM837).

Is there a reason why some layouts use a pair of duals instead of a quad?  Yes, several.

• First, as many here can attest, sometimes layut of a board really IS easier with a pair of duals than with a quad.  Normally, we do want to be able to have the smallest footprint possible, so you'd think 14 pins is better than 16, but having two op-amp sections on one side of a chip can crowd a little too much and make trace-routing and wiring awkward.
• Sometimes, one pair of op-amps will be doing something different than the other pair and "you gotta keep 'em separated".  For example, in something like the John Hollis Zombie chorus, two op-amps are used for the LFO, and two are used for the audio path.  Normally, that type of LFO circuit produces a sudden draw on current that results in a spike on the supply line which we hear as a tick, corresponding to LFO speed.  having that LFO circuit be confined to the one dual op-amp allows us to use some standard tricks for "decoupling" the power line for the LFO, such that its sudden hunger for current does not impact on any other chips in the overall circuit.  If the two op-amps making up the LFO were part of the same quad op-amp including the audio path, that sort of fix would not be physically possible, and we'd be forced to hear the ticking.

[ppatchmods]

I'm wanting to create a drop in adapter that will hold 2 tl072's and drop in the place of 1 tl074. They sell them but I wanted to do it on perf.

[petemoore]

  No sub for data sheet verifications on the pinout.
 Standard opamps come in various packages:
 We commonly use single [8pin], dual [8pin] and quad opamps.
 Watch the pinout, have 1:1 ratio between the # of trangles in the schematic and number of opamp stages.
 Have done various adaptations of Dual to Singles...most of the other possibilities except a quad to dual conversion. If all the signal pins match the schematic and the power requirements are rewired to satisfy the new OA [ie each dual needs it's own supply], it has to work.

[familyortiz]

No problem using 2 duals instead of 1 quad. Don't forget to use decoupling caps on both chips very close to the chip.

[12Bass]

I'm wanting to create a drop in adapter that will hold 2 tl072's and drop in the place of 1 tl074. They sell them but I wanted to do it on perf.

Not really worth the trouble unless the op amps need to be electrically isolated for some reason (as noted above).  Generally, I'd just use the TL074. 

When listening critically in a high fidelity scenario, I have found that single op amps tend to sound slightly better than their dual counterparts.  I haven't made a direct comparison been duals and quads, though many of the best op amps are not available in a quad.  However, such differences are much less likely to be relevant, or even noticeable, in guitar effects.  That said, I did make a pair of quad DIPs out of dual SOICs mounted on a 14-pin DIP socket for use in my A/DA flanger clone.  Very delicate soldering...!

[blooze_man]

Slightly off topic but that is a really nice photo!

[12Bass]

Slightly off topic but that is a really nice photo!

Thanks!  Was taken with my Canon A80 in macro mode at f/8 using a tripod.  Sadly, it no longer functions...   

[ppatchmods]

thanks everybody. i decided just to order the tl074 and be done with it.

[Gurner]

That was an awful lot of advice you generated above for something in the end you just decided to bite the bullet & pay 35c for! (nevertheless I enjoyed the photo & all the talk of triangles)